First, the current occurrence of diseases and pests
1. Spring inchworm: According to the post-winter survey, the mortality rate is 17.3%, and the parasitic rate is 29.4%, which is higher than last year and slightly higher than that of previous years. Temperatures in March were higher than in the same period last year, and spring was earlier than in previous years. According to the phenology and accumulated temperature, feathering began on March 5, and the feathering period was 8-10 days earlier than in previous years. From March 8 to 10, it entered the peak of feathering, began spawning on March 16, the temperature rose rapidly in March, the spawning period began on March 23, and hatching began on April 6. Affected by the cooling in early April, the worm grows slowly and is currently dominated by hatching larvae. The feathering date of the spring inchworm is close to 2016. The feathering of spring inchworm detection and reporting lamps in March is as follows:
2, cotton leaf mites: it is observed that the stinging activity began around March 13, which is the earliest year of activity in recent years, earlier than last year (April 10) and calendar year (March 25-30), and spawning around March 25. According to the survey of weeds in the forest belt around April 7, the rate of mites on the lone vegetable is 5--13%, the number of mites in the 100 plants is 8-17, the rate of mites in the bitter herb is 16%, the number of insects in the 100 plants is 24, and the number of eggs in the 100 plants is 87.
3. Cotton bollworm: According to the spring survey, the mortality rate after wintering is 12.6%, which is slightly higher than in previous years and significantly higher than in the past two years.
4. Aphids: According to the spirit of the division documents, spring flower aphids were carried out, and the whole greenhouse was applied to a total of 65 sheds, and the efficiency reached more than 95% through the investigation after application. According to the fixed-point observation of outdoor wintering hosts in spring, the mortality rate of wintering eggs was 33.1%, which was slightly higher than last year. According to the high temperature in March, the wintering eggs began to hatch around March 9, 18 days earlier than last year, about 10 days earlier than the calendar year, and reached the peak of incubation on March 14, according to the characteristics of high temperature in mid-to-late March, the basic incubation ended by March 18. The fertility period is generally about 15 days earlier than last year.
5, corn borer: according to recent surveys, the mortality rate after wintering is 21.7%, which is higher than last year and previous years.
6, ground tiger: according to the current survey, the old mature larvae began to rise to the soil surface, and have not yet pupated. Due to the relatively simple planting structure at present, the number of ground tigers is very small.
7. Natural enemies: According to the characteristics of high temperature in March, phenology is advanced, and various pests and natural enemies appear in advance. At present, natural enemies are concentrated in alfalfa and wheat fields.
Second, the relationship between recent climatic factors and the occurrence of pests and diseases
1. Climatic factors
The average temperature in the Xiaye land reclamation area in March was 7.5 °C, which was 7.5 °C higher than the same period in the calendar year and 9.3 °C higher than that in the same period last year; the precipitation in the Lower Wild Land Reclamation Area in March was 15.3 mm, which was 50% more than the same period of the calendar year, which was significantly more than the same period last year. It is estimated that the average temperature in the Lower Wild Reclamation Area in April will be about 13.5 °C, which is about 0.9 °C higher than the same period in the calendar year; compared with the same period last year, it will be about 0.2 °C lower. In April, the precipitation in the Lower Wild Land Reclamation Area was about 14.3mm, which was about 20% less than the same period in the calendar year, and significantly less than the same period last year. Final frost period: Expected to occur in late to early Mid-April, slightly earlier than in previous years; later than in 2017.
2. Prediction of the occurrence trend of diseases and insect pests in the next stage
(1) Spring inchworm: Affected by the weather process around April 10 (rainfall cooling), it is recommended that all units closely monitor the forest belt that has occurred heavily in previous years, and control the forest belt with local heavy weight, and the appropriate period for prevention and control is expected to be April 18-25.
(2) Cotton leaf mites: According to the current occurrence and the characteristics of low temperature and temperature in recent days, it is not conducive to the spread and spread of cotton leaf mites. Expected: Full by the end of mid-April.
(3) Aphids: With the rise in temperature in recent days, it is expected that the aphids on the outdoor wintering host will begin to produce winged aphids in late April and spread.
(4) Ground tiger: According to the progress of development, it is expected that pupal pupae will begin in recent days.
III. Comprehensive defense recommendations
In the current comprehensive deepening of reform in the early stage, all units should attach great importance to plant protection work, improve awareness, must always adhere to the "prevention first, comprehensive prevention and control" policy, establish a modern plant protection concept of "scientific plant protection, public plant protection, green plant protection", strengthen the understanding of reduction and control of harm, and vigorously promote green prevention and control technology. According to the current occurrence of diseases and insect pests, combined with the prediction of the occurrence trend of major diseases and insect pests in agriculture and forestry in 2018, the following suggestions are proposed:
1. Conscientiously do a good job in the investigation of the base number of insect sources in spring to provide a reliable basis for agricultural production, forecasting and prevention.
2. Do a good job in seed coating, ensure the toothing rate of seeds, and reduce the incidence of diseases at the seedling stage.
3. Conscientiously do a good job in cleaning the countryside, shoveling and pupaing, etc., so as to reduce the survival rate of various pests after wintering.
4. Do a good job in the investigation and prevention of forest pests such as early spring spring inchworm, Yang Mengni night moth, yuqian borer and so on.
5. Earnestly grasp the chemical weeding work in cotton fields, ensure the sustainable control of weeds, and prevent the occurrence of herbicide and drug accidents.
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!