GR1010470B - Method of producing improved grafted seedlings in particular watermelon seedlings by use of lighting means - Google Patents

Abstract

The present invention relates to a method used destined for producing improved grafted seedlings, in particular watermelon grafted seedlings consisted of a grafted upper part and a lower part bearing the root system. This method is achieved by use of lighting means and comprises three distinct successive stages: the first stage of growth and production of seedlings to be grafted; the second stage of curing the grafted seedlings and the third stage of fortifying the grafted seedlings of the second stage. According to the invention, the production of the grafted seedlings takes place in a controlled environment where LED lamps are advantageously used as an exclusive or sometimes complementary light source. The invention also relates to the use of said method in the production of high-quality grafted seedlings intended for cultivation and ready for planting in the field.

Description

METHOD OF PRODUCING IMPROVED VACCINES

SEEDS ESPECIALLY WATERMELON WITH THE USE OF MEDIA

LIGHTING

DESCRIPTION

Object of the invention

The present invention relates to a method of producing seedlings, in particular watermelon Cucurbitaceae which consists of three distinct stages. This method concerns the production of watermelon seedlings, specifically citrullus lanatus through grafting. This also concerns the production of high quality grafted watermelon seedlings using lighting means in particular LED lamps. The method according to the invention consists of three distinct main stages, a first stage of production and development of seedlings to be inoculated, a second stage of inoculation and healing and a third stage of hardening of the inoculated seedlings. The invention also relates to the use of this method for the production of grafted seedlings for the purpose of planting them directly in the ground.

Scope of the invention

The object of the present invention concerns the field of health and food. Watermelon is produced and exploited commercially either from grafted seedlings or from cuttings or seeds. It is known that watermelon is an economically important product which is propagated mainly by grafting. This use of inoculated plants represents one of the most modern and important means of disease prevention, concerning the root system of plants, while at the same time satisfying the demand of consumers for safe products with limited use of plant protection substances. Also, the production of improved seedlings contributes to a good and stable production of agricultural products since we create stronger root systems and more efficient above-ground stems with the result that better commercial exploitation is possible, which contributes to an optimal agricultural development. The invention proposes a method of producing improved seedlings in a completely controlled environment with undisturbed conditions, high humidity and using different spectrum lighting in the seedling healing chambers. The method can also concern other vegetable species such as tomato, melon, etc.

State of the art

Watermelon is an economically important export product of our country, with the result that the need to improve competitiveness becomes useful given that the demand for grafted watermelon seedlings is very high.

In the document CN104813857A, entitled 'Watermelon seedling cultivation technology of light emitting diode (LED) plant lamp based on conditions without natural light', on 5/8/2015 it refers to seedling cultivation that is done exclusively in controlled conditions without the presence of natural light at all , but with the use of artificial light where, among other things, the red:blue light ratio, i.e. the two most important parts of the light spectrum for plant growth, as well as its spectrum, is different from that proposed in the present invention.

In the document CN207094230U, entitled Α LED lamp for watermelon light control that grows seedlings', on 13/3/2018, a lamp system with a microprocessor, sensor, etc. is proposed for the production of self-rooting watermelon seedlings.

Document CN213369004U, entitled 'Light-emitting diode (LED) lightsupplementing seedling raising frame for watermelon grafted seedlings', dated 08/06/2021 discloses a vertical cultivation system with a specific LED lamp with an emphasis on a technique for easy and quick movement of the shelves for ease of work and does not refer to the method for producing seedlings for inoculation and/or for the inoculated seedlings. Likewise in the document CN212259881 U, entitled 'Special light supplement lamp for watermelon grafting seedling raising', dated 1/1/2021, an arrangement of a vertical cultivation system with a specific LED lamp and a specific arrangement of shelves including a series of sensors for collecting information is proposed.

Also document CN202799783U, entitled 'LED (light-emitting diode) lightsupplying seedling-culturing frame for watermelon grafted seedlings', dated 20/3/2013 refers to an arrangement of a vertical cultivation system using 4 lamps on each shelf.

Document number CN107926342A, entitled 'Method for cultivating shortstrong seedlings of grafting rootstocks', dated 4/20/2018 discloses a method using LED lamps to produce seedlings with the desired characteristics used as rootstocks in the grafted seedling production process . In addition, the recommended use of the lamps is during the night to increase the photoperiod.

Also in document CN103650927A, entitled 'Method for promoting grafted seedlings to quickly heal', dated 3/26/2014, a method is disclosed for the successful and rapid healing of grafted watermelon seedlings using specific environmental conditions and LED lamps as the sole source of illumination , while the red:blue light ratio is different from that proposed in the present invention.

