Fluorine-B composition, plant growth regulator and application thereof

Abstract

The invention relates to a fluorine-B composition, a plant growth regulator and application thereof, and belongs to the technical field of pesticides. The invention provides a fluorine-ethyl composition which comprises flumetralin and ethephon, and the mass ratio of flumetralin to ethephon is 1: (0.05-20). A tip control drug flumetralin and a tip killing drug ethephon are creatively combined together to prepare the fluorine-B composition, the compound preparation of flumetralin and ethephon can synergistically control and inhibit litchi winter shoots, the pesticide effect is mild, the lasting period is longer, the safety is extremely high, and compared with a conventional chemical control drug independently used, the effect is better, and the effect is better. The control effect on the litchi winter shoots is more comprehensive and excellent, germination of the winter shoots can be controlled, nutrient accumulation of a tree body is facilitated, flower bud differentiation is promoted, and the growth of the litchi winter shoots with a certain length can be obviously controlled or killed, so that nutrient consumption of the tree body is reduced, and the survival rate of the litchi is increased. And a solid foundation is laid for high and stable yield in the second year.

Description

Technical Field

[0001] The present invention relates to the technical field of pesticides, and in particular to a fluorine-ethyl composition, a plant growth regulator and applications thereof. Background Art

[0002] In autumn and winter, litchi trees will produce a large number of new shoots under suitable conditions. These new shoots cannot produce flower spikes or be cultivated into fruiting mother branches, and are called winter shoots. Winter shoots not only consume nutrients from the tree, but also seriously affect flower bud differentiation and flowering and fruiting in the next year, resulting in yield losses. Winter shoots grow slowly. If they are not matured in time, they are more likely to suffer frost damage when encountering low temperatures, thus affecting the growth and health of the tree. Doing a good job of controlling litchi winter shoots is conducive to accumulating nutrients for the tree, promoting flower bud differentiation, and laying a good foundation for flowering and fruiting and high and stable yields in the second year.

[0003] The treatment of winter shoots includes controlling the germination of winter shoots and inhibiting the growth of winter shoots that have already emerged. In addition to physical methods such as ring cutting and root cutting, it is more common to use chemical drugs for regulation, such as paclobutrazol as a shoot control drug, and ethephon or oxyfluorfen as a shoot killing drug. When the autumn shoots of litchi are mature, the shoots are controlled, or the winter shoots are killed uniformly after they have grown to a certain length before the shoots are controlled. However, the chemical control drugs currently used for litchi are complex and diverse, with different drug properties and application techniques, and all have certain limitations and shortcomings. Some drugs have high requirements for the time of use, and the effect is not good if the time is missed; some drugs will cause drug damage and affect the health of the tree if the concentration and temperature conditions are not properly controlled during use.

[0004] Paclobutrazol is used in large quantities, has a short duration of efficacy, and has a long residual period. Improper use can lead to premature aging of the tree. At the same time, paclobutrazol has a poor control effect on new shoots that have already sprouted, so there are high requirements for the timing of medication. Generally, it is used before the autumn shoots of litchi mature and the winter shoots sprout. Affected by climate and cultivation management, the maturity of the autumn shoots of litchi or the sprouting of winter shoots are usually uneven, making it difficult to achieve unified control. Therefore, when using shoot control drugs, if the winter shoots have already sprouted, the efficacy will be greatly affected.

[0005] Flumetralin is a relatively new type of contact plant growth regulator. It is quickly absorbed, acts quickly, and has a long lasting effect. It is usually used as a sprout inhibitor. Its residual amount is small, so it is extremely safe.

[0006] Ethephon and oxyfluorfen are mainly used to inhibit the winter shoots of litchi that have grown to a certain length. Ethephon has a wide range of uses and can kill new shoots that have just grown a few centimeters, causing them to gradually shrink and shed leaves. It has a mild effect and can also accelerate the aging of autumn shoots, promote tree dormancy, and adjust the ratio of male and female flowers. However, shoot-killing drugs have high requirements for litchi varieties, concentrations, water usage, and temperature. If used improperly, they can easily cause leaf fall and tree damage, affecting flowering and tree health.

