First, the current occurrence of diseases and insect pests
1, cotton leaf mites: affected by the temperature and rainfall in April, since entering May, the development of cotton leaf mites, the spread and spread rate is slower, so far the cotton field has not found the central plant of leaf mites; according to the survey of weeds (field swirling flowers, solitary vegetables, bitter wheat vegetables) on the ground, the average mite plant rate is 30%, the highest is 45%; the amount of 100 mites is 61 heads, the highest is 117, and the number of eggs in 100 plants is 27-41, which is higher than the previous base number.
2, cotton seedling disease: affected by the rain in April, the cotton field in our region after the emergence of seedlings are common plots have occurred, according to the survey, the incidence rate is between 40-100%, the disease index is 45, compared with the same period last year.
3, aphids: according to the observation of outdoor wintering hosts, aphids began to differentiate on April 25, and winged aphids began to differentiate on April 30, and have moved to the housewarming host (groundside weeds), according to the survey, the central plant has not been found in the cotton field.
4, cotton bollworm: according to the lamp temptation observation, due to the large temperature fluctuations in April, the adult insects have not yet begun to feather.
5. Spring inchworm: According to observations, some early development began to enter the soil at the end of April to prepare for pupae, and on May 2, under the influence of high winds, 70-90% of the larvae were forced into the soil, affecting the normal development of spring inchworm.
6. Yang Mengni nocturnal moth: According to the development progress of the insect, the heavy forest belt was prevented before the end of April, coupled with the windy weather on May 2, which effectively inhibited the occurrence and harm of the insect and the development progress; according to the current observation, there are also a small number of old mature larvae with heavy local harm.
7, natural enemies: according to the lantern temptation and weeds outside the field observation, the current main grasshoppers, the number of bees, hunting bugs have begun to increase.
Second, the relationship between recent climatic factors and the occurrence of pests and diseases
It is estimated that the average temperature in our region in May is about 20.5 °C, which is about 0.6 °C higher than the same period of the calendar year; it is about 2 °C higher than the same period last year. In May, the precipitation in our district was about 23mm, which was about 20% more than the same period of the calendar year and about 10% less than the same period last year.
The weather in early May is expected: the average temperature in our region in early May is about 17.5 °C, which is about 0.3 °C lower than the same period of the calendar year; it is about 0.9 °C higher than the same period last year. In early May, the precipitation in our district was about 8.0mm, which was about 10% more than the same period in the calendar year, and about 10% more than the same period last year.
Third, the trend of diseases and insect pests in the next stage is predicted
(1) Cotton leaf mites: According to climatic conditions, it is expected that the central plants of cotton leaf mites will occur in the cotton fields in the end of mid-May.
(2) Cotton bollworm: According to the analysis of accumulated temperature and climatic conditions combined with historical data, it is predicted that the feathering period of adult insects in the wintering generation is early May.
(3) Aphids: It is expected to begin to move into the cotton fields in mid-May.
(4) Yang Mengni nocturnal moth: According to the current development progress, it is expected that it will enter the pupae peak on May 15.
IV. Comprehensive Defense Recommendations
Since the recent temperature has begun to rise, which is conducive to the occurrence and development of various insect pests, in view of the current occurrence of various diseases and insect pests, it is recommended that all units mainly do the following plant protection work:
1. According to the current situation, all units should strengthen the investigation of diseases and insect pests and grasp it in a timely manner
Various pests and diseases occur dynamically.
2. According to the development progress of cotton bollworms, each unit should do a good job in repairing and installing the frequency vibration insecticidal lamps in time, prepare for the booby-trapping and monitoring of adult cotton bollworms in the wintering generation, effectively monitor and trap the overwintering adults, and turn on the lights on May 10.
3. Strengthen the investigation and prevention of cotton leaf mites in early cotton fields, timely blockade of plots with large base numbers on the edge of the ground, use drugs to prevent and control special acaricides, and strictly prohibit the use of broad-spectrum pesticides.
4. Strengthen the investigation of cotton aphids inside and outside the cotton field, and closely monitor the occurrence and development of cotton aphids and cotton black aphids in the cotton fields.
5. For the plots that have not been controlled after the emergence of seedlings, the prevention and control of cotton thrips in a timely manner combined with chemical adjustment is combined to reduce the harm of thrips.
6. Earnestly do a good job in the investigation and prevention of diseases at the seedling stage of cotton, and according to the severity of the occurrence of diseases in various places, timely cultivate, increase the ground temperature, and reduce the occurrence of diseases at the seedling stage of cotton.
7. Enter the field management stage, scientifically and rationally use pesticides to ensure that agricultural production and the environment are safe. Adhere to the scientific use of pesticides, timely recycling and burial of various pharmaceutical packaging.
Source: 8th Division Xiaye Land Reclamation District 121 Regiment Center Disease and Insect Detection and Reporting Station 2019 Disease and Insect Intelligence Phase IV, Graphic Editor: Tianshan Plant Protection, reprint please indicate the source!