BR112020004341A2 - method for producing sugar cane seedlings - Google Patents

Abstract

The invention relates to methods for the production of sugarcane seedlings, comprising treatment with growth regulators, a single pruning stage and treatment with phytohormones.

Description

“METHOD FOR PRODUCTION OF SUGARCANE CANCLE”

[0001] The invention relates to methods for the production of sugarcane seedlings, which includes treatment with growth regulators, a single pruning stage and treatment with phytohormones.

[0002] Sugarcane crops (Saccharum sp.) Are of great importance in the global socioeconomic scenario, both in terms of income generation and currency production. In recent years due to the increased demand for bioenergy, areas cultivated with sugarcane are increasing worldwide, as well as investments in factories to produce mainly alcohol and electricity.

[0003] Sugarcane is an important food and bioenergy crop and a significant component of the economy of many countries in the tropics and subtropics. The value of sugarcane is mainly based on its high productivity, the efficient use of agricultural inputs such as water, fertilizer, labor and is locally convertible into high-value products, such as sugar, molasses, ethanol and energy. Sugarcane is produced in almost 100 countries. Although the sugarcane cultivation area occurs only in 1.5% of the total world cultivated land, the world production of total biomass harvested from sugarcane in terms of wet weight is the highest of all plants of culture.

[0004] Sugarcane is an allogamous perennial (cross) plant, probably originating in the regions of Indonesia and New Guinea, belonging to the Poaceae family,

Saccharinae subtribe of the Andropogoneae tribe, genus Saccharum. Its current cultivars are interspecific hybrids, with the species Saccharum officinarum, Saccharum spontaneum, Saccharum sinense, Saccharum barberi, Saccharum robustum and Saccharum edule, all participating in the assembly of cultivated species / varieties genotypes. The real sugar cane seed is a karyopsis type fruit. Karyopsis is described as a simple, dry, indehiscent, uniseminated fruit whose seed coating grows along with the pericarp along its entire length (2009, Rules for seed analysis, Ministry of Agriculture, Livestock and Supply, Brasília) . The seeds are oval, brown or yellowish and about 1.5 mm long.

[0005] Sugarcane reproduces sexually. However, seed production depends on specific environmental characteristics, for example, the need for constant conditions of high temperature and humidity for germination. Additionally, cultivated sugarcane species exhibit high complexity of their genome structure. Cultivated sugarcane species are derived from interspecific hybridization, resulting in highly polyploid and aneuploid genomes. The genomes of cultivated sugarcane species exhibit a high level of heterozygosity. (Moore et al. And Zhang et al. In Sugarcane: Physiology, Biochemistry and Functional Biology, Ed .: Moore and Botha, Wiley 2014, Chapters 1 and 23, respectively)

[0006] The highly heterozygous and complex genome and the crossing behavior of sugarcane prevent the generation of genetic and phenotypically uniform sugarcane plants from seeds. Environmental conditions influence uniform and complete seed germination. For variety maintenance, amplification and cultivation sugar cane has always been and still is propagated vegetatively. In conventional sugarcane production systems, crops are established by sprouting vegetative shoots. Sugarcane crops are conventionally established from stem parts (shavings). Crops established from cuttings are called cane-plant to differentiate from cane-soca. Punch crops are grown from the part of the plant remaining in the soil after harvest (bagasse) (Bonnett in Sugarcane: Physiology, Biochemistry and Functional Biology, Ed .: Moore and Botha, Wiley 2014, Chapter 3).

[0007] Etefon (Phosphonic acid (2-chloroethyl)) is used in sugarcane cultures as a ripener, inducing stem maturation and leaf desiccation. Silva et al. (2007, Bragantia 66, 545-552) reveals a stimulating effect of etefon applied as a ripener in the tillering of the sugarcane stalk culture up to six months after application. In any case, successively grown roving crops show productivity losses that accumulate annually starting in the first year. Therefore, successive regrowth crops in a field are therefore only possible for a few generations. Prolonged use of stubble crops would lead to a depreciation of economically unacceptable productivity. From time to time, new generations of culture have, therefore, been established in a given field by replacing stubble cultures with plant cultures.

[0008] The conventional method for restoring new sugarcane crops from shavings has some long-known disadvantages.

[0009] To establish sugarcane crops in fields, the cuttings are placed in ridges from end to end and covered with soil. The stem parts used as shavings commonly comprise more than one, often three, sometimes more dormant axillary shoots. Each sprout from a single cut has the potential to produce a new sugarcane plant. However, sprout germination is not consistent in terms of germination number and germination time. Therefore, sugar cane plants grown in a field established from cuttings are not distributed equally. The field shows areas with high densities and those with lower plant densities. This leads to the competition of plants for sunlight and nutrients in high plant density field areas and a waste of available sunlight and nutrients in areas with low plant density with the consequence that the total productivity potential of sugarcane plants - sugar in a given field is not fully exploited.

[0010] Stolf et al. (1981, In: CONGRESSO NACIONAL da STAB, 2, Rio de Janeiro. Anais ... 3/4, 443-456) and Serafim et al. (2013, STAB, Piracicaba 31, 22-25) showed that the average germination rate was 50% for manual planting, and

35% for mechanical planting when using conventional cuttings. This low germination rate results in the formation of a non-uniform crop with a low density of primary tillers (mother tillers), causing a fall in the productivity of sugarcane fields, even in the first growing cycle, if there is none replanting operation. However, replanting incurs additional costs for labor and seedling material.

[0011] Sugarcane shavings are conventionally produced from commercially grown crops. However, the seedling material must be produced in nurseries or fields separated from sugarcane crops to enable the production of disease-free planting material. Transporting large volumes of sugarcane planting material from its production site to the fields generates significant costs in sugarcane plantations. In addition, sugar cane nurseries require a substantial amount of land, assistance, labor and investment in crop protection products.

[0012] About 9 to 12 tons of sugar cane stems per hectare are used in manual planting, while mechanized planting requires 18 to 24 tons per hectare. The planted material is buried in the soil, and cannot be used for the production of valuable products, such as alcohol, sugar, electricity (Stolf and Lee, 1990, Álcool & Açúcar, São Paulo, 10 (53), 20-25) . In another experiment, 6-8 tons per hectare of seed stems, containing three shoots, were necessary to establish commercial crops. Planting material costs for sugarcane

sugar vary from 22 to 25% of total production costs, and thus constitute a major part of the expenditure on sugarcane cultivation (Srivastava et al., 1981, In: CONGRESSO NACIONAL DA STAB, 2, Rio January ... Anais ... 3/4, 443-456).

[0013] Therefore, over time, different approaches to improve the production of sugarcane planting material have been followed.

[0014] The tissue culture micropropagation technology was developed for large-scale propagation of sugarcane planting material (Snyman et al., 2011, Plant Cell Rep. 47, 324-249). Mishra et al. (2014, Sugar Tech 16 (3), 255-263) reveal methods for in vitro multiplication (micropropagation) of sugarcane plants comprising excising the youngest sprout from the top of a sugarcane plant as an explant , transfer the bud to a tissue culture, apply growth regulators for bud elongation, apply hormones for proliferation (tillering) of elongated buds, transfer tillers to hormone-containing rooting medium and harden tillers rooted in a greenhouse. The promotion of lateral branch formation (tillering) by ethylene induction through ethrel (2-chloroethyl phosphonic acid) in lower concentrations, but not in high concentrations of sugarcane cultures in vitro is demonstrated.

[0015] However, micropropagation technologies are still very expensive in the production of planting material for establishing commercial crops (Bonnett in Sugarcane: Physiology, Biochemistry and

Functional Biology, Ed .: Moore and Botha, Wiley 2014, Chapter 3).

[0016] Approaches for producing sugarcane planting material without involving in vitro and / or tissue culture were also followed.

[0017] One approach uses tillers and is called the budding method or seblang. Tilling and aerial branching in sugarcane depend on and can be induced by external factors, in particular, growing conditions, such as fertilization and irrigation. In the budding method, sugar cane plants are grown in light and on fertile soil and tillering is promoted by establishing wide spacing between plants, shallow planting, frequent watering and wide fertilization. After root development, tillers including roots are cut from the parent plants and planted separately, allowing them to till again after repeated cutting and separate planting of tillers (Van Dillewijn, 1952, Botany of sugar-cane. Waltham, Mass. USA Chronica Botanica, 371).

[0018] An additional approach is known as the rayungan method. Rayungan is an Indonesian term, which refers to the development of a single shoot (primary shoot) from the lateral (axillary) shoots of a sugarcane stem, after pruning the apex of the parent plant. The primary lateral branches are excised from the mother plant and planted (Sugiyarta & Winarsih, 2009, Sugar Tech 11 (1), 22-27).

