WO2020160277A1 - Reflective-striped mulch and methods of using - Google Patents

Abstract

In one aspect, the disclosure relates to a reflective-striped mulch film comprising a central portion comprising a reflective material and peripheral portions adjacent the first and second side edges of the central portion comprising black mulch. When used in the production of a crop, the reflective-striped mulch film can provide a lower soil temperature during establishment of a plant, as compared to a black mulch. This abstract is intended as a scanning tool for purposes of searching in the particular art and is not intended to be limiting of the present disclosure.

Description

REFLECTIVE-STRIPED MULCH AND METHODS OF USING

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims benefit of U.S. Provisional Application No. 62/798,917, filed January 30, 2019, which is hereby incorporated herein by reference in its entirety.

BACKGROUND

[0002] Florida is the primary producer of winter strawberries ( Fragaria xananassa Duch.) in the United States because of its mild subtropical climate. The price received by Florida strawberry growers is highly variable throughout the season, with the highest prices typically occurring during the early season months of November, December, and January. According to U.S. strawberry market data from 2012-17, the average grower price in November was $22.80 per 3.6-kg flat, followed by $18.94, $14.38, $11.40, and $8.88 for the months of December through March, respectively (USDA, 2018). Because the Florida strawberry industry is threatened by new challenges such as international competition, rising production costs, and growing labor shortages, Florida strawberry growers require further improvements in early yields to remain profitable (Wu et al., 2015).

[0003] Bare-root transplants are typically established in raised beds covered with black plastic mulch, which has long been considered important to achieve adequate wintertime soil warming (Brooks, 1959). Traditional transplanting date used by Florida strawberry growers is early to mid October. Following planting, transplants become exposed to high daily air temperatures that can exceed 30 °C for up to six weeks. During this time, plants develop flower buds, while establishing adequate canopy growth capable of supporting fruit production, which usually begins in mid- November. Yields slowly increase throughout the winter, with peak production occurring in March.

[0004] To speed up establishment and increase early yields, Florida strawberry growers have recently begun to advance transplanting dates from mid-October to late September. As a result, plants are exposed to even greater heat stress conditions than they normally would be when planted in October. For example, maximum daily air temperatures were approximately 34 °C in the third week of Sept. 2016, but only 28 °C in the second week of Oct. 2016. Combining advanced planting dates with black plastic mulch can cause excessive heat stress conditions, especially because establishment-period soil temperatures often exceed 35 °C under black plastic mulch. A number of studies indicate that temperatures above 30 °C can induce physiological complications in strawberry, including slowed, abnormal growth (Geater et al., 1997; Heilman and Travis, 1988; Zhang et al. , 1997), reduced protein content (Gulen and Eris, 2015), and low root oxygen consumption (Sakamoto et al., 2016). Plants could experience excess heat stress that leads to inhibited growth and fruit development when planted on black plastic mulch in late September. Similar heat stress problems exist in other winter and early spring strawberry production regions worldwide, including Spain and Egypt. To mitigate the negative impact of seasonal temperature extremes, growers need an alternative to black plastic mulch. These needs and other needs are satisfied by the present disclosure.

SUMMARY

[0005] In accordance with the purpose(s) of the disclosure, as embodied and broadly described herein, the disclosure, in one aspect, relates to a mulch film comprising: a central portion extending in a first direction and having a first side edge and a second side edge, said central portion comprising a reflective material; a first peripheral portion adjacent the first side edge of the central portion and extending in the first direction; and a second peripheral portion adjacent the second side edge of the central portion and extending in the first direction; wherein the first peripheral portion and the second peripheral portion comprise black mulch.

[0006] Also disclosed is a method for production of a crop, comprising: providing a bed of soil having a central raised portion and two shoulder portions; disposing on the bed of soil the mulch film as described above, wherein the central portion of the mulch film generally corresponds to the raised portion of the bed, and the first and second peripheral portions of the film generally correspond to the shoulder portions of the bed; planting a plant into the bed of soil through a hole in the central portion of the mulch film; and providing water and sunlight to the plant.

[0007] Other systems, methods, features, and advantages of the present disclosure will be or become apparent to one with skill in the art upon examination of the following drawings and detailed description. It is intended that all such additional systems, methods, features, and advantages be included within this description, be within the scope of the present disclosure, and be protected by the accompanying claims. In addition, all optional and preferred features and modifications of the described embodiments are usable in all aspects of the disclosure taught herein. Furthermore, the individual features of the dependent claims, as well as all optional and preferred features and modifications of the described embodiments are combinable and interchangeable with one another.

BRIEF DESCRIPTION OF THE FIGURES

[0008] Many aspects of the present disclosure can be better understood with reference to the following drawings. The components in the drawings are not necessarily to scale, emphasis instead being placed upon clearly illustrating the principles of the present disclosure. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views.

[0009] FIG. 1A shows bed layout in the 2016-17 and 2017-18 seasons, in accordance with Example 1.

[0010] FIG. 1 B shows overall bed width, bed shoulder width, and reflective metalized stripe width along with location of planting holes and sensors for bed center temperature (BCT) and bed shoulder temperature (BST), in accordance with Example 1.

[0011] FIG. 1 C shows overhead photos showing‘Florida Radiance’/’Florida Fortuna’ on black (left), fully metalized (middle), and metalized-striped (right) plastic mulches at 70 days after planting in the 2017-18 season, in accordance with Example 1.

[0012] FIG. 2A shows average hourly root-zone temperatures at a 10-cm depth for the bed center and bed shoulder for the 2017-18 growing season in accordance with Example 1.

[0013] FIG. 2B shows data relating to the number of hours of statistically significant differences as well as the maximum change in temperature († = increased temperature, j = decreased temperature) for each comparison shown on the left (B = black mulch, M = fully metalized mulch, MS = metalized-striped mulch) in accordance with Example 1. Comparisons are given as the second mulch type relative to the first mulch type.

[0014] FIG. 2C shows representative photos of the growth stage of ‘Florida Radiance’/’ Florida Fortuna’ for each month of the 2017-18 growing season in accordance with Example 1.

[0015] FIG. 3 shows average weekly marketable fruit yield for ‘Florida Radiance’/’Florida Fortuna’ (top) and ‘Florida Beauty’ (bottom) during the 2016-17 (left) and 2017-18 (right) seasons. Mean separation letters indication significant difference at P < 0.05 if lowercase and P < 0.10 if uppercase, with the top, middle, and bottom letters corresponding to the means of black, metalized, and reflective metalized-striped mulch, respectively, in accordance with Example 1.

[0016] FIG. 4 shows average maximum monthly air temperatures at a 60-cm height during the 2016-17 and 2017-18 seasons as well as the 10-year average (2008-2017). The table indicates the number of days in which maximum daily temperature exceeded 30 °C from the planting to 30 Nov. Data were collected at GCREC in Balm, FL and provided by the Florida Agricultural Weather Network, in accordance with Example 1. [0017] FIG. 5 is an elevation view of the disclosed reflective-striped mulch as used with a raised bed of strawberry plants, as compared to black plastic mulch and an entirely reflective plastic mulch. The figure shows a schematic summary of the benefits of the reflective-striped mulch, as compared to black plastic mulch and entirely reflective plastic mulch, in the initial growth stage of the plants and in the late growth stage of the plants.

[0018] FIG. 6A shows Experimental layout in the 2015-16 and 2016-17 seasons. The mulch type and cultivar for each plot as well as data logger placement, in accordance with Example 2.

[0019] FIG. 6B shows a representative photo of‘Florida Radiance’/’Florida Fortuna’ transplants on white-striped mulch (foreground) and black mulch (background) taken on 29 Sept. 2016, in accordance with Example 2.

[0020] FIG. 6C shows Overall bed width, shoulder width, and white stripe width are provided alongside placement of planting holes and root-zone temperature sensors, in accordance with Example 2.

[0021] FIG. 7A shows average hourly root-zone temperatures at a 10-cm depth for the bed centers (A-D) and bed shoulders (E-H) under each mulch type, in accordance with Example 2. Statistically significant differences in hourly averages of root-zone temperatures between mulch types are denoted by an asterisk.

[0022] FIG. 7B shows representative photos of the growth stage of‘Florida Radiance’/’ Florida Fortuna’ (l-L) for each month, in accordance with Example 2.

[0023] FIG. 8 shows Average maximum monthly air temperatures at a 60-cm height during the 2015-16 and 2016-17 seasons as well as the 10-year average, in accordance with Example 2. The table in the lower left corner provides the number of days from planting to 30 Nov. on which the maximum daily air temperature exceeded 30 °C for all three trials. Data were collected at GCREC in Balm, FL and provided by the Florida Agricultural Weather Network.

[0024] FIG. 9 shows data regarding‘Florida Radiance’/’Florida Fortuna’ production on four white-striped mulches in accordance with Example 3.

[0025] FIG. 10A shows data regarding‘Florida Radiance’/’Florida Fortuna’ quality production on four mulches in accordance with Example 3.

[0026] FIG. 10B shows data regarding ‘Florida Radiance’/’Florida Fortuna’ first quality distribution on four mulches in accordance with Example 3.

[0027] FIG. 11 shows images of‘Florida Radiance’/’Florida Fortuna’ planted on four mulches in accordance with Example 3.

[0028] FIG. 12A shows data regarding‘Florida Brilliance’ total production on four mulches in accordance with Example 3.

[0029] FIG. 12B shows data regarding‘Florida Brilliance’ quality production % on four mulches in accordance with Example 3.

[0030] FIG. 13 shows data regarding‘Florida Brilliance’ first quality distribution on four mulches in accordance with Example 3.

[0031] FIG. 14 shows images of‘Florida Brilliance’ planted on four mulches in accordance with Example 3.

[0032] FIG. 15A shows data regarding‘Florida Beauty’ total production on four mulches in accordance with Example 3.

[0033] FIG. 15B shows data regarding‘Florida Beauty’ quality production % on four mulches in accordance with Example 3.

[0034] FIG. 16 shows data regarding‘Florida Beauty’ first quality distribution on four mulches in accordance with Example 3.

[0035] FIG. 17 shows images of ‘Florida Beauty’ planted on four mulches in accordance with Example 3.

[0036] FIG. 18A shows data regarding plant mortality for‘Florida Radiance’/’Florida Fortuna’, ‘Florida Brilliance,’ and‘Florida Beauty,’ on black plastic mulch in accordance with Example 3.

[0037] FIG. 18B shows data regarding plant mortality for‘Florida Radiance’/’Florida Fortuna’, ‘Florida Brilliance,’ and ‘Florida Beauty,’ on white spray-painted mulch in accordance with Example 3.

[0038] FIG. 19A shows data regarding plant mortality for‘Florida Radiance’/’Florida Fortuna’, ‘Florida Brilliance,’ and‘Florida Beauty,’ on reflecting silver mulch in accordance with Example 3.

[0039] FIG. 19B shows data regarding plant mortality for‘Florida Radiance’/’Florida Fortuna’, ‘Florida Brilliance,’ and‘Florida Beauty,’ white plastic mulch in accordance with Example 3.

[0040] FIG. 20 shows data on mortality for‘Florida Radiance’/’Florida Fortuna’ on four mulches in accordance with Example 3.

[0041] FIG. 21 shows images related to mortality of ‘Florida Radiance’/’Florida Fortuna’ on various mulches in accordance with Example 3. [0042] FIG. 22 shows data on mortality for‘Florida Brilliance’ on four mulches in accordance with Example 3.

[0043] FIG. 23 shows images related to mortality of ‘Florida Brilliance’ on various mulches in accordance with Example 3.

[0044] FIG. 24 shows data on mortality for‘Florida Beauty’ on four mulches in accordance with Example 3.

[0045] FIG. 25 shows an image related to mortality of ‘Florida Beauty’ on black plastic mulch in accordance with Example 3.

[0046] FIG. 26A shows an exemplary reflective-striped mulch according to the various aspects described herein.

[0047] FIGS. 26B-26F show sectional views of various exemplary reflective-striped mulches, viewed along A-A of FIG. 26A according to the various aspects described herein.

[0048] FIG. 27 shows photographic images and thermographic images of representative plots using black mulch, fully metalized mulch, and the disclosed reflective-stripe metalized-stripe) mulch, in accordance with Example 4.

[0049] FIGS. 28A-28B show results pertaining to photosynthesis of an exemplary plot using reflective-striped mulch, in accordance with Example 4. FIG. 28A shows photosynthesis rates measured with an infrared gas analyzer at different light levels on both upper and lower leaf surfaces. FIG. 28B is a schematic illustration of plants grown on the exemplary reflective-striped mulch film can receive both direct sunlight and reflected light.

[0050] FIG. 29A shows spectroradiometer measurements of direct sunlight, in accordance with Example 4. FIG. 29B shows spectroradiometer measurements of sunlight filtered through one leaf, in accordance with Example 4. FIG. 29C is a schematic illustration of plants receiving both direct light, and light filtered through a leaf having a low red/far-red ratio.

[0051] Additional advantages of the disclosure will be set forth in part in the description which follows, and in part will be obvious from the description, or can be learned by practice of the disclosure. The advantages of the disclosure will be realized and attained by means of the elements and combinations particularly pointed out in the appended claims. It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the disclosure, as claimed.

DETAILED DESCRIPTION [0052] In view of the foregoing, disclosed herein is a new mulch film that has a reflective center portion with black peripheral portions. Also disclosed are methods of production of crops such as winter strawberries using a reflective-striped mulch. The disclosed methods and reflective-striped mulch can reduce heat stress on winter strawberries during establishment, while maintaining the warming effects of black mulch during winter.

[0053] Many modifications and other embodiments disclosed herein will come to mind to one skilled in the art to which the disclosed compositions and methods pertain having the benefit of the teachings presented in the foregoing descriptions and the associated drawings. Therefore, it is to be understood that the disclosures are not to be limited to the specific embodiments disclosed and that modifications and other embodiments are intended to be included within the scope of the appended claims. The skilled artisan will recognize many variants and adaptations of the aspects described herein. These variants and adaptations are intended to be included in the teachings of this disclosure and to be encompassed by the claims herein.

