The application of plant growth regulator on tomato
Tomato is a kind of thermophilic and photophil plant that has fertilizer tolerance and semi drought resistance. It can grow well and will be easy to achieve high yield under warm climate, enough light and less rainfall; under high temperature, rainy climate and when there is lack of light, which will all cause weak growth and serious disease of corns.
a. Accelerate germination
By soaking seed with plant growth regulator, it can improve germination speed and germination percentage as well as the seedling will grow evenly and become strong.
Gibberellins: it can be used in soaking seeds for 6h with the concentration of 200-300 mg/L.
Sodium nitrophenolate: it can be used in soaking seeds for 6h with the concentration of 6-8 mg/L.
Diethyl aminoethyl hexanoate: it can be used in soaking seeds for 6h with the concentration of 10-12 mg/L.
By spraying 20-25mg/L NAA or sodium naphthalene acetate on the sprout before cutting, it can promote the formation of adventive root as well as promote the formation and development of root system; by spraying 10-12mg/L NAA or sodium naphthalene acetate on the seedling, it can promote the growth and development of root system and breed strong seedling.
NAA or sodium naphthalene acetate also can promote the growth and development of tomato root system when it is used in coating seed and seedling or used in tender branch cutting. However, consider the using convenience and cost, this kind of drug generally is seldom used.
c. Prevent spindly growth in the seedling stage
By using the following several drugs, it can prevent spindly growth of seedling, shorten internode, thicken stalk, dwarf plant, promote flower bud differentiation and lay a foundation for the increasing of yield in the late period.
Spraying method: by mist spraying 300mg/L chlormequat chloride in 2-4 true leaf stage, the seedling will become stocky as well as the flower number will increase.
Water root: when the plant height has reached 30-50cm after transplanting, water root with 200mL chlormequat chloride under the concentration of 250mg/L, thus it can prevent spindly growth of plant.
Soak root: soak root with 500mg/L chlormequat chloride for about 20min before planting, thus it can improve seedling quality, promote flower bud differentiation as well as can promote precocity and achieve high yield.
Chlormequat chloride should not be used in weak seedling or poor land, besides, the working concentration should not exceed 500mg/L.
Regarding the leggy seedlings, by foliage spraying 10-20mg/L paclobutrazol in 5-6 true leaf stage, it can effectively control spindly growth. Besides, seedling will become strong and it can also promote the germination of axillary bud.
Attention: strictly control concentration and do not spray the drug repeatedly. Prevent the drug from falling on the soil, avoid root application and prevent drug from leaving in the soil.
d. Prevent fallen flowers and fallen fruits
In order to prevent fallen flowers and fallen fruits that caused by the floral organ dysplasia under low temperature or high temperature, below several drugs can be used.
2,4-D: 10mg/L 2,4-D can be dropped on flowers.
4-Chlorophenoxyacetic acid sodium salt: it can be sprayed at the side of the floorra or flower after 1-2d of flowering under the concentration of 20-30mg/L by using mistorizer. Under high temperature, the working concentration can be slightly reduced, while under low temperature, the working concentration can be increased. It can also be sprayed on panicles under the concentration of 8-15mg/L.
NAA or sodium naphthalene acetate: 10mg/L NAA or sodium naphthalene acetate can be sprayed on the blade surface.
Sodium nitrophenolate: 4-6mg/L sodium nitrophenolate can be sprayed on the blade surface.
The above mentioned drugs can all be used in preventing fallen flowers and fallen fruits. Besides, it can also accelerate the enlargement of fruits and increase the output in the early stage.
Attention: avoid splashing 2,4-D on branches or leafbud as well as the concentration should be controlled in 10-15mg/L so as to prevent phytotoxicity. When the concentration exceeds 25mg/L, the malformed fruit will generate, however, when the concentration is too low, it will have no effect on preventing fallen flowers and fallen fruits.
After spraying 2,4-D on the plant, seedless fruit can be obtained. However, the seed breeding field is forbidden to be used again.