[0019] In comparison to the rayungan method, the stratified rayungan method produces many shoots that arise in a single secondary shoot due to the decapitation of the primary shoots (first lateral order). The primary and secondary branches are removed from the stem together with the parts of the node to which the bud is attached to produce unrooted seedlings. The number of shoots produced in the stratified rayungan method depends on the position of the bud on the stem, viability depends on the number of leaf blades in the stem and for rooted shoots with less than four leaves, it must be treated with rooting stimulants, such as indolacetic acid (Sugiyarta & Winarsih, 2009, Sugar Tech 11 (1), 22-27).

[0020] Keethipala et al. (2001, Sugar Tech 3 (3), 106-108) disclose a method including the decapitation of sugarcane mother plants, followed by the decapitation of primary lateral branches, followed by the decapitation of secondary lateral branches, followed by decapitation. tertiary shoots, separation of side shoots from the mother plants and subsequent transfer to polyethylene bags for rooting. The production of planting material takes 15 - 16 months including growth of mother plants for about 8 months. A mother stem is said to produce up to 40 side shoots when the beheading is carried out at least three times.

[0021] JP 08280244 discloses the production of sugarcane seedlings from axillary shoots. The sugar cane mother plants are decapitated inducing the formation of primary lateral branches. The primary side branches are again beheaded to induce production of secondary side branches. Secondary side shoots can be excised from plants to produce seedlings. However, in order to prepare a sufficient number of side branches, the decapitation of the second side branches followed by the decapitation of tertiary side branches and higher order side branches are preferred in efficient seedling multiplication. At least two, but preferably four or more times, beheading is required.

[0022] JP 2003 204716 and JP 2000 135025 reveal the production of sugarcane planting material by decapitating a stem at a height of approximately 120 cm from a fully sugarcane mother plant grown (approximately 3 meters high). The primary branches developed from axillary shoots are grown until seven leaves are present and cut again at the base of the primary shoot. Secondary branches are cut again at the same stage in the same way as primary branches. Tertiary or even higher-order shoots produced after further cutting of next-order shoots are excised from the stem of the mother plant and transferred to a nursery to take root before transplanting in a field.

[0023] The so-called single-eye method is based on the fact that a small volume of knot tissue together with a single root primer that adheres to a bud is sufficient to develop in a sugarcane seedling, although seedlings established from minimal tissue appear thin (Ramaiah et al., 1977, Proc Inter Soc Sugar Cane Technol, 1509-1513). Based on this, several methods have been described for the production of sugarcane seedlings that depend on the cuttings that comprise a single node or even on the so-called pieces of bud that comprise a bud excised only together with a portion of the respective stem stem of sugar cane.

[0024] An example of the so-called single-eye method used in some regions to propagate sugarcane comprises producing mother shoot that has at least four aerial inter-nodes in the stems and then cutting the stems into parts comprising a knot (eye). The cut surfaces are dipped in hot paraffin, stem parts are germinated in special containers and young plants are hardened before being transplanted into the field (Van Dillewijn, 1952, Botany of sugar-cane. Waltham, Mass. USA Chronica Botanica, 371 ).

[0025] WO 2012/140177 discloses a method for producing a sugarcane seedling comprising cutting mother stems into parts that comprise at least one knot (including a bud), placing these parts in a moist medium for grow buds from the buds, cut the top part of the buds emerging from buds above the apical meristem, cut the top part of the newly emerged (primary) buds from the buds above the apical meristem, optionally repeat the last step, cut lateral branches obtained, plant these branches in the growth medium and grow seedlings from the branches. As exemplified, the production of seedlings from cutting the mother stems in parts until planting took at least 105 days.

[0026] A series of patent applications using single-bud (eye) clippings has been published. All of these requests are based on the use of stem parts (shavings) from sugar cane plants that comprise a single node (including a sprout) and on the direct planting of these single node shavings in the field to create sugarcane crops. -sugar. The amount of sugarcane plants to establish a sugarcane crop and the tonnage of seedling material can be reduced by using stem parts that have a single knot compared to conventional methods that use three cuttings bud. Based only on the described single-stem trimming method, WO 2009/000398 emphasizes cold storage (below 15 ° C) of single-stem cuttings before planting in the field. WO 2009/000399 emphasizes that single-shoot cuttings can be treated or coated without growth-promoting compounds including pesticides, sugars, fertilizers or nutrients / micronutrients before direct planting in the field. WO 2009/000400 emphasizes that single-stem cuttings can be treated in a way to retain moisture from stem parts (including paraffin encapsulating) before planting in the field. WO 2009 000401 emphasizes that single-shoot cuttings can be treated with crop protection chemicals including fungicides, insecticides, herbicides or plant activators before direct planting in the field. WO 2009 000402 emphasizes that single-shoot cuttings can be treated with a coating (eg paraffin) to retain moisture from stem parts and a crop protection chemical (including fungicides, insecticides, herbicides or plant activators) ) or a compound that has growth-promoting activity before no-tillage in the field.

[0027] The sprout chunk technology uses even smaller parts of a sugarcane plant to create a seedling compared to the single sprout trimming method. The sprout pieces are produced from sugarcane stems by excising axillary sprouts together with surrounding stem material without cutting the stem completely. The sprout pieces have the advantage of being even smaller than the cuttings conventionally used in sugarcane planting and that a single stem can be used to produce more sprout pieces compared to two or three sprout configurations, which reduces the area needed to grow cane and the volume of planting material to be transported to the fields. In addition, the remaining part of the stem used to excise the sprout can be processed into valuable products such as sugar, alcohol, electricity.

[0028] Ravindra et al., 2013 (Sugar Tech 15 (1), 27-35) reveal the comparison of mechanical planting of sugarcane seedlings produced from pieces of sprouts to the manual planting of such seedlings. The productivity and quality of sugar cane juice planted by both methods were comparable, in which the costs were higher for manual planting.

[0029] Ramaiah et al., 1977 (Proc Inter Soc Sugar Cane Technol, 1509-1513) reveal the comparison of sugarcane cultures established by the use of seedlings produced from sprout pieces to sugarcane cultures -sugar established by conventional three-seed trim planting. A fungicide treatment of the sprout pieces before transferring to the growth medium was included in the method. No significant difference in productivity was observed between the cultures established by both methods, but the cost of the sprout method was significantly lower. This was mainly due to the fact that much less material from mother plants had to be used in the sprout method (200 - 300 kg per hectare) compared to the conventional planting method (8,000 kg per hectare).

[0030] Jain et al. (2010, Sugar Tech 12 (1), 67-69) reveal that the treatment of sprout pieces with Etefon (2-chlorethyl phosphonic acid) or CaCl2 has positive effects on the sprouting frequency of sprout pieces, number and weight of roots and seedling weight of seedlings obtained from shoots. It is also revealed a previous finding that Etefon and CaCl2 promote the sprouting of sugarcane shavings and underground shoots (tillers).

[0031] Loganandhan et al. (2013, Sugar Tech 15 (1), 98-102) summarize the main results previously obtained in planting sugarcane crops from pieces of sprout and compare the planting of sugarcane from the piece of sprout produced in nursery sugarcane seedlings to the conventional trimming method. In the bud chunk method, fungicide treatment of the chunks prior to transfer to the growth medium is recommended. The fields planted with nursery seedlings produced from pieces of shoots showed higher tiller numbers, higher crushable stem numbers and higher yields. Ideal parameters are presented in relation to age and sprout size, cultivation medium and tray size for creating seedlings from sprout pieces. Additionally, a wider spacing between seedlings transplanted to the field is proposed to increase productivity.

[0032] An additional known approach is the so-called multiple-bag method originally developed by Silva (1975, In: Copersucar Seminar of the sugar agro-industry, 3. Águas de Lindóia, Anais ... Águas de Lindóia: COPERSUCAR, 211-214) control of rickets disease of the brassiere (infection with Leifsonia xyli subsp. Xyli). The determining aspect of this method is that each sugarcane seedling or trim is included in a confinement (plastic bags or tubes) and planted in the field in conjunction with the confinement. Sugarcane seedlings for the multi-bag method can be obtained using the rayungan (stratified) method (Keethipala et al., 2001, Sugar Tech 3 (3), 106-108) using the single bud method (eye ) method (Landell et al., 2013, Ribeirão Preto: Instituto Agronômico de Campinas, 16 (IAC. Documents, 109).

[0033] Landell et al. (2013, Ribeirão Preto: Instituto Agronômico de Campinas, 16 (IAC. Documents, 109) reveal a method for obtaining sugarcane shavings from single-eye shavings (a knot). Stems from 5 to 10 months of age. age are cut into disks approximately 3 cm high, where each disk comprises a bud, primordial roots and reserve tissue.The stem disks are treated with crop protection chemicals, in particular fungicides and heat (to suppress growth of pests) before they are transferred to a substrate and placed in a greenhouse (budding nursery) .After 12 days, the sprouted (germinated) discs are placed in containers (plastic bags or tubes) and transferred to another greenhouse (growth nursery). After a period of 60 days, containers including clippings can be transplanted into the field.