[0054] Although specific terms are employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation.

[0055] As will be apparent to those of skill in the art upon reading this disclosure, each of the individual embodiments described and illustrated herein has discrete components and features which may be readily separated from or combined with the features of any of the other several embodiments without departing from the scope or spirit of the present disclosure.

[0056] Any recited method can be carried out in the order of events recited or in any other order that is logically possible. That is, unless otherwise expressly stated, it is in no way intended that any method or aspect set forth herein be construed as requiring that its steps be performed in a specific order. Accordingly, where a method claim does not specifically state in the claims or descriptions that the steps are to be limited to a specific order, it is no way intended that an order be inferred, in any respect. This holds for any possible non-express basis for interpretation, including matters of logic with respect to arrangement of steps or operational flow, plain meaning derived from grammatical organization or punctuation, or the number or type of aspects described in the specification.

[0057] All publications mentioned herein are incorporated herein by reference to disclose and describe the methods and/or materials in connection with which the publications are cited. The publications discussed herein are provided solely for their disclosure prior to the filing date of the present application. Nothing herein is to be construed as an admission that the present invention is not entitled to antedate such publication by virtue of prior invention. Further, the dates of publication provided herein can be different from the actual publication dates, which can require independent confirmation.

[0058] While aspects of the present disclosure can be described and claimed in a particular statutory class, such as the system statutory class, this is for convenience only and one of skill in the art will understand that each aspect of the present disclosure can be described and claimed in any statutory class.

[0059] It is also to be understood that the terminology used herein is for the purpose of describing particular aspects only and is not intended to be limiting. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the disclosed compositions and methods belong. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the specification and relevant art and should not be interpreted in an idealized or overly formal sense unless expressly defined herein.

[0060] Prior to describing the various aspects of the present disclosure, the following definitions are provided and should be used unless otherwise indicated. Additional terms may be defined elsewhere in the present disclosure.

A. DEFINITIONS

[0061] As used herein,“comprising” is to be interpreted as specifying the presence of the stated features, integers, steps, or components as referred to, but does not preclude the presence or addition of one or more features, integers, steps, or components, or groups thereof. Moreover, each of the terms “by”, “comprising,” “comprises”, “comprised of,” “including,” “includes,” “included,”“involving,”“involves,”“involved,” and“such as” are used in their open, non-limiting sense and may be used interchangeably. Further, the term“comprising” is intended to include examples and aspects encompassed by the terms“consisting essentially of” and“consisting of.” Similarly, the term“consisting essentially of” is intended to include examples encompassed by the term“consisting of.

[0062] As used in the specification and the appended claims, the singular forms“a,”“an” and “the” include plural referents unless the context clearly dictates otherwise.

[0063] It should be noted that ratios, concentrations, amounts, and other numerical data can be expressed herein in a range format. It will be further understood that the endpoints of each of the ranges are significant both in relation to the other endpoint, and independently of the other endpoint. It is also understood that there are a number of values disclosed herein, and that each value is also herein disclosed as“about” that particular value in addition to the value itself. For example, if the value “10” is disclosed, then “about 10” is also disclosed. Ranges can be expressed herein as from“about” one particular value, and/or to“about” another particular value. Similarly, when values are expressed as approximations, by use of the antecedent“about,” it will be understood that the particular value forms a further aspect. For example, if the value“about 10” is disclosed, then“10” is also disclosed.

[0064] When a range is expressed, a further aspect includes from the one particular value and/or to the other particular value. For example, where the stated range includes one or both of the limits, ranges excluding either or both of those included limits are also included in the disclosure, e.g. the phrase“x to y” includes the range from‘x’ to‘y’ as well as the range greater than‘x’ and less than‘y’ . The range can also be expressed as an upper limit, e.g.‘about x, y, z, or less’ and should be interpreted to include the specific ranges of‘about x’,‘about y’, and‘about z’ as well as the ranges of ‘less than x’, less than y’, and‘less than z’. Likewise, the phrase‘about x, y, z, or greater’ should be interpreted to include the specific ranges of ‘about x’,‘about y’, and‘about z’ as well as the ranges of ‘greater than x’, greater than y’, and‘greater than z’. In addition, the phrase“about‘x’ to‘y’”, where‘x’ and‘y’ are numerical values, includes“about‘x’ to about‘y’”.

[0065] It is to be understood that such a range format is used for convenience and brevity, and thus, should be interpreted in a flexible manner to include not only the numerical values explicitly recited as the limits of the range, but also to include all the individual numerical values or sub ranges encompassed within that range as if each numerical value and sub-range is explicitly recited. To illustrate, a numerical range of “about 0.1 % to 5%” should be interpreted to include not only the explicitly recited values of about 0.1 % to about 5%, but also include individual values (e.g., about 1 %, about 2%, about 3%, and about 4%) and the sub-ranges (e.g., about 0.5% to about 1.1 %; about 5% to about 2.4%; about 0.5% to about 3.2%, and about 0.5% to about 4.4%, and other possible sub-ranges) within the indicated range.

[0066] As used herein, the terms“about,”“approximate,”“at or about,” and“substantially” mean that the amount or value in question can be the exact value or a value that provides equivalent results or effects as recited in the claims or taught herein. That is, it is understood that amounts, sizes, formulations, parameters, and other quantities and characteristics are not and need not be exact, but may be approximate and/or larger or smaller, as desired, reflecting tolerances, conversion factors, rounding off, measurement error and the like, and other factors known to those of skill in the art such that equivalent results or effects are obtained. In some circumstances, the value that provides equivalent results or effects cannot be reasonably determined. In such cases, it is generally understood, as used herein, that“about” and“at or about” mean the nominal value indicated ±10% variation unless otherwise indicated or inferred. In general, an amount, size, formulation, parameter or other quantity or characteristic is“about,”“approximate,” or“at or about” whether or not expressly stated to be such. It is understood that where“about,”“approximate,” or “at or about” is used before a quantitative value, the parameter also includes the specific quantitative value itself, unless specifically stated otherwise.

[0067] As used herein, the terms “optional” or “optionally” means that the subsequently described event or circumstance can or cannot occur, and that the description includes instances where said event or circumstance occurs and instances where it does not.

[0068] Unless otherwise specified, temperatures referred to herein are based on atmospheric pressure (i.e. one atmosphere).

B. REFLECTIVE-STRIPED M ULCH

[0069] In one aspect, the disclosure relates to a reflective-striped black mulch film. More specifically, in one aspect, the present disclosure relates to a mulch film comprising a central reflective portion extending in a first direction and having a first side edge and a second side edge, and two peripheral black mulch portions disposed adjacent to the first side edge and second side edge, respectively, of the reflective portion.

[0070] Plastic mulch is a thin plastic film commonly used for vegetable production. It is installed over a raised bed (soil) and can serve many functions, including weed control, retention of fumigants, disease prevention, food safety, etc. Plastic mulch films or sheets can directly impact the microclimate around a plant by modifying the radiation budget (absorptivity vs. reflectivity) of the surface and decreasing the soil water loss. The soil temperature under a mulch film or sheet depends in part on the thermal properties (reflectivity, absorptivity, or transmittancy) of a particular material in relation to incoming solar radiation.

[0071] Although plastic mulch is available in different colors, black plastic mulch has been used predominantly for winter strawberry production worldwide. Black mulch films typically comprise an opaque blackbody absorber and radiator. Referring to FIG. 5, The black plastic mulch 100 can absorb most UV, visible, and infrared wavelengths of incoming solar radiation 10 and can re radiate absorbed energy in the form of thermal radiation or long-wavelength infrared radiation. At least some of the solar energy absorbed by black mulch is lost to the atmosphere through radiation and forced convection. Because thermal conductivity of the soil 102 is high, relative to that of air, much of the energy absorbed by black portion can be transferred to the soil 102 by conduction 20 if contact is good between the plastic mulch 100 and the surface of the soil 102. The main advantage of black plastic mulch 100 is to absorb sunlight, thereby warming the soil 102, particularly at the root zone 106, and promoting growth and fruit production of the plants 104 during wintertime. For example, strawberry growers in Florida have relied on black plastic mulch for nearly 60 years.

[0072] In hot weather, however, soil warming is detrimental as it can cause excessive soil warming at the root zone 106 and heat stress in strawberry plants 104. It is common to have excessively high air temperature during the establishment period of winter strawberry production. For example, strawberry growers in Florida plant as early as late September, during which time air temperature often exceeds 30 °C (86 °F) - the upper limit for optimum strawberry growth. In this situation, soil warming by black plastic mulch 100 can be harmful to strawberry growth and fruit development.

[0073] Alternatives to black plastic mulch have been investigated. For example, plastic mulch with reflective colors, such as white and silver (metalized) can reflect sunlight and cool the soil. Black plastic mulch has high shortwave radiation absorption, causing it to drastically raise root- zone temperatures (RZT) by conducting thermal radiation towards the bed center (Ham et al. , 1993). Conversely, reflective and/or metalized mulch films have low shortwave radiation absorption, so they conduct less radiation into the soil and maintain lower RZT than black mulch.

[0074] Referring to FIG. 5, fully reflective or metalized mulch films 200 have the potential to improve early season fruit development by at least partly alleviating heat stress conditions during the establishment period (Andino and Motsenbocker, 2004; Vos et al. , 1995). Generally, reflective metalized mulch films 200 can reduce soil temperatures particularly at the root zone 206 compared to black mulch by reflecting (30) a greater proportion of incoming solar radiation 10 (Ham et al., 1993). Reflective metalized mulch films 200 have proven widely effective at increasing marketable fruit yields compared to black mulch for a number of horticultural crops, including tomato ( Solanum lycopersicum) and bell pepper ( Capsicum annuum ), which are both major crops in Florida (Andersen et al., 2012; Diaz-Perez, 2010; Greer and Dole, 2003; Hutton and Handley, 2007). Relatively few studies have compared reflective mulch films to the standard black plastic mulch for subtropical strawberry production. Perhaps most notably, Albregts and Chandler (1993) found entirely white and yellow painted mulch films to improve early season yields compared to black plastic mulch for Florida strawberry production. However, black plastic mulch outperformed yellow mulch and white mulch in the late season, possibly due to insufficient wintertime soil warming by these two more reflective mulch films. Referring to FIG. 5, in the late growth stage, the reflective mulch films 200 may cause cooling of the soil 202, particularly at the root zone 206, because the reflective mulch film 200 reflects (30) a significant amount of the incoming solar radiation 10, rather than transferring it to the soil 202.

[0075] Although cooling of the root-zone 206 is beneficial in hot weather, it can reduce plant growth and fruit production of the strawberry plant 204 during wintertime. Therefore, currently available plastic mulch products have both advantages and disadvantages for winter strawberry production.

[0076] Some previous studies have examined the effect of combining two different colors in one plastic mulch type, mostly by adding a black center stripe to reflective silver mulch. The positive effects of this multi-colored mulch type compared to entirely black or silver mulch include increased canopy-level light capture, soil warming during spring establishment, improved yield of bell pepper, and reduced incidence of virus symptoms in tomato (Csizinszky et al., 1999; Diaz- Perez, 2010; Hutton and Handley, 2007). Metalized mulch with a black center stripe is meant to warm transplants during spring establishment and reduce soil temperatures during hot summer months. In contrast, the reflective-striped mulch film of the present disclosure provides the opposite soil warming pattern.

[0077] Referring to FIG. 5, the disclosed reflective-striped mulch 300 combines the benefits of reflective/metalized mulch films and the black mulch films. An exemplary reflective-striped mulch has a central reflective zone 301 , comprising reflective material, and peripheral zones 303 comprising black mulch. The central reflective zone 301 covers a significant portion of the top of the raised bed of soil, or it covers substantially the entire top surface of the raised bed of soil. In an aspect, the central reflective zone 301 has a width that is about 70% to about 100 % the width of the top of the raised bed of soil. Each of the peripheral zones 303, are disposed in the shoulder region of the raised bed of soil. The top of the raised bed of soil may partially overlap one or both peripheral zones 303, but according to various aspects, one or both peripheral zones 303 overlap the top of the raised bed of soil only slightly or not at all. In the initial growth stage, the when the air temperature is higher, at least a portion of the incoming solar radiation 10 is reflected (30) by the central reflective zone 301 , providing cooling at the root zone 306 at the initial growth stage. In the late growth stage, when the air temperature is lower, a significant amount of the incoming solar radiation 10 is absorbed (20) by the peripheral zones comprising black mulch 303, which warms the root-zone 306 during the colder months. It has been found that subtropical winter strawberry growers can benefit from the disclosed reflective-striped mulch design that is reflective in the center and black on the shoulders. By having the dual benefits of reflective mulch and black mulch, reflective- striped mulch 300 can maintain sufficiently cool root-zone temperatures during establishment and sufficiently warm root-zone temperatures during the cool winter months.

[0078] Having described the benefits of the reflective-striped mulch, we now turn to a description of the reflective-striped mulch. Referring to FIG. 26A, according to the disclosure, the reflective- striped mulch film 400 comprises a sheet or a film extending in a first direction, L, having a length in the first direction, and a transverse dimension that extends in a second direction, t, that is perpendicular to the first direction L. The reflective-striped mulch film 400 has a first side 401 that, when the reflective-striped mulch 400 is placed on a crop, faces toward the soil, and a second side 402 that is opposed to the first side 401. The reflective striped mulch film 400 comprises a central reflective portion 404 extending in the first direction L, and two peripheral black mulch portions 403 extending in the first direction L on both sides of the central reflective portion 404.

