lodging, as an important factor affecting maize high and stable yield, has been paid more and more attention in recent years. in addition to strengthening cultivation management and other agronomic measures, spraying plant growth regulator to control vigor and lodging products has been more and more widely used in maize cultivation and management; however, the use period of corn vigor control agent is very long. the key is to grasp the use of drugs in the period of time can achieve twice the result with half the effort. if we miss the use of drugs in the critical period, the effect will often be discounted, and even bring about negative harm.
i. the best timing for maize prosperity control
maize blooming control agent is used for 6-12 leaves of maize, and the optimum use period is 7-9 leaves, that is, from the "foot height" to the "knee height" of maize. this period is the early jointing stage of maize. spraying can make the stalk of maize thicker, internode shorter, ear height lower, and the number of "overlord roots" layers and strips increased, which can be effectively prevented. the lodging of maize can also promote the movement of nutrients to ears and reduce empty trees and bald tips.
2. the hazards easily caused by missing the critical period
as mentioned earlier, the best time to apply corn blooming agent is 6-12 leaf stage, and the best time to use it is 7-9 leaf stage. if the effect is not said too late or too early, it will cause harm.
premature hazards of vigorous control: the use of vigorous control agent in the period of less than 6 leaves of maize is recommended after the period of 6 leaves because of the premature control, which results in low vigorous stalks and low stalks of maize.
harm of late control of exuberance: too late use of corn exuberance control agent, more than 12 leaves, maize has passed jointing stage, will cause the following problems:
(1) incorrect shrinkage of maize: the base 1-3 internodes should be shortened, but now the middle 4-5 internodes are shorter than the base 1-3 internodes, which can not effectively prevent maize lodging, but also lead to poor growth of maize, resulting in a reduction in maize yield in the later period.
(2) influencing maize ear differentiation: after jointing, the ears of maize begin to differentiate. if the growth of maize is controlled at this time, it will affect the ear differentiation of maize, resulting in less maize pollen, thereby affecting maize pollination, and finally affecting maize yield. so it must not be too late to control the prosperity of corn.
iii. control of use concentration and notes
strict control of application concentration
as a plant growth regulator, maize vigorous control agent (30% amine fresh and ethylene water) has different physiological effects on plants in different concentration ranges. too low concentration can not achieve the desired effect, and too high concentration can produce serious side effects. therefore, choosing the appropriate concentration is the key to apply cwp.
for example, ethephon was used as corn control agent, and its best application concentration was 300-500 mg/kg. the ethylene concentration of this concentration was favorable for spraying 6-12 leaves of maize.
matters needing attention
1. when spraying, pay attention to spraying high, not low, sweep away, avoid re-spraying. if it rains within 6 hours after spraying, the dosage should be reduced by half and sprayed again.
2. drought and rainless years can appropriately reduce the use of wangwang control drugs, such as the recommended dosage of 30% amine fresh ethylene water agent 20-25 g/mu; a number of drought is not used, once the key medication period is missed, maize in the later period is liable to grow rapidly at the first sight of rainwater, resulting in unstable root and stem base, greatly increasing the late lodging rate; amino fresh ester component in corn flourishing control agent has the functions of drought resistance, disease resistance, stress resistance and so on. it is effective.
resist high temperature and drought, alleviate the impact of drought, and promote the healthy growth of maize.
3. in rainy years, the usage can be increased appropriately, such as the recommended dosage of 30% amine fresh ethylene water agent 25-30 g/mu.