The right time to control cotton aphid

(agricultural Wealth Network) the period from late July to early and mid-August is the recurrence period of cotton aphid. Aphids can be divided into seedling aphids and summer aphids, which are two ecotypes of cotton aphids that differentiate and adapt to different environmental conditions. It is mainly concentrated in the back of cotton leaves or tender head to absorb juice. The summer aphid in the cotton area of the Yellow River basin mainly occurs from the middle of July to the middle of August, which can cause the upper tender leaves of cotton to curl, the middle leaves to appear oil leaves, and seriously lead to the shedding of buds and bolls. Because most of the cotton was ridged and the leaves were dense when the aphids occurred, many farmers reported that the aphids were more difficult to control than seedling aphids.

I. what has happened

At present, cotton aphid is common in Hengshui city, and some plots are seriously harmful. The number of three-leaf aphids per hundred plants in Wuyi County is 3000 to 5000, with a maximum of more than 20,000, and serious leaves have been curled; the number of three-leaf aphids per hundred trees in the highest land of the old city is more than 10,000, and the rate of rolled-leaf plants is 36%. The meteorological department predicts that the city still maintains high temperature in July, and the precipitation is close to perennial. the high temperature and muggy weather, sometimes sunny and sometimes rainy weather is conducive to the occurrence of cotton aphid. Here, I would like to remind the broad masses of farmers to closely strengthen field observation, timely and scientific drug control, so as to minimize the yield loss caused by cotton aphids. The chemical control methods of cotton aphid in the field are provided as follows:

II. Prevention and control methods

1. Rotate the use of potions. Acetamiprid, imidacloprid, chlorpyrifos and other conventional pesticides in the field are used alternately to reduce the possibility of drug resistance of aphids. Once aphids develop resistance to a certain chemical, even if the times of drug use and concentration are increased, the ideal control effect will not be achieved.

two。 Spray the occurrence site thoroughly. Now cotton is in full bloom, the plant is tall, spraying must be careful, focus on spraying the back of the middle and lower leaves of cotton, strictly prevent missed hit, leakage spray, and effectively ensure the quality of each spray. Because the breeding speed of aphids is fast, it will cause a large number of residual insects if it cannot be sprayed through at one time, which will increase the difficulty of prevention and control next time. Generally, the amount of liquid used per mu is 50-60 kg.

3. Advocate the selection of some new drugs. For plots where the conventional use of acetamiprid, imidacloprid and other traditional agents has no obvious control effect, new agents such as 10% acetamiprid water agent, 20% carbosulfan EC or 10% chlorothioline can be selected to control. General 10% chlorothioline wettable powder 20 grams per mu or 10% enacetamide water 20 milliliters per mu.

4. The medication should be at the right time. During the period of high temperature, we should avoid the noon time and use the medicine in the morning and evening as far as possible, which is better before 10:00 in the morning and after 4 p.m., on the one hand, it can ensure personal safety, on the other hand, it can avoid the rapid evaporation and loss of liquid caused by high temperature, and reduce the efficacy.