First, the symptoms of damage: soybean cyst nematode disease mainly damage soybean root tip. The bean root was stimulated by nematodes to form nodular tumors. The roots of the diseased plants were found to be underdeveloped and the root nodules were sparse. White or yellowish-white granules, the nematode cysts, were seen in the roots, and the cysts became darker in color and brownish in the later cysts. The tumors range in size from one size to the other, some are as small as grains, some form "root clusters," rough surfaces, and nematodes in the tumor. The diseased plants were short and the leaves were yellowing. When the plants were severe, the plants wilted and died. The fields were yellow, green and green, and they were uneven.
Second, the route of transmission and disease conditions: soybean root-knot nematodes eggs winter in the soil, tapeworm soil is the main source of primary infection. On soybeans, the optimum temperature for reproduction is 24～35°C. Soybeans have 3 to 4 generations in one season. The first generation is the most serious one. It is a type of settled nematode, which is invaded by new roots. The temperature is suitable for invasion at any time. Continuous cropping of soybean fields is heavy. Acidic or neutral soils are suitable for nematode reproduction. Sandy soil and infertile land facilitate nematode disease III. Comprehensive prevention and control measures
1. Rotation: 3 years or more of rotation with non-host plants.
2. Appropriate no-tillage: No-tillage can reduce the spread of the disease, thereby reducing the incidence.
3, selection of anti-nematode disease varieties according to local conditions. It is not advisable to use the same resistant variety in the same area for a long period of time.
4. Chemical control (1) Seed dressing: Use 1.5% of the seed weight of 1.5% Mycelia Granules, sifting 100-200 times wet soil, and sow directly after seed dressing.
(2) Soil treatment: It is required that the chemical be applied to the soil of 20 cm in the surface layer and be practically layered with the seeds. Per acre can be used 5% methicillin phosphate granules 8 kg, or 15% aldicarb Granules 0.7-1 kg, or 5% phorate granules 8 kg, or 10% aldicarb Granules 2.5-5 kilogram. Ditch 15-20 days before sowing and mix with fine soil and apply to soil. Note: The application amount should be strictly controlled so as to avoid phytotoxicity. The above pesticides have relatively high toxicity, and it is forbidden to use water to make a direct spray of suspension.
Second, the route of transmission and disease conditions: soybean root-knot nematodes eggs winter in the soil, tapeworm soil is the main source of primary infection. On soybeans, the optimum temperature for reproduction is 24～35°C. Soybeans have 3 to 4 generations in one season. The first generation is the most serious one. It is a type of settled nematode, which is invaded by new roots. The temperature is suitable for invasion at any time. Continuous cropping of soybean fields is heavy. Acidic or neutral soils are suitable for nematode reproduction. Sandy soil and infertile land facilitate nematode disease III. Comprehensive prevention and control measures
1. Rotation: 3 years or more of rotation with non-host plants.
2. Appropriate no-tillage: No-tillage can reduce the spread of the disease, thereby reducing the incidence.
3, selection of anti-nematode disease varieties according to local conditions. It is not advisable to use the same resistant variety in the same area for a long period of time.
4. Chemical control (1) Seed dressing: Use 1.5% of the seed weight of 1.5% Mycelia Granules, sifting 100-200 times wet soil, and sow directly after seed dressing.
(2) Soil treatment: It is required that the chemical be applied to the soil of 20 cm in the surface layer and be practically layered with the seeds. Per acre can be used 5% methicillin phosphate granules 8 kg, or 15% aldicarb Granules 0.7-1 kg, or 5% phorate granules 8 kg, or 10% aldicarb Granules 2.5-5 kilogram. Ditch 15-20 days before sowing and mix with fine soil and apply to soil. Note: The application amount should be strictly controlled so as to avoid phytotoxicity. The above pesticides have relatively high toxicity, and it is forbidden to use water to make a direct spray of suspension.