Let's talk about the symptoms of phytotoxicity caused by plant growth regulators.
I. Phytotoxic Symptoms of Plant Growth Regulators
When we use plant growth regulators, we often suffer from phytotoxicity due to improper use. For example:
1, injury symptoms of paclobutrazol
Paclobutrazol is a common triazole plant growth retardant, which can be absorbed by the roots and leaves of crops, inhibit the synthesis of gibberellin in plants, reduce the biosynthesis of indoleacetic acid, increase the release of ethylene, delay the division and elongation of plant cells, shorten internodes, make plants dwarf and compact, promote the formation of flower buds, protect flowers and fruits, and sterilize. For example, we often use it to control the prosperity of fruit trees, potatoes and peanuts.
However, excessive use of paclobutrazol or large soil residue often leads to short plants, small underground rhizomes, deformity, curly leaves, dumb flowers, premature shedding of old leaves at the base, twisted and atrophied young leaves and so on.
For example, cotton plants are short and dwarfed, fruit branches cannot be stretched, leaves are deformed, branches are clustered, and buds and bolls fall off. Peanut leaves are small, plants are short, fruits are small and premature.
Because paclobutrazol remains in the soil for a long time, it will also cause phytotoxicity to the next crop, and often there will be phytotoxicity symptoms such as no emergence, late emergence, low emergence rate and abnormal seedlings.
2. Poisoning symptoms of Zhuangzhusu
Growth promoters will lead to smaller and thicker leaves, dense internodes, more lateral buds and uneven plant growth, resulting in a large number of buds and bolls falling off, leading to late maturity of cotton. The growth promoter rarely causes phytotoxicity to gramineous crops such as corn, wheat and rice, and its dosage range is wide.
Generally speaking, growth promoters will not cause phytotoxicity to the next crop.
3, chlormequat chloride phytotoxicity symptoms
The efficacy of chlormequat chloride is stronger than that of chlormequat chloride, which will lead to serious dwarfing of plants, inability to extend fruit branches, abnormal leaves, cotyledons of chicken feet, cluster of lateral buds, short internodes of fruit branches, brittle branches and leaves of plants and easy to break.
If seeds are soaked with excessive chlormequat chloride, the root system will be bent, the growth of young leaves will not be serious, the emergence will be delayed and the seedlings will be distorted.
Chlormequat chloride is easy to cause phytotoxicity to dicotyledonous plants such as soybean, lentil, cucumber and cotton, but not to monocotyledonous plants such as wheat and corn. Chlormequat chloride generally does not affect the next crop.
4. Ethephon's toxic symptoms
When ethephon is slightly damaged, the top of the plant is easy to wilt, and the leaves, flowers and young fruits at the lower part of the plant gradually turn yellow and fall off, and the residual fruits mature ahead of time. When the pesticide damage is serious, the leaves turn yellow and fall off quickly, and the fruits mature and fall off quickly, which leads to the plant withering.
Ethephon will cause phytotoxicity whether it is used too much or not. Ethephon damage has no effect on the next crop.
5. Symptoms of 5.NAA poisoning
The mild phytotoxicity of NAA is the shedding of flowers and young fruits, which has little effect on plant growth. Severe phytotoxicity is characterized by leaf atrophy, petiole turnover, leaf abscission and rapid fruit abscission.
The phytotoxicity caused by soaking seeds and roots with NAA is characterized by less root deformity, no roots and no seedlings. Some NAA will affect the next crop, but most of them will not.
Poisoning symptoms of 6,2,4-drops
2.4-D is both an anti-falling agent and a herbicide, so it must be used with caution. The toxicity of 2.4-D is very common.
2.4-D Mild phytotoxicity symptoms are soft and bent petiole, drooping leaves, turnover of top leaves, abnormal leaves and fruits, and prone to hollow fruits and cracked fruits. Serious phytotoxicity is that the leaves of plants droop, turn over, deform and shrink, and the growing points of plants gradually wither and die.