[0007] Therefore, there is an urgent need for a plant growth regulator that combines shoot control and shoot killing, has a long lasting effect, is highly safe, has a low dosage, is flexible to use, and can effectively control shoots even if winter shoots have sprouted a certain number and length. Summary of the invention

[0008] The purpose of the present invention is to overcome the shortcomings of the prior art and provide a fluorine-ethyl composition, a plant growth regulator and its application which combine shoot control and shoot killing, have a low dosage, are flexible to use, and can effectively control shoots even if winter shoots have sprouted a certain number and length.

[0009] To achieve the above object, the technical solution adopted by the present invention is:

[0010] In a first aspect, the present invention provides a fluorine-ethylene composition, comprising flumetralin and ethephon, wherein the mass ratio of flumetralin to ethephon is flumetralin:ethephon=1:(0.05-20).

[0011] The invention combines flumetralin with ethephon to form a fluorine-ethylene composite, which is applied to litchi treetops to synergistically inhibit the growth of winter shoots and control the number of winter shoots, thereby increasing the yield of litchi.

[0012] As a preferred embodiment of the fluorine-ethylene composition of the present invention, the mass ratio of flumetralin to ethephon is flumetralin:ethephon=1:(0.1-10). Under the preferred ratio range, the fluorine-ethylene composition of the present invention has better control and inhibition effects on litchi winter shoots.

[0013] As a preferred embodiment of the fluorine-ethylene composition of the present invention, the mass ratio of flumetralin and ethephon includes but is not limited to at least one of flumetralin:ethephon=1:0.1, flumetralin:ethephon=1:0.2, flumetralin:ethephon=1:0.5, flumetralin:ethephon=1:1, flumetralin:ethephon=1:2, flumetralin:ethephon=1:3, flumetralin:ethephon=1:4, flumetralin:ethephon=1:5, flumetralin:ethephon=1:6, flumetralin:ethephon=1:7, flumetralin:ethephon=1:8, flumetralin:ethephon=1:9 and flumetralin:ethephon=1:10.

[0014] In a second aspect, the present invention provides the use of the above-mentioned fluorine-ethyl composition in the preparation of plant growth regulators.

[0015] In a third aspect, the present invention provides a plant growth regulator comprising the above-mentioned fluorine-ethyl composition and an agricultural adjuvant.

[0016] As a preferred embodiment of the plant growth regulator of the present invention, the plant growth regulator composition accounts for 5-60% of the total mass of the composite plant growth regulator.

[0017] As a preferred embodiment of the plant growth regulator of the present invention, the plant growth regulator composition accounts for 10-50% of the total mass of the composite plant growth regulator.

[0018] As a preferred embodiment of the plant growth regulator of the present invention, the agricultural adjuvant includes at least one of a carrier, a solvent, a cosolvent, a dispersant, an emulsifier, a wetting agent, a synergist, an antifreeze agent, a stabilizer, a defoamer and a pH regulator. The plant growth regulator of the present invention may also include commonly used agricultural adjuvants such as a spreader and a rheological agent.

[0019] As a preferred embodiment of the plant growth regulator of the present invention, the solvent includes but is not limited to at least one of water, methyl oleate, toluene, benzene, xylene, acetone and soybean oil.

[0020] As a preferred embodiment of the plant growth regulator of the present invention, the cosolvent includes but is not limited to at least one of monohydric alcohol, polyhydric alcohol, cyclohexanone, acetone, glycol ether, epoxy soybean oil, sodium benzoate and sodium salicylate.

[0021] As a preferred embodiment of the plant growth regulator of the present invention, the dispersant includes but is not limited to at least one of sodium lignin sulfonate, white carbon black, sodium sulfate, sodium phosphate, styrene-acrylic acid copolymer, and sodium naphthalene sulfonate.

[0022] As a preferred embodiment of the plant growth regulator of the present invention, the emulsifier includes but is not limited to at least one of xanthan gum, fatty alcohol polyoxyethylene ether, methyl oleate, dibenzyl biphenyl polyoxyethylene ether, calcium dodecylbenzene sulfonate and styrene.

[0023] As a preferred embodiment of the plant growth regulator of the present invention, the wetting agent includes but is not limited to at least one of sodium lignin sulfonate, sodium lauryl sulfate, polyoxyethylene alkyl ether, and fatty alcohol polyoxyethylene ether.

