The use of plant growth regulators should be reasonable
Currently, a wide variety of plant growth regulators has been widely used in agricultural production. These chemicals have a positive effect to the aspects of regulating crop growth and development, increase production and improve the quality. However, if used improperly, it often tends to be counterproductive, and will have a negative effect. Therefore, the use of growth regulator should pay attention to the scientific.
Choose the corresponding regulator
Each growth regulator has certain physiological activity, and a specific use of the terms and conditions, so it should be application based on the characteristics of crop varieties, fertility and the purpose of growth regulators. If you want to improve leafy crops, should choose the growth of GA and other regulators; to improve crop tillering ability and anti-lodging, should used growth retardants, such as chlormequat chloride; for the promotion of fruit bud differentiation, should use daminozide, paclobutrazol and other chemicals; to achieve the purpose of protecting flowers and fruits of fruit trees, you can choose 2,4-D, 920 and other hormones.
Choose the right site for use
The reaction of root, stems, leaves, flowers, fruit and other parts of crops is different to the different chemicals, or the same drug in different concentrations. For example, to 2,4-Dichlorophenoxyacetic acid, with a concentration of 10-20ppm of liquid spraying citrus, can contribute to the growth of young fruit enlargement. However, when the concentration more than 15ppm, it has a significant inhibitory effect for shoots and leaves, and even cause leaf distortion. Therefore, you should pay attention to the necessary parts of the alignment crops for medication, do not blindly spraying, otherwise prone to injury. In general, if it is easily absorbed by roots, then the effect of soil application is the best, such as paclobutrazol, chlormequat, etc.; If promote root cuttings early onset, it is appropriate for dipping method; to reduce the abscission of young fruit, it can use smear method.
Strictly control the concentration and frequency of medication
Plant growth regulator on the growth and development of crops has the dual effect of promotion and inhibition. When appropriate concentration, it shows the effect of promote leaf growth, nurturing seedlings, protecting flowers and fruits of forward gain; when the concentration is too high will cause the plant metabolic disorders, inhibit the growth, and even cause death. If you see some distortions in citrus leaves malformations and even shedding into the bare branches of the tree, which is caused by high concentration when using 2,4-D. Therefore, the ratio should be in strict accordance with the preparation of liquid. At the same time, you should control the frequency of use of growth regulators.
Determine the best time to use
When using paclobutrazol to regulate the conflicts about spring shoot, summer shoot and fruit of citrus, the best spray time is bud stage. At this time, spraying can inhibit the growth of spring shoots, excessive suppression of summer shoot tip rate of around 90%, while fall tree has no effect. It also should pay attention to environmental factors such as temperature, light, humidity, impact, and should know that low concentrations under high temperature, slightly higher concentrations at low temperatures; avoid spraying during the summer months in the sun, while the light is too strong cause excessive drying liquid, which is not conducive to leaf absorption; if it rains in a short time after application will wash away the liquid, spraying should complement.
In addition, plant growth regulator is not a panacea, it can only play a supporting role, cannot be a substitute for other cultural practices. Therefore, only in the enhanced use of growth regulators on the basis of a comprehensive cultivation technique, you can effectively play its role.