[0034] Mohanty et al. (2015, Sugar Tech 17 (2), 116-120) reveal the production of sugar cane seedlings from cut pieces of healthy sugarcane plants by allowing sprouts to germinate in feedlots ( cones) before transplanting to the field (SSI technology). The number, length and perimeter of sugarcane that can be crushed, the average cane weight and the average productivity were significantly higher in the sugarcane fields planted by SSI technology compared to the fields planted by conventional cuttings (each comprising three shoots).

[0035] From the discussion above, these known methods for producing sugarcane planting material each have their advantages and disadvantages.

[0036] Although still used in many sugar cane producing countries and in areas where conventional methods using two, three or more sprouts to plant sugarcane crops, a large amount of material is needed which, on the one hand, reduces the harvested material that can be converted into valuable products and, on the other hand, requires an enormous amount of tonnage of planting material to be transported to the fields. The highest costs in planting sugarcane arise from the production of the respective planting material.

[0037] Micropropagation of tissue culture is very expensive to produce commercial sugarcane planting material and, therefore, is not competitive in relation to conventional planting methods.

[0038] Due to the reduced chip size compared to conventional methods, the single-shoot (eye) method saves seed material and costs for transporting sugarcane planting material to the field. However, single-cut (eye) cuttings planted directly in the field show a decreased germination rate compared to planting three or more cuttings that lead to reduced productivity per hectare (Darpana & Patel, 2014, The Biosacn 9 ( 1), 5557).

[0039] The sprout pieces reduce the amount of material to be removed from the mother plant and, thus, allow more material from the mother plant to be harvested and converted into high value products. However, Shanthy & Ramanjaneyulu (2014, Indian Res. J. Ext. Edu 14 (3), 93) reveal that the creation of sugarcane seedlings from pieces of sprouts has problems even when practiced in a nursery: The sprout pieces must be removed from young plants (6-8 months); even slight damage to the shoots needs to be avoided; requires high-quality soil to grow seedlings; cutting pieces of sprouts from sugar cane stems is laborious.

[0040] The rayungan method requires a large amount of space, due only to the primary side branches being used as planting material (Sugiyarta & Winarsih, 2009, Sugar Tech 11 (1), 22-27). The use of secondary and higher order side shoots in the stratified rayungan method requires less space than the rayungan method, but many budding steps (decapitation) are necessary. After each sprouting, time is required until the shoots of the next higher order emerge. Thus, the stratified rayungan method is time-consuming and laborious.

[0041] The use of sugarcane crops as mother plants to produce sugarcane seedling material is known to exhibit a high risk of producing infected seedling material. Thus, it is well accepted that sugar cane for the production of seed cane must be grown separately from sugarcane crops. Seedlings being raised in a nursery additionally contribute to creating disease-free sugarcane planting material and save water during the seedling growth phase. The use of pre-grown seedlings to create sugarcane crops allows the establishment of a well-defined planting scheme that leads to a regular crop support and, thus, to an increase in the productivity of harvested and friable stems.

[0042] Therefore, there is still some need for further improvement in the production of sugarcane seed material.

[0043] Therefore, the aim of the present invention is to provide a method for producing eligible sugarcane seedling material to establish sugarcane crops efficiently in terms of time, cost and hand workforce.

[0044] Therefore, a first embodiment of the invention relates to a method for producing a sugarcane seedling comprising the steps of a) treating sugarcane plants with a plant growth regulator that releases ethylene b ) additionally grow the sugar cane plants sprinkled according to step a) c) prune the top parts of the main stems and the top parts of the newly produced side branches of the sugar cane plants grown according to with step b) d) additionally grow the pruned sugarcane plants obtained in step c) e) remove side branches from the plants obtained in step d) f) treat the side branches obtained according to step e) with an auxin g) transfer the side shoots treated according to step f) on a growing substrate and grow side shoots in a conditioned climate h) obtain sugarcane seedlings (rooted) from side shoots grown according to with the step g).

[0045] The term “sugar cane” as used in this document should have the current common meaning in the art, comprising the species Saccharum spontaneum L., Saccharum sinense (Roxb) Jesw., Saccharum barberi Jesw., Saccharum officinarum L ., Saccharum robustum Brandes & Jeswiet ex Grassl. and Saccharum edule Hassk. Saccharum spontaneum and Saccharum robustum are wild species. Saccharum sinense, Saccharum barberi, Sacchatum officinarum and Saccharum edule are commonly known and also understood as representing “cultivated sugarcane species” or “cultivated sugarcane plants”.

(Moore et al. In Sugarcane: Physiology, Biochemistry and Functional Biology, Ed .: Moore and Botha, Wiley 2014, Chapter 1).

[0046] “Sugarcane seedling” is understood as used in this document as being a young sugar cane plant that has leaves, a stem (stem, stem) and roots. The shavings represent a specific modality of a sugarcane seedling.

[0047] "Trim" is to be understood in this document as meaning a trim, comprising root (or roots) and shrub (or shoots) including leaves.

[0048] "Trim" should be understood in this document to mean stem or billet parts that comprise one or more knots including lateral (axillary) shoots.

[0049] The age of a sugarcane plant is determined by calculating the time between the actual date and the start date. Age can be calculated in common terms of time measurement, such as days, months, years, but is preferably measured in this document in months. In the art, several systems have been established to grow sugarcane plants or sugarcane crops. When the seedlings are planted, the starting date is the day the seedling is transferred to normal growing conditions or the seedling is transplanted to the field. When the sugarcane cane plants are grown, the starting date is the date on which the tillers became visible in the bagasse. When cuttings are used to plant sugar cane plants, the start date is the date on which seedlings emerge from the soil.

[0050] “Soqueira” should be understood in this document as a plant or culture that is grown from bagasse (Roots and rhizomes, remain under the ground)

[0051] “Bagasse” is commonly understood in the art and is also understood in this document as being part of a sugarcane plant that is left in the soil after harvesting including underground roots and rhizomes.

[0052] “Profiles” as used in this document have the common meaning in the technique and should be understood as meaning shoots that arise from the underground shoots (below the soil surface) of the main stem (stem, stem).

[0053] The sugarcane plants in step a) of the method for producing a sugarcane seedling according to the invention can be any sugarcane plant, including sugarcane plants sugar from a commercial variety or sugar cane plants of varieties that must be propagated including new varieties to be propagated for commercialization. Thus, the method for producing a sugarcane seedling according to the invention can be used to produce sugarcane seedling material from existing commercial varieties or can be used for multiplication of (new) varieties . The sugarcane plants in step a) of the method for producing a sugarcane seedling according to the invention may have grown from any suitable material, such as single or multiple cuttings, cuttings, stumps, buds, seedlings, in which the seedlings may have been obtained from any suitable material, including in vitro culture or grown tissue or propagated material.

[0054] "Piece of bud" is commonly understood in the art and should be understood in the present document as meaning a short stem part comprising a part of a node including a single lateral (axillary) bud.

[0055] In relation to step a) of the method for producing a sugarcane seedling according to the invention, the sugarcane plants are aged between 4 months to 14 months, preferably between 5 months to 12 months, more preferably, between 5 months to 10 months, even more preferably, between 5 months to 9 months, even more preferably, between 5 months to 8 months, particularly preferably, between 5 months to 7 months and most preferably, between 6 to 7 months when treated with a growth regulator that releases ethylene.

[0056] "Plant growth regulator that releases ethylene" should be understood in this document as meaning a chemical substance that induces the production of ethylene in plant tissue and / or that induces the release of ethylene from plant tissue.

[0057] It is known in the art that ethylene itself, when applied to plants, stimulates its own production in plant tissues and the release of ethylene from these tissues (Woodward & Bartel, 2005, Annals of Botany 95, 707735; EF George et al. (eds.), 2008, Plant Propagation by Tissue Culture 3rd Edition, Springer, 227281). Therefore, it is understood that the ethylene itself in this document as representing a plant growth regulator that releases ethylene.

[0058] Additional ethylene plant growth regulators are known in the art and comprise substances that stimulate the production of ethylene in plants and their subsequent release into the surrounding environment. Such substances include the substances 1-aminocyclopropane-1-carboxylic acid (ACC), natural methionine auxins and synthetic auxins.

[0059] Substances that release ethylene from plants are also known in the art. The most common substance that is absorbed by plants, decomposed later by the plant followed by the release of ethylene is 2-chlorethyl phosphonic acid (CAS number: 16672- 87-0), also known by the common name “Etefon” (EF George et al (eds.), 2008, Plant Propagation by Tissue Culture 3rd Edition, Springer, 227-281).