[0024] As a preferred embodiment of the plant growth regulator of the present invention, the synergist includes but is not limited to at least one of diatomaceous earth, sodium sulfate, fatty alcohol polyoxyethylene ether, methyl oleate, and D-citric acid.

[0025] As a preferred embodiment of the plant growth regulator of the present invention, the antifreeze agent includes but is not limited to at least one of polyols, diethylene glycol, ethylene glycol butyl ether, dichloromethane, dimethyl sulfoxide, calcium chloride, sodium acetate, and magnesium chloride.

[0026] As a preferred embodiment of the plant growth regulator of the present invention, the stabilizer includes but is not limited to at least one of white carbon black, diatomaceous earth, xanthan gum, bentonite, ascorbic acid, sodium thiosulfate, benzophenone, monohydric alcohol, dihydric alcohol, and polyol.

[0027] As a preferred embodiment of the plant growth regulator of the present invention, the defoaming agent includes but is not limited to at least one of ethanol, propanol, isopropanol, butanol, dodecanol, and tetradecanol.

[0028] As a preferred embodiment of the plant growth regulator of the present invention, the pH regulator includes but is not limited to at least one of sodium sulfate, sodium hydroxide and hydrochloric acid.

[0029] As a preferred embodiment of the plant growth regulator of the present invention, the carrier includes at least one of white carbon black, diatomaceous earth, kaolin and bentonite.

[0030] As a preferred embodiment of the plant growth regulator of the present invention, the dosage form of the plant growth regulator includes but is not limited to at least one of a suspension, a wettable powder, a water dispersible granule, a granule, an emulsifiable concentrate, a microemulsion, an aqueous emulsion and an oil suspension. The plant growth regulator of the present invention is not limited to a specific dosage form, and can be prepared into different dosage forms for application according to actual conditions.

[0031] In a fourth aspect, the present invention provides the use of the above-mentioned fluorine-ethyl composition or plant growth regulator in controlling the germination and growth of litchi winter shoots.

[0032] In a fifth aspect, the present invention also provides a method for controlling the germination and growth of litchi winter shoots, comprising the following steps:

[0033] (1) diluting the above-mentioned fluorine-ethyl combination or the above-mentioned plant growth regulator into a liquid medicine, spraying the liquid medicine on the top and peripheral branches of the litchi tree when the autumn shoots of the litchi are about to mature and the winter shoots begin to sprout, until water drips from the leaf tips;

[0034] (2) 15-30 days after the application of the pesticide, spray the pesticide solution of step (1) again according to the growth of the litchi winter shoots according to the operation of step (1), and continue to observe until the litchi winter shoots stop growing, and then end the application of the pesticide.

[0035] As a preferred embodiment of the method for controlling the germination and growth of litchi winter shoots of the present invention, in step (1), the concentration of the fluorine-ethyl composition or plant growth regulator after being diluted into a liquid medicine is 200-350 ppm.

[0036] As a preferred embodiment of the method for controlling the germination and growth of winter shoots of litchi according to the present invention, in step (1), the time when the autumn shoots of litchi are about to mature and begin to germinate is the time when the autumn shoots of litchi are mature and begin to germinate until the length of the new shoots is 0-10 cm. The present invention has been verified through experiments that even though the winter shoots of litchi have already germinated, the growth of winter shoots can still be effectively inhibited and controlled after application, and the application conditions are wider, and there is no need to apply traditional plant growth regulators such as paclobutrazol before the winter shoots germinate, and at the same time, the impact of poor yield caused by uncontrolled winter shoots due to weather changes can be alleviated.

[0037] As a preferred embodiment of the method for controlling the germination and growth of litchi winter shoots of the present invention, in step (1), the time when the litchi autumn shoots are about to mature and the winter shoots begin to germinate is the time when the litchi autumn shoots are mature and the winter shoots begin to germinate to the length of the new shoots 0.5-8 cm.

[0038] As a preferred embodiment of the method for controlling the germination and growth of litchi winter shoots of the present invention, in step (1), the time when the litchi autumn shoots are about to mature and the winter shoots begin to germinate is the time when the litchi autumn shoots mature and the winter shoots begin to germinate to the length of the new shoots 1-5 cm.