[0079] According to the disclosed embodiments, the central reflective portion 404 comprises a reflective material that has a low emissivity, e.g., having an emissivity of less than about 0.9, or less than about 0.8, or less than about 0.7, or less than about 0.6, or less than about 0.5, or less than about 0.4, or less than about 0.3. In various aspects, the central reflective portion 404 has a reflectivity of greater than 60%, or greater than 70%, or greater than 80%, or greater than 90%. According to certain aspects, the reflective material comprises a white material. In an aspect, the white material has an emissivity in the range of about 0.8 to about 0.9. In an aspect, the white material has a reflectivity greater than 60%. According to certain aspects, the reflective material is a metalized material. In an aspect, the metalized material has an emissivity in the rangte of about 0.2 to about 0.3. In an aspect, the metalized material has a reflectivity greater than 90%. According to certain aspects, the reflective material comprises an aluminum-containing composition. The ability of reflective-striped mulch 400 to act as insulator and trap heat in the root-zone at night is due to the optical properties of the reflective material - specifically the reflective material’s low emissivity. Emissivity (e) is a measure of the relative amount of longwave radiation emitted from a material’s surface compared to the longwave radiation emitted by a perfectly emitting blackbody (e = 1.0) at the same temperature and wavelength (Tarara, 2000). Ham et al. (1993) studied the optical properties of different plastic mulch surfaces and reported that mulch surfaces with high longwave transmittance also had high longwave emissivity. In their study, black mulch (e = 0.87) resulted in the highest daytime temperatures and coolest nighttime temperatures, while aluminum-painted mulch (e = 0.28) resulted in the coolest daytime temperatures but highest nighttime temperatures of all eight mulches examined.

[0080] According to certain aspects, the black mulch portions 403 comprise any suitable black mulch material that has a high emissivity, e.g., having an emissivity of greater than 0.9. The black mulch portion 403 may comprise any known or later developed black mulch material having the necessary or desired properties described herein.

[0081] Reflective metalized (aluminum) mulch surfaces are characterized by low shortwave absorption, high shortwave reflection, and low longwave transmittance (Ham et al., 1993). Because of their low shortwave absorption, metalized mulch films are slow to gather energy throughout the day. However, the low emissivity and longwave transmittance of metalized mulch films produce an insulating effect whereby thermal radiation is not rapidly emitted from the bed surface at night. By comparison, black mulch rapidly gathers heat throughout the daytime and also rapidly emits heat to the cooler surrounding nighttime air. In this way, plants on black mulch experience greater diurnal root-zone temperature fluctuation than plants on fully metalized mulch or reflective metalized-striped mulch. Despite this, there are several studies which suggest that diurnal root-zone temperature fluctuations have little overall effect on strawberry growth and yield when temperature extremes are avoided (Gonzalez-Fuentes et al., 2016; Kumakura and Shishido, 1994).

[0082] According to the disclosure the reflective-striped mulch films 400, or components thereof, can comprise a polymeric material. The polymeric material can be, for example, polymers or copolymers of polyethylene, poly(vinyl chloride), polybutylene, ethylene and vinyl acetate, or combinations thereof. The mulch film can comprise one or more biodegradable additives such as natural fibers or biodegradable polymers. The mulch film can be in the form of a film such as a blown film or a cast film, a textile such as a nonwoven or woven textile, or a combination thereof. The disclosed reflective-striped mulch film 400 or sheet can comprise a plurality of layers, for example, a coextruded film or sheet or a laminate of two or more films or sheets.

[0083] Referring to FIG. 26B, in an aspect of the disclosure, the reflective-striped mulch film 400 can comprise a black mulch material 403 extending the full transverse dimension of the reflective- striped mulch film 400, having a reflective material 404 disposed on the second side 402 of the reflective-striped mulch film 400, having a transverse dimension that is less than the transverse dimension of the reflective-striped mulch film 400. In some aspects, the reflective material 404 can be substantially centered on the black mulch film or sheet 402 and running the substantial length of the black mulch film or sheet 403. In an aspect of the disclosure, the reflective material 404 can comprise a reflective coating that is disposed on the black mulch film 403. For example, the reflective material 404 may be a reflective coating material that is deposited onto the black mulch film 403, such as by extruding or spraying or painting, or the like. In an aspect, the reflective material 404 can be a latex or acrylic-based paint disposed on the mulch film 403. In another aspect, the reflective material 404 can be a coating comprising a layer of metalized material. The coating may have any thickness that can provide the necessary or desired properties discussed herein. In an aspect, the reflective material 404 can be a coating having a thickness of about 25 nanometers thick.

[0084] Still referring to FIG. 26B, in another aspect of the disclosure, the reflective material 404 can comprise a reflective film or sheet that is separately formed and laminated to the black mulch film 403. For example, the reflective material 404 may comprise a reflective film or sheet that is formed and superposed and bonded to the black mulch film 403.

[0085] Referring to FIGS. 26D-26F, in other aspects of the disclosure, the reflective-striped mulch film 400 can comprise a central reflective material 404 having a first side edge 406 and a second side edge 408, with a first black mulch film 403a coupled with the first side edge 406 of the central reflective material 404, and a second black mulch film 403b coupled with the second side edge 408 of the reflective material 404, forming a unitary reflective-striped mulch film 400. The reflective material 404 can be bonded to the first and second black mulch films 401 and 402 using any suitable means, including, for example, thermal bonding, mechanical bonding, adhesive bonding, ultrasonic bonding, or the like, including combinations thereof. The first side edge 406 can be coupled with the first black mulch film 403a in an overlapping or abutting configuration. Likewise, the second side edge 406 can be coupled with the second black mulch film 403a in an overlapping or abutting configuration.

[0086] Referring to FIG. 26C, in an aspect, the reflective material 404 can comprise a multi-layer film 604, comprising a plurality of layers such as layers 605, 606, and 607, wherein at least one layer comprises a reflective material. Additional layers may include one or more support layers, or colored layers, or a combination thereof. In an aspect, the reflective material 404 comprises a multi-layer film 604 having first transparent polymeric film layer, a second metallic layer, and a third colored polymeric film layer, where the second layer is disposed between the first layer and the third layer. In an aspect the multi-layer film 604 is disposed on the black mulch film with the transparent polymeric film layer facing outward (e.g., toward the sun and/or air). The multi-layer film 604 may be disposed on at least one side of the black mulch film 403, as shown in FIGS. 26C, or it may be attached to two or more black mulch films 403a, 403b, as shown in FIGS. 26C- 26F. [0087] In an aspect of the disclosure, the reflective-striped mulch film can be prepared in advance of its installation. For example, the reflective-striped mulch film can be provided as a roll good material having the central reflective portion, and the black mulch peripheral portions, which material can be installed on the bed. In other aspects, the reflective-striped mulch film can be assembled or prepared, at least in part, at the time of installation at the bed. For example, a reflective coating can be applied to a black mulch film around the time of installation at the bed, or a black mulch layer and a reflective layer may be separately provided, and then assembled at about the time of installation.

[0088] In an aspect of the disclosure, the width of the central reflective portion is from about 30% to about 50% of the total width of the reflective-striped mulch film. The width of the central reflective portion, the width of one or both of the black mulch portions, and/or the overall width of the reflective-striped mulch film can be determined based on a number of factors including, for example, the width of the underlying crop bed, planting configurations and densities, and the desired results. It is preferable that the central reflective portion covers a significant portion of the bed top of the underlying crop bed. In an aspect, the width of the reflective portion is greater than 70% or greater than 80% or greater than 90% or greater than 95% of the the bed top width of the underlying crop bed. In an aspect, the width of the reflective portion is from 70% to 100% of the bed top width of the underlying crop bed. In one aspect, the reflective-striped mulch film has an overall width of from about 75 cm to about 85 cm, and the reflective central portion has a width of from about 45 cm to about 55 cm.

C. METHOD OF USE

[0089] According to another aspect of the disclosure, a method for crop production includes using the reflective-striped mulch film described herein. The disclosed methods can be used for any suitable vegetable crop grown on plastic mulch, including, for example, snap beans, watermelons, cucumbers, peppers, summer squash, cantaloupes, pumpkins, muskmelons, other cucurbits, eggplant, peppers, tomatoes, other solanaceous crops, lettuce, other leafy greens, onion, or strawberries. According to some aspects of the disclosure the methods involve the production of winter strawberries,

[0090] According to a disclosed method, at least a part of a field may be covered with the disclosed reflective-striped mulch film prior to the start of the growing season. Generally speaking the mulch film may be applied using a film applicator which applies strips of film on the ground. A machine called a plastic layer or a bed shaper can be pulled over the field creating a row of plastic mulch covering a planting bed. The planting beds can be flat beds (i.e., the surface of the plastic mulch is level with the surrounding soil surface), or can be raised beds (i.e., the surface of the plastic mulch is higher than the surrounding soil surface). Narrow rows of exposed soil are left between the strips of film. A drip irrigation line can also be placed under the mulch film. At some point after the mulch film has been laid, holes are punched in the film at predetermined locations, and young plants or seeds can be planted through the holes in the plastic mulch. There are two types of strawberry transplants: bare-root and plug transplants. After exposure to water and sunlight, the plants grow through the holes in the plastic mulch.

[0091] According to the disclosed methods, the reflective-striped mulch film can improve growing conditions particularly in subtropical conditions. The reflective center portion can cool the soil at the root zone during establishment, while the black peripheral portions can warm the soil during winter.

[0092] According to the disclosed methods, use of the reflective-striped mulch film can reduce the soil (root zone) temperature at the bed center during the establishment period as compared to similar methods utilizing black mulch. The use of reflective-striped mulch film can reduce the duration of heat stress conditions in the soil during the establishment period, as compared to similar methods utilizing black mulch.

[0093] According to the disclosed methods, use of the reflective-striped mulch film can result in reductions in plant mortality. In typical commercial strawberry cultivars, using a black mulch film, 10 to 20% transplant mortality is common. It was unexpectedly found that the disclosed reflective- stripe mulch can reduce the mortality of plants to less than 10% or less than 5% or less than 2.5% plant morality. In some aspects, the reflective strip mulch can result in substantially zero plant mortality.

[0094] According to the disclosed methods, use of the reflective-striped mulch film can result in reductions in the plastic mulch surface temperature and canopy-level air temperature. The disclosed reflective-striped mulch film can result in the plastic mulch surface temperature that is at least about 1 °C lower, or at least about 2 °C lower, or at least about 3°C lower than the plastic mulch surface temperature resulting from the use of black plastic mulch. The disclosed reflective- striped mulch film can result in a canopy-level air temperature that is at least about 1 °C lower, or at least about 2 °C or at least about 3°C lower than the canopy-level air temperature resulting from the use of black plastic mulch. These temperature reductions can reduce plant stress during the establishment period.

[0095] According to the disclosed methods, use of the reflective-striped mulch film can improve early season fruit yield, as compared to a similar method utilizing black mulch. In some aspects, the early season fruit yield can be improved without negatively affecting fruit quality late season yields, or production costs.

[0096] According to the disclosed methods, use of the reflective-striped mulch film can result in yield increases in both bare-root and plug transplants. The disclosed reflective-striped mulch film can result in a yield increase of more than about 30% or more than about 40% or more than about 50% or more than about 60% or higher, as compared to the yield produced with the use of a black plastic mulch.

[0097] Because early season strawberries garner higher market prices, improving early season fruit yield is important to Florida growers. Reflective striped mulch films have the potential to improve early season fruit development by at least partly alleviating heat stress conditions during the establishment period (Andino and Motsenbocker, 2004; Vos et al., 1995). In combination with the continued development of early-yielding cultivars, which can produce fruits at higher temperatures and longer photoperiods than the current major cultivars, reflective striped mulch films could prove critical to the long-term viability of Florida’s strawberry industry by reducing heat stress and further improving early season yields.

[0098] Before proceeding to the Examples, it is to be understood that this disclosure is not limited to particular aspects described, and as such may, of course, vary. Other systems, methods, features, and advantages of foam compositions and components thereof will be or become apparent to one with skill in the art upon examination of the following drawings and detailed description. It is intended that all such additional systems, methods, features, and advantages be included within this description, be within the scope of the present disclosure, and be protected by the accompanying claims. It is also to be understood that the terminology used herein is for the purpose of describing particular aspects only, and is not intended to be limiting. The skilled artisan will recognize many variants and adaptations of the aspects described herein. These variants and adaptations are intended to be included in the teachings of this disclosure and to be encompassed by the claims herein.

D. EXAMPLES

[0099] The following examples are put forth so as to provide those of ordinary skill in the art with a complete disclosure and description of how the articles and/or methods claimed herein are made and evaluated, and are intended to be purely exemplary of the disclosure and are not intended to limit the scope of what the inventors regard as their disclosure. Efforts have been made to ensure accuracy with respect to numbers ( e.g ., amounts, temperature, etc.), but some errors and deviations should be accounted for. Unless indicated otherwise, parts are parts by weight, temperature is in °C or is at ambient temperature, and pressure is at or near atmospheric.

