Application of botanical insecticides

Common chemicals have varying degrees of drug damage to vegetables and fruits, such as omethoate should not be used 30 days before harvest, malathion is harmful to melons and peaches, fenitrothion is harmful to cruciferous plants, and fruits and vegetables should not be used 15 days before harvest. Dichlorvos should not be used a week before fruit trees and vegetables are harvested. Therefore, the use of pesticides is prohibited in the flowering period of fruit trees and vegetables, and botanical pesticides should be vigorously promoted. Now the relevant botanical pesticides are introduced as follows: first, Portulaca oleracea alias horse tooth, and so on. Annual fleshy herbs. Stem recumbent or oblique upward, branched by base, Terete, up to 30 cm long, light green, sunny often brownish red, smooth and glabrous. Leaves alternate, sometimes opposite, Bing extremely short, leaf blade fleshy, Obovate, entire, 1-3 cm long and 5-14 mm wide, stipules small, scarious, flowers bisexual. The insecticidal rate of Portulaca oleracea to soybean aphids was 46.9%. Second, open hemp alias hole tooth root and so on. Perennial herbs. The rhizome is thick, curved, with several stem scars, commonly known as holes, black on the surface, gray-white on the cross section, erect stem, simple, 1-1.5 m high, lower cauline leaves with long stalks, base slightly expanded into sheath-shaped, large-shaped 2-3-Ternate compound leaves or 2-Ternate compound leaves, leaflets ovate, acuminate, terminal leaflets often 3-lobed and pinnately notched, lateral leaves with irregular coarse serrate margin, often pinnately notched or lobed. The upper leaves are smaller. Use 14 grams of whole grass to 300 ml of water, boil for 1 hour, filter and spray vegetable aphids, the insecticidal effect is 57%. Third, pulsatilla perennial herbs. Up to 50 cm tall, the whole plant is densely whitish pilose, the root conical, thick and straight. Basal leaves numerous, Ternate, long stipitate, leaf blade broadly ovate, central lobe stipitate, 3-parted, lobes 2-3-parted. Pulsatilla 500 grams plus 5 kilograms of water, boil or soak for 1 day, after filtration can control ground tigers, aphids and other soft pests. Fourth, white chrysanthemum is also known as Coptis chinensis, broken intestines grass and so on. Perennial herbs. 30-80 cm tall, main root slender, much branched, khaki or dark brown, dense fibrous root, stem erect, much branched, slender white pilose, red-yellow sap in the body, leaves alternate, 1-pinnately parted, basal leaves 10-15 cm long, leaflets 5-8 pairs, tapering from top to bottom, apical leaflet broadly Obovate, apex obtuse, margin irregular. The main results are as follows: (1) 1.5 kg of white koji, 0.5 kg of lime, 3 kg of water and boiling for 1 hour are used for the control of cabbage insects, and the insecticidal rate is up to 70%. (2) the whole grass is cut at flowering stage, dried in the shade, rubbed into powder and sprinkled on the vegetable field, which has a special effect on ground fleas. (3) it is effective to control aphids and beetles by drying 800 grams of whole grass and soaking in 5 kg hot water for 1-2 days. Fifth, dragon tooth grass alias fairy crane grass and so on. Perennial herbs. Up to 30cm to 70cm, all with white long hairs and glandular hairs. The rhizome develops, with slender fibrous roots, and a conical white bud curving upward from the end of autumn. Stem erect, angled, upper part branched. Odd-pinnately compound, alternate, with basal leaves, apex acute or long acuminate, base cuneate, margin coarsely serrate. The effect of whole grass mashing plus 21 kg of water, filtration and residue spraying on the control of aphids reached 70%. In addition to the above-mentioned plants, there are other common wild plants in the forest, such as solitary plant, Pinellia ternata, transparent bone grass, northeast mint, northeast gentian, egg leaf peony, Xanthium sibiricum, etc., which are rich in resources, widely distributed and convenient to use. no pollution, no drug harm, it is worth popularizing.