[0060] Etefon has the following formula:

[0061] Etefon is commercially available, for example, from Sigma-Aldrich (Sigma-Aldrich Chemie GmbH, Munich, Germany). Etefon is the active compound of several agricultural products such as Ethrel® (Bayer S / A, Rua Domingos Jorge, 1,100 - CEP: 04779-900 - São Paulo / SP).

[0062] The term “etefon” as used in this document should not only include the acid form, but also salts thereof. Preferred salts in conjunction with the present invention are alkali metal, alkaline earth metal or etheron ammonium salts. In relation to alkali metal salts, sodium and potassium salts are preferred in this document. In relation to the alkaline earth metal salts of etefon, magnesium and calcium salts are preferred in this document.

[0063] The term "auxin" is understood to include natural and synthetic auxins.

[0064] "Natural auxins" are those that are produced by plants and comprise the substances indole-3-acetic acid (IAA), 2-phenylacetic acid (PAA), 4-chloroindol-3-acetic acid (4-C1-IAA ), indole-3-butyric acid (IBA) (Sauer et al., 2013, J. Exp. Botany 64 (9), 2565-2577).

[0065] "Synthetic auxins" are those produced not naturally in plants and comprise alpha-naphthylacetic acid (NAA), 3,6-dichloroanisic acid (dicamba), 2,4-dichlorophenoxyacetic acid (2,4-D), acid 2 , 4,5-trichlorophenoxyacetic (2,4,5-T), 2-methyl-4-chlorophenoxyacetic acid (MCPA), 4-amino-3,5,6-trichloropicolinic acid (picloram), 2-chloro-3 ( 2,3-dichlorophenyl) propionitrile (CDPPN), para-chlorophenoxyacetic acid (PCPA), beta-naphthyloxyacetic acid (NOA), 2,4-dichlorophenylselene acetic acid, 3- (benzo [b] selenienyl) acetic acid (EF George et al. (eds.), 2008, Plant Propagation by Tissue Culture 3rd Edition, Springer, 175-204), 2-chloro-3- (3-chloro-2-methylphenyl) propionitrile (CCMPPN), 2-chloro-3- (2,3-dichlorophenyl) butyronitrile (CDPBN) (Nemeth, 1981, Scientia Horticulturae 14, 253259). Indole-3-propionic acid (IPA) acts on plants as an auxin, it is produced naturally by bacteria present in the human gastrointestinal tract, but not by plants. Therefore, it is understood in the present document as being a synthetic auxin.

[0066] In relation to step a) of the method for producing a sugarcane seedling according to the invention, the plant growth regulator that releases ethylene can be any substance that results in the release of ethylene from the tissue of plant to the surrounding environment. Preferably, the plant growth regulator that releases ethylene in step a) of the method for producing a sugarcane seedling according to the invention is selected from the group consisting of 1-aminocyclopropane-1-carboxylic acid (ACC), natural or synthetic auxins or etefon.

[0067] In this regard, the preferred natural auxins to be used in step a) of the method to produce a sugarcane seedling according to the invention are indole-3-acetic acid (IAA), 2-phenylacetic acid (PAA), 4-chloroindol-3-acetic acid (4-C1- IAA), indole-3-butyric acid (IBA), more preferably, IAA, IBA or PAA, most preferably, IAA or IBA.

[0068] The preferred synthetic auxins to be used in step a) of the method to produce a sugarcane seedling according to the invention are NAA (alpha-naphthylacetic acid), dicamba (3,6-dichloroanisic acid), 2,4-D (2,4-dichlorophenoxyacetic acid), 2,4,5-T (2,4,5 trichlorophenoxyacetic acid), MCPA (2-methyl-4-chlorophenoxyacetic acid), picloram (4-amino- 3,5,6- trichloropicolinic), CDPPN (2-chloro-3 (2,3-dichlorophenyl) propionitrile), PCPA (para-chlorophenoxyacetic acid), NOA (beta-naphthyloxyacetic acid), 2,4-dichlorophenylselenoacetic acid, 3- (benzo [b] selenienyl) acetic, more preferably, are NAA, dicamba, 2,4-D,

2,4,5-T, MCPA or picloram, even more preferably, are NAA, 2,4-D, dicamba, MCPA or picloram, most preferably they are 2,4-D, dicamba, MCPA or picloram.

[0069] In the most preferred embodiment of the invention, the plant growth regulator that releases ethylene in relation to step a) of the method for producing a sugarcane seedling according to the invention is etefon or a salt thereof.

[0070] The treatment of plants with auxins usually shows a detrimental effect on plant growth, as demonstrated by the fact that several synthetic auxins (for example, 2,4-D, dicamba, picloram) are used as active ingredients in herbicides or are used as pre-harvest desiccants, leading to the drying of plant leaves. The plant growth regulator etefon is also commonly used in subtropical regions to induce the drying of sugarcane. Therefore, it was surprising that auxins and growth regulators when applied to sugarcane plants induce the production of side shoots rather than stopping plant growth when used commonly.

[0071] Treatment with a plant growth regulator that releases ethylene in relation to step a) of the method to produce a sugarcane seedling according to the invention means applying a plant growth regulator that releases ethylene through any means that directly puts the sugarcane plant in contact with a plant growth regulator that releases ethylene. Therefore, treatment includes applying gaseous substances, such as ethylene, through aeration, solid substances in the form of powders or in the form of solutions, emulsions or dispersions.

[0072] Solutions, emulsions or dispersions can be applied by any suitable means to the sugar cane plants, preferably they are applied by spraying the sugar cane plants in step a) of the method to produce a sugarcane seedling according to the invention with a respective solution, emulsion or dispersion. Dicamba, 2,4-D, MCPA or picloram is commercially available as readily formulated herbicides.

[0073] Etefon is also commercially available as a readily formulated growth regulator (eg Ethrel®, Bayer S / A). The respective formulations can be used to appropriately prepare dilute solutions or, where applicable, emulsions or dispersions to treat the sugarcane plants in step a) of the method for producing a sugarcane seedling according to the invention. .

[0074] In a specifically preferred embodiment of the invention in step a) of the method according to the invention to produce a sugarcane seedling, a solution comprising etefon or a salt thereof is sprinkled on the sugarcane plant -sugar.

[0075] Sprinkling may be performed by any suitable means, including manual sprinkling with manual sprinkler devices of any type, mechanical sprinkling through the use of the respective devices such as tank sprinklers, automatic sprinklers, etc. The skilled person knows different spray methods and devices. The method and type of sprinkler, equipment or sprinkler device are not decisive and can be chosen by the person skilled in the art according to the circumstances determined.

[0076] In a preferred embodiment of the invention, the sugarcane plants in step a) of the method for producing a sugarcane seedling according to the invention are sprinkled with a solution comprising etphon in an amount of 14.5 grams per liter (g / l) to 36.0 g / l, more preferably, in an amount of 18.5 g / l to 33.0 g / l, even more preferably, in an amount of 22 , 0 g / l to 29,5 g / l, even more preferably, in an amount of 24,5 g / l to 27,5 g / l, most preferably, in an amount of 25,5 g / l to 26,5 g / l. The quantities in g / l are calculated based on the dry weight of active ingredient (etefon) present in 1 liter of final solution (spray).

[0077] When using commercially available products Ethrel® 720 (Bayer S / A) or Etefon 720 (for example, Kenso agacare, Bulimba, Qld 4171, Australia or Cheminova, North Ryde, NSW 2113, Australia), cane plants in step a) of the method for producing a sugarcane seedling according to the invention are sprayed with a solution comprising Ethrel® 720 or Etefon 720 in an amount of 20.0 milliliters per liter (ml / l) to 50.0 ml / l, more preferably, in an amount of 26.0 ml / l to 46.0 ml / l, even more preferably, in an amount of 31.0 g / l to 41.0 ml / l, even more preferably, in an amount of 34.0 ml / l to 38.0 ml / l, most preferably, in an amount of 35 ml / l to 37 ml / l.

[0078] In another preferred embodiment of the invention, the plant growth regulator that releases ethylene in relation to step a) of the method for producing a sugarcane seedling according to the invention is preferably applied, sprinkled on the top of the sugarcane plants, preferably, the plant growth regulator that releases ethylene is applied, preferably, sprayed only on the top of the sugarcane plants.

[0079] "Cup" is to be understood in conjunction with the present invention as the top leaves of a sugarcane plant or support that forms a continuous layer of leaves.

