Affected by the long-term dry weather since the wheat planting, the pests and diseases in the wheat area will have a serious trend. According to the National Crop Pest Monitoring Network, due to multiple factors such as arid climate and large number of wintering bases for pests and diseases, the occurrence of major pests and diseases of crops this year will be significantly focused on the previous year. The area of ​​various pests and diseases is expected to exceed 6 billion mu, and the prevention and control tasks and The difficulty is more than normal.
According to the National Climate Center, the temperature in most parts of China this spring is generally high, and the precipitation is less, which is conducive to the occurrence of pests such as wheat spiders and aphids. It is expected that as the temperature rises, the area of ​​various pests and diseases will rapidly expand, with the temperature. The recovery and the irrigation area of ​​wheat fields will increase, and the occurrence of wheat spiders and sheath blight will be significantly increased.
A precipitation process between 25 and 28 in the arid zone will be beneficial to alleviate the drought. It is expected that there will be light rain (snow) in the meteorological arid areas such as the eastern part of the northwest, north China, Huanghuai and northern Susong in the northwestern region, and moderate rain (snow) in some areas.
At present, winter wheat is about to enter the rejuvenation period, and pests such as nursery, wheat spiders, underground pests, and sheath blight will also develop rapidly and enter the critical period of the hazard; monitoring should be strengthened to prevent it early.
The wheat spider mainly harms wheat and other crops in the spring and autumn. Adults and nymphs can be harmed. After the plants are damaged, the leaves show yellow-white spots, the plants are short and the development is blocked. The heavy spots merge into plaques and the photosynthesis is destroyed. The transpiration is increased and the leaves are dry and dead.
Control methods: First, take agricultural control. The use of rotation for cropping, rational irrigation, deep harvesting and stalking after wheat harvest can eliminate the overwintering eggs in large numbers, and significantly reduce the density of insects in the three wheat seedlings and spring. The second is to take chemical control. Each tur is 1500 times with 40% dicofol, or 2,000 times with 15% Broom emulsifiable concentrate, or 1500 times with 15% eucalyptus, or 40% oxidized dimethoate 1500 times, which has good control effect and can cure aphid.
Rhizoctonia solani mainly overwinters in the soil with sclerotia, and can also overwinter with mycelium and sclerotia on diseased straw and other host residues. The pathogen has a wide range of hosts, strong viability, and a wide range of bacterial sources. In the second year, the sclerotia in the soil floats on the surface of the water, germinating and invading the rice plant, forming lesions, and then growing hyphae to spread around. The sclerotia has multiple germination characteristics, which cause multiple infestation with water drifting. At moderate temperature (25 ~ 32 ° C) high humidity conditions, the use of nitrogen fertilizer is too late, excessive, the field water is too deep, long-term retention, etc. is beneficial to the disease.
The control of rice sheath blight should be based on agricultural measures and combined with chemical control. (1) Grasp the cultivation and disease prevention centered on the management of fertilizer and water. The fertilizer should pay attention to the steady application of nitrogen and phosphorus, and increase the application of potassium and zinc fertilizer. In order to apply the base fertilizer and ensure the panicle fertilizer, it is not appropriate to apply nitrogen fertilizer to raise seedlings in the middle of rice growth. The principle of “pre-shallow, medium-sun, and post-wet†should be implemented in irrigation. (2) The prevention and treatment of pesticides is mainly to protect the last 3 to 4 leaves of rice plants, and the application should not be too early (before jointing) or too late (after heading period). Pharmacy selection: 5% Jinggangmycin water 150 ml per mu or 12.5% ​​Moulds clear water 100-200 ml, or 20% sclerotin suspension 60-100 ml or 15% rust WP WP 50 g, Spray 50-70 kg of water. When spraying, ensure the water consumption and spray it into the rice plant and base.
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