In the later stage of late rice, rice planthoppers are difficult to treat, and it is difficult to occur in many peaks. In the late stage, paddy fields have no water layer, and it is difficult for the liquid to contact the rice worm body effectively, and the late rice planthopper is resistant to the drug. Therefore, it is necessary to change the prevention and treatment methods in a targeted manner.
Insect pests were treated at the younger stage of nymphs. When rice planthoppers become old nymphs and adults, drug resistance will be significantly enhanced. Therefore, it is necessary to pay attention to the field survey and seize the low-age drug for nymphs. In the younger age of nymphs (larvae) (without long wings or just appearing wing buds), the best control effect is at peak period. In the late late rice hybrid rice, there were 1500-2000 nymphs and one or two instar larvae per 100 instars (1000 to 1500 larvae of conventional rice and 2nd instar nymphs), or four or five instar nymphs per 100 instars (its size was close to that of adults). To be listed as a control object.
Change the blind use of drugs for targeted drugs. To prevent the late rice planthopper in late rice, 20-25 grams of buprofezin (Ultrad, Prazomide) is generally sprayed on the water at 2500-3000 times. For older larvae, it can be sprayed with 20% to 3,000 times of 10% chlorhexidine EC. For paddy fields where nymphs and adults are relatively severe, a combination of buprofezin (a single dose produced by Suqian Pesticides Plant) and 10% peothroblastic emulsion (or a combination of knock-down strong dichlorvos) can be used.
Change the fine mist spray to coarse spray. Late rice, liquid medicine is difficult to enter the base of the rice plexus, to increase the amount of liquid medicine, and the use of coarse spray (removal nozzle), try to make the liquid into the base of the rice plexus. Generally, the amount of liquid used per mu is 70-80 kg. Penetrate the lower part of the plant. If the paddy field is dry, use 10% pequorate EC 30g per mu, or 25% buprofezin 25g water 300kg, and put it in a dung-drum and apply it to the base of the rice paddy using a scoop. Before the application, it is best to chase in widths in accordance with the width of 2.5 meters (heading period should not be rushed, should be carried out after the milk period), the formation of operation, easy to apply the liquid to the base of the rice paddy, in order to facilitate contact with insects body. If it is possible to use an aquifer, it is best to store a shallow water layer about 7 centimeters deep when applying pesticides. Do not release the water outside the field within 3-4 days after application, and do not put water into the field. After 3-4 days, Only drain water, or allow it to dry naturally.
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