1. EXAMPLE 1

[00100] The objective of this Example is to examine the effects of a reflective-striped plastic mulch on soil temperature, plant growth, fruit yield, and earliness using two of Florida’s most current early-yielding strawberry cultivars.‘Florida Radiance’/’Florida Fortuna’, which currently accounts for about 60% of Florida’s strawberry market, is a short-day cultivar not recommended for September planting since it has a relatively weak plant habit and fruit can become elongated and unmarketable under high temperatures (Whitaker et al., 2008).‘Florida Beauty’ is an early-yielding weak day-neutral that possesses a compact canopy, making it well-suited for advanced planting dates (Whitaker et al., 2017). ‘Florida Radiance’/’Florida Fortuna’ is a seasonal flowering genotype, so its flowering and fruiting are tightly controlled by photoperiod and temperature, while ‘Florida Beauty’ is an everbearing genotype which can basically produce flowers and fruits throughout the entire growing season (Heide et al., 2013). To understand the potential importance of utilizing a multi-colored mulch film, a reflective metalized-striped mulch was compared to fully metalized mulch as well as the industry standard black plastic mulch. To follow recent Florida strawberry growing trends of advancing planting from mid-October to late September, this Example examined the effect of reflective metalized-striped mulch when planting was advanced to late September in two growing seasons: the 2016-17 season; and the 2017-18 season.

a. Materials and Methods [00101] Bed Preparation and plant establishment

[00102] Strawberry field trials were conducted at the University of Florida Institute of Food and Agricultural Science Gulf Coast Research and Education Center (GCREC) in Balm, FL during the 2016-17 and 2017-18 winter and spring growing seasons. The field site’s soil (Myakka fine sand siliceous hypothermic Oxyaquic Alorthod) had a pH and organic matter content of 6.8 and 1.5%, respectively. On 10 Sept. 2016 and 14 Aug. 2017, commercial equipment was used to prepare the GCREC’s strawberry fields, such that all beds were initially covered with entirely black plastic mulch. The beds used in the Example measured 91 m long, 81 cm wide at the base, 71 cm wide at the shoulders, and 25 cm high at the bed-top. During the initial preparation, beds were fumigated with PicClor 60 (1 ,3-dichloropropene + chloropicrin; 303 kg/ha) to reduce incidence of soil pathogens and weeds. One line of drip irrigation tubing (0.95 L/hr/emitter) with a 30.5 cm emitter spacing was laid 2.5 cm deep at each bed’s center. To reduce the effect of experimental mulch types on fumigation efficacy, 0.02-mm thick black plastic mulch was stretched over all beds. The experimental mulch types were not applied during the initial bed preparation days of 10 Sept. 2016 and 14 Aug. 2017. A map showing the experimental layout and bed dimensions are provided in FIGs. 1A and 1 B.

[00103] On 27 Sept. 2016 and 14. Sept 2017, four full-length beds underwent final preparation, which consisted of replacing the previously laid black plastic mulch with sample mulch films. Each of the four beds were randomly divided into equal length sections of black mulch, fully metalized mulch, and metalized-striped mulch (Imaflex, Inc., Thomasville, NC; Can-Block XSB v-TIF silver/black), as shown in FIG. 1A. Metalized coatings on the fully metalized mulch and metalized- striped mulch were a 25-nm thick layer of aluminum. The center stripe on the metalized-striped mulch was 51 cm wide, as shown in FIG. 1 B. FIG. 1C shows overhead photos of each plastic mulch film. The Example utilized a split-plot design with mulch type as the whole-plot factor and cultivar as the sub-plot factor. In each season, 24 plots were used to test two cultivars on three mulch types across four beds, with each bed serving as a replicate. On 28 Sept. 2016 and 25 Sept. 2017, bare-root transplants with three to four leaves were received from Crown Nursery (Red Bluff, CA). On 29 Sept. 2016, transplants of ‘Florida Radiance’/’Florida Fortuna’ were planted in their respective plots at a density of 32 plants per plot, while transplants of ‘Florida Beauty’ were planted at a density of 16 plants per plot due to plant material constraints from the nursery. On 26 Sept. 2017, transplants of‘Florida Radiance’/’Florida Fortuna’ and‘Florida Beauty’ were both planted in their respective plots at a density of 20 plants per plot. Plants were spaced in double rows with 38 cm between planting holes and 30 cm between rows as shown in FIG. 1 B. Following commercial practices, the plants received 9 hours of overhead irrigation during daylight hours for 10 days after transplanting. Fertilizer (6-2-4 N-P-K) was administered through the drip tape three times per week at a rate of 1.12 kg N ha^-1 d^-1. Plants were watered daily via drip irrigation. Pest and disease control were performed following current recommendations from the University of Florida (Peres, 2015).

[00104] Soil Temperature.

[00105] Soil temperature was monitored from November through February of the 2016-17 season and October through February of the 2017-18 season. Soil temperature was monitored using two Decagon RT-1 temperature sensors in two plots of each of the three mulch types, thus 12 RT-1 sensors were used in total. Soil temperature was logged every 30 minutes by EM50G data loggers (Decagon Devices, Pullman, WA). Soil temperatures were monitored at both the bed center and the bed shoulder, as shown in FIG. 1 B. Bed center temperature (BCT) was recorded at a 10-cm depth and 20 cm from the bed shoulder toward the bed center. Bed shoulder temperature (BST) was recorded at a 10-cm depth and 5 cm from the bed shoulder toward the bed center.

[00106] Plant Growth.

[00107] Canopy area measurements were taken three times in the 2016-17 season and six times in the 2017-18 season. Overhead photos of each sample plot were captured using a camera elevated on a monopod to a height of 2.1 m over the bed surface. Canopy area was determined by analyzing the photos using the image processing software Image J (National Institute of Health, Bethesda, MD). The image scale was set according to the known bed width in each photo. Image color threshold was determined by adjusting hue, saturation, and brightness values to distinguish green canopy pixels from all background pixels. Threshold values were manually determined for each day on which photos were taken to account for differences in ambient light, cloud cover, and shadow distribution. After thresholding, the images were converted to a binary format in which canopy pixels became black and background pixels became white. The total area of the black canopy pixels was measured and recorded. Individual plant canopy areas were determined by dividing the whole plot canopy area by the number of living plants per plot.

[00108] In the 2016-17 season, runners were removed, counted, and weighed at 10 and 12 weeks after planting (WAP). In the 2017-18 season, runners were sampled from all plots at nine weeks after planting. At the end of the 2016-17 season, three plants from each plot were randomly sampled, separated into roots, leaves, and stems, and then dried at 65 °C for 48 hours to determine tissue dry weight. At the end of the 2017-18 season, two plants from each plot were randomly sampled to determine fresh weight, crown number, petiole number, and leaf area.

[00109] Fruit yield and quality.

[00110] Strawberries were harvested twice weekly from mid-November to early March of both seasons. The harvested fruits were graded following the U.S. Dept. Agr. grading standards (USDA, 2006). Fruits weighing more than 10 grams and free from disease, pest, or mechanical damage were considered marketable. The number and weight of fruits from each plot was recorded. To determine soluble solids content (SSC) in the 2016-17 season, four fruits from each ‘Florida Radiance’/’ Florida Fortuna’ plot were sampled on 25 Jan. and 15 Feb. To determine SSC in the 2017-18 season, four fruits from each ‘Florida Radiance’/’ Florida Fortuna’ plot were sampled on 25 January. Strawberry juice from the aggregate samples was analyzed with a digital refractometer to measure SSC for each plot.

[00111] Statistical Analysis.

[00112] In both seasons, there were six treatments, which were factorial combinations of three mulch types and two cultivars. There were four replications per treatment in both seasons, for a total of 24 plots (FIG. 1A). The experiments utilized a split-plot design with mulch type as the whole-plot factor and cultivar as the sub-plot factor. All statistical analyses were performed using SAS Enterprise Guide 7.1 (SAS Institute, Cary, NC). Soil temperatures were compared between mulch types for each hourly average within a month using standard one-way analysis of variance (ANOVA). Yield, quality, and growth data were analyzed separately for each planting date by two- way ANOVA. The GLIMMIX procedure was used to analyze elongated fruit proportion data for both seasons. Mean separation was performed using the Tu key- Kramer method and significance was established at P< 0.05 unless otherwise noted.

b. Results and Discussion

[00113] To evaluate the RZT cooling effects of fully metalized mulch and metalized-striped mulch, bed center temperature (BCT) and bed shoulder temperature (BST) were monitored at a 10-cm depth throughout each growing season.

[00114] Soil temperature data showed the same trend in both seasons. The more comprehensive data from the 2017-18 season, which included October soil temperature monitoring, are presented in FIG. 2A. Plants on black mulch experienced significantly higher BCT than plants on fully metalized mulch or metalized-striped mulch, especially throughout the establishment period (Oct. and Nov.). In October, the average afternoon BCT was significantly reduced by 3.7 °C under fully metalized mulch and 3.1 °C under metalized-striped mulch compared to black mulch (FIG. 2B). In November, both fully metalized mulch and metalized-striped mulch significantly reduced the average afternoon BCT by 3.2 °C compared to black mulch. In addition to reducing the magnitude of establishment period heat stress conditions, the metalized mulch films also significantly reduced the duration of heat stress conditions. Because many reports suggest RZT above 30 °C can result in poor growth and development of Fragaria species (Geater et al., 1997; Sakamoto et al., 2016; Zhang et al., 1997), 30 °C was used as a heat stress temperature threshold in this Example. Throughout October, BCT exceeded 30 °C for an average of 164 hours under black mulch (Table 1). This duration was significantly reduced to 136 hours under fully metalized mulch and non-significantly reduced to 153 hours under metalized-striped mulch. Throughout November, BCT exceeded 30 °C for an average of 108 hours, but the duration was significantly reduced to only 40 and 46 hours under fully metalized and metalized-striped mulch, respectively. Many previous studies have found metalized mulch films to maintain lower daytime RZT than black mulch by reflecting more incoming shortwave radiation (Diaz-Perez, 2010; Diaz-Perez and Batal, 2002; Diaz-Perez et al. , 2005; Lamont, 2005; Tarara, 2000). The results here with reduced RZT under more reflective mulch types are consistent with these previous observations.

Table 1. Effect of mulch type on the average number of hours

in which bed center temperature exceeded 30°C.

No hours BCT > 30 °C^Z

_ Mulch _ Oct. _ Nov Dec. Jan. Feb

Black 164 a^y 108 a 21 a 1 a 57 a

Fully metalized 96 b 40 b 0 b 0 b 2 b

Metalized-striped 107 ab 46 b 4 b 0 b 42 a

z - Number of hours in which bed center temperature exceeded 30 °C y - Means within a column not followed by the same lowercase letter

are significantly different at P < 0.05.

[00115] Because they had different shoulder colors, the fully metalized mulch and metalized- striped mulch had contrasting effects on BST throughout the growing season. Compared to black mulch, the average hourly BST in October was significantly reduced by up to 4.1 °C under fully metalized mulch compared to only 1.1 °C under metalized-striped mulch (FIG. 2B). The same trend was seen throughout November and December. By January, however, there were no significant differences in daytime BST between black mulch and metalized-striped mulch. In contrast, fully metalized mulch reduced the average afternoon BST in January by up to 2.9 °C compared to black mulch. One reason that black mulch and metalized-striped mulch caused similar wintertime soil warming is their similar black shoulders. Plant canopies mostly covered the bed center by January (FIG. 2C). As a result, only the bed shoulders remained exposed to interact with incoming solar radiation. This caused greater daytime soil warming under black mulch and metalized-striped mulch, which both had black shoulders that effectively absorb solar radiation and conduct it as thermal radiation along a temperature gradient towards the bed center. Consequently, metalized-striped mulch did not reduce BCT compared to black mulch in January and February. The data from this Example indicate that metalized-striped mulch was capable of warming winter soils just as well as black mulch, which has soil warming properties that have long been considered necessary to profitable winter strawberry yields in Florida (Albregts and Chandler, 1993; Brooks, 1959).

[00116] Beyond reducing daytime soil temperatures compared to black mulch, it was also found that fully metalized mulch and metalized-striped mulch resulted in higher nighttime and pre-dawn root-zone temperatures than black mulch. In October, fully metalized mulch and metalized-striped mulch significantly increased the average BCT compared to black mulch for nine hours out of the night (data not shown), with a maximum increase of 1.15 °C occurring just before dawn (FIG. 2B). The ability of fully metalized mulch and metalized-striped mulch to act as insulators and trap heat in the root-zone at night is due at least in part to the optical properties of their aluminum coating - specifically aluminum’s low emissivity. Emissivity (e) is a measure of the relative amount of longwave radiation emitted from a material’s surface compared to the longwave radiation emitted by a perfectly emitting blackbody (e = 1.0) at the same temperature and wavelength (Tarara, 2000). Ham et al. (1993) studied the optical properties of different plastic mulch surfaces and reported that mulch surfaces with high longwave transmittance also had high longwave emissivity. In their study, black mulch (e = 0.87) resulted in the highest daytime temperatures and coolest nighttime temperatures, while aluminum-painted mulch (e = 0.28) resulted in the coolest daytime temperatures but highest nighttime temperatures of all eight mulches examined.

[00117] Metalized (aluminum) mulch surfaces are characterized by low shortwave absorption, high shortwave reflection, and low longwave transmittance (Ham et al., 1993). Because of their low shortwave absorption, metalized mulch films are slow to gather energy throughout the day. However, the low emissivity and longwave transmittance of metalized mulch films produce an insulating effect whereby thermal radiation is not rapidly emitted from the bed surface at night. By comparison, black mulch rapidly gathers heat throughout the daytime and also rapidly emits heat to the cooler surrounding nighttime air. In this way, plants on black mulch experience greater diurnal root-zone temperature fluctuation than plants on fully metalized mulch or metalized-striped mulch. Despite this, there are several studies which suggest that diurnal root-zone temperature fluctuations have little overall effect on strawberry growth and yield when temperature extremes are avoided (Gonzalez-Fuentes et al., 2016; Kumakura and Shishido, 1994). It is theorized that small changes in diurnal RZT fluctuation by the metalized mulch films were unimportant to affecting early yield in this Example. Instead, it is believed that earliness improvement resulted from a reduction in the magnitude and duration of heat stress conditions throughout the hot early season afternoons.

[00118] Metalized mulch types improved early yield

[00119] There was a trend of improved early season fruit yield by fully metalized mulch and metalized-striped mulch in both seasons, though the effect was significant only in the 2016-17 season (Table 2). Conversely, the plastic mulch ^c cultivar interaction did not significantly affect fruit yield in either season. As a result, data presented in this section are pooled by the main effect of plastic mulch type.

Table 2. Effect of cultivar, mulch type, and their interaction on early, late, and total yield of strawberries in the 2016-17 and 2017-18 seasons.

