symptoms:
Warm and cool nights, rainy and high humidity weather are conducive to the occurrence of the disease. At the beginning of the disease, it produces pale green water-stained small spots, and then turns into yellow-brown to brown large spots, which are limited by leaf veins and appear spots, the leaf dorsal spots are slightly raised, and when the humidity is high, the surface of the spots is thick and dark gray mold, that is, the sporangia and sporangia of pathogenic bacteria. Symptoms are not obvious in dry weather.
Prevention and control methods:
1, the implementation of rotation, the choice of moderate height, easy drainage and irrigation of the field block, autumn and winter deep turning, apply enough rotten organic fertilizer, the use of high ridge or half high ridge planting; timely cultivation, whole branches, remove diseased fruits, diseased leaves.
2. At the beginning of the disease, spray 66.8% Prosen Valerella wettable powder 600-800 times liquid, or 52.5% fast water purification dispersible granules 1500 times liquid, or 70% manganese zinc and ethyl aluminum wettable powder 500 times liquid, or 70% propensian zinc wettable powder 600 times liquid, or 72.2% downy mildew water agent 600 times liquid, or 60% fluoromex zinc wettable powder 800 times liquid, or 69% manganese zinc enoyl wettable powder 600 times liquid.
Root-knot nematodes develop at a suitable temperature of 25-30 ° C, the larvae lose their ability to live when they encounter low temperatures of 10 ° C, and die at 48-60 ° C after 5 minutes, survive in the soil for 1 year, and all die in 2 years. The disease occurs mainly in the root of eggplant, especially the branch root. Many near-spherical nodules are formed on the roots, like candibals connected to each other, the initial surface is white, then brown or black, the upper part of the ground is atrophied or yellowed, and it is easy to wilt or wilt when the weather is dry.
1. Advocate the application of organic active fertilizer or bio-organic compound fertilizer, and rational crop rotation.
2. Root-knot nematodes are mostly distributed in the topsoil layer of 3-9 cm, and deep turning can reduce the damage.
3. Nematodes occur during the growth of eggplant, and field management should be strengthened, and the disease residue should be thoroughly treated, and burned or buried deeply. At the same time, fertilize or irrigate reasonably to enhance host resistance. It can be irrigated with 2000 times liquid liquid with 48% toxic and spicy emulsion, which can also treat underground pests that eat roots.
Harmful features:
The larvae feed on leaves and young stems. Adults are light greyish brown. The baseline and outer transverse line are black, jagged, with gray-yellow bands in between, with a dark brown spot. The outer transverse line of the hindwing is greyish yellow within the outer transverse line and also has a dark brown spot. The old mature larvae have a brownish-green head and a pair of black spots on the sides of the top of the head. The body is yellowish-green , with dark brown spots on the 3rd and 4th segments of the abdomen. The thorax is brown, the gastropods are yellow-green, and the ends of the feet are black.
1. Seize the peak period of egg hatching to the peak of 2 years old, that is, the larvae are not mothed into the fruit before the drug is applied. The agent can be selected from 25% cicada lice net suspension 550 times liquid, or 48% poison xin emulsion 2000 times liquid, or 1.8% avermectin emulsion 3500 times liquid, or 15% amperamine suspension 4000-5000 times liquid, or 5% fiproclamide emulsion 1500 times liquid, or 20% stubborn insect emulsion 1500 times liquid, or 10% cypermethrin emulsion 1500 times liquid.
2. Grasp the pupae stage of the old mature larvae into the soil, and spray the soil with 48% toxic xin emulsion 2000 times liquid, which can reduce the source of pests, but it is generally suitable for use 40 days before fruit picking.
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