[0080] After the sugarcane plants have been treated with a plant growth regulator that releases ethylene, new side shoots will be produced in the mother stems of the treated plants when grown additionally according to step b) of the method to produce a sugarcane seedling according to the invention. It was surprisingly found that the treatment of sugarcane plants with specific amounts of etefon induced the production of lateral branches. In addition, it was found that the number of shoots increased significantly after the application of etefon to the sugarcane plants in comparison to the rayungan method, in which the production of lateral shoot is induced by pruning of the cane stem. main sugar. 2 to 3 times more side shoots could be produced on a single plant when using etefon, compared to the traditional rayungan method. Thus, the use of ethephon reduces the space required for the production of side shoots, due to the fact that less mother plants are used to produce a specific amount of side shoots. In addition, it was found that the production of lateral branches after treatment with etefon is more uniform compared to traditional methods. Therefore, the lateral shootings produced on the mother stem are all at a comparable and similar stage of development. Thus, the additional treatments required to produce sugarcane seedlings can be carried out at one point in time for all plants saving time compared to different groups of plants that must be treated differently. This saves labor and time and, consequently, costs. In addition, a more uniform side crop production makes it possible to improve the precise planning of the seedling production process. When, for example, it is known that a predetermined quantity of seedlings is required at a defined point in time, it can be easily defined when to start with seedling production, when to perform additional steps and when the required quantity of new seedlings will be available. Thus, the method revealed in the present document enables the precise planning of seedling production and, thus, allows the punctual delivery of seedlings to the farmer.

[0081] “Stalk” is commonly understood and should have the meaning in this document as referring to the grindable stem of a sugarcane plant formed by repeating phytometric units, each containing a knot and an inter- at the.

[0082] "Stem" is used in the technique as well as in this document synonymously and interchangeably with the terms "stem" or "stem".

[0083] "Sarmento" should mean in this document as a young stem that emerges from a bud.

[0084] "Lateral shoot" is commonly understood and should be understood in this document as all shoot that arise at the location of a bud located in the aerial parts (above ground) of a stem or shoot. The generic term “lateral shoot” encompasses primary and secondary shoots and all higher order shoots that arise at the location of a bud located in the aerial parts (above ground) of the stem.

[0085] "Lateral sarmento" is used in the technique as well as in this document synonymously and interchangeably with the term "axillary sarmento".

[0086] "Primary lateral branch" is commonly understood and should be understood in this document as referring only to those branches that arise directly from a bud located in the aerial parts of the stem.

[0087] "Secondary lateral branch" is commonly understood and should be understood in this document as referring only to those branches that arise directly from a bud located in the primary lateral branch.

[0088] Similarly, the lateral branches of the highest order (tertiary, quaternary, etc.) are commonly understood and should be understood in this document as referring only to those branches that arise directly from a bud located in a branch of the lateral previous lower order (secondary, tertiary, etc., respectively).

[0089] "Mother stem" should be understood in this document as referring to the stem from which the planting material is derived or excised (cut).

[0090] The growth of the sugarcane plants in relation to step b) of the method for producing the sugarcane seedling according to the invention can be done as conventionally known. The plants can be kept under the conditions in which they were previously grown. An expert in the art knows well the conditions under which sugarcane must be grown.

[0091] In relation to step b) of the method for producing a sugarcane seedling according to the invention, the sugarcane plants are grown until the side branches are produced, preferably the plants sugarcane are grown for another 14 days to 21 days after sprinkling, more preferably, for another 16 days to 19 days after sprinkling, even more preferably, for 17 days to 18 days after sprinkling, still more preferably, the sugarcane plants are grown for an additional 14 days to 16 days after sprinkling.

[0092] Pruning in step c) of the method for producing a sugarcane seedling according to the invention can be done by conventionally known methods. Pruning can be done by hand using any suitable tool or pruning can be done using suitable machines. Preferably, the top of the main stems and the top of the side branches recently produced in step c) of the method for producing the sugarcane seedling according to the invention are cut in a position that removes the apical meristem from the stem. The newly produced side branches to be cut in step c) of the method for producing a sugarcane seedling according to the invention can comprise primary and secondary side branches.

[0093] "Apical meristema" as used in this document has the common meaning in the technique and is understood to be the growth point at the top (tip) of the stem or the stem that is responsible for the vertical growth of the stem or stem, respectively.

[0094] The growth of sugar cane plants after pruning will lead to the production of secondary or higher order side shoots from the lower order primary side shoots. The growth of the sugarcane plants in relation to step d) of the method for producing a sugarcane seedling according to the invention can be done as known conventionally. The plants can be kept under the conditions in which they were previously grown. An expert in the art knows well the conditions under which sugar cane must be grown.

[0095] In relation to step d) of the method for producing a sugarcane seedling according to the invention, the sugarcane plants are grown until secondary or even higher lateral branches are produced preferably sugar cane plants are grown for an additional 20 days to 23 days after pruning, more preferably sugar cane plants are grown for an additional 18 days to 21 days after pruning, even more preferably, the sugarcane plants are grown for another 16 days to 19 days after pruning.

[0096] In step e) of the method for producing a sugarcane seedling according to the invention, the newly formed branches are removed from the mother stem. The side branches to be removed from the mother stem can be primary or secondary side branches, preferably, side branches to be removed from the mother stem are secondary side branches. The side branches can be removed from the mother stems by cutting the side branches using knives or using specific tools, such as bud extracting scissors.

[0097] Optionally, the side branches removed in step e) of the method for producing a sugarcane seedling according to the invention are kept at a reduced temperature after removal of the mother stem. This optional part of step e) is, in particular, used when the side branches must be stored for some time before treatment with an auxin according to step f) is carried out. If the side shoots are kept at low temperature, preferably the side shoots are transferred immediately to a low temperature environment after removal of the mother stem. In this regard, the immediate transfer of side branches at reduced temperature should preferably be understood as meaning transfer of side branches to a reduced temperature environment for less than 25 minutes, more preferably, for less than 20 minutes, even with more preferably, for less than 15 minutes, even more preferably, for less than 10 minutes, most preferably, for less than 5 minutes after removal of the mother stem.

[0098] The reduced temperatures in the optional part of step e) of the method for producing a sugarcane seedling according to the invention preferably mean a temperature at which it is significantly below the ambient temperature from which the branches preferably, the reduced temperature is between 12 ° C and 18 ° C, more preferably between 13 ° C and 17 ° C, even more preferably 14 ° C and 16 ° C.

[0099] In a preferred embodiment of the invention, the side branches in the optional part of step e) of the method for producing a sugarcane seedling according to the invention are kept at a reduced temperature for a maximum of 30 hours, with more preferably at most for 24 hours, even more preferably, at most for 18 hours, even more preferably, at most for 12 hours, most preferably, at most for 6 hours.

[0100] The reduced temperature environment in the optional part of step e) of the method for producing a sugarcane seedling according to the invention can be established by any suitable means by an element skilled in the art. The environment can be, for example, refrigerated boxes, cooling bags, coolers, etc.

[0101] When the side branches were kept under reduced temperature according to the optional part of step e) of the method for producing a sugarcane seedling according to the invention, the side branches are treated with an auxin immediately after they are removed from the reduced temperature environment and subsequently transferred to a growth substrate.

[0102] In the event that the optional step of step e) of the method for producing a sugarcane seedling according to the invention is not carried out, treatment with an auxin according to step f) of the method for producing a seedling of sugar cane according to the invention is carried out shortly after the removal of the side branches of the plants, preferably, the treatment with an auxin is carried out between 0 minutes (min) and 180 min, more preferably, between 0 min and 150 min, even more preferably, between 0 min and 120 min, even more preferably, between 0 min and 90 min, even more preferably, between 0 min and 60 min, most preferably, between 0 min and 30 min after the removal of the side branches of the plants.

[0103] Preferably, only the bottom parts of the side branches are treated with an auxin in step f) of the method for producing a sugarcane seedling according to the invention. Preferably 2 cm (cm) to 10 cm, more preferably 2 cm to 8 cm, even more preferably 2 cm to 6 cm and most preferably 2 cm to 5 cm from the bottom part of the lateral branch it is dipped in a solution containing auxin in step f) of the method to produce a sugarcane seedling according to the invention.

[0104] Treatment with an auxin in step f) of the method for producing a sugarcane seedling according to the invention can take place by any suitable means, for example, so that the bottom part of the side branches can be sprinkled or brushed or dipped in a solution containing auxin.

[0105] The auxin in step f) of the method for producing a sugarcane seedling according to the invention can be a natural auxin or a synthetic auxin.

