Diseases and pests control of rice

The panicle stage of rice is a crucial period when diseases and pests are prone to occur frequently. The prevention and control of diseases and pests during the panicle stage is a key link to ensure a full harvest of rice. In order to effectively control the damage caused by rice diseases and pests and ensure the safety of rice production in our city, it is hoped that each district and county will, based on the actual occurrence of rice diseases and pests in their local areas, and in combination with factors such as the disease resistance of the variety, the growth period of rice, and climate, scientifically formulate classified prevention and control plans, and guide farmers to do a good job in the prevention and control of diseases and pests during the panicle period. 

I. Major Pests and Diseases 

Rice leaf roller 

The peak period of the rice substitute leaf roller moth is relatively long and the number of moths is large. On August 16th, the average number of moths per mu in the city still reached 1,083. Before August 20th, the average number of moths per mu was several hundred. It was not until August 23rd that it dropped below 100. The peak period of egg incubation in the fields will last until the end of August. 

After the previous prevention and control, the early larvae of the moth peak were well controlled. Field investigation shows that the larva count in the field was 11,300 per mu, with the highest reaching 23,300 per mu. The egg count was 28,300 per mu, with the highest reaching 110,000 per mu. The leaf rolling rate was 2.09%. The average larva count in the natural observation garden is 64,500 per mu, with the highest reaching 160,800 per mu. 

2. Rice sheath blight 

After prevention and control measures, the disease in most of the fields has been effectively controlled. According to a recent survey, the average disease strain rate across the city was 7.84%, with the highest being 30.34%. The disease index was 3.06, with the highest being 12.46. The average disease plant rate and disease index were both higher than those of the same period of the previous year (disease plant rate 5.28%, disease index 1.9). The average disease plant rate in the natural observation garden was 23.35%, with the highest being 52.67%, and the average disease index was 10.57, with the highest being 26.25. 

According to the weather forecast, the weather in this city from the end of August to the first half of September will have no adverse effect on the occurrence of rice sheath blight. It is expected that the disease will continue to rise until the first half of September. 

3. Rice planthopper 

Field investigation showed that the total number of three types of planthoppers was 18,800 per mu, including 1,800 brown planthoppers per mu, 5,400 white-backed planthoppers per mu, and 11,600 gray planthoppers per mu. The total number of eggs of the three types of planthoppers was 84,300 per mu, including 13,100 per mu for the white-backed planthopper, 51,500 per mu for the grey planthopper, and 19,700 per mu for the brown planthopper eggs, which were found in some fields. 

Under light monitoring, the numbers of all three types of planthoppers were relatively low. In August, the cumulative number of planthoppers under light was 8.96 for brown planthoppers, 12.98 for gray planthoppers, and 41.86 for white-backed planthoppers. 

4. Youdaoplaceholder0 

The number of borers has been on the rise since the end of July. Since August, a total of 107.39 borers have been lured by a single lamp in the city, slightly lower than 125.68 in the same period last year. The number of rice stem borers has reached 110.53 (104.16 last year), slightly higher than the same period last year. It is expected that the third generation of rice borer will start hatching in late August, and the peak period of the ant moth in the field can last until early September. If it is not effectively controlled, it will cause considerable losses. 

5. Rice blast disease 

According to recent observations, the rice varieties mainly promoted in this city have relatively good resistance to panicle neck blight. However, some minor varieties have poor disease resistance, and the disease is widespread and severe in the field. In recent years, the occurrence of rice blast in our city has generally shown a trend of expanding area and worsening severity. If the weather is favorable in the later period, the risk of suijin plague will be relatively high. 

Ii. Prevention and Control Suggestions 

According to the investigation of the seedling conditions, the rice sown before May 31 is expected to start to form ears by the end of August, the rice sown in early June is expected to break through around August 30, and the rice sown after mid-June is expected to start to break through around September 5. 

All districts and counties are requested to promptly organize and carry out the prevention and control of diseases and pests during the panicle stage based on the characteristics of disease and pest occurrence in the fields and different rice varieties and growth stages. The specific opinions are as follows 

1. Prevention and control time and targets: 

For the first time: For fields sown in early June, the sowing period is from August 30th to September 3rd; for fields sown after mid-June, the sowing period is from September 4th to September 8th. It is mainly used to treat rice leaf roller, sheath blight, neck blight and rice curd disease. It also treats rice borer. In fields with an excessive number of brown planthopper eggs, it is used to control the planthopper to reduce the base number. 