Therefore, if 2.4-D is used improperly, it will kill plants like a herbicide, which is mainly harmful to dicotyledons and less harmful to monocotyledons.
7. Poisoning symptoms of triacontanol
When the dosage of triacontanol is large or the purity is not high, it will lead to plant bending and abnormal root system at seedling stage, and the young leaves will bend when growing.
8. Symptoms of brassinolide injury
Brassinolide is an endogenous hormone and is safe. But if used excessively, the plants will grow wildly, the fruits will be few and small, and the fruits will become stiff in the later stage.
9. Phytotoxic symptoms of gibberellin
Gibberellin can stimulate growth, break dormancy and improve fruit setting rate, and it is also a rescue agent for growth retardants such as paclobutrazol and chlormequat chloride. However, if used improperly, it will lead to fruit stiffness, cracking, astringent taste and ripening.
10, compound symptoms of sodium nitrophenolate.
Mild phytotoxicity will inhibit the growth of plants and hinder the development of young fruits. Serious phytotoxicity is wilting, yellowing and death of plants. However, sodium nitrophenolate is less harmful, mainly to sensitive crops such as peach trees and watermelons, which will lead to falling flowers and fruits and hollow fruits.
1 1, harmful symptoms of aminomethyl ester
@ A wisp of breeze 275985082 My friend left a message, and he asked how to use urethane. Please reply here.
First of all, let's talk about the poisoning symptoms of aminoethyl ester, which will lead to pale yellow spots on plant leaves, and then gradually expand into dark brown and finally transparent.
Aminomethyl ester is a new plant growth regulator, which can increase the contents of chlorophyll, protein and nucleic acid, enhance the photosynthetic rate of plants, increase the activity of some enzymes in plants, enhance the metabolic function of plants, enhance their absorption capacity, and adjust the water balance in plants, thus improving the cold resistance and drought resistance of plants.
Aminoacetate is easy to decompose when it meets alkaline substances, and has no nutrients, so it is not suitable for unrestrained use and high temperature use. It can be mixed with retarder such as chlormequat chloride, chlormequat chloride and paclobutrazol to promote fruit setting.
Why do plant growth regulators have phytotoxicity? What is the reason?
Second, the causes of plant growth regulators
1, if leaves are curled, hardened and dark green near flowers and fruits, most of them are caused by too high drug concentration or too much water immersion.
2. If the leaves at the growing point are curled, shriveled, deformed and grow slowly, it is caused by the accumulation and poisoning of plant growth regulators.
In good weather, although plant growth regulator poisoning already exists, normal plant growth masks the phenomenon of plant growth regulator poisoning, so the symptoms are not easy to be detected or mild in sunny days. However, after continuous rainy weather, when plants can't carry out normal photosynthesis, root absorption will go wrong, so there will be symptoms of plant poisoning at this time.
So, what should we do when plants are harmed by plant growth regulators?
Third, the first-aid measures of plant growth regulator injury
1, when the drug damage is not too serious, you can spray water to alleviate the drug damage. Generally, when the phytotoxicity is not enough to kill plants, the mixture of urea and potassium dihydrogen phosphate can be sprayed for rescue, usually once every 15, 2? Three times can reduce drug damage.
2. If the symptoms of phytotoxicity have appeared, the mixed solution of calcium fertilizer, cytokinin and water-soluble fertilizer can be sprayed once every 7 days for 2? Three times. Or the mixture of humic acid fertilizer and calcium fertilizer is applied with water, 7? /kloc-once every 0/0 day, and it can be saved after more than 2 consecutive flushes.
3. Targeted rescue agents can also be sprayed, such as paclobutrazol, chlormequat chloride, uniconazole and other delay agents, and gibberellin can be sprayed for rescue, once every 7 days or so, and basically the effect of relieving the injury can be basically achieved for three consecutive times.
Well, let's talk about the causes, symptoms and emergency measures of plant growth regulators. Please correct any deficiencies. If you have any questions about plant growth regulators, you can leave a message in the comment area and discuss it together ~