First, the current occurrence of diseases and pests
1, cotton leaf mites: According to the recent survey of weeds (solitary vegetables, field spinners, dandelions), cotton leaf mites saw mites on April 15, 5-10 days earlier than the calendar year, and the development progress was significantly earlier than last year, slightly earlier than the calendar year. The rate of mites in solitary vegetables was 2.3%, and the amount of mites in 100 plants was 3.2 heads; the rate of mites in tianhua was 4.8%, and the amount of mites in 100 plants was 6.4 heads.
2, spring inchworm: according to observations, the current insect 2-3 years old, the largest up to 4 years old, has entered the binge eating period, most of the field forest occurrence is lighter, the local forest belt (mainly elm trees, poplar trees) occurs heavier, the leaves are obviously missing, incomplete. According to the survey, the number of 20cm branch insect mouths is generally 0-2, and the maximum is 5--6, which is lighter than last year and calendar year (affected by the 2017 flight defense).
3, Yang Mengni night moth: According to the recent survey of poplar forest belt by the plant protection station: 0-1 head of 20cm branch larvae, most of which are 1--2 year old larvae, and 35% of the trees that have occurred seriously have found the insect, which has caused harm to local poplar trees, which is lighter than in previous years.
4, aphids: affected by climatic conditions and environmental conditions, overwintering parasites on April 17 to produce winged aphids, close to the same period last year, slightly earlier than the calendar year, the current proportion of winged aphids in the total amount of aphids between 30--50%.
5, cotton seedling diseases: according to the recent stable and rapid recovery of the climate, cotton in late April has emerged seedlings, which is not conducive to the occurrence of diseases, there is no rotten seed situation at present, and the incidence is lighter than the same period in previous years.
6, Elm money borer: the amount of elm forest belt is slightly lighter than in previous years, the average tree is 0--1 head per 20cm branches, up to 3 heads, it is currently the peak period of harm, with the fall of Elm money, it began to transfer the harm on the ground.
7. Corn borer: According to monitoring, corn borer is currently in a larval state.
8, natural enemies: according to the recent net fishing, alfalfa land hundred net small flower bugs 14.2 heads, ladybugs 55.2 heads, grass worms 1 head, bees 6 heads, spiders 5.8 heads, hunting bugs 1.6 heads; wheat ground hundred nets of small flower bugs 8.5 heads, ladybugs 9.8 heads, grass moths 0.5 heads, bees 1.25 heads, spiders 0.5 heads, hunting aphids 1.5 heads, food aphids 0.75 heads. Grasshoppers and spiders are lower than in previous years, and other predators are close to the same period of the calendar year.
Second, the relationship between recent climatic factors and the occurrence of pests and diseases
1. Climatic factors
The average temperature in the Lower Wild Land Reclamation Area in mid-April was 13.3 °C, which was 0.4 °C higher than the same period in the calendar year and 1.1 °C lower than that of the same period last year; in mid-April, the precipitation in the Lower Wild Land Reclamation Area was 6.4 mm, which was slightly more than the same period in the previous year, and significantly less than the same period last year.
It is estimated that the average temperature in the Lower Wild Land Reclamation Area in late April will be about 16.5 °C, which is about 1.0 °C higher than the same period of the calendar year; it will be about 1.2 °C lower than the same period last year; the precipitation in the Lower Wild Land Reclamation Area will be about 4.0 mm in late April, which is about 40% less than the same period in the calendar year; it is significantly more than the same period last year.
2. Prediction of the occurrence trend of diseases and insect pests in the next stage
(1) Cotton leaf mites: After the cotton cotyledons are flattened, it is expected to begin to move into the cotton fields in early May.
(2) Spring inchworm: According to the current development progress and climatic conditions, the best time for prevention and control before April 30 is expected, and it is expected that individual development will begin to fall into the ground early in early May.
(3) Aphids: It is expected that the cotton fields will begin to move into the cotton fields after the seedlings are widely emerging in early May.
(4) Cotton seedling diseases: Due to this year's climatic conditions, the occurrence of diseases is relatively mild, and it is recommended that all units strengthen medium cultivation in time for the strip fields of cohesive soil after emergence, improve the ground temperature, and inhibit the degree of disease occurrence.
(5) Yu Qian Borer: It began to turn into field hazards on April 25, and it is recommended that all units closely monitor the occurrence and development of the insect.
(6) Cotton bollworm: According to the analysis of accumulation temperature and historical data, it is expected that the overwintering adult insects will begin to feather in early May.
(7) Corn borer: According to the climate and development progress, it is expected that pupae will begin in mid-May.
IV. Comprehensive Defense Recommendations
It is necessary to adhere to the plant protection policy of "prevention first, comprehensive prevention", establish a modern plant protection concept of "scientific plant protection, public plant protection, and green plant protection", vigorously promote green prevention and control technology, and put forward the following suggestions according to the current monitoring and occurrence of major diseases and insect pests:
1. Cotton leaf mites: After sowing, the plots with large bases are blocked by the edge of the land with an obligate acaricide, which reduces the field base of cotton leaf mites and controls the spread of cotton leaf mites.
2. Timely cultivation of cotton after emergence to reduce the incidence of diseases at the seedling stage.
3. Do a good job in the prevention and control of forest pests such as spring inchworm, Yang Mengni night moth, Yu Qian borer, etc., which is currently the appropriate period for the prevention and control of the insect, and the prevention and control of heavy field forests should be carried out before April 30.
4. Do a good job in the investigation and prevention of thrips, combined with chemical adjustment, more than 70% of the cotton emergence rate uses acetamiprid and imidacloprid to prevent and control thrips.
5, do a good job in the installation and maintenance of insecticidal lamps, end before May 1, May 4 began to hang insecticidal lamps, and by special personnel to open and cancel the insecticidal lights and record the number of various insects received.
6. Before the chemical adjustment and pest control, all units should do a good job in the inspection of pharmaceutical equipment and the cleaning of medicine cans, and do a good job in the burial and treatment of pesticide packaging.
Author: Liu Ruihong, source: Eighth Division 121 Regiment Center Disease and Insect Detection and Reporting Station, Graphic Editor: Tianshan Plant Protection, please indicate the source of the reprint!