The specific prevention and control time should be appropriately adjusted according to the local characteristics of pest and disease occurrence, different rice varieties and growth stages. Most rice varieties, especially those with relatively poor resistance to rice blast and those that have previously experienced leaf plague, should be treated with pesticides at the stage of the disease breaking. For indica and japonica hybrid varieties, as well as other varieties susceptible to rice koji disease, the application of medicine should be carried out 5 to 7 days before the break. 

The second time: 7 to 10 days after the first control (the interval days should be appropriately adjusted according to the type of pesticide selected and the field control effect). It is mainly used to treat ear and neck plague, and also to treat sheath blight, rice curd disease, rice borer, rice leaf roller.

For varieties with uneven panicles or particularly long panicle periods, the third control should be carried out 7 to 10 days after the second application, mainly treating rice curd disease and panicle neck plague. The second control target should be adjusted in a timely manner before control based on the occurrence of pests and diseases in the later stage, especially the migration of brown planthoppers. 

2. chemical control

(1) For the prevention and control of ear and neck plague: 26% inacyl · ether ester suspension concentrate at 60 to 90 milliliters per mu can be selected, or 40% fluorocycline Suspension concentrate 40 to 80 milliliters per mu. The above-mentioned pesticides can also treat sheath blight. 

(2) For the control of sheath blight and rice mold disease: 20 to 40 milliliters of 24% Jinggangmycin water solution or 6% Jinggangmycin can be used per mu. Pyrimethanil water solution 100 ml/mu, or 11% Jinggang · hexazolol wettable powder 60 g/mu, or 10% Jinggang · Bacillus cereus suspension 150 ml/mu. For fields with a high incidence rate or areas with perennial high incidence, 20 to 40 milliliters of 250 grams per liter of pyraclostrobin suspension or 24% hexazole can be selected. 25 milliliters of pyraclostrobin suspension, or 325 grams per liter of benzophenyl? 40 milliliters of pyraclostrobin suspension, or 75% tebuconazole? 15 grams of pyrimethanil water dispersible granules, or 75% oxime? 15 grams of tebuconazole water dispersion granules, or 20 milliliters of 30% thiafur · tebuconazole suspension, or 30 milliliters of 125 grams/l fluconazole suspension, etc. 

(3) Control of rice leaf roller: Each mu can be treated with Anemone? 15 milliliters of 16% indoxacarb suspension, or 20 milliliters of 14% suspension, or 30 milliliters of 10% suspension, or 16 milliliters of 15% indoxacarb suspension, or 8 to 9 grams of 30% indoxacarb water dispersible granules, or 16 grams of 15% suspension. For areas where 螟虫 is widespread, it is recommended to use 20 to 30 milliliters of 24% methoxycarbazide suspension, or 40 to 50 milliliters of 6% avetrel chlorobenzyl suspension, or 10 milliliters of 200 grams per liter chlorantraniliprol suspension per mu. 

(4) Prevention and Control of brown planthoppers For each mu, 20 to 25 grams of 25% flufenidone wettable powder can be selected, or 10 to 12 grams of 50% pymetrozine wettable powder, or 20 grams of 25% pymetrozine wettable powder or suspension, or 3 to 5 grams of 60% endifenidone wettable powder, or 4 to 8 grams of 50% endifenidone soluble granules, or 20 to 30 milliliters of 20% endifenidone water solution. 

Iii. Precautions 

Organic phosphorus should be used with caution in areas where bees are raised, shrimps are raised and crabs are raised. When applying pesticides, a small machine should be chosen for spraying. In areas surrounded by fish ponds and shrimp ponds, it is prohibited to discharge field water into rivers. 

2. During the hot season, it is advisable to spray the pesticide in the morning and evening as much as possible to prevent poisoning. At the same time, avoid showers and thunderstorms. In case of rainy weather, seize the gaps in the rain and apply the medicine in time. If it rains within 4 hours after prevention and treatment, make up for it in time. 

3. For general spray machines, the water consumption per mu should be no less than 45 kilograms. When multiple pesticides are mixed, the water consumption should be appropriately increased on this basis. Spray as large a machine as possible. After prevention and control, a thin water layer should be maintained in the field for two days. 

4. Pay attention to rotating medications and scientifically mixing them. Within one reproductive period, the same type of medicine should not be used more than three times, and the same medicine should not be used consecutively twice. In principle, only one type of agent should be selected for the same control target each time.