Brassica napus threatens the life of rapeseed. If it is not well controlled, it will bring great harm to rapeseed production. Therefore, it is very important to control locusts at various growth stages of rapeseed.
1, seedling stage: aphids suck more juice in the back of the leaf, resulting in stagnant growth of the seedlings, and even death, then cure, radical cure. It can be sprayed with 40% dimethoate 1000 times or 2.5% deltamethrin 3000 times. Seedlings should be sprayed once in the early morning before the dew on the seedlings. Before transplanting, the seedlings should be soaked in 40% dimethoate 2000 times for 2-5 minutes to prevent the locusts from entering the field with the seedlings. .
2. Wintering period: If the seedlings are transplanted to Daejeon with aphids, the radish sprouts will lurk in the heart and leave the winter. Peach hawksbill generally hides on the back of the leaves that are close to the soil for the winter. At this time, 40% dimethoate can be used to dilute 75 kg of water in 100 ml, or 5% of malathione emulsion can be used to control 800 times.
3, convulsions period: 3-4 months rape began to convulsions, locusts first gathered to the main branch of the bud damage, and later with the branch hair and divergence to the various branches of buds, pedicels, vegetables on the damage. Generally in the main branch of the bud early with 40% Dimethoate 2000 times spray treatment, can also be used 0.5 kg detergent and 1 kg of urea water 100 kg spray.
4, flowering period. At this time, most of the locusts cluster on the buds, pedicels, or pedicels to suck juice, causing the flowers to have no pods, or the seeds in the pods are not full. It can be controlled with 20% sterile ester 800 times or 2.5% deltamethrin 2500-3000 times. (Henan Xue Jinshan)