_ Marketable fruit yield (t ha *) _

_ 2016-17 _ 2017-18 _

Cultivar _ Plastic mulch _ Early _ Late Total Early _ Late _ Total

Black 12.1 bc^z 15.0 27.1 8.8 15.3 Ab 24.2

Florida Radiance Fully metalized 13.2 ab 16.4 29.6 11.8 15.9 Ab 27.7

_ Metalized-striped 14 2 a 15 9 30 1 13 4 19 0 A 32 4

Black 11.2 c 13.9 25.1 10.5 12.1 B 22.6

Florida Beauty Fully metalized 12.9 ab 14.9 27.8 11.7 11.9 B 23.7

Metalized-striped 13.7 a 14.8 28.4 12.6 13.9 B 26.5

_ Averaged data _

Florida Radiance 13.2 15.8 28.9 11.3 16.7 a 28.1 a

Florida Beauty _ 12 6 14 5 27 1 11 6 12 7 b 24 2 b

Black 11.7 b 14.4 26.1 9.7 13.7 23.4

Fully metalized 13.0 a 15.7 28.7 11.8 13.9 25.7

_ Metalized-striped 13 9 a 15 3 29 3 13 0 16 5 29 4

Source of variation P-valuc

Cultivar 0.1633 0.2311 0.1450 0.7297 0.0002 0.0062

Plastic mulch 0.0182 0.7326 0.1525 0.1796 0.0914 0.1272

Cultivar ^c Plastic mulch 0.8187 0.9825 0.9943 0.3790 0.5364 0.3063 z - Means within a column not followed by the same lowercase letter are significantly

different at P < 0.05 according to Tukey’s test.

[00120] In the 2016-17 season, fully metalized mulch and metalized-striped mulch significantly increased early yields by 1 1 % and 19%, respectively, compared to black mulch. In the 2017-18 season, fully metalized mulch and metalized-striped mulch led to non-significant early yield increases of 22% and 34%, respectively. By contrast, neither late season nor total season yields were significantly affected by plastic mulch type in the 2016-17 or 2017-18 season. Regardless, there was still a prominent trend of total season yield improvement by fully metalized mulch and metalized-striped mulch. For example, metalized-striped mulch led to a non-significant total season yield increase of 26% compared to black mulch in the 2017-18 season. Metalized-striped mulch resulted in numerically higher early and total yields than fully metalized mulch in both seasons.

[00121] As expected, early season yields were more affected by plastic mulch type than late season yields. Plastic mulches influenced the daytime energy balance around the crop both above and below the soil mostly by either reflecting or absorbing incoming solar radiation per their specific optical properties (Ham et al. , 1993; Tarara, 2000). Since exposure of the mulch surface to incoming solar radiation is highest in the early season when plant canopies are small, the mulches imparted their greatest impact on the plant energy balance during establishment. [00122] Two previous studies have examined the effect of reflective mulch for annual raised bed strawberry production under subtropical conditions. In Brazil, Yuri et al. (2012) found no difference in winter strawberry yields between black and silver reflective mulch treatments. In Florida, Albregts and Chandler (1993) evaluated eight colors of plastic mulch for winter strawberry production. For two consecutive seasons, yellow mulch and white mulch increased early season yields (then considered November through February) by 26% to 33% compared to black mulch, but they had no significant effect on total season yields because of their negative impact on late season yields. Compared to this Example, Albregts and Chandler (1993) utilized cultivars and planting dates that were less likely to promote high early yields. Because of different market conditions, they planted roughly three weeks later and continued to harvest for almost two months longer than this Example. Their longer harvest period may account for differences in the effect of reflective mulch on late season yields between their study and this Example. Using modern early- yielding cultivars and late September planting dates, significant increases in early yield and non significant increases in late yield by fully metalized mulch and metalized-striped mulch were observed in this Example. The effects of root-zone cooling by the fully metalized mulch and metalized-striped plastic mulch on improved strawberry yields are further discussed below.

[00123] Metalized mulch types improved fruit development without affecting plant growth

[00124] In this Example, yield gains by fully metalized mulch and metalized-striped mulch resulted from an increase in the number of fruits produced by each plant rather than an improvement in fruit size. The average fruit size during the 2016-17 early season was the same across all three mulch treatments (Table 3). During this same period, plants on fully metalized mulch and metalized-striped mulch produced 13% and 20% more fruits than plants on black mulch, respectively, indicating that significant early marketable yield increases in the 2016-17 season were almost entirely a result of improved fruit development and fruit set.

Table 3. Effect of cultivar, mulch type, and their interaction on the number of marketable fruit per plant during the early, late, and total periods of the 2016-17 and 2017-8 seasons.

_ 2016-17 _

No. fruit plant^-1 Fruit size (g)

Cultivar Plastic mulch Early Late Total Early Late Total

Black 14.4 B^z 19.0 33.4 19.4 ab 18.4 ab 19.0 ab

Florida

Radiance Fully metalized 15.0 B 20.3 35.3 20.0 a 18.7 a 19.5 a

Metalized-

16.4 A 20.4 36.8 19.8 a 18.2 ab 19.2 a striped

Black 14.0 B 17.8 31.8 17.7 be 18.1 ab 17.9 be

Florida Beauty Fully metalized 17.0 A 19.8 36.8 17.2 c 17.8 ab 17.4 c

Metalized-

17.7 A 20.8 38.4 17.4 c 16.5 b 17.0 c striped

Averaged data

Florida Radiance 15.3 b 19.9 35.2 19.7 a 18.5 a 19.2 a

Florida Beauty _ 16 2 a 19 4 35 7 17 4 b 17 5 b 17 4 b

Black 14.2 b 18.4 32.6 18.6 18.2 18.4

Fully metalized 16.0 ab 20.1 36.0 18.6 18.3 18.5

Metalized-

17.0 a 20.6 37.6 18.6 17.4 18.1 striped

Source of variation P- value

Cultivar 0.0409 0.7245 0.7207 0.0000 0.0100 0.0000

Plastic mulch 0.0079 0.5446 0.1038 0.9870 0.0964 0.2952

Cultivar ^c Plastic mulch_ 0 0997 0 8626 0 5869 0 2607 0 2881 0 1263 z - Means within a column not followed by the same lowercase letter are significantly

different at P < 0.05, while means within a column not followed by the same uppercase

letter are significantly different at < 0.10, according to Tukey’s test

[00125] Interestingly, canopy image analysis did not reveal any changes in canopy area by plastic mulch type for any sampling date in either season (data not shown). This observation suggests that fruit development is more sensitive than vegetative growth to heat stress caused by black plastic mulch. It is well documented that temperatures above 30 °C can suppress floral development, pollen tube growth, pollen viability, and overall fruit set in strawberries (Kumakura and Shishido, 1994; Ledesma and Sugiyama, 2005; Wang and Camp, 2000). In a growth chamber experiment, Ledesma et al. (2008) found that across two different short-day strawberry cultivars, increasing day/night temperatures from 23/18 to 30/25 °C significantly reduced the number of inflorescence produced. The 30/25 °C day/night treatment subsequently had a lower percentage of successful fruit set and number of fruits produced compared to the 23/18 °C treatment. Furthermore, Kadir et al. (2006) found that increasing day/night temperatures from 20/15 to 30/25 °C significantly reduced fruit yields without inhibiting shoot dry matter accumulation. They also found that exposure to 30 °C for more than two weeks inhibits strawberry flower development regardless of cultivar heat sensitivity. In this Example, as discussed earlier, fully metalized mulch and metalized-striped mulch both significantly reduced the magnitude and duration of heat stress conditions compared to black mulch. Based on the evidence from previous studies that high root-zone and air temperatures can inhibit flower and fruit development, it is theorized that heat stress mitigation by metalized mulch films in this Example was responsible for at least partially alleviating floral inhibition in the crown and improving early fruit set and marketable yields.

[00126] Fully metalized versus metalized-striped mulch

[00127] The main objective of the reflective-striped plastic mulch design was to create optimal growing conditions for winter strawberry production under subtropical conditions by utilizing the reflective (metalized) center stripe to cool the root zone during establishment and the black shoulders to warm soils during winter. It was hypothesized that reflective metalized-striped mulch, by having the dual benefits of metalized and black mulch films, could outperform fully metalized mulch. Several observations indicated that metalized-striped mulch was more beneficial than fully metalized mulch, although certain direct comparisons between the two plastic mulches showed no significant difference. For example, metalized-striped mulch resulted in 7% more marketable fruit than fully metalized mulch in the 2016-17 early season (Table 2). During this same period, yields of ‘Florida Radiance’/’ Florida Fortuna’ were significantly improved by metalized-striped mulch, but not fully metalized mulch, compared to black mulch.

[00128] However, the benefits of adding a reflective metalized center stripe to black plastic mulch were best illustrated in the 2017-18 season. Despite an above-average number of hot days during establishment (FIG. 3), metalized-striped mulch produced 10% greater early marketable yields than fully metalized mulch for both cultivars. Beginning in January, which experienced below- average daily temperatures, metalized-striped mulch began to noticeably outperform fully metalized mulch (FIG. 4). Weekly yields of‘Florida Radiance’/’Florida Fortuna’ were significantly improved compared to black plastic mulch for five weeks using metalized-striped mulch, but just three weeks using fully metalized mulch. Additionally, marketable late season yields of ‘Florida Beauty’ were reduced by fully metalized mulch but improved by metalized-striped mulch compared to black mulch (Table 2). The findings indicate that metalized-striped mulch is well- suited to optimize soil microenvironment conditions throughout the dynamic environmental conditions of Florida’s winter strawberry production season.

[00129] Practical applications of metalized-striped mulch [00130] In order to stay cost-effective in an increasingly competitive winter strawberry market, Florida strawberry growers need a practical, easily-implementable solution for reducing establishment heat stress and improving early fruit yields (Guan et al., 2016). Two strawberry cultivars that differ in heat stress tolerance and early season yield patterns were used in this Example. ‘Florida Beauty’, the earliest cultivar available in Florida, is day neutral so it has the ability to initiate flowers at longer photoperiods and higher temperatures than short-day cultivars (Whitaker et al., 2017). As a result,‘Florida Beauty’ is recommended for planting between 20 Sept and 1 Oct. in Florida to allow for adequate vegetative growth before flowering begins. By contrast,‘Florida Radiance’/’Florida Fortuna’ is a short-day cultivar with a relatively weak plant habit and low heat-tolerance, so it is recommended for planting between 5 and 15 Oct. (Whitaker et al., 2008). Despite such contrasting characteristics, no significant cultivar ^c plastic mulch interaction was found in this Example. This observation suggests that reflective-striped mulch is a promising management option that can consistently improve early yields of a wide range of strawberry cultivars by mitigating heat stress associated with extremely early planting (e.g. late Sept in Florida).

[00131] In the Example, neither flavor (data not shown) nor fruit size were affected by plastic mulch type (Table 3). It is important that growers do not sacrifice fruit quality for the sake of increased early season yields, since flavor and fruit size are two essential quality parameters considered by intermediary strawberry buyers and the end consumer (Gallardo et al., 2015). Overall, the findings indicate that black plastic mulch with a metalized-center stripe can improve early season strawberry yields by up to 34% compared to black mulch without negatively affecting fruit quality, late season yields, or production costs.

2. EXAMPLE 2

[00132] The objective of this Example was to examine the effects of white-striped plastic mulch on soil temperature, plant growth, fruit yield, and earliness across three of Florida’s most current early-yielding strawberry cultivars.‘Florida Radiance’/’Florida Fortuna’, which currently accounts for about 60% of Florida’s strawberry market, is a short-day cultivar not recommended for September planting dates since high temperatures during fruit development can lead to elongated, sometimes unmarketable fruits.‘Florida Beauty’ is an early-yielding cultivar released by the University of Florida in 2016. It is day-neutral and possesses a compact canopy, making it well-suited for advanced planting dates.‘Florida Brilliance’, released in 2017, can quickly establish a robust and open canopy before producing relatively high early season yields. It will be important to understand how white-striped mulch affects strawberry cultivars with varying heat stress sensitivity and growth characteristics. To conduct our trial in accordance with recent growing trends, we examined the effect of white-striped mulch when planting was advanced to late September in two seasons.

a. Materials and Methods [00133] Plant establishment and treatments

[00134] Strawberry ( Fragaria xananassa Duch.) field trials were conducted at the University of Florida Institute of Food and Agricultural Science Gulf Coast Research and Education Center in Balm, FL during the 2015-16 and 2016-17 seasons. The site’s soil (Myakka fine sand siliceous hyperthermic Oxyaquic Alorthod) had a pH and organic matter content of 6.8 and 1.5%, respectively. In both seasons, 91.4-m long pressed beds were prepared in late August. To reduce the occurrence of weeds and soil pathogens, the beds were fumigated according to commercial standards with PicClor 60 (1 ,3-dichloropropene + chloropicrin; 122.5 kg/ acre). Each bed had one line of drip irrigation tubing (0.87 L 30.5 rrr¹ min^-1 , 30.5 cm emitter spacing) laid 2.5 cm deep at the bed’s center. The beds were then covered with a 0.02 mm thick black plastic mulch.

[00135] A map of the experimental layout for each season is shown in FIG. 6A. In mid-September of both seasons, half of the plots on each bed had a 51 -cm wide white stripe applied (FIG. 6B) to the bed center using inverted marking paint (Rust-oleum Corporation, Vernon Hills, IL). Paint was applied in a uniform, opaque layer such that the black mulch was completely covered within the 51 -cm wide center stripe. Bare-root transplants with three to four leaves were received from Crown Nursery (Red Bluff, California) in September of both seasons. In the first season, transplants of ‘Florida Radiance’ (marketed as‘Florida Fortuna’ outside the U.S. and Canada) and‘Florida Beauty’ were planted in their respective plots on 26 Sept at a density of 21 plants per plot. For the 2016-17 season, an additional cultivar and planting date were added. Transplants of ‘Florida Radiance’/’Florida Fortuna’,‘Florida Beauty’, and‘Florida Brilliance’ were planted in their respective plots on either 29 Sept or 17 Oct. at a density of 14 plants per plot. Plant spacing and bed dimensions are given in FIG. 6C. To aid in establishment, the plants received 9 h of overhead irrigation during daylight hours on each of 10 d after transplanting. Fertilizer (6-2-4 N-P2O5-K2O) was applied through the drip tape three times weekly at a rate of 7.84 kg N ha^-1 w^~1. After establishment, plants were watered daily via drip irrigation. Pest and disease control were performed based on weekly scouting reports and current recommendations from the University of Florida (Peres, 2015).