The document number CN107821045 A 20180323 DW201831 and title 'Grafting small watermelon by light cultivation method comprises soil treatment, applying fertilizer having e.g. nitrogen-phosphorus-potassium fertilizer, leveling, covering with net, grafting, transplanting, pollination and harvesting', concerns cultivation in the soil and the proposed method mainly concerns fertilization with the best utilization of soil nutrients in all seasons of the year. Similarly, document CN109380068 A 20190226, entitled 'Cultivation method for overcoming low-temperature stiff seedlings of watermelons and melons' discloses a method of cultivation technique for better management of watermelon and melon seedlings during establishment in the field under low ambient temperatures.

The documents CN111567335 A 20200825, entitled 'Method for rapidly cultivating early spring watermelon seedlings at low cost' and CN111567335 A 20200825 DW2020072 describe a method of producing self-rooted watermelon seedlings at low cost using LED lamps during the night.

Thus, the above either refer to the management of seedlings during their storage and/or during their cultivation in the ground, or mainly refer only to the healing chamber with the main objective of developing a root system from the inoculated seedling.

Purpose of the invention

The present invention aims at the production of improved seedlings, especially of watermelon, according to a method of growing and producing grafted seedlings of high quality, where after its completion, a final product with the best agronomic characteristics such as higher yields and earliness is obtained, since it is created thanks to the method according to present invention stronger root system and more efficient above-ground stem. At the same time, with the method proposed according to the present invention, the production of safe products with limited use of plant protection products for the consumer is achieved, while the cost of producing seedlings is reduced since a reduction in the required production cycle is achieved and the percentages of high quality seedlings are increased. In addition, the use of LEDs as a means of illumination proposed according to the invention either as supplementary light or as exclusive light during the various stages, instead of other light sources such as a traditional light source is with lower energy consumption, longer life while the lower heat emission in combination with the special conditions and characteristics according to the ways of realizing the invention additionally allows the placement of shelves in a denser density.

Therefore, according to the method proposed by the present invention, the production of high-quality grafted watermelon seedlings is carried out at a competitive price, which will contribute to a successful agricultural production that is significantly friendlier to the environment.

In addition, the invention relates to the use of this method to obtain seedlings that are ready for planting in the field.

Brief description of the invention

Our invention refers to a method of producing grafted seedlings mainly of watermelon including the following three distinct successive stages:

1-the stage of development and production of seedlings for inoculation, which in particular consists of an inoculum and a substrate,

2-the healing stage of the above inoculated seedlings, which includes the healing of the inoculation incisions,

3-the hardening stage of these grafted seedlings.

The present invention advantageously relates to a process for the production of inoculated seedlings according to the above three stages and in particular additionally using specific LED lamps as a supplementary source and means of illumination for stages 1 and 3, and as an exclusive source and means of illumination in stage 2.

With the method proposed according to the invention, a reduction of the required production cycle is achieved, while at the same time the percentages of high quality seedlings are significantly increased.

Design description

Figure 1 shows the three main distinct stages of inoculated watermelon seedling production.

Figure 2 shows the arrangement for installing the seedlings, in particular the cart with shelves in a vertical arrangement where, according to an advantageous embodiment of the invention, LEDs are installed as a means of illumination.

Figure 3 diagrammatically shows the plant height of final product grafted watermelon seedlings produced by embodiment A without the use of LEDs and compared to embodiment B according to the invention as described in Table 1 below.

Figure 4 illustrates the final root node diameter of inoculated watermelon seedlings produced by embodiment A without the use of LEDs and compared to embodiment B according to the invention as described in Table 1 below.

Figure 5 illustrates the final product leaf area of inoculated watermelon seedlings produced by embodiment A without the use of LEDs and compared to embodiment B according to the invention as described in Table 1 below.

Figure 6 shows in comparison the dry weight of the final product aerial part of inoculated watermelon seedlings produced by embodiment A without the use of LEDs and compared to embodiment B according to the invention as described in Table 1 below.

Figure 7 also shows in comparison the final product root system dry weight of inoculated watermelon seedlings produced by embodiment A without the use of LEDs and compared to embodiment B according to the invention as described in Table 1 below.