[0039] Compared with the prior art, the present invention has the following beneficial effects:

[0040] The invention creatively combines the shoot control drug flumetralin and the shoot killing drug ethephon to prepare a fluorine-ethylene composition. The composite preparation of flumetralin and ethephon brings good synergistic effect for controlling and inhibiting litchi winter shoots, has a longer lasting effect and is extremely safe. Compared with the use of conventional chemical control drugs alone, the control effect on litchi winter shoots is more comprehensive and excellent. It can not only control the germination of winter shoots, which is beneficial to the accumulation of tree nutrients and promote flower bud differentiation, but also has obvious control or shoot killing effect on litchi winter shoots that have been extracted to a certain length, thereby reducing the nutrient consumption of the tree, and laying a solid foundation for high and stable yields in the second year. At the same time, the composition has mild efficacy, can prolong the medication time window, is more flexible and convenient when applying the medicine, and saves time and labor. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 The winter shoot control conditions of litchi trees before and after the application of pesticides in treatment group 4 of the present invention, where A is before the application of pesticides and B is 25 days after the application of pesticides;

[0042] Figure 2 The winter shoot inhibition of litchi trees before and after the application of pesticides in treatment group 4 of the present invention, where A is before the application of pesticides, and B is 7 days after the application of pesticides;

[0043] Figure 3 The winter shoot inhibition of litchi trees before and after the application of pesticides in treatment group 4 of the present invention, where A is before the application of pesticides, and B is 7 days after the application of pesticides;

[0044] Figure 4 This is the winter shoot inhibition of litchi trees before and after application of pesticides in treatment group 4 of the efficacy example of the present invention, where A is before application of pesticides, and B is 7 days after application of pesticides. DETAILED DESCRIPTION

[0045] In order to better illustrate the purpose, technical solutions and advantages of the present invention, the present invention will be further described below in conjunction with specific embodiments.

[0046] Unless otherwise specified, other materials, reagents, etc. used in the embodiments, comparative examples and effect examples can be obtained from commercial sources.

[0047] Example 1

[0048] An embodiment of the plant growth regulator of the present invention, the dosage form of the plant growth regulator described in this embodiment is a wettable powder, including flumetralin, ethephon, sodium lignin sulfonate, sodium dodecyl sulfate, white carbon and diatomaceous earth, and the mass ratio is flumetralin: ethephon: sodium lignin sulfonate: sodium dodecyl sulfate: white carbon: diatomaceous earth = 25:2.5:3:1.5:5:63.

[0049] The preparation method of the wettable powder is as follows: the above components are put into a stirrer to be fully mixed, and then the materials are crushed by a jet mill to obtain a wettable powder product.

[0050] Example 2

[0051] An embodiment of the plant growth regulator of the present invention, the dosage form of the plant growth regulator described in this embodiment is a suspension, including flumetralin, ethephon, polyoxyethylene alkyl ether, xanthan gum, sodium sulfate, bentonite and deionized water, and the mass ratio is flumetralin: ethephon: polyoxyethylene alkyl ether: xanthan gum: sodium sulfate: bentonite: deionized water = 12.5:5:6:0.5:1:1:74.

[0052] The preparation method of the suspension agent is as follows: the above components are put into a shearing preparation kettle to be fully mixed, and then the materials are slowly passed through a sand mill to be ground to a mixed particle size that meets the requirements, thereby obtaining a suspension agent product.

[0053] Example 3

[0054] An embodiment of the plant growth regulator of the present invention, the dosage form of the plant growth regulator described in this embodiment is an oil suspension, including flumetralin, ethephon, fatty alcohol polyoxyethylene ether, magnesium aluminum silicate, bentonite and methyl oleate, and the mass ratio is flumetralin: ethephon: fatty alcohol polyoxyethylene ether: magnesium aluminum silicate: bentonite: methyl oleate = 5:5:4:0.3:1:84.7.

[0055] The preparation method of the oil suspension concentrate is as follows: the above components are put into a shearing preparation kettle to be fully mixed, and then the materials are slowly passed through a sand mill to be ground until the mixed particle size meets the requirements, so as to obtain an oil suspension concentrate product.

[0056] Comparative Example 1

[0057] A comparative example of the plant growth regulator of the present invention, the dosage form of the plant growth regulator of this embodiment is a suspension, comprising 25% by mass of paclobutrazol. The preparation method of the suspension is the same as that of Example 2.

