In September 2019, Tianshan Plant Protection surveyed the damage loss of cotton blind bugs to cotton in southern Xinjiang, and the damage loss rate of cotton blind bugs in some cotton planting areas was generally 5 to 15%, while the cotton field spots where cotton blind bugs seriously occurred, a large number of cotton leaves were broken, the cotton blind bug bell rate could reach 80% to 100%, and some cotton field spots caused a no harvest. At present, the cotton fields in southern Xinjiang are encountering a period of cotton blind bug hazards, because since April, there has been a lot of rainfall and weeds in the fields, and there is a possibility that cotton blind bugs will break out into disasters. It is hoped that through the analysis and prevention and control technical experience of this article, it will provide a reference for the prevention and control of cotton blind bugs in 2020!
First, the occurrence of cotton blind bugs in 2019
(1) The harm of cotton blind bugs at the seedling stage of cotton is revealed
In the cotton field survey on May 13-18, 2019, the cotton seedlings were in the 3 to 5 true leaf stage, the cotton field was accompanied by cotton blind bug hazards, and the cotton field partial spot cotton blind bug hazard caused the cotton leaf break rate to reach 5% to 20%.
(2) Cotton blind bug hazard loss period
At the end of July 2019, a group of cotton fields in southern Xinjiang were investigated, and a large number of cotton leaf holes were found, and the holes were mostly in the top leaves of cotton, especially the edge of the cotton field, and the Wangchang district was the most. To the cotton inter-row investigation, there are more small peaches on the ground, and the small bells that fall off the bracts and peel off the leaves show that there are many tumor spots on the skin of the cotton bells, and the field budding rate is less, and the bell falling rate is large. From the survey, 80% of the bells have nodule marks, that is, the obvious symptoms of cotton blind bugs. A large number of cotton blind bug nymphs and adults were found in the middle and upper bell buds that had not fallen off on the cotton plant, and there were more spots with more broken leaves, and an average of 1 to 3 cotton blind bug nymphs could be seen on a small bell. The situation of cotton blind bugs eating cotton bells has always been accompanied by the flowering period of cotton.
Second, the causes of cotton blind bugs
(1) Analysis of the causes of cotton blind bugs at the seedling stage of cotton
1. There are many weeds and a large number of cotton blind bugs
Judging from the field survey from April to May, the low temperature and humidity and the large number of weeds in the cotton field are very conducive to the increase of the population of cotton blind bugs. Judging from the experience of the past years, as long as there is more rain and more weeds, it is often the year when the cotton blind bugs erupt. According to the survey, alfalfa grows well, cotton blind bug occurrence is larger, if the cotton once the growth is strong, and the occasional alfalfa in late May grows old, it is very easy to cause cotton blind bugs from the outside of the cotton field to the cotton field migration hazard. In addition, due to the bad market conditions in jujube trees and other places, the weed control in the orchard is unfavorable, and the orchard is also the birthplace of cotton blind bug breeding, and it is very easy to cause the harm of cotton blind bugs near the orchard or the cotton field.
2. The tender growth of cotton is conducive to the harm of cotton blind bugs
High temperature and high humidity are extremely conducive to the vegetative growth of cotton. In 2019 as a whole, cotton growth is generally late, the growth of seedlings is weak, the idea of cotton farmers to promote the growth of seedlings is larger, and there are many cotton fields using sodium compound nitrate phenol, gibberellin and amino acid fertilizers, resulting in ultra-conventional growth of cotton seedlings, cotton seedlings growing vigorously, nutrient growth is excessive, leaf hypertrophy, and the occurrence of cotton blind bugs is induced.
3. Hybrid cotton problem
Due to the strong growth potential, insect resistance and good quality of hybrid cotton, in recent years, the penetration rate of hybrid cotton is high, and the growth of cotton seedling stage is strong, if the cotton seedling stage is not controlled in time, cotton is very easy to cause growth and induce the harm of cotton blind bugs.
(2) Analysis of the causes of cotton bug breeding during the boll stage of cotton
1. Wangchang cotton field is harmful
From the point of view of the cotton field with more broken leaves, especially the cotton field near the jujube garden, it was found that all the small bells and big bells were dropped by the cotton blind borer, and there was no bell in the middle and lower part of the plant, only flowers and buds, and the cotton plants and fruit branches were umbrella-shaped, which was seriously harmful. Judging from the whole cotton field, the rate of broken leaves and moth bells in the cotton area on the edge of the ground is high. Cotton is growing vigorously, the rows are closed, the fields are closed, and the cotton blind bugs are heavy.
Heavy occurrence occurs in the cotton area near the jujube garden, especially in the cotton area without high weed barrier between the jujube cotton. The harm of cotton blind bugs in the cotton field near the Jujube field is heavy, which is related to the fact that the flowering period of the Jujube has passed (the puffing fruit stage), while the gray jujube is still flowering and bearing fruit, and the cotton blind bugs in the nearby jujube cotton field are less harmful than the nearby Jujube field.