Detailed description of the invention

Our invention refers to a method of producing grafted seedlings mainly of watermelon of the Cucurbitaceae family where a means of illumination is used, as a complementary or exclusive source of illumination, which consists of the following successive three stages:

1-the stage of development and production of seedlings for inoculation, which in particular consists of an inoculum and a rootstock, and the step of inoculation

2-the healing stage of the above grafted seedlings, which follows the last above step defined in the above stage 1 and includes the healing of the grafting sections,

3-the hardening stage of these inoculated seedlings of stage 2

The present invention according to a more specific advantageous embodiment of the method concerns a process for the production of grafted seedlings according to the above three stages using as a means of illumination specific LED lamps as a supplementary source of illumination for stages 1 and 3, and as an exclusive source lighting in stage 2

According to a main way of carrying out the invention, the 1st first stage of development and production of seedlings for inoculation 1 according to the invention initially includes the selection of an inoculum, in particular a watermelon hybrid (Citrullus lanatus) which will form the upper part and a subject , in particular a bispecific hybrid of pumpkin (Cucurbita maxima x C. moschata TZ-148) which will form the lower part.

Then we sow the above which we are interested in cultivating and which will constitute the vaccine, as well as the sowing of the above subject which has the root system as specifically mentioned above, in trays for each preferably 171 and 128 positions respectively , where they are then transferred to a growth chamber, called a growth chamber, for germination.

After germination, the above trays are transferred to a greenhouse where they preferably remain for 10 days, where

- the trays with the vaccine are subjected to natural lighting and additional supplementary light using LEDs emitting diodes, while

-the discs with the subject are submitted without supplementary light.

Inoculation is then followed using the lateral cut technique and the inoculated seedlings are planted in trays, preferably 72 places.

For the needs of the integration of the method according to the invention and the measurements in the various experiments, a watermelon hybrid which constitutes the upper part and in particular a Celine F1 was chosen as an inoculum and as a rootstock which constitutes the lower part a courgette twin hybrid in particular a Curcubita maxima x C. Moschata TZ-148.

Their botanical classification according to the references in the literature is:

-Regarding the watermelon vaccine

. Kingdom: Plantae

· Phylum / Tribe: Embryophyta

. Class / Homotaxia: Dicotyledoneae

. Order: Cucurbitales

. Family: Cucurbitaceae

. Genus / Genus: Citrullus

· Species: C. lanatus

-and as for the pumpkin subject

. Kingdom: Plantae

. Phylum / Tribe: Embryophyta

. Class / Homotaxia: Dicotyledoneae

. Order: Cucurbitales

. Family: Cucurbitaceae

. Genus / Genus: Cucurbita

. Species / Species: C. maxima or · Species: C. Moschata

According to a specific embodiment of the invention, during the first stage 1 above, the disks are transferred to a growth chamber with a controlled atmosphere where the temperature is about 25° C and the relative humidity is 95-98% and with the absence of light for at least 72 hours for the trays containing the inoculum, and 48 hours for the trays containing the rootstock, until the seeds germinate.

According to a more specific way of carrying out the invention during the above stage 1, the temperature at which the vaccine develops after their transfer to the greenhouse is at a minimum night temperature of approximately 21.5° C.

According to a particularly advantageous way of carrying out the invention, LED lamps according to the above step are used as means of supplementary light illumination, and this is done with an emission spectrum of 88% red and 12% blue light, resulting in an added light intensity of 100 - 10 mipi rrrV<1> at the height of the plants and for a photoperiod of 18 hours. In a particular way of carrying out the invention, the above subject of the pumpkin according to the above is grown without supplementary light and even more specifically at a minimum night temperature of 20° C for a duration of 7 days and 14° C for a duration of 3 days.

According to an even more specific way of carrying out the invention, during the above stage 1 according to the invention, during sowing in the above trays a mixture of peat, perlite and vermiculite is added in a ratio of 5:1:2.

According to a further specific way of carrying out the invention, during the above stage 1 according to the invention, after inoculation with the lateral cut technique, the above inoculated seedlings are planted in the above trays, preferably 72 places, where in particular a mixture is added peat, perlite and vermiculite in a ratio of 3:1:1.

According to the realization of the invention, the 2nd stage of the healing of the inoculated seedlings consists of the following steps:

- the trays with the above inoculated seedlings of stage 1 are immediately transferred to a healing chamber with a controlled environment in which the temperature is constant at 25° C and with recirculated air and where in particular they remain there preferably for 6 days.

- the above trays are placed on trolley shelves where lighting means are installed which constitute the exclusive source of illumination.

According to a specific embodiment according to the invention, during the above step of curing stage 2, the relative humidity amounts to 98% for the first days, 93% for the fifth day and 89% for the sixth day.

According to a specific advantageous embodiment according to the invention, during the above healing stage 2, LEDS lamps with an emission spectrum consisting of 88% red and 12% blue light are used as artificial lighting means, resulting in emitting a light intensity of 85 - 5 μmol m<-2>s<-1> at the height of the plants and for a photoperiod of 18 hours.

