Vegetable spray to prevent pests

When planting vegetables, insect pests are one of the important factors that hinder the normal growth of vegetables. There are many kinds of vegetable pests, and the living habits of each type of pests are different. Generally, they can be classified into three categories: sucking juice, food leaf and drill collar. .
1. Controlling drill collar pests such as rapeseed must be sprayed at the peak of egg hatching.
2, sucking aphids and some leaf-feeding pests are concentrated in the host's leaf back and twig damage, should be sprayed in a "dotted circle" way, that is, the nozzle of the sprayer first sprays the leaves of the plant, then The buckle is sprayed on the tender head, so that the plant and the worm are all in contact with the medicament, and a better control effect is obtained. The older larvae of Spodoptera litura and Spodoptera exigua are concealed during the day, so spraying the pests during the growing season should be carried out in the evening.
3, the host's growth characteristics are different, the spraying time and method are also pay attention to. Summer cowpea blooms from 7:30 to 10:30 in the morning. After this time, the petals are all closed. The first instar larvae of the cowpea are concentrated on the flower buds, petals or stalks and receptacles. Spraying at 9:00 am The behavior is appropriate, so that the worm can be more fully exposed to the agent.
4. The leaves of cabbage vegetables are covered with a layer of wax powder. When the biological insecticide Bt is used to control cabbage caterpillars, 0.1% detergent powder solution should be added to the liquid to reduce the surface tension and evenly distribute the liquid in the leaves. Improve the effectiveness of the control.