Regarding 4-chlorophenoxyacetic acid sodium salt, it should not be sprayed in the whole plant, or it will lead to mild leaf shrinking, long narrow leaf and small leaf. At this time, by strengthening water and fertilizer management, it can promote the germination of new leaves. Control the concentration in less than 8 mg/L when it is sprayed on the whole plant. Besides, try to reduce the dosage when it is used in the vegetable greenhouse or under high temperature.
e. Delay senility and increase output
By using the following several drugs, it can inhibit seedling damping-off, prevent anthracnose, blight and viral disease in the late period and breed strong seedling. Besides, it can improve fruit setting rate in the middle and later periods, increase fruit shape and output, delay the senescence of plant and extend picking time.
Diethyl aminoethyl hexanoate: spray 25-30kg diethyl aminoethyl hexanoate per mu in the seedling stage under the concentration of 10mg/L. While in the field period, foliage spray 50kg diethyl aminoethyl hexanoate per mu under the concentration of 12-15mg/L and spray it again after 10 days.
DCPTA: spray 25-30kg DCPTA per mu under the concentration of 25mg/L in the seedling stage. While in the field period, spray 50kg DCPTA per mu under the concentration of 30mg/L and spray it again after 7-10 days.
Brassinolide: spray 25-30kg brassinolide per mu under the concentration of 0.0lmg/L in the seedling stage. In field period, spray 50kg brassinolide per mu under the concentration of 0.05mg/L and spray it again 7-10 days.
Triacontanol: spray 50L triacontanol per mu on tomatoes under the concentration of 0.5mg/L (the optimal concentration). By spraying it every 7-10 days (totally 2-3 times) in the growing period and mixing it with monopotassium phosphate or urea, it will achieve obvious yield-increasing effect.
Accurately master applying concentration when using the above drugs and prevent influencing plant growth caused by high concentration; besides, these kinds of drugs should not be mixed with alkaline pesticides.
When using triacontanol, pay attention to the quality. This is because when the drug becomes turbid, it will influence the using effect of triacontanol; when spraying triacontanol, it can be mixed with pesticides and microelements (but it should not be mixed with alkaline pesticide) as well as gibberellin, auxins, cytokinin and other growth regulators, but it should not be mixed with growth inhibitors.
f. Promote precocity of tomatoes
Ethephon: it can be used in the picking time of tomatoes so as to promote precocity, which has been widely used in the production and has achieved obvious effect. It can not only promote precocity and increase output, but also will be beneficial for the maturity of tomatoes in the later period. It can also be used in the storage and processing of tomatoes so as to be convenient for centralized processing. Besides, after being treated with ethephon, the lycopene, sugar and acid content of tomato will be similar with the normal mature fruits. As ethephon is a kind of water-soluble ethene generant, it will keep stable when the pH value is less than 4.1. However, when it is absorbed by plant issue, ethephon will be dissolved and will release ethene as the PH value of tomato plant is higher than 4.1, thus the tomato plant will generate physiological effect that can adjust the growth and development of tomatoes.
The application methods are as follows:
Smear method. When the tomato fruit is about to enter color-changed period (when the tomato fruit appears to be white) from green mature period, we can soak towelette or yarn gloves in 4000mg/L ethephon solution and wipe or contact it with tomato fruit. After being treated with ethephon, the fruit can become mature 6-8 days earlier, besides, the fruit will have bright luster.
Soak fruit. 2 000mg/L ethephon can be sprayed on the tomato fruit or can be soaked on the fruit for 1min so as to accelerate the ripening of tomato fruit that has entered the color-changed period, in which the tomatoes will be replaced in warms places (about 22-25 degrees Celsius) or indoors. However, these kinds of fruits will not be as bright as the fruits that grow on the plant.
Spray the drug in the field. Regarding one-time harvest tomatoes, 1000mg/L ethephon solution can be sprayed on the whole plant in the later growth stage when most of fruits have turned red and there is still a part of green fruits that cannot be used in processing, thus it can accelerate ripening of green fruit. Regarding some late season cultivation autumn tomatoes or high mountain tomatoes, ethephon can be sprayed on the plant or fruit in the late growth period when the air temperature starts to drop so as to prevent frost and promote precocity of fruit.
When using ethephon, the working concentration should be strictly controlled; besides, ethephon should not be sprayed in the normal growing season of tomatoes. This is because after using ethephon on the plant, especially using high concentration ethephon, it may inhibit the growth and development of plant, branches and leaves will turn yellow in a short time as well as will seriously influence the output.