County Shengxin Metal Products Co., Limited , http://www.hbwire-mesh.com
If the corn is used, the application of dichlorvos, trichlorfon, phoxim, 2.4-D, etc., or excessive application may result in harmful symptoms; such as 2.4-D applied or drifted. The leaves can be curled into onion leaves, the lower stems and leaves are clustered together, and the aerial roots are not in contact with the soil; excessive application of phoxim can whiten the leaves partially or mostly, causing the leaves to dry and freeze like a freeze. Use pesticides or herbicides, above a certain concentration, can form abnormal color of the leaf class, such as white spots or brown spots, young shoots and roots curled or thickened, plant growth is inhibited, the leaves are shortened or the grains are exposed; fertilizers at the time of sowing Excessive use of pesticides or insecticides will always cause the seeds to germinate or die after they are unearthed, the remaining seedlings are dwarfed, and the leaves turn yellow or die. Excessive application of chemical fertilizers, such as soluble nitrogen, potassium and Other fertilizers close to the seed, will inhibit seed germination or death after emergence of seedlings; organophosphorus pesticides such as phoxim produce discoloration and other phytotoxicity is hydrophobic organic phosphorus The pesticide is adsorbed by the green leaf body or surrounding tissues, causing the chloroplast function to stagnate, thereby hindering the electron conduction reaction, ie, the Hill reaction, inhibiting photo synthesis, discoloration, the more serious the phytotoxicity, the reduction of carbohydrate content in the body, and the total nitrogen content. Relative increase.
Production is different due to conditions such as corn variety, developmental stage and environmental factors. Different degrees of phytotoxicity will cause the leaves to die, discolor, deformity and so on.
Second, prevention and treatment methods:
1. Formulated fertilization technology, timely and appropriate application, not excessive.
2. When using herbicides, strictly select the variety and master the dosage, avoid the concentration is too high, and should not be sprayed directly in the flare period.
3. Do not use sensitive insecticides such as trichlorfon and dichlorvos in corn fields. Strictly control the dosage when applying phoxim to control underground pests.
4. If the concentration is too high, it should be watered immediately.
5. After the occurrence of phytotoxicity, it is necessary to strengthen management.
6. If necessary, spray the Fengbao I type active liquid fertilizer 400~500 times.
Author: Da'an City, Jilin Province town of Long marsh Xin agricultural science school
First, sensitive drugs and phytotoxic symptoms
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