Control methods of Cotton aphids

Cotton aphid is one of the main pests of cotton. Five kinds of aphids have been found, including cotton aphid, cotton long tube aphid, alfalfa aphid, jujube aphid and bean root aphid. Cotton aphid is one of the most important pests in cotton in China. The cotton area in the Yellow River valley and Liaohe River valley is the most harmful, followed by the Yangtze River valley cotton area. Let's take a look at the control methods of cotton aphids.

Symptoms of cotton aphids

Cotton aphids occur 20-30 generations a year in southern China and 10-20 generations a year in northern cotton areas. In most parts of the country, eggs overwinter on hibiscus, pomegranate, prickly ash and holly, insert the back or tender part of cotton leaves with piercing mouthparts, suck the juice, the damaged leaves curl to the back, and there is honeydew excreted by aphids on the leaf surface, which often breeds mold, and the plants become dwarf, leaves become smaller and the number of leaves decreases after damage. The appearance of bud is late, the number of buds and bolls is reduced, and so on.

Agricultural control of cotton aphids

1. Planting insect-resistant varieties is an effective measure to control cotton aphids, such as planting 372 and so on.

2. Intercropping can increase the species and number of natural enemies and control the damage of aphids, such as cotton-wheat intercropping, cotton intercropping with mung bean and green manure, flower arrangement and trapping crops such as corn, rape, sorghum and so on.

3. Flood-drought rotation can reduce the occurrence of cotton aphid, and cotton and rice rotation can be carried out where conditions permit.

4. Deal with the overwintering host, reduce the source of aphids in early spring, and generally remove weeds inside and outside the cotton field before the cotton seedlings are unearthed. It is possible to control the overwintering hosts of Zanthoxylum bungeanum, pomegranate, hibiscus and holly, which can reduce the number of aphids in cotton field.

Chemical Control of Cotton aphids

1. Seed dressing: before sowing, cotton seeds per mu and 3% furan granule 1.5-2kg, mix evenly, or mix seeds with Tiemike (also known as aldicarb), with 50 grams of active ingredients per mu, aphid damage can be controlled for 40 days. Seed dressing with 3911 (methamidophos) emulsion or granule or seed coating agent has a good effect.

2. Spray: dilute 1000-1500 times spray with 50% monocrotophos, 50% phoxim, 40% omethoate, 40% aphids, 35% aphids, 50% phosphoramines and so on.

3. Heart dripping: 80% 100 times diluted with 40% omethoate emulsion or 40% monocrotophos or 50% methamidophos emulsion, and the aphid damage can be controlled by dropping the solution on the top of cotton seedlings with a sprayer.

4. Stalk coating: the stem coating agent is prepared with 40% omethoate emulsion or 40% monocrotophos or 50% methamidophos emulsion, polyvinyl alcohol and water according to the proportion of 1-0. 1-1-5. With a device similar to a brush, the solution is applied to the purple-green part of the cotton stem, and the aphid prevention effect is more than 90%.