[0058] Comparative Example 2

[0059] A comparative example of the plant growth regulator of the present invention, the plant growth regulator of this embodiment is in the form of an aqueous solution, comprising 40% by mass of ethephon. The preparation method of the aqueous solution is the same as that of Example 2.

[0060] Comparative Example 3

[0061] A comparative example of the plant growth regulator of the present invention, the plant growth regulator of this embodiment is in the form of a suspension, comprising 25% by mass of flumetralin. The preparation method of the suspension is the same as that of Example 2.

[0062] Effect example

[0063] The plant growth regulators obtained in Examples 2-3 and Comparative Examples 1-3 were subjected to shoot control and shoot killing tests.

[0064] Select litchi trees with the same tree size and growth, and apply pesticides when the litchi autumn shoots are mature and the winter shoots begin to sprout. The pesticide application steps include the following steps:

[0065] (1) The plant growth regulators obtained in Examples 2-3 and Comparative Examples 1-3 and clean water were diluted to form liquid medicines, and the application concentrations were shown in Table 1. The liquid medicines were sprayed on the top and peripheral branches of litchi when the autumn shoots of litchi were about to mature and the winter shoots began to sprout, until water dripped from the leaf tips;

[0066] (2) 15-30 days after applying the pesticide, spray the pesticide solution of step (1) again according to the growth of the litchi winter shoots according to the operation of step (1), and continue to observe until the litchi winter shoots stop growing, then end the pesticide application.

[0067] Table 1 Application concentrations of different drug treatments

[0068] Group Drug treatment Application concentration (ppm) 1 Example 2 233 2 Example 2 350 3 Example 3 200 4 Example 3 333 5 Comparative Example 1 300 6 Comparative Example 2 200 7 Comparative Example 3 200 8 Blank control /

[0069] Before applying the pesticide, extract two large autumn shoots from the middle and upper parts of each tree in the southeast, northwest and northeast directions to investigate the number and length of winter shoots. After applying the pesticide, regularly investigate the number and growth length of winter shoots, and calculate the control rate and inhibition rate of winter shoots according to the following formula:

[0070] Winter shoot control rate (%) = (average number of winter shoots in blank control - average number of winter shoots in drug treatment) / average number of winter shoots in blank control × 100;

[0071] Winter shoot inhibition rate (%) = (average length of winter shoots in blank control - average length of winter shoots treated with chemical) / average length of winter shoots in blank control × 100.

[0072] In the second year after the experiment, the yield was measured when the litchi fruits were harvested, and the yield increase rate was calculated according to the following formula.

[0073] Yield increase rate (%) = (average yield of drug treatment - average yield of control treatment) / average yield of control treatment × 100;

[0074] The above results can be seen in Figure 1-4 , Table 2-3.

[0075] Table 2 Effects of different treatment groups on litchi winter shoots

[0076]

[0077] like Figure 1-4 As shown, 25 days after spraying the plant growth regulator of Example 3, the litchi tree as a whole basically did not sprout new winter shoots, indicating that the vegetative growth of the tree was inhibited and transformed to the direction of flower bud differentiation; the winter shoots that had already sprouted withered and fell off after being treated with the composition. On the one hand, the growth of the winter shoots was inhibited, which could reduce the consumption of nutrients in the tree. On the other hand, the remaining winter shoot stems could control the sprouting of new winter shoots, thereby achieving control and inhibition of the winter shoots of the litchi tree from different directions.

[0078] As shown in Table 2, when the autumn shoots of litchi mature and the winter shoots begin to sprout, spraying a plant growth regulator containing flumetralin and ethephon has an excellent effect on controlling the winter shoots of litchi. The shoot control rates of treatments 1 to 4 are 88.76%, 94.06%, 86.68% and 89.89%, respectively, and the shoot control rates of treatments 5 to 7 are 58.75%, 21.35% and 61%, respectively, indicating that the compositions of Examples 2 and 3 are better than the effects of using shoot control agents or shoot killers alone in controlling the sprouting of litchi winter shoots.