[00136] Soil Temperature [00137] Soil temperature was monitored from November through February of both seasons. In the 2015-2016 season, soil temperature was monitored in only two plots with one sensor under each mulch type. In the 2016-2017 season, a total of 12 RT-1 temperature sensors were used to measure soil temperature with two sensors in three plots of each mulch type. Soil temperatures were logged every 30 minutes by six Em50 data loggers (Decagon Devices, Pullman, WA). Root- zone temperature was monitored at both the bed center and the bed shoulder according to the dimensions given in FIG. 6C. Bed center temperature (BCT) was recorded at a 10-cm depth and 20 cm from the bed shoulder toward the bed center. Bed shoulder temperature (BST) was recorded at a 10-cm depth and 5 cm from the bed shoulder toward the bed center.

[00138] Plant growth

[00139] Canopy area measurements were taken twice in the 2015-16 season and three times in the 2016-17 season. Overhead photos of each experimental plot were captured using a camera elevated on a monopod to a height of 2.1 m over the bed surface. Canopy area was determined by analyzing the photos using the image processing software Image J (National Institute of Health, Bethesda, MD). The image scale was set according to the known bed width in each photo. Image thresholding was performed by adjusting hue, saturation, and brightness values to distinguish green canopy pixels from all background pixels. Threshold values were manually determined for each day on which photos were taken to account for differences in ambient light, cloud cover, and shadow distribution. After thresholding, the images were converted to a binary format in which canopy pixels became black and background pixels became white. The total area of the black canopy pixels was measured and recorded. Individual plant canopy areas were determined by dividing the whole plot canopy area by the number of living plants per plot.

[00140] In the 2015-16 season, runners were removed, counted, and weighed at 7, 10, and 16 weeks after planting (WAP). In the 2016-17 season, runners were sampled from all plots at 10 and 21 weeks after the first planting date. At the end of both seasons, three plants from each plot were randomly sampled, separated into roots, leaves, and stems, and then dried at 65 °C for 48 hours to determine tissue dry weight.

[00141] Fruit yield and quality.

[00142] Strawberries were harvested twice weekly from mid-November to early March of both seasons. The harvested fruit were graded following the U.S. Dept of Agriculture grading standards (USDA, 2006). Fruits weighing more than 10 g and free from disease, pest, or mechanical damage were considered marketable. The number and weight of fruits from each plot was recorded. In 2016-17, the number and weight of elongated fruit from each harvest was also recorded. Elongated fruit are produced mainly by ‘Florida Radiance’/’Florida Fortuna’ when exposed to high temperatures in the early season (Whitaker et al., 2008). To determine soluble solids content (SSC) in the 2015-16 season, four fruit from each plot were sampled on 12 November and 1 1 February. To determine SSC in the second season, four fruit from each‘Florida Radiance’/’Florida Fortuna’ plot were sampled on 25 Jan. and 15 Feb. Strawberry juice from the aggregate samples was analyzed with a digital refractometer to measure SSC for each plot.

[00143] Statistical analysis.

[00144] The experiments utilized a split-plot design with mulch type as the whole-plot factor and cultivar as the sub-plot factor. There were four treatments in the 2015-16 season with two mulch types and two cultivars. There were six treatments for each planting date in the 2016-17 season with two mulch types and three cultivars. Soil temperatures were compared between mulch types for each hourly average within a month using a standard t-test. Fruit yield and quality and plant growth data were analyzed separately for each planting date by two-way analysis of variance using SAS Enterprise Guide 7.1 (SAS Institute, Cary, NC). In cases of non-significant plastic mulch x cultivar interaction, data were pooled by each main effect. The GLIMMIX procedure was used to analyze elongated fruit proportion data for the 2016-17 season. Mean separation was performed using the Tukey-Kramer method and significance was established at P< 0.05 unless otherwise noted.

b. Results and discussion

[00145] Root-zone temperature effects of white-striped mulch.

[00146] Because trends from the two seasons were similar, only the more comprehensive 2016- 17 soil temperature data are presented (FIG. 7A). Soil temperature monitoring at both the bed center (see A-D) and bed shoulder (see E-H) revealed localized patterns of microclimate modification by white-striped mulch. Root-zone temperatures measured at the bed center were substantially reduced under white-striped mulch throughout the hottest midday hours of November (FIG. 7A, see A). November bed center temperature averages were reduced under white-striped mulch compared to black mulch from 11 :00 through 17:00, with a maximum reduction of 4.5 °C (33.5 vs. 29.0 °C) occurring at 15:00. Though soil temperature data were not collected in October, trends are expected to be comparable, if not more pronounced, due to greater solar influx and less canopy shading of the bed center. Our data suggest that on average, root-zone temperatures are significantly reduced under white-striped mulch during more than 25% of the daytime hours in October and November.

[00147] It has been widely documented that both wild and cultivated Fragaria spp. are adversely affected by high root-zone temperatures above 30 °C (Heilman and Travis, 1988; Ledesma and Kawabata, 2016). When grown in suspension culture, strawberry cells exposed to 30 °C exhibited slowed, atypical growth (Zhang et al., 1997). In a hydroponics experiment which held root-zone temperatures constant for 21 d, strawberry plants grown at 29 °C gained nearly twice the fresh mass as plants grown at 35 °C (Geater et al., 1997). More recently, strawberry plants grown hydroponically at a constant root-zone temperature of 30 °C exhibited low oxygen consumption, a sign of reduced root cell respiration (Sakamoto et al., 2016). In this Example, white-striped mulch reduced the highest afternoon soil temperatures below 30 °C, within a range suitable for normal growth and development.

[00148] Unlike bed center temperature, bed shoulder temperature was not affected by white- striped plastic mulch (FIG. 7A, see E-H). This indicates that the effect of cooling by the white stripe is limited to the area immediately under the white stripe. Because the shoulders of both mulch types are black, they are effective at absorbing solar radiation and subsequently warming soils beneath the black mulch. During the cold winter months when the possibility of freezing temperatures threatens to damage plants, it is expected that the exposed black shoulders will be able to absorb solar radiation and transfer heat via conduction to the cooler bed center where most of the plant roots are located. By implementing white-striped mulch, growers can effectively reduce soil temperatures during the early season when heat stress can affect season-long plant performance while still maintaining late season yields.

[00149] Plant growth effects.

[00150] Plant growth measures were only affected by white-striped mulch in the 2015-16 season (Tables 4 and 5). Canopy area measurements taken 7 WAP showed that, for both cultivars, plants on white-striped mulch had 1 1 % greater canopy area than those on black mulch (Table 4). The beneficial effect of white-striped plastic mulch on plant biomass accumulation was diminished by 12 WAP. It is likely that plant growth improvement by white-striped plastic mulch was detectable only in the 2015-16 season because of relatively high early season temperatures. In 2015, there were 27 d in which the maximum daily temperature exceeded 30 °C between planting and the end of November (FIG. 8). For the first planting date of 2016, there were only 13 d in which the maximum daily temperature exceeded 30 °C between planting and the end of November. These data suggest that plants were subjected to greater heat stress during establishment in 2015-16 than in 2016-17. It is possible that prolonged heat stress conditions of 2015-16 led to more consistent growth improvements by white-striped mulch as well.

Table 4. Effect of cultivar and mulch type on canopy area

at two times throughout the 2015-16 season.

Canopy area (cm² plane¹)

Cultivar Plastic mulch 7 WAP^a 12 WAP

Florida Radiance 770 1279

Florida Beauty 713 1229

Black 703 B^b 1267

_ White-striped 779 A 1241

Source of variation p value

Cultivar 0.1403 0.8800

Plastic mulch 0.0570 0.2400

a - WAP = Weeks after planting

b - Means within a column not followed by the same uppercase letter

are statistically different at P < 0.10 according to Tukey’s test

[00151] Plant biomass measurements performed at the end of the 2015-16 season showed that white-striped mulch increased root dry weight by 26% compared to black mulch (Table 5). Shoot dry weight, however, was unaffected by plastic mulch color when sampled at the end of the season. Kadir et al. (2006) reported that strawberry roots are more sensitive than shoots to the adverse effects of high temperature stress. In a growth chamber experiment, it was found that increasing daytime air temperatures from 20 to 30 °C had no effect on shoot biomass accumulation, but reduced root biomass by 20% (Kadir et al., 2006). In our experiment, runner growth was inconsistently affected by white-striped mulch (data not shown). Taken together, our results suggest that under stressful growing conditions, such as the consistently high (> 30 °C) temperatures experienced in the fall of 2015, white-striped mulch can effectively improve plant growth.

Table 5. Effect of cultivar and mulch type on end-of-season dry weight partitioning

measurements in the 2015-16 season.

Cultivar Plastic mulch Root DW^a (g) Shoot DW (g) RSR^b Florida Radiance 5.30 b^c 40.0 0.108 b

Florida Beauty 7.90 a 43.8 0.168 a

Black 5.49 b 47.8 0.122

White-striped 6.90 a 46.0 0.154

Source of variation value Cultivar 0.0051 0.1666 0.0192

Plastic mulch 0.0189 0.6719 0.1421 a DW = Dry weight

b RSR = Root-to-shoot ratio

c Means within a column not followed by the same lowercase letter are

significantly different at P < 0.05 according to Tukey’s test

[00152] Increased early and total yields by white-striped mulch

[00153] The yield response to white-striped plastic mulch varied depending on seasonal conditions and planting date (Table 6). The response was relatively more consistent across cultivars for the 2015-16 season and for the second planting of the 2016-17 season. Because the plastic mulch ^c cultivar interaction was not significant for these two trials, the data discussed in this section are pooled by the main effect of plastic mulch type. In 2015-16, yield improvements by white-striped mulch were 31 % in the early (November-January) season but non-significant in the late (February-March) season, resulting in non-significant effects on total season yield. In 2016-17, the mid-October planting date resulted in significant yield improvements by white- striped mulch of 20% in the early season and 15% across the entire season.

Table 6. Effect of cultivar, mulch type, and their interaction on early and total yield of

strawberries in the 2015-16 and 2016-17 seasons.

Marketable fruit yield (t ha ¹ )

15-16 16-17 PI 16-17 P2 Nov- Feb- Nov- Feb- Nov- Feb-

Cultivar Plastic mulch Total Total Total

Jan Mar Jan Mar Jan Mar

Florida Radiance Black 5.2d^b 14.9 20.1c 8.1c 15.1b 23. ID 8.9c 13.6 22.5ab

White-striped 7.4c 14.0 21.4bc 11.8ab 17.9ab 29.6BC 11.2ab 15.3 26.5a Florida Beauty Black 9.5b 16.2 25.7ab 11.3abc 14.2b 25.5CD 8.5c 10.9 19.4b

White-striped 12.0a 16.1 28.1a 10.3bc 13.7b 24.0D 9.3bc 12.5 21.8ab Florida Brilliance Black N/A^c N/A N/A 14.5a 19.4a 33.9AB lO. lbc 13.6 23.7ab

White-striped N/A N/A N/A 14.5a 21.1a 35.5AB 12.3a 14.6 26.9a Pooled data

Florida Radiance 6.3b 14.5b 20.8b 9.9b 16.5b 26.4b 10.1a 14.4 24.5a

Florida Beauty 10.8a 16.1a 26.9a 10.8b 14.0c 24.8b 8.8b 11.8 20.6b

Florida Brilliance _ N/A N/A N/A 14 5a 20 2a 34 7a 11.2a 14 1 25 3a

Black 7.4b 15.5 22.9 11.3 16.2 27.5 9.1b 12.8 21.9b

White-striped 9.7a 15.1 24.8 12.2 17 6 29 7 10 9a 14 1 25 1a

Source of variation P value

Cultivar 0.0000 0.0460 0.0003 0.0000 0.0000 0.0000 0.0002 0.0428 0.0062 Plastic mulch 0.0003 0.5447 0.1147 0.1930 0.3014 0.2066 0.0001 0.1221 0.0225 Cultivar ^c Plastic

0.7292 0.5702 0.6029 0.0246 0.2087 0.0251 0.3191 0.9281 0.8056 mulch a The first (29 Sept. 2016) and second (17 Oct. 2016) planting dates of 2016-17 are denoted as‘ 16-17 R and‘16-17 P2’, respectively.

b Means within a column not followed by the same lowercase letter are significantly different at P < 0.05, while means within a column not followed by the same uppercase letter are significantly different at P < 0.10, according to Tukey’s test.

c N/A = Not applicable

[00154] The average maximum daily temperatures of November and December 2015 were 2.7 and 3.0 °C above the 10-year averages for those months, respectively (FIG. 8). These remarkably high average maximum temperatures in the early season likely resulted in proportionally high heat stress mitigation by white-striped mulch. White-striped mulch led to an 11 % improvement in canopy size across both cultivars when measured in late November 2015. Canopy size, which we are using as a proxy for leaf area, has been shown to be directly related to the number of fruits produced by a strawberry plant (Darrow, 1966). The increase in canopy size during the critical transition period from vegetative establishment to reproductive development may partially explain the large magnitude of earliness improvement by white-striped mulch in this season.

