Integrated control of cotton bollworm in apple nursery

The hazards of cotton bollworm in apple nursery are mainly concentrated in July-August, and the occurrence of nursery mites in crops such as wheat, corn and vegetables is severe. The hazard of cotton bollworm in nursery nursery begins with feeding the newly grafted buds, causing dead buds and reducing the grafting survival rate. When the grafted seedlings grow rapidly, they feed on the young shoots and young leaves of the scion, affecting the scion. The growth rate, the occurrence of bifurcation and even the phenomenon of "sweeping seedlings", thus reducing the quality of seedlings. The main measures for its prevention and control are:

First, the winter deep turn over the characteristics of cotton bollworm in winter in the soil for wintering, before the freezing of the early winter, combined with the application of organic fertilizer to deepen the soil of the nursery, so that the organic fertilizer can be turned into the ground, increase soil organic matter, ripening In the soil, the wintering insects in the soil can be turned out to be frozen or eaten by birds, thereby reducing the number of cotton bollworms in the nursery in the coming year.

Second, the drug control The control of cotton bollworm in apple nursery is mainly based on chemical control. Adults of the first generation of Helicoverpa armigera usually appear in the upper and middle of June, and lay eggs in the apple seedlings in late June. At this time, it is better to use the 1200 times of Qingfeng No. 1 chemical control effect. Other preventive agents include 2000 times 2.5% Uranus EC, 2000 times 2.5% Kungfu EC, 1500 times 5% Fuling, 4000 times killing mites and 1500 times methomyl. Helicoverpa armigera occurs in 3 to 4 generations in 1 year. Generally, from July, larvae of different ages endanger the young shoots and young leaves of apple grafted seedlings in nursery. Therefore, it should be sprayed once every 10 days from the end of June. After the end of August, the application of the insecticide can be gradually reduced.

Third, the trap of adult insects In order to reduce the number of insects in the apple nursery, according to the habit of the cotton bollworms, the method of trapping adult insects can be used. Adults of cotton bollworms are most active at 7 to 9 pm and 3 to 5 in the morning. In the small-area nursery field, the cotton bollworm adults are used to gather the newly withered poplar branches, and the poplar branches are tied into the ground, and 10 per acre are inserted to induce adult insects. Use a plastic bag cover to pounce moths before sunrise every day. According to the situation, the poplars should be replaced once a week for 3 to 4 weeks. In large-area nursery fields, according to the phototaxis and chemotaxis of adult insects, install 1 black light every 20 mu, turn on the lights overnight, place 1 pot of water at 10~15cm under the lamp, add a small amount of kerosene to the water surface, and put the pot in the morning. The adult is fished out.

Fourth, biological control Large-area seedlings, can also be used to release Trichogramma or spray Bt preparation method for cotton bollworm control. If necessary, manual squeezing of larvae can also be used to reduce the damage of cotton bollworms.

Jia Dongmei Wang Ruibao (Golden Tree Station, Jiaozhou City, Shandong Province 266300)

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