Occurrence and Control Methods of Burdock Fruit Diseases

1. Aphids: Adults and nymphs occur at the seedling stage and the budding stage, sucking sap. Stems, leaves, flowers and fruits can all be infested, affecting the normal growth and development of the plant.

Control method: When they occur, spray with 40% dimethoate 800-fold solution, 8% dichlorvos emulsion 2,000-fold solution, or lime-tobacco water.

2. Ctenoplusia agnata: The larvae chew the leaves, causing notches and holes, affecting the normal growth and development of the plant.

Control method: Spray with 50% phosphamidon emulsifiable concentrate 1,500-fold or 90% trichlorfon 800-fold solution, once every 7-10 days, for several consecutive applications.

3. Leaf spot disease: In July and August, during high-humidity and rainy seasons, it occurs frequently. Irregular yellow-green lesions appear on the lower leaves, later turning light brown, which can cause all the leaves to dry up and fall off.

Control method: When diseased leaves are found, remove and burn them immediately. In the early stage, spray Bordeaux mixture at 1:1:150, once every 5-7 days, for 2-3 consecutive applications.

4. Powdery mildew: It occurs easily when it is humid and ventilation and light are poor. After onset, a layer of grayish-white powder appears on both sides of the leaves, then black spots develop, and finally the leaves all dry up and fall off.

Control method: Pay attention to ventilation and light penetration in the field, remove diseased leaves and burn them, and spray 0.3-0.5 degree Beaume lime-sulfur mixture, once every 7-10 days, for 3-4 consecutive applications.