[00155] Because there was less heat stress in 2016-17 compared to 2015-16, there was also less heat stress mitigation by white-striped plastic mulch, and subsequently less yield improvement. By delaying transplanting to mid-October in 2016-17, all treatments experienced a trend of reduced early and total season yields compared to the earlier planting. This is most likely because plants had less time to establish vigorous vegetative growth before the onset of flowering and fruiting. It is also possible that the later planting date delayed the transition from vegetative to reproductive growth such that it occurred during a period of higher-than-average temperatures, which intensified the effects of white-striped mulch to result in improved earliness. The average maximum air temperatures of December, January, and February of the 2016-17 season were 2.2, 2.5, and 2.5 °C above the 10-year averages for those months, respectively (FIG. 8). Since these high temperatures continued into the winter months, the effect of white-striped mulch was apparently significant enough to also improve total season yields for the second crop of the 2016- 17 season. These results suggest that there exists a complex relationship between unique seasonal conditions, the crop’s phenology, and physiological responses to microenvironment modification by white-striped plastic mulch.

[00156] Regardless of the magnitude of yield improvement by white-striped mulch, it would appear that the effect results from an increase in both the number of fruit produced by each plant and the average fruit size (Table 7). The response of marketable fruit number to white-striped mulch was more pronounced than the response of fruit size. In the early part of 2015-16, the number of marketable fruit per plant increased by 26% over white-striped mulch while fruit size was increased by only 3.5%. For the second planting of 2016-17, increases in early season marketable fruit number and fruit size by white-striped mulch were 14% and 1 1 %, respectively. In the same trial, total season marketable fruit number was improved 12% by white-striped mulch while fruit size remained unaffected. In terms of early season marketable fruit yield, fruit number, and fruit size, the results of our study are very similar to those obtained in one of the original evaluations of colored plastic mulch for Florida strawberry production. In that study, significant early (then considered Nov. -Feb.) yield improvements by entirely white plastic mulch of 30% and 33% in two respective seasons were reported (Albregts and Chandler, 1993). White mulch improved the number of fruit per plant by 18% without affecting fruit size in the first season, while improving fruit number and size by 20% and 11 %, respectively, in the second season. In both the current experiment and the 1993 study, white mulch led to significantly improved early season fruit set and yields without having as significant effects on plant and fruit size. This suggests that in both cases, yield improvement by white-striped mulch resulted from a physiological shift in development, rather than a consistent improvement in overall plant grow.

Table 7. Effect of plastic mulch type on the number of marketable fruit per plant and fruit weight averaged across all cultivars for the 2015-16 season and second planting of the 2016-17 season.

No. marketable fruit plant ¹

15-16 16-17 P2^a

Plastic mulch Nov-Jan _ Nov-Jan Total

Black 10.0 b^b 12.0 b 28.2 b

White-striped 12.6 a 13.7 a 31.5 a

Source of variation P value

Plastic mulch 0.0008 0.0021 0.0304

Fruit size (g)

Black 17.3 b 14.8 b 18.0

White-striped 17.9 a 16.5 a 18.5

Source of variation P value

Plastic mulch 0.0422 0.0437 0.1859

a The second planting date of 2016-17 (17 Oct. 2016) is denoted as‘ 16- 17 P2’.

b Means within a column not followed by the same lowercase letter are

significantly different at < 0.05 according to Tukey’s test. [00157] Comparisons of late season yield between the 1993 study and the present study highlight the potential importance of white-striped mulch, which can retain some soil warming capabilities in the winter via the black shoulders (FIG. 7A). In Albregts and Chandler (1993), both the bed tops and rounded shoulders were painted white. Because their entirely white-painted mulch reduced January and February afternoon soil temperatures at a 10-cm depth by up to 3.0 °C compared to black mulch, it was likely not capable of sufficiently warming soils in Florida’s cool winter months. As a result, yields suffered over the white mulch in the late season months of March and April. Despite strong trends of improved early season yield by white mulch, late season yields were reduced enough to decrease total season yields below those of the black mulch treatment in two of their three trials. In other environments where soil warming by black mulch is considered beneficial for optimum strawberry yields, such as California and Canada, entirely white mulch has also proved detrimental (Hughes et al. , 2013; Johnson and Fennimore, 2005). This phenomenon of cold-season yield reduction by white mulch was not observed in our study, likely because of the black shoulders. There was a trend of improved total season yield by white-striped mulch in all three trials (Table 6). White-striped mulch was apparently effective at maintaining optimal soil microenvironments throughout the Florida production season, which is characterized by high temperatures during establishment and occasionally freezing temperatures during peak production.

[00158] Cultivar-dependent yield responses to white-striped mulch

[00159] The plastic mulch ^c cultivar interaction played a significant role in improving early and total yields of‘Florida Radiance’/’Florida Fortuna’ when planting was advanced to mid-September in the 2016-17 season (Table 6). For the first planting date of 2016-17, early and total yields of ‘Florida Radiance’/’Florida Fortuna’ showed improvements by white-striped mulch of 46% and 28%, respectively, while neither‘Florida Beauty’ nor‘Florida Brilliance’ exhibited significant yield benefits. Genetic differences between the three cultivars are likely responsible for their varying responses to white-striped mulch. ‘Florida Radiance’/’Florida Fortuna’ is known for having a relatively weak plant habit and performs best when planted between 5 Oct. and 15 Oct. (Whitaker et al., 2008). By advancing planting ahead of the recommended period,‘Florida Radiance’/’Florida Fortuna’ was likely exposed to heat stress beyond the cultivar’s genetic capability to adapt and sustain normal yields. Thus, white-striped mulch may have proved particularly important for improving the early season-yields of ‘Florida Radiance’/’Florida Fortuna’ compared to the other two cultivars tested. This effect may be seen across all three trials, as‘Florida Radiance’/’Florida Fortuna’ consistently exhibited the most positive response of fruit earliness to white-striped mulch (Table 6).

[00160]‘Florida Beauty’ is day neutral and possesses a compact plant canopy, making it well- suited for early planting (Whitaker et al., 2017). Because it can initiate flowering at longer photoperiods and higher temperatures than short-day cultivars,‘Florida Beauty’ is recommended for planting between 20 Sept and 1 Oct. under subtropical production systems in the northern hemisphere. This helps to ensure the establishment of adequate vegetative growth before the plants start producing harvestable fruit in mid-November. Since temperatures in the early part of the 2016-17 season were not excessively high and‘Florida Beauty’ is well adapted to advanced planting, these factors may have contributed to the lack of yield improvements by white-striped mulch in the 2016-17 season. However, it is likely that even‘Florida Beauty’ was not fully capable of coping with the high temperatures early in the 2015-16 season. It seems that as a result, the cultivar benefited from an early season yield improvement of 26% by white-striped mulch.‘Florida Brilliance’ was only tested in the 2016-17 season, so we are not able to compare its response to mulch type under differing seasonal temperatures. The cultivar’s yield and earliness were unaffected by white-striped mulch when planting was advanced in 2016-17. However, when planted in mid-October,‘Florida Brilliance’ exhibited an early yield increase of 22% by white- striped mulch. These data suggest that‘Florida Brilliance’ is also well-suited for advanced planting, since its performance was only improved by white-striped mulch for the later planting date.

[00161] Effect of white-striped mulch on fruit quality.

[00162] In both instances of early yield improvement by white-striped mulch, fruit size was also improved. The average fruit size across all cultivars was increased 3.5% and 11 % during the early parts of the 2015-16 and 2016-17 seasons, respectively (Table 7). Plastic mulch color had no significant effect on soluble solids content during either the early or late season (data not shown.

[00163] We also observed a reduction in elongated fruit produced by‘Florida Radiance’/’Florida Fortuna’ planted on white-striped mulch in the 2016-17 season (Table 8).‘Florida Radiance’ (known as‘Florida Fortuna’ internationally), which currently accounts for 50% and 60% of Spain and Florida’s strawberry markets, respectively, will sometimes produce elongated or“bullet shaped” fruit when transplanted early and exposed to high temperatures in October and November (Whitaker et al., 2008). This physiological disorder, which is not observed in‘Florida Beauty’ or‘Florida Brilliance’, concerns growers since the irregularly-shaped fruit are considered unmarketable if the effect becomes too pronounced. For the advanced planting, 2.25% of the marketable yield were elongated over black mulch, but only 0.40% were elongated over white- striped mulch. Similar reductions were also observed when planting was delayed to mid-October.

Table 8. Effect of plastic mulch type on the absolute yield of elongated fruit and percentage of marketable fruit produced by‘Florida Radiance’/’Florida Fortuna’ during the 2016-17 season.

Elongated fruit yield

Plastic mulch t ha ¹ % yield

Black 0.52 a^a 2.25 a

White-striped 0.12 b 0.40 b

Source of variation P value

Plastic mulch 0.0459 0.0000

a Means within a column not followed by the same lowercase letter are

significantly different at P < 0.05.

[00164] Practical implications of white-striped mulch

[00165] Subtropical strawberry growers have long sought solutions for improving early season fruit yield. T raditionally, growers transplant in early to mid-October and harvest from November to March. With much of the fruit harvest concentrated in February and March, fruit volumes are limited in the early season, so market prices tend to be much higher during this time. Motivated to shift the production window and help capitalize on high wintertime demand, University of Florida researchers have begun releasing strawberry varieties that are both well-suited for early planting dates and have higher early yields at traditional planting dates. White-striped mulch appears to effectively compliment advanced planting practices and early yielding cultivars to further augment earliness for winter strawberry production in Florida. White-striped mulch also has the potential to reduce heat stress in other subtropical strawberry producing countries, such as Australia, Brazil, India, and Thailand (Curi etal., 2016; Das et al., 2007; Pipattanawong, 2015). White-striped mulch is proposed as an easily-implementable, low-cost solution for producing a greater number of larger fruits during the early season. In the case of ‘Florida Radiance’/’ Florida Fortuna’, white- striped mulch also alleviates the problem of elongated fruit to offer a more consistent yield of regularly shaped marketable fruit. Overall, our results suggest that implementing white-striped plastic mulch is a promising strategy for subtropical strawberry growers to advance planting dates and improve early season yields.

3. EXAMPLE 3

[00166] The objective of this Example was to evaluate productivity and mortality of three varieties of strawberries, and four types of mulch, as described below.

[00167] The trial was established in a complete tunnel at Frescapricho, S.L. (N37°5'23.487W6°32'25.51 "). Three varieties (‘Florida Radiance’/’Florida Fortuna’, ‘Florida Brilliance’ and‘Florida Beauty’) and four types white-striped mulching (black, white, reflecting silver plastics and acrylic based spray paint) were tested.‘Florida Radiance’/’Florida Fortuna’ was the witness. Production and mortality of the varieties planted on the different types of mulching were compared.

[00168] Plantation was under conventional system, on sandy soil which was previously disinfected with Agrocelhone^® (1.3 Dichloropropene -60.8 %- and Chloropicrin -33.3 %), by irrigation system (23 g/ ml). Planting framework was 27 x 27 cm. Plantation date was October 15 (‘Florida Beauty’) and 16 (‘Florida Radiance’/’Florida Fortuna’ and‘Florida Brilliance’), the root system of the plants was not disinfected and the covering structure (600 gauges plastic) was applied on November 1. A Datalogger system was used to have a continuous record of the maximum, minimum temperatures and relative humidity of the trial. Environmental conditions were recorded starting on November 23, when the Datalogger was available.

[00169]‘Florida Beauty’ (Rio Eresma nursery) and ‘Florida Radiance’/’Florida Fortuna’ (Campinas nursery) plant quality was good and looked healthy in general. ‘Florida Brilliance’ plants (Campinas nursery) had to be carefully selected before plantation, due to the small size and the apparently poor root system. The final design of the trial can be seen in the following Table 9:

Table 9: Trial Design for Example 3

[00170] The trial site was evaluated once per week, recording production and mortality per mulching treatment and variety. In addition, the second quality, rotten fruit and mortality causes, and necessary operations (trimming of the flowers, weeds elimination, etc.) for the best development of the plants were taken in account.

[00171] The season began with medium-high temperatures during the first stages of the plants’ development. Maximum temperatures were between 36.3 and 18.1 °C (14:33-16:33 pm), minimum levels remained between 2.0 and 15.9 °C (1 :33-8:33 am). Relative humidity were between 99.9 and 20.2 % (last data during the central hours of the day). These weather conditions as well as the late date of plantation caused a low speed plant development, which did not allow early fruit production in general (first harvestings between weeks 51 , at the latest, the first week of 2019). The earliness and production of the plants depend widely on the variety and the type of mulching treatment.

[00172] One factor to take in account when reviewing the results is that first‘Florida Beauty’ flowers were trimmed in November 6, in order to stimulate the plant development.

[00173]‘Florida Beauty’ planted on Black and Reflecting Silver Plastics was the earliest variety of the trial (first harvesting December 19). ‘Florida Brilliance’ was the following, planted on Reflecting Silver Plastic, a week later. ‘Florida Radiance’/’Florida Fortuna’ was the latest, two weeks later than ‘Florida Beauty,’ planted on Reflecting Silver Plastic and White Spray Paint treatments. Black Plastic was the treatment that produced the latest fruits for all varieties except White Spray Paint for‘Florida Beauty.’

a. Productivity

[00174]‘Florida Radiance’/’Florida Fortuna’.

[00175] The first harvest was on December 31 planted on white spray paint and reflective silver plastic, and more than a week later planted on white and black plastic. The total accumulated fruit production until January 9, was 1 1.6, 6.4, 4.5 and 0.9 g plant, planted on reflective silver plastic, white spray paint, white and black plastic respectively (FIG. 9), indicating ‘Florida Radiance’/’Florida Fortuna’ was the most productive when planted on reflective silver plastic.

[00176] Referring to FIGs. 10A and 10B, 100 % of total production was first quality for all type of white-striped mulching, only in black plastic appeared second-class fruit (66.7 %, due to small sized fruits), but this is not necessarily significant, because of the total production was very small (less than 1.0 g plant). In addition, no rotten fruit was registered for the considered period. Images of the‘Florida Radiance’/’Florida Fortuna’ planted on the four mulches are provided in FIG. 11.

[00177]‘Florida Brilliance’

[00178] The first harvest was on December 24 planted on reflective silver plastic, less than a week later (January 4) planted on white plastic and two weeks later on white spray paint mulching (January 8). Black plastic did produced any fruit as of January 9 observation.