According to the main embodiment of the method according to the invention, stage 3 of curing the inoculated seedlings includes the following steps:

-after the seedlings leave the above healing chamber, the trays are transferred to a greenhouse for hardening for a period of preferably 14 days where they preferably remain at a minimum temperature of 21.5°C,

- where the inoculated seedlings are grown under natural lighting and an illumination medium is additionally used as a source of supplementary light.

According to a particularly advantageous embodiment according to the invention, during the above step B of the hardening stage 3, as a means of illuminating additional light LEDs are used with an emission spectrum consisting of 88% red and 12% blue light, with result in adding a light intensity of 100 - 10 μmol m<-2>s<-1> to the height of the plants and for a photoperiod of 18 hours.

After the last stage 3 the plants are the final product and are ready to be transplanted into the field.

The invention also relates to the use of the method according to the above steps according to the invention for the purpose of producing watermelon seedlings intended and ready for transplanting in the field.

The method of producing grafted seedlings according to the invention can be extended and used in other vegetable species for the production of grafted seedlings such as pepper, tomato, eggplant, cucumber and melon.

Further, a comparative evaluation was performed on the lighting means between two embodiments of the method according to the invention of producing grafted watermelon seedlings where in embodiment A other lighting means were used during the production process, while in embodiment B LEDs were used according to the process and characteristics mentioned above in the description. Specifically, in embodiment A, high pressure sodium lamps were used in stages 1 and 3, while fluorescent lamps were used in stage 2. The special characteristics concerning the atmosphere such as temperature and humidity were the same in both realizations. The results of the evaluation are described below.

The measurement of the color and the determination of the chlorophyll content did not show significant differences between the two methods (Table 1).

Important quality parameters such as height, root node diameter and leaf area of seedlings were significantly greater in the second embodiment B according to the invention by 20%, 7% and 59%, respectively (Figure 3, Figure 4 and Figure 5).

The fresh weight of the aerial part and root system was found to be significantly greater in the B treatment by 37% and 67%, respectively (Table 1). Likewise, the dry weight of the aerial part and root system was found to be significantly greater according to the invention by 43% and 39%, respectively (Figure 6 and Figure 7). In contrast, the ratio of dry weight of root system to aerial part had no significant differences (Table 1).

Therefore, according to the above specific advantageous way of carrying out the method according to the invention, the quality parameters of the grafted watermelon seedlings are favored by the presence of light with a high percentage of red and blue light as these increase the weight of the aerial part and root system associated with the photosynthesis, while the growth of shoots and leaves is also favored.

Thus, according to the main embodiment of the invention, the experimental results regarding the morphological, physiological and colorimetric final product characteristics of grafted watermelon seedlings produced according to embodiment A and B according to the invention are listed below in Table 1 in comparison. Means (n = 20 ± SD) followed by an asterisk are statistically significantly different at a significance level a < 0.05 (t-test).

ACHIEVEMENTS METHOD

Parameter

Aboveground fresh weight (g) 3.12 ± 0.06 4.26 ± 0.10 * Root fresh weight (g) 0.60 ± 0.03 1.00 ± 0.04 * Root-aboveground ratio 0.16 ± 0.01 0.16 ± 0.01 Chlorophyll content 48.46 ± 2.43 48 .65 ± 1.63 Lightness 37.92 ± 0.34 38.30 ± 0.31 Chroma 16.72 ± 0.45 18.08 ± 0.46

Hue angle 132.00 ± 0.35 131.67 ± 0.25 a/b -0.90 ± 0.01 -0.89 ± 0.01

REFERENCES-Bibliography

• Mallick MFR, Masui M. 1986. Origin, distribution and taxonomy of melons.

Sci Hortic, 28, 251-261

· Bemis WP, Rhodes AM, Whitaker TW, Carmer SG. 1970. Numerical taxonomy applied to cucurbita relationships. Amer J Bot, 57, 404-412

Claims (16)