[0079] The shoot inhibition rates of treatments 1 to 4 were 70.00%, 78.82%, 72.35%, and 88.24%, respectively, and the shoot control rates of treatments 5 to 7 were 35.88%, 91.18%, and 41.18%, respectively, indicating that the compositions of Examples 2 and 3 had a good inhibitory effect on winter shoots that had grown a certain length, and the shoot inhibition rate increased with the increase of ethephon concentration. However, ethephon is affected by varieties, temperature, and concentration, and it is easy to cause phytotoxicity if it is not properly used. The concentration cannot be increased at will, and the use of ethephon alone has almost only a shoot inhibition effect, and the shoot control effect is extremely poor.

[0080] Table 3 Effects of different treatments on litchi yield

[0081]

[0082] As shown in Table 3, due to the adverse weather in winter and spring during the test period, the flowering and fruiting of litchi were affected, resulting in a decrease in the yield of litchi compared with the same period in previous years. However, it can still be seen from the data in Table 3 that the plant growth regulators of Examples 2 and 3 have good yield-increasing effects, and compared with Treatment 5 and Treatment 7 using the shoot-controlling drug alone, the yields increased by 39.37%, 66.46%, 33.23%, 46.30% and 27.80%, 52.64%, 22.17%, 34.15% respectively; compared with Treatment 6 using the shoot-killing drug ethephon alone, the yields increased by 137.90%, 184.14%, 127.42%, 149.73% respectively.

[0083] Based on the above test results, it can be seen that the combination of flumetralin and ethephon has a good synergistic effect. Compared with the use of conventional chemical control drugs alone, the effect is more comprehensive and excellent. It can not only control the germination of winter shoots, but also has a good inhibitory effect on winter shoots that have grown to a certain length. It is beneficial to the accumulation of nutrients in litchi trees and promotes the differentiation of flower buds, laying a solid foundation for the stable and high yield of litchi in the second year.

[0084] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the essence and scope of the technical solution of the present invention.

Claims

1. A fluorine-ethylene composition, characterized in that: The invention comprises flumetralin and ethephon, wherein the mass ratio of flumetralin to ethephon is flumetralin:ethephon=1:(0.05-20).

2. The fluorine-ethylene composition according to claim 1, characterized in that The mass ratio of flumetralin and ethephon is flumetralin:ethephon=1:(0.1-10).

3. Use of the fluorine-ethyl composition as claimed in any one of claims 1 to 2 in the preparation of a plant growth regulator.

4. A plant growth regulator, characterized in that The invention comprises the fluorine-ethylene composition as described in any one of claims 1 to 2 and an agricultural adjuvant.

5. The plant growth regulator according to claim 4, characterized in that The plant growth regulating composition accounts for 5-60% of the total mass of the composite plant growth regulator.

6. The plant growth regulator according to claim 5, characterized in that The plant growth regulating composition accounts for 10-50% of the total mass of the composite plant growth regulator.

7. The plant growth regulator according to claim 4, characterized in that The agricultural adjuvant includes at least one of a solvent, a co-solvent, a dispersant, an emulsifier, a wetting agent, a synergist, an antifreeze agent, a stabilizer, a defoaming agent and a pH regulator.

8. Use of the fluorine-ethyl composition according to any one of claims 1 to 2 or the plant growth regulator according to any one of claims 4 to 7 in controlling the germination and growth of litchi winter shoots.

9. A method for controlling the germination and growth of litchi winter shoots, characterized in that: The following steps are involved: (1) diluting the fluorine-ethyl composition of any one of claims 1 to 2 or the plant growth regulator of any one of claims 4 to 7 into a liquid medicine, spraying the liquid medicine on the top and peripheral branches of the litchi tree when the autumn shoots of the litchi are about to mature and the winter shoots begin to sprout, until water drips from the leaf tips; (2) 15-30 days after the application of the pesticide, spray the pesticide solution of step (1) again according to the growth of the litchi winter shoots according to the operation of step (1), and continue to observe until the litchi winter shoots stop growing, and then end the application of the pesticide.

10. The method according to claim 9, characterized in that Including at least one of the following (I) to (II): (I) In step (1), the concentration of the fluorine-ethylene composition or plant growth regulator after dilution into a liquid medicine is 200-350 ppm; (II) In step (1), the time when the autumn shoots of litchi are about to mature and the winter shoots begin to sprout is the time when the autumn shoots of litchi are mature and the winter shoots begin to sprout to the length of the new shoots 0-10 cm.

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