Judging from the survey of other cotton fields that have not been near the jujube garden, some spots also have cotton blind bugs that harm a large number of leaf-breaking leaves, especially the cotton blind bugs in the cotton area where the closed leaves are enlarged in the wangwang fields.
2. Pesticide use deviation, poor control ability of cotton blind bugs
Due to the large-scale planting of hybrid insect-resistant cotton, cotton plants have strong growth potential, partial nitrogen fertilizer, and cotton is easy to flourish. In the early stage, there were few cotton bollworms, and there were fewer pesticides used in cotton fields that killed cotton bollworms and cotton blind bugs. Cotton farmers do not pay attention to the harm and prevention of cotton blind bugs, and only formulate a large number of pesticides to kill cotton aphids, such as imidacloprid, acetamidine or carbamate and other pesticides have poor efficacy in preventing cotton blind aphids. Cotton fields generally enter the full flowering period, locomotives enter the ground less, aircraft prevention and control of cotton blind bugs liquid concentration is high, the effect is not good, to the cotton blind bugs a large number of occurrence to provide a good suitable living environment.
3. The base number of cotton blind bugs is large, and the amount of insect sources is greatly increased
Cotton, vegetables, alfalfa, fruit trees and other crops that cotton blind bugs like to eat are planted in a large area, and the orchard land is extensively managed and overgrown with weeds, providing a rich food source for cotton blind bugs, resulting in an increase in the amount of insect sources.
4. The harm of cotton blind bugs and cotton thrips is not clearly distinguished
From the investigation, it was found that cotton bells with tumors are more common thrips. It has been identified by some agricultural households or so-called experts as a harm to cotton thrips, including the phenomenon of tin peach, requiring the extensive use of pesticides to control cotton thrips. In fact, it is the wound spots caused by cotton blind bugs that attract cotton thrips to feed.
Third, cotton blind bug prevention and control technology
(1) Strengthen investigation and monitoring, seize the critical period of prevention and control, and use drugs in a timely manner
From the perspective of the hazard characteristics of cotton blind bugs, cotton blind bugs have the habit of eating the young leaves of cotton first, and mainly eat the young leaves at the top of cotton. When the leaf breaking rate of 100 cotton plants reaches more than 10%, and the situation of mothbells is found, it is necessary to use drugs to prevent and control in time, and the appropriate insecticide should be selected for prevention and control in time to eliminate the cotton blind bugs in the spot state. From the perspective of the harm of cotton blind bugs in the cotton fields of southern Xinjiang, the occurrence situation is different from that of northern Xinjiang, which mainly eats cotton young bells, while northern Xinjiang mainly eats cotton young buds, so insect prevention should not be blind, and it is necessary to adapt to local conditions and scientifically and reasonably prevent and control insect pests on the basis of investigation.
(2) Use cotton blind bugs to fear light habits and spray drugs reasonably
Cotton blind bugs generally move on the top of the cotton plant before 9 a.m. or after 8 p.m. or on rainy days, and rest in the middle of the cotton plant and the back of the leaves around noon, so they should be controlled with drugs when they are active.
(3) Reasonable fertilization and timely whole branches
Balanced fertilization prevents excessive growth of cotton. For the early whole branch of the partial cotton plant, it is especially necessary to remove the invalid plant, open the field passage, maintain the ventilation and light transmission between the rows, promote the healthy growth of the cotton plant, and create an environment that is not conducive to the occurrence of cotton blind bugs to reduce its harm.
(4) Method of application
Since adults can fly, nymphs crawl quickly, and should be turned up and down when controlling spraying, and closed on all sides. The surrounding cotton fields are uniformly medicated, centralized prevention and control, and unified prevention and control to prevent adult insects from migrating between cotton fields. At the same time, in order to prevent and control thoroughly, in the critical period of the occurrence of cotton blind bug nymphs, it has been prevented twice in a row, and once every 5 to 7 days to prevent cotton blind bugs from reproducing in cotton fields.
(5) Accurate application of the drug
According to the habits of cotton blind bugs, pesticides with better contact killing and strong systemic properties are selected for mixed spraying and alternating use. At present, there are many varieties of pesticides for the prevention and control of cotton blind bugs, including flufenacillitrile, polybactericide, ethyl spironoid, furofuranamine, acetamidine, thiamethoxam, avermectin, chlorpyrifos, malathion and so on. Nicotinic pesticides such as imidacloprid or part of acetamidine for the control of cotton thrips have a very poor effect on the prevention and control of cotton blind bugs, and it is necessary to distinguish between drugs. Since most of the pesticides for the prevention and control of cotton blind bugs have no systemicity, it is necessary to ensure that all cotton plants are in place, and it is recommended to spray up and down the crane with a boom to penetrate the prevention and control.
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