[0106] In one embodiment of the invention, auxin in step f) of the method for producing a sugarcane seedling according to the invention is selected from the group consisting of indole-3-acetic acid (IAA) , 2-phenylacetic acid (PAA), 4-chloroindol-3-acetic acid (4-C1- IAA), indole-3-butyric acid (IBA), alpha-naphthylacetic acid (NAA), beta-naphthyloxyacetic acid (NOA) , 2,4-dichlorophenylselenoacetic acid, 3- (benzo [b] selenienyl) acetic acid, indole-3-propionic acid (IPA), 2-chloro-3- (3-chloro-2-methylphenyl) propionitrile (CCMPPN), 2-chloro-3- (2,3-dichlorophenyl) propionitrile (CDPPN), 2-chloro-3- (2,3-dichlorophenyl) butyronitrile (CDPBN). In a preferred embodiment of the invention, auxin in step f) of the method for producing the sugarcane seedling according to the invention is selected from the group consisting of IAA, PAA, 4-C1-IAA, IBA, NAA, NOA, IPA or CDPPN, more preferably, auxin in step f) of the method for producing a sugarcane seedling according to the invention is selected from the group consisting of IAA, IBA, NAA, IPA, even more preferably, auxin in step f) of the method for producing a sugarcane seedling according to the invention is selected from the group consisting of IAA, IBA or NAA, even more preferably, auxin in step f) of the method for producing a sugarcane seedling according to the invention is selected from the group consisting of IBA or NAA, with the most preference, auxin in step f) of the method for producing a sugarcane seedling according to the invention is IBA.

[0107] In an embodiment of the invention, auxin in step f) of the method for producing a sugarcane seedling according to the invention, the side branches are treated with an auxin solution, in which the auxin concentration in the solution is between 0.5 gram per liter (g / l) to 2.7 g / l, preferably between 0.7 g / l and 2.5 g / l, more preferably between 0.9 g / l 1 to 2.3 g / l, even more preferably, between 1.1 g / 1 to 2.1 g / l, even more preferably, between 1.3 g / 1 to 1.9 g / l, most preferably, between 1.5 g / l and 1.7 g / l.

[0108] In a specific embodiment of the invention, auxin in step f) of the method for producing a sugarcane seedling according to the invention, the side branches are treated with an auxin solution, where auxin is IBA and the concentration of IBA in the solution is between 0.5 gram per liter (g / l) to 2.7 g / l, preferably between 0.7 g / l and 2.5 g / l, more preferably, between 0.9 g / l to 2.3 g / l, even more preferably, between 1.1 g / l to 2.1 g / l, even more preferably, between 1.3 g / l to 1.9 g / l l, with maximum preference, between 1.5 g / l and 1.7 g / l.

[0109] The lateral shootings according to step f) of the method for producing a sugarcane seedling according to the invention are transferred to a growth substrate after treatment with an auxin. The growth allows the production of roots through the lateral branches. Preferably, the growth substrate is present in a container. The container can be selected from any suitable container, such as vases, buckets, trays, bags or trays with separations and the like. The containers can be made of synthetic and / or natural material, including biodegradable material. Separate pans, buckets or trays that allow the growth of a single side crop in a single growth area are preferred.

[0110] The growth substrate can be any substrate eligible for growing sugarcane. The substrates eligible for sugarcane are well known for an element skilled in the art. Preferably, the substrate comprises vermiculite and / or coconut fiber, more preferably, vermiculite and coconut fiber in a ratio of 1: 5 to 5: 1, even more preferably, vermiculite and coconut fiber in a ratio of 1 : 3 to 3: 1, even more preferably, vermiculite and coir in a ratio of 1: 2 to 2: 1 and, most preferably, vermiculite and coir in a ratio of 1: 1.

[0111] After transferring to a growth substrate of the side branches, or, as applicable, the containers comprising the side branches are grown in a conditioned climate. The environment for establishing a conditioned climate according to step g) of the method for producing a sugarcane seedling according to the invention is not decisive, as long as it at least allows the growth of the sugarcane branches. under uniform humidity and / or temperature conditions. It is preferable to use an environment for growing sugar cane buds that is equipped with technical means to control humidity and / or temperature. More preferably, the climate-conditioned environment is a greenhouse, even more preferably, a greenhouse equipped with air and / or humidity control.

[0112] In relation to step g) of the method for producing a sugarcane seedling according to the invention, the climate is, on average, preferably conditioned to a temperature between 24 ° C and 36 ° C, with more preferably, for a temperature between 26 ° C and 34 ° C, even more preferably, for a temperature between 28 ° C and 32 ° C, even more preferably, for a temperature between 29 ° C and 31 ° C and, most preferably, for a temperature of about 30 ° C.

[0113] The relative humidity of the conditioned climate according to step g) of the method for producing a sugarcane seedling according to the invention is preferably conditioned to 70% to 98%, more preferably, to 75% to 98%, even more preferably, to 77% to 98%, even more preferably, to 80% to 98%, particularly preferably, to 80% to 95%, most preferably, to 80% to 90%.

[0114] The lateral branches are grown in step g) of the method to produce a sugarcane seedling according to the invention until the roots have been sufficiently developed by the branches. Preferably, the side branches are grown under conditioned climate in step g) of the method to produce a sugarcane seedling according to the invention for at least 5 days, more preferably, at least 7 days, even more preferably for at least 10 days.

[0115] The side branches are grown under conditioned climate in step g) of the method to produce a sugarcane seedling according to the invention, preferably for a maximum of 15 days, more preferably, a maximum of 13 days, even more preferably, at most for 12 days, even more preferably, at most for 11 days, with most preference, at most for 10 days.

[0116] Preferably, the side branches are grown under conditioned climate in step g) of the method to produce a sugarcane seedling according to the invention for 5 days to 15 days, more preferably, for 5 days at 13 days, even more preferably, for 5 days to 12 days, even more preferably, for 5 days to 11 days, most preferably, for 5 days to 10 days.

[0117] In the method to produce a sugarcane seedling according to the after the side branches grown according to step g) develop roots, the seedlings are obtained according to step i). Seedlings can be grown on sugar cane plants in any suitable and desirable way. Seedlings can, for example, be grown in containers in any suitable and desirable environment or they can be transferred to the fields. Seedlings can be grown for additional amplification purposes by simply repeating, for example, the method for producing a sugarcane seedling according to the invention or they can be transferred to a field to establish a cane crop. sugar and / or for the production of additional seed cane.

[0118] Another embodiment of the present invention relates to a method for producing a sugarcane seedling according to the invention comprising an additional step j) which consists of growing the seedling obtained in step i) in an environment of acclimatization.

[0119] The growth of seedlings obtained by the method according to the invention to produce a sugarcane seedling in an acclimatization environment is, in particular, recommended to be carried out on seedlings intended to be transferred to the natural environment , including fields, to further grow sugar cane plants.

[0120] The term “acclimatization environment” as used in this document should be understood as being an environment that allows the adaptation of sugarcane seedlings (gradually) in another environment, in particular, adaptation in humidity and / or different and more volatile temperature.

[0121] The acclimatization environments and the configuration of the respective conditions for sugarcane seedlings are known for an element versed in the technique.

[0122] The acclimatization is done with the progressive modification of temperature and humidity, until it is equal or is similar to the conditions of temperature and humidity of the environment in the region in which it is intended that the sugarcane seedlings are transferred. The conditions can be chosen according to the common knowledge of an element versed in the technique and depend on the determined environment in which it is intended that the sugarcane seedlings are transferred.

[0123] Preferably, the seedlings obtained by a method according to the invention for producing a sugarcane seedling are grown according to the additional step j) in an acclimatization environment for 16 days to 28 days, more preferably, for 18 days to 26 days, even more preferably, for 18 days to 24 days, even more preferably, for 19 days to 22 days, most preferably, for about 21 days.

[0124] The main advantages of the method for producing a sugarcane seedling according to the invention disclosed in the present document can be summarized as follows.

[0125] More than 95% of the lateral shoots produced in the main stem developed into viable seedlings. The high reproduction rate reduces the number of main stems and, thus, the space needed to produce a defined number of seedlings. Labor costs and space in the establishment of seedlings are also reduced due to a lower number of side shoots having to be discarded after the growth phase for root development. The development of uniform lateral shoot after treatment with etefon should be partially responsible for the high survival rate after the root growth phase.

[0126] Compared to known methods for producing sugarcane seedlings, the multiplication rate that defines the number of sugarcane seedlings that can be produced from a single sugarcane stem or tiller is increased. In the so-called conventional multi-bag method, which uses cuttings (single bud / eye) germinated in a growth substrate that contains a bag, the multiplication rate is about 1:20. The conventional sprout chunk method has a multiplication rate of about 1:40. For the method for producing a sugarcane seedling according to the invention, multiplication rates from 1: 200 to 1: 350 were observed. Thus, compared to conventional methods, far less sugar cane plants must be grown to produce the same number of seedlings when using the method to produce a sugarcane seedling according to the invention disclosed in this document. . This saves space for growing sugar cane plants and resources, such as water, fertilizer, crop protection agents, labor, etc.