[00179] The total accumulated fruit production until the last observation was 6.9, 2.6 and 2.4 g plant (FIG. 12A), planted on reflective silver plastic, white plastic and white spray paint respectively, indicating that‘Florida Brilliance,’ as well as‘Florida Radiance’/’Florida Fortuna’, was the most productive when it was planted on reflective silver plastic, though 40.5 % less productive than‘Florida Radiance’/’Florida Fortuna’ on this type of mulching. In addition,‘Florida Brilliance’ was 42.2 % and 62.5 % less productive than‘Florida Radiance’/’Florida Fortuna’, when it was planted on white plastic and white spray paint respectively. Again this is not necessarily significant because the productions were very small in all cases.

[00180] Referring to FIGS. 12B and 13, 100 % of total production was first quality for black plastic, white spray paint and reflective silver plastic. 15.4 % of the production has been second quality due to misshapen fruits for white plastic. In addition, no rotten fruit has been registered for the considered period. Images of the‘Florida Brilliance’ planted on the four mulches are provided in

FIG. 14.

[00181]‘Florida Beauty’

[00182]‘Florida Beauty’ was the earliest variety planted on reflective silver plastic (first harvest on December 19, almost two weeks earlier than‘Florida Radiance’/’Florida Fortuna’, planted on the same mulching treatment). The same earliness resulted for black plastic, but against what is good data for the reflective plastic, black plastic makes the variety the least productive in this type of mulching. White plastic and white spray paint first harvestings, were two and four days later than the others respectively.

[00183] Referring to FIGS. 15A and 15B, the total accumulated fruit production as of the observation on January 9, was 31.4, 20.6, 14.3 and 3.6 g plant, planted on reflective silver and white plastics, white spray paint and black plastic respectively, making‘Florida Beauty’ the most productive variety in all cases for this period: 63.0 and 78.0 % more productive than‘Florida Brilliance’ and‘Florida Radiance’/’Florida Fortuna’ respectively, planted on reflective silver plastic; 78.1 and 87.4 % more productive than‘Florida Radiance’/’Florida Fortuna’ and‘Florida Brilliance’ respectively, planted on reflective white plastic; 83.2 and 55.2 % more productive than‘Florida Brilliance’ and‘Florida Radiance’/’Florida Fortuna’ respectively, planted on white spray paint mulching; and finally, 100.0 and 75.0 % more productive than‘Florida Brilliance’ and‘Florida Radiance’/’Florida Fortuna’ respectively, planted on black plastic.

[00184] Referring to FIGS. 15B and 16, all the treatments have produced high levels of second quality fruit, always due to small, misshapen fruits or cracking. White spray paint (20.3 %), followed by white plastic (14.6 %) and reflecting silver plastic (12.4 %) presented the worse values, while black plastic only 2.8 % and it also the same value for rotten fruit, though just the same as the previous cases, this is not necessarily significant because the production on the black plastic mulching was very low. Images of the‘Florida Beauty’ planted on the four mulches are provided in FIG. 17.

b. Mortality

[00185] Referring to FIG. 18A, black plastic produced the highest mortality for ‘Florida Radiance’/’Florida Fortuna’ (18.2 %).‘Florida Brilliance’ and‘Florida Beauty’ had a good behavior with respect to this parameter, keeping the mortality values at very low values (2.0 and 1.5 % respectively).

[00186] Referring to FIG. 18B, white spray paint maintained mortality values very low for all varieties. No mortality for‘Florida Beauty’ was recorded, planted on this kind of mulching.

[00187] Referring to FIG. 19A, the reflecting silver plastic was the best mulching for‘Florida Radiance’/’Florida Fortuna’ and‘Florida Beauty’ (0.0 % mortality and it also, as observed above, best productions). On the contrary, is the worst mulching for‘Florida Brilliance,’ since the highest values of mortality occurred with this treatment. Even so, 3.7 % is a low value for mortality in this context.

[00188] Referring to FIG. 19B, the white plastic was again, the same as the black plastic, a bad treatment for‘Florida Radiance’/’Florida Fortuna’ but not for the others. 8.2 % is a relatively high value for the mortality in this context, though is not as high as the value for the black plastic.

[00189]‘Florida Radiance’/’Florida Fortuna’

[00190] Referring to FIG. 20, white and black plastics showed the first values for mortality the first week of November. Both values were low, though white was double that of black plastics (2.0 and 1.0 % respectively). Later mortality stopped, until the middle of December, when the mortality for both treatments appeared again. The difference between both treatments was, once the mortality appeared, much higher on black than in white plastic. The problem for the white spray paint appeared the second week of January, but still was only 1.0 %. No mortality was reported for reflective silver plastic.

[00191] Referring to FIG. 21 , on black plastic mulching, the mortality was apparently due to anthracnose and Phytophthora spp. symptoms. On white spray paint and white plastic, only anthracnose symptoms were reported.

[00192]‘Florida Brilliance’

[00193] Referring to FIG. 22,‘Florida Brilliance’s mortality appeared for all treatments the first week of November. The highest value was for reflective silver plastic (3.1 %). Later, mortality stopped for all treatments except for the reflective silver plastic until the end of December, and black plastic, which begin again the second week of January. The mortality remained in all cases below 3.5 %.

[00194] Referring to FIG. 23, On black and white plastic mulching, the mortality was apparently due to anthracnose symptoms. On reflective silver plastic, it seemed to be Phytophthora spp. Symptoms.

[00195]‘Florida Beauty’

[00196] Referring to FIG. 24, No mortality was reported for white spray paint and reflective silver plastic and in‘Florida Beauty.’ Only black and white plastics produced a minimum mortality (1.5 and 1.0 % respectively) the first week of November. Referring to FIG. 25, The mortality causes were virotic and thin plants (plants without reserves enough for the establishment of the root system).

4. EXAMPLE 4

[00197] The objective of this Example was to examine the effects of reflective-striped plastic mulch on soil temperature, and photosynthesis rates across three of Florida’s most current early- yielding strawberry cultivars -‘Florida Radiance’/’Florida Fortuna’, ‘Florida 127’, and ‘Florida Brilliance’ - as compared to black mulch and fully metalized mulch, throughout the 2018-2019 growing season.

[00198] a. Plant establishment and treatments

[00199] A field trial was conducted at the GCREC in Balm, FL during the 2018-2019 season. The site’s soil (Myakka fine sand siliceous hyperthermic Oxyaquic Alorthod) had a pH and organic matter content of 6.8 and 1.5%, respectively. Raised beds were made using commercial farm equipment on 14 Aug. 2018. Field preparation was performed as in the Example 1. The installation of experiment mulch films was completed on 26 September 2018.

[00200] Bare-root transplants of three strawberry cultivars,‘Florida Radiance’/’Florida Fortuna’, ‘Florida 127’, and ‘Florida Brilliance’, were received from a commercial strawberry nursery (Production Lareault Inc., Quebec, Canada) several days before transplanting. Transplants were planted in their respective plots on 27 September at a density of 16 plants per plot. To aid in establishment, the plants received 9 hours of overhead irrigation during daylight hours on each of 10 days after transplanting. Fertilizer (6-2-4 N-P2O5-K2O) was applied through the drip tape three times weekly at a rate of 7.84 kg N ha^-1 w^-1. After establishment, plants were watered daily via drip irrigation. Pest and disease control were performed based on weekly scouting reports and current recommendations from the University of Florida (Peres, 2015).

[00201] b. Soil Temperature

[00202] Soil temperature, plant growth, fruit yield and quality were monitored from November through February of the 2018-2019 growing season, using the same methods used for Examples 1 and 2. The same trends that were observed in Examples 1 and 2 with respect to soil temperature, plant growth, fruit yield and quality were again observed during Example 3.

[00203] Referring to FIG. 27, thermographic images were taken using a thermal camera (FLIR E53; FLIR Systems, Wilsonville, OR, USA) on representative plots from each mulch to confirm the soil temperature results. Images were taken around noon during the early growth stage. The images show that with the solid black mulch the entire bed exhibited increased temperatures, while the fully metalized mulch produced relatively lower bed temperatures, indicating cooling of the bed under the metalized mulch. Finally, with the metalized-striped much, the soil exhibited warming in the bed shoulders (where the black mulch is present) and cooling in the central zone, within the reflective stripe. This demonstrates that as compared to black plastic mulch, reflective- stripe mulch films can lower the root-zone temperature under the stripe, while warming the root- zone temperature on the bed shoulders. The cooling effects within the stripe is important to reduce heat stress in newly established transplants, which are highly sensitive to heat stress. On the other hand, soil warming is beneficial for fruit development during cool winter months. This root- zone temperature optimization throughout the growing season can contribute to the fruit yield increases especially during the early season.

[00204] c. Photosynthetic Effects

[00205] Photosynthesis rates were determined for a representative plot using reflective-striped mulch. Referring to FIG. 28A, photosynthesis measurements were performed using an infrared gas analyzer (LI6400XT; LI-COR Biosciences, Lincoln, NE, USA) on both upper and lower leaf surfaces around noon during the early growth stage. Measurements were made at different light levels (0, 200, 400, 600, 1000, 1400, and 2000 pmol/m²/sec) to characterize photosynthetic light responses. During measurements, reference CO2 concentration, air flow rate, and block temperature were maintained constant at 400 pmol/mol, 500 pmol/sec, and 28 °C, respectively.

[00206] Referring to FIG. 28B, the schematic illustration shows that plants grown on reflective- striped mulch films can receive both direct sunlight and reflected light, as compared to plants grown on black plastic mulch which can receive only direct sunlight. Referring to FIG. 28A, both upper and lower leaf surfaces showed similar light responses, with photosynthesis increasing with light intensity. Notably, photosynthesis of lower leaf surface was about 65% of the upper leaf surface, suggesting that plants grown on reflective-stripe mulch films can improve light capture and hence photosynthesis, which in turn contributes to the promotion of plant growth and fruit production.

[00207] Referring to FIGS. 29A-29B, a spectroradiometer (SS-110; Apogee Instruments, Inc., Logan, UT, USA) was used to characterize the light emission spectrum for the sunlight, as well as for the light that was filtered through one leaf. Measurements were made during the peak fruit production period. Referring to FIG. 29A, the direct sunlight had a ratio of red light to far-red light of 1.512. Referring to FIG. 29B, in comparison, for light that passed through one leaf layer, the ratio of red light to far-red light was 0.169. The significant reduction in the ratio of red light to far- red light suggests that strawberry leaves absorb more red light than far-red light. As shown in the schematic of FIG. 29C, it is believed that the low red/far-red ratio can promote flowering (Takeda et al. 2008), and therefore it is expected that the disclosed reflective-stripe mulch films can promote flowering by changing the light quality of reflected light.

E. REFERENCES

[00208] The following references, which are cited herein, are incorporated by reference in their entirety, to the extent they are consistent with the present disclosure.

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[00209] It will be apparent to those skilled in the art that various modifications and variations can be made in the present disclosure without departing from the scope or spirit of the disclosure.

Other embodiments of the disclosure will be apparent to those skilled in the art from consideration of the specification and practice of the disclosure disclosed herein. It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the disclosure being indicated by the following claims.

Claims

CLAIMS What is claimed is:

1. A mulch film comprising:

a central portion extending in a first direction and having a first side edge and a second side edge, said central portion comprising a reflective material;

a first peripheral portion adjacent the first side edge of the central portion and extending in the first direction; and

a second peripheral portion adjacent the second side edge of the central portion and extending in the first direction;

wherein the first peripheral portion and the second peripheral portion comprise black mulch.

2. The mulch film of claim 1 , comprising a black mulch film extending in the first direction, and comprising the first peripheral portion and the second peripheral portion.

3. The mulch film of claim 2, wherein the central portion comprises a reflective coating on the black mulch film.

4. The mulch film of any one of the preceding claims, wherein the central portion comprises a reflective film or sheet disposed on the black mulch film.

5. The mulch film of any one of the preceding claims, wherein the reflective material has an emissivity of less than about 0.4.

6. The mulch film of any one of the preceding claims wherein the reflective material is white or silver in color.

7. The mulch film of any one of the preceding claims, wherein the reflective material comprises aluminum.

8. The mulch film of any one of the preceding claims, wherein the centralized portion has a width measured orthogonal to the first direction that is at least about 30% to about 50% of a width of the entire mulch film.

9. A method for production of a crop, comprising:

providing a bed of soil having a central raised portion and two shoulder portions;

disposing on the bed of soil the mulch film according to any one of claims 1 to 8, wherein the central portion of the mulch film generally corresponds to the raised portion of the bed, and the first and second peripheral portions of the film generally correspond to the shoulder portions of the bed; planting a plant into the bed of soil through a hole in the central portion of the mulch film; providing water and sunlight to the plant.

10. The method of claim 9, wherein the soil temperature in the central raised portion of the bed of soil is at least about 3 °C lower than for a similar method using only a black mulch.

1 1. The method of claim 9 or 10, wherein the soil temperature in the shoulder portion of the bed of soil is higher than for a similar method using only a reflective mulch.

12. The method of any one of claims 9 to 1 1 , wherein the duration of heat stress conditions in the soil is reduced, as compared to similar methods utilizing only a black mulch.

13. The method of any one of claims 9 to 12, wherein the method results in an early season fruit yield that is greater than for a similar method utilizing only a black mulch.

14. The method of claim 13, wherein the method results in fruit quality, late season yields, production costs, or combination thereof, that are equal to or better than those resulting from a similar method utilizing only black mulch.

15. The method of any one of claims 9 to 14, resulting in a transplant mortality rate of less than 10%.

16. The method of any one of claims 9 to 15, resulting in a plastic mulch surface temperature that is at least 2 °C lower than a plastic mulch surface temperature resulting from a similar method using only a black mulch film.

17. The method of any one of claims 9 to 16, resulting in a canopy-level air temperature that is at least 2 °C lower than a canopy-level air temperature resulting from a similar method using only a black mulch film.