1. A method of producing grafted seedlings, in particular of watermelon, from an inoculum that constitutes the upper part and a rootstock bearing the root system, where the use of lighting means is provided, and is characterized by including the following successive stages: 1<o>- the stage of development and production of seedlings for inoculation, which in particular consists of an inoculum and a substrate, where the inoculation step follows 2° - the healing stage of the inoculated seedlings of stage 1, which includes the healing of the inoculation cuts, and 3° - the hardening stage of the above grafted seedlings of stage 2. 2. A method of producing grafted seedlings, in particular of watermelon, according to the preceding claim wherein LED lamps are used as lighting means. 3. A method of producing grafted seedlings according to any one of claims 1-2, characterized in that the first step 1 comprises the following steps, - initially the above vaccine is sown, as well as the above subject which carries the root system, in trays for each preferably 171 and 128 positions respectively, -then they are transferred to a growth chamber, which is called a growth chamber, for germination, where - then after germination, the above trays are transferred to a greenhouse where in particular they remain, preferably for 10 days, and the trays with the above vaccine are subjected to natural lighting and additional supplementary light using artificial lighting means, while the trays with the subject are submitted without supplementary light, and then -follows the step of inoculation using the lateral section technique and where then the inoculated seedlings are planted in trays, preferably 72 positions. 4. A method of producing grafted seedlings according to claim 3, characterized in that during step 1 the discs are transferred to a growth chamber with a controlled environment in which the temperature is about 25°C, the relative humidity 95-98% and with the absence of light for at least 72 hours for the above trays containing the inoculum and for a duration of 48 hours for the above trays containing the rootstock, until the seeds germinate. 5. A method of producing inoculated seedlings according to claim 2 or 4, which is characterized in that during stage 1 the temperature at which the inoculum develops after their transfer to the greenhouse is at a minimum night temperature of approximately 21.5°C. 6. A method of producing inoculated seedlings according to any one of the preceding claims 1 -5, characterized in that during the first stage comprising the development of the inoculum, LED lamps with an emission spectrum of 88% red and 12 % blue light, as a result of which a light intensity of 100 - 10 μmol m<-2-1> is added to the height of the plants and in particular for a photoperiod of 18 hours, while the above substrate grows without supplementary light, in particular still in a minimal night temperature of 20° C for a duration of 7 days and 14° C for a duration of 3 days. 7. Method for producing grafted seedlings according to any one of claims 3 to 6, which is characterized in that during the first stage 1, during sowing, a mixture of peat, perlite and vermiculite is added to the above trays in a ratio of 5:1: 2, while after inoculation with the lateral cut technique when planting the above grafted seedlings in the above trays, preferably 72 positions, a mixture of peat, perlite and vermiculite is added in a ratio of 3:1:1. 8. A method of producing grafted seedlings according to any one of claims 3 to 7, characterized in that step 2 comprises the following steps, - the above trays with the inoculated seedlings of stage 1 are immediately transferred to a healing chamber with a controlled environment in which the temperature is particularly stable at 25° C and in recirculated air, and where in particular they remain there preferably for 6 days, and -where the above trays are placed on trolley shelves where the lighting means are installed which constitute the exclusive source of lighting for the latter. 9. A method for producing grafted seedlings according to any one of claims 1-8, characterized in that during the above second step of curing the grafted seedlings, LEDS lamps with an emission spectrum consisting of 88% red and 12% are used as lighting means blue light, resulting in emitting a light intensity of 85 - 5 μmol m<-2>S<-1> at plant height and for a photoperiod of 18 hours. 10. A method of producing grafted seedlings according to any one of claims 8 to 9, characterized in that during the above curing stage, the relative humidity in the curing chamber is 98% for the first four days, 93% for the fifth day and 89 % for the sixth day. 11. A method of producing inoculated seedlings according to any one of claims 8 to 10, characterized in that the third step of curing the inoculated seedlings comprises the following steps, -after the exit of the seedlings from the above curing chamber of stage 2, the trays are transferred to a greenhouse for hardening for a period of preferably 14 days where they remain preferably at a minimum temperature of 21.5° C, where - the inoculated seedlings are grown under natural lighting and with the use of an illumination medium as supplementary light. 12. A method for producing grafted seedlings according to any one of claims 1-11, characterized in that during the third stage of hardening of the grafted seedlings, light emitting diodes (LEDs) are used as a means of supplementary illumination, as a source of supplementary illumination with a spectrum emission consisting of 88 % red and 12 % blue light, resulting in a light intensity of 100 - 10 μmol m<-2>s<-1> at plant height and for a photoperiod of 18 hours. 13. A method of producing inoculated seedlings according to claims 1-12, wherein the above inoculum is a watermelon hybrid and wherein in particular it belongs to the species Citrullus lanatus. 14. A method of producing grafted seedlings according to any one of claims 1-13, wherein the root system forming rootstock is a bispecific hybrid of squash, in particular a Cucurbita maxima x C. moschata TZ-148. 15. Inoculated watermelon seedlings obtained according to the method as defined by any of the preceding claims 1-14. 16. Use of the method as defined in any of claims 1-14 for the production of inoculated seedlings intended for cultivation and ready for planting in the field.