[0127] Compared to conventional methods for producing sugarcane seedlings, the amount of time required to grow sugar cane buds in a conditioned climate is reduced when using the method to produce a sugarcane seedling sugar according to the invention described in this document. In the so-called conventional multi-bag method, for example, at least 60 days are required for the production of lateral seed from pieces of sprout under conditioned climate. In the method for producing a sugarcane seedling according to the invention disclosed in the present document, a time period of about 28 days is required for growth under conditioned climate for production and root acclimation. A maximum of 36 days is required, but in general, less time for growth under conditioned climate in the method for producing a sugarcane seedling according to the invention disclosed in this document. This is a significant reduction in time for growth under conditioned climate required in the seedling production process, which reduces input costs to establish the required climate.

[0128] With the method for producing a sugarcane seedling according to the invention disclosed in this document, not only more sugarcane seedlings per stem (space), but also seedlings of superior uniformity can be compared to conventional methods for producing sugarcane seedlings. This was mainly due to the effect that treatment with a growth regulator that releases ethylene does not impact the viability of axillary shoots, but allows the production of lateral seedling in a wide range of nodes from the base to the top of the cane stem. -of sugar.

[0129] In addition, the lateral branches developed much more uniformly after treatment with a growth promoter that releases ethylene, when compared to conventional methods for producing sugarcane seedlings. The superior uniformity of side branches increases the number of viable sugarcane seedlings that can be produced from these branches.

[0130] Conventional methods for producing a sugarcane seedling comparable to the method disclosed in this document require several consecutive pruning operations. The use of a growth promoter that releases ethylene in the method for producing a sugarcane seedling according to the invention reduces the number of pruning operations necessary for a single one. This again saves time and manpower in seedling production.

[0131] Sugarcane seedlings produced by a method to produce a sugarcane seedling according to the invention can be transplanted into the field, for example, to establish a sugarcane crop ( commercial) or for the propagation of a desired variety, a desired breeding line or a desired parent of a hybrid.

[0132] Therefore, an additional embodiment of the invention relates to a method for establishing a sugarcane crop comprising the steps of a) obtaining or producing seedlings according to a method for producing a sugarcane seedling according to the invention b) transplant the seedlings according to step a) to a field.

[0133] In conjunction with the present invention, the term "sugarcane culture" has the common meaning and should be understood in this document as being any specific sugarcane plant or variety that is or is intended to be grown or grown on a scale for profit or subsistence and which, after growth, is harvested for food, clothing, livestock, fodder, biofuel, medicine or other uses by humans. In particular, the term “sugarcane culture” has the common meaning in this document as being any specific sugarcane plant or variety that is or is intended to be grown or grown in groups on a scale to profit and which, after growth, is harvested to supply sugar, ethanol, forage and / or bagasse for the production of electricity. By the term intended to be grown in the current definition, it must be made explicitly clear that any reproductive or propagating material eligible to produce any specific sugarcane plant or variety intended to be grown or cultivated as a crop is understood by the term “crop sugar cane".

[0134] The term “sugarcane culture” as used in this document is generic and comprises the terms “commercial sugar cane (culture)” and “cultivated sugarcane species”.

[0135] Transplantation in step b) of the method for establishing a sugarcane culture according to the invention can be done with any known means suitable for an element skilled in the art. The transplantation of seedlings can be performed by manual labor or can be done by planting a machine as revealed, for example, by Ravindra et al. (2013, Sugar Tech 15 (1), 27-35).

[0136] An additional embodiment of the invention relates to the use of a seedling obtained or obtainable by a method for producing a sugarcane seedling according to the invention to establish a culture of sugar cane.

[0137] An advantage of establishing a sugarcane crop by transplanting sugarcane seedling obtained by a method to produce a sugarcane seedling according to the invention is that the seedling sugar cane can be planted in the field in an equal distribution. Therefore, the spacing between rows and plants in a row can be adapted as desired. It is known in the art that uniform spacing between plants increases productivity in terms of number, length and weight of crushable stems in sugarcane crops (Mohanty et al., 2015, Sugar Tech 17 (2), 116-120). Therefore, with the efficient seedling production method revealed in this document, a farmer's income will be increased due to the costs of producing sugarcane seedling being reduced and, at the same time, productivity can be increased. The regular and more frequent replacement of sugarcane crops by planting new seedlings instead of growing a number of sugarcane crops is also possible with the method of establishing a sugarcane crop according to the invention due the fact that the costs of producing seedlings by the method for producing a sugarcane seedling according to the invention disclosed in this document are reduced and the higher costs for replanting with seedlings can be overcompensated by improving productivity due to regular planting and adjusted to the circumstances in comparison to the growing regrowth crops.

[0138] The treatment of sugarcane with etefon has been shown to have several different effects. The induction of lateral shootings after the treatment of sugarcane plants with etefon has not been described. In particular, it has not been described that the treatment of sugarcane canopy leaves with etefon would increase the production of lateral shoots and the uniformity in the production of lateral shoot. This effect of etefon is first described in this document.

[0139] Therefore, an additional embodiment of the invention relates to the use of etefon to induce the growth of lateral seed in sugarcane plants. A preferred embodiment of the invention consists of using a solution containing ethephon to sprinkle the crown (leaves) of a sugarcane plant to induce the growth of lateral shoot. Preferably, the solution containing etefon used to sprinkle the crown (leaves) of a sugarcane plant to induce the growth of lateral shoot contains etefon in an amount of 14.5 grams per liter (g / l) at 36 , 0 g / l, more preferably, in an amount of 18.5 g / l to 33.0 g / l, even more preferably, in an amount of 22.0 g / l to 29.5 g / l, still more preferably, in an amount of 24.5 g / l to 27.5 g / l, and most preferably, in an amount of 25.5 g / l to 26.5 g / l. Preferably, the solution containing etefon used to sprinkle the canopy (leaves) of a sugarcane plant to induce growth of lateral shoot is sprinkled on the canopy (leaves) of a sugarcane plant aged 4 months to 12 months, more preferably, 5 months to 11 months, even more preferably, 6 months to 10 months, even more preferably, 7 months to 9 months.

[0140] A further embodiment of the invention consists of using a seedling obtainable or obtained by a method for producing a sugarcane seedling according to the invention to establish a (commercial) sugar cane crop.

[0141] Another embodiment of the invention consists of using a seedling obtainable or obtained by a method for producing a sugarcane seedling according to the invention to establish, grow, harvest and subsequently process a sugarcane crop of sugar. Here, processing preferably means grinding. More preferably, processing means grinding, obtaining sugar cane juice and subsequently producing sucrose from the juice through crystallization or subsequently producing ethanol from the juice through fermentation.

[0142] Description of the Figures Fig. 1: Average number of inter-nodes per stem / tiller of sugarcane plants at 0 DAS (Days After Sprinkling Ethrel® 720 or pruning, respectively) and at 14 DAS. Fig. 2: Shows the results for the average number of shoots (buds) per stem / tiller obtained for each of the different treatments as described in the Example

2. Fig. 3: Dose response curve for the number of shoots produced in response to the amount of Ethrel® 720 (etefon) sprayed on sugarcane plants. Fig. 4: Image for comparison of sugar cane plants that have been treated with etefon (pots 3 and 4) and sugar cane plants that have been decapitated / pruned instead of treatment with etefon (pots 1 and 2 ). Fig. 5: Image showing cuts of lateral stem / tillers. Fig. 6: Number of dead (not rooted) side shoots after transferring side shoots to a growth substrate depending on pre-treatment with different amounts of indolbutyric acid. Fig. 7: Survival rate (rooting) of lateral shoots in relation to treatment with indolbutyric acid, its concentration and regression curve based on the data points obtained. Examples

1. Inter-node production after treatment with etefon versus pruning

[0143] Sugarcane plants (variety RB92579) were grown in randomized blocks in a greenhouse. The treatments with etefon (Ethrel® 720) were carried out by sprinkling the canopy of six-month-old sugarcane plants according to Table 1. A set of plants was not sprinkled with etefon, but instead in addition, the tops of the stems were decapitated below the apical meristem. Each experiment was carried out in five independent repetitions.

[0144] The average number of nodes per stem / tiller on day 0 (day on which treatment with etefon or pruning, respectively, was performed) and the average number of nodes on day 14 (14 days after treatment with etefon or pruning, respectively, was performed) were determined. The results are shown in Table 1 and in Fig. 1. No. Quantity of Pruning Quantity Number of Ethrel® 720 inter-nodes etefon [g / l] per stem / tiller [ml / l] on day 0 on day 14 T1 0 , 0 0 Yes 8 8 T2 12,0 8.62 No 8 9 T3 22,0 15,84 No 7 9 T4 30,0 21,60 No 8 11 T5 40,0 28,80 No 8 10 T6 50,0 36.00 No 7 8

[0145] Table 1: Number of inter-nodes of sugarcane plants present on day 0, defined as the point in the pruning time (T1) or treatment with different concentrations (T2 to T6) compared to the number of inter-nodes 14 days after the respective treatments. The quantity of etefon in mg / l was calculated in the manufacturer's label information Ethrel® 720 according to which the product comprises 720 g of etefon per liter. The results were subjected to analysis of variance, using the 5% F test and the t-significance test (p <0.05).

[0146] It is derivable from the data obtained, that pruning prevents the production of new nodes in sugarcane plants. Treatment with etefon prevented the production of new nodes in sugarcane plants. During the 14-day period after sprinkling the cane canopy with etefon, an average of two new nodes per stem / tiller were produced, while the pruned sugarcane plants did not produce new inter- us during that period. It can be concluded that pruning prevents further inter-node development while ethephon does not.

2. Development of lateral shoot after application of ethephon followed by pruning versus subsequent pruning

[0147] The sugarcane plants were grown and treated (pruning or application of etefon) as described in Example 1.

[0148] Fourteen days after the pruning or application of etefon, a simultaneous pruning of the top of the sugarcane stems and lateral branches was performed in treatments T2, T3, T4, T5 and T6. In T1 treatment, only the pruning of the lateral branches was performed at that point in time. At the end of the experiment period, the number of sugarcane tillers, inter-nodes and side shoots in the different treatments was determined. The results were subjected to analysis of variance using the 5% F test. In cases of significant variations, Fisher's exact test (p <0.05) was applied and regression analysis was performed in order to determine the best dose of ethephon to be used.

[0149] Fig. 2 shows the results obtained for the average number of lateral shoots per stem / tiller in each of the different treatments. A positive effect of applying Ethrel® 720 is observed in the production of sugarcane side branches. The average of all treatments that used Ethrel® 720 was approximately 30 side shoots per stem / tiller. For conventional methods, when using only subsequent pruning treatments, the number of side branches of sugar cane was 13 on average.

[0150] The highest production of lateral branches was observed with the application of 40 ml / l of Ethrel® 720 (equal to 28.80 g / l of etefon). At this concentration, an average of 40 lateral cane shootings per stem / tiller were obtained. In the control treatments, when using the subsequent pruning without application of etefon, an average of 13 lateral shoots per stem / tiller were obtained. Comparison examples of sugarcane plants treated with etefon followed by pruning compared to subsequently pruned sugar cane plants, but without treatment with previous etefon are shown in Fig. 4.

[0151] With the results obtained from concentrations of Ethrel® 720 sprinkled on sugarcane plants versus production of lateral branches by sugarcane stem / tillers, a regression equation was established. The second degree polynomial model determined the equation: Y = -0.0149X2 + 1.0792X + 13.272 (R2 = 0.7373)

[0152] The respective dose response curve is shown in Fig. 3.

[0153] This equation has a high correlation coefficient (r) of 86%, indicating that the equation represents a sufficient correlation between the production of sugarcane side branches with the application of different doses of Ethrel® 720.

[0154] Using the above equation, it was calculated that the maximum production of approximately 35 lateral branches per stem / tiller was obtained by spraying the crown of sugarcane plants with a solution comprising 36 ml / l of Ethrel® 720 (equivalent to 25.92 grams of etefon per liter of spray solution).

3. Root development versus auxin concentration

[0155] The plants were grown and treated as described in Examples 1 and 2 according to T2 to T6 in the Table

1. The side branches were cut from the stems / tillers as exemplified in Fig. 5 and the bottom end of the side branches was submerged in a solution containing indolbutyric acid (IBA). About 100 side branches were submerged in each case in a solution comprising 0.0 gram per liter (g / l), 0.5 g / l, 1.0 g / l, 1.5 g / l or 2.0 g / l of indolbutyric acid (IBA). Soon after, the sugar cane sprouts were placed in trays containing substrate (1: 1 of vermiculite and coconut fiber) and placed in an environment with a temperature of approximately 27 ° C and a relative humidity of about 85 %. After a period of 10 days, the lateral branches were evaluated. A count of dead plants was performed. Dead side shoots indicated that no rooting occurred. The surviving lateral branches developed a root system and developed in a sugarcane seedling. The results were subjected to analysis of variance at 5% probability and subsequent regression analysis to compare mean values.

[0156] The results are shown in Fig. 6. Without the application of indolbutyric acid (0 g / l), an increase in the death of lateral branches was observed (23 seedlings). After application of 0.5 g / l; 1.0 g / l; 1.5 g / l and 2.0 g / l of indolbutyric acid, 6, 7, 5 and 2, respectively, dead side shoots were obtained. This is a clear reduction in the death rate of sugarcane side branches compared to side branches that were not treated with indolbutyric acid.

[0157] The percentage of viable plants (% of surviving plants) has been calculated. With the results obtained, a regression equation was established representing the correlation between the concentration of indolbutyric acid versus rooting and survival of lateral branches (Fig. 7).

[0158] The second degree polynomial model determined the equation: Y = -7.7143X2 + 25.229X + 76.543 (R2 = 0.8376)

[0159] This equation has a high correlation coefficient (r) of 92%, indicating that the equation represents a sufficient correlation between rooting and the application of indolbutyric acid. Using this model, it was found that the maximum rooting of lateral branches was obtained in a concentration of 1.6 g / l of indolbutyric acid (approximately 97% of the buds produce root and survive).

[0160] Despite the ideal indolbutyric acid considered to be ideal at 1.6 g / l, when using the equation above, it can be observed that from the data points presented in Fig. 7 that the survival rate of lateral shoot it is above 90% in each case when indolbutyric acid is used between 0.5 g / l and 2.0 g / l. In contrast to the same without treatment with indolbutyric acid, the survival rate of lateral shoots is below 75%. Thus, the treatment of sugar cane side branches with any concentration of indolbutyric acid between 0.5 g / l to 2.0 g / l significantly increases root formation and the development of sugarcane seedlings.

Claims (16)

1. Method for producing sugarcane seedlings, the method being characterized by understanding the steps of a) treating sugarcane plants with a plant growth regulator that releases ethylene b) additionally growing cane plants sugar sprinkled in accordance with step a) c) prune the top parts of the main stems and the top parts of the newly produced side branches of the sugar cane plants grown according to step b) d) additionally grow the pruned sugarcane plants obtained in step c) e) remove side branches from the plants obtained in step d) f) treat the side branches obtained according to step e) with an aid g) transfer the branches side treated according to step f) on a growing substrate and growing side branches in a conditioned climate h) obtaining sugarcane seedlings from side branches grown according to step g). 2. Method, according to claim 1, characterized by the fact that, in step a), the crown of the sugarcane plants is treated with a plant growth regulator that releases ethylene. Method according to either of claims 1 or 2, characterized in that the concentration of plant growth regulator that releases ethylene in step a) is between 14.5 g / l and 36.0 g / l. Method according to any one of claims 1 to 3, characterized in that the plants in step b) are grown for an additional 16 to 19 days after treatment with a growth regulator that releases ethylene. Method according to any one of claims 1 to 4, characterized by the fact that the plants in step d) are grown for an additional 20 to 23 days after pruning. Method according to any one of claims 1 to 5, characterized in that step e) comprises an additional part which consists of keeping the side branches removed at reduced temperature after removal of the mother stem. Method according to any one of claims 1 to 6, characterized in that the concentration of auxin in step e) is between 1.1 g / l and 2.1 g / l. 8. Method according to any one of claims 1 to 7, characterized in that the auxin in step f) is selected from the group consisting of indolbutyric acid (IBA), indole-3-acetic acid (IAA) , 2-phenylacetic acid (PAA), 4-chloroindol-3-acetic acid (4-C1-IAA), alpha-naphthylacetic acid (NAA) or beta-naphthyloxyacetic acid (NOA). Method according to any one of claims 1 to 8, characterized in that the climate in step g) is conditioned to a temperature between 24 ° C to 36 ° C. 10. Method according to any one of claims 1 to 9, characterized by the fact that the climate in step g) is conditioned to a relative humidity of 70% to 98%. 11. Method according to any one of claims 1 to 10, characterized in that the lateral branches are grown under a conditioned climate according to step g) for at least 5 days. Method according to any one of claims 1 to 11, the method being characterized by comprising an additional step j) which consists of growing the seedling obtained in step i) in an acclimatization environment. 13. Method, according to claim 12, characterized by the fact that, in step j), the seedlings are grown in the acclimatization area for 19-25 days. 14. Method for establishing a sugarcane crop, the method being characterized by comprising the steps of a) obtaining seedlings according to any of the methods of claims 1 to 13 b) transplanting the seedlings according to step a ) for a field. 15. Use characterized by being a seedling obtainable by a method for producing a sugarcane seedling as defined in any one of claims 1 to 13 to establish a sugarcane crop. 16. Use characterized by being a seedling obtainable by a method for producing a sugarcane seedling as defined in any one of claims 1 to 13 to establish, grow, harvest and subsequently process a sugarcane crop sugar.