Control methods of diseases and insect pests of lotus root caused by brown spot and black spot rot and wilt virus

Field management of lotus root

First, lotus root brown spot. One of the common diseases in the lotus leaf is a light brown spot on the leaf, causing local dryness. Prevention and treatment: reasonable close planting to ensure ventilation and light penetration of lotus root field; appropriate application of phosphorus and potassium fertilizer to improve lotus root resistance and timely removal of diseased and residual plants. At the initial stage of the disease, spray with 1000 times of 25% carbendazim or 75% chlorothalonil.

Second, black spot of lotus root. Brown streak, also known as brown streak, occurs only on leaves. In severe cases, the disease spots converge and the leaves are withered and yellow. Prevention and treatment: thoroughly remove the diseased and residual leaves in the field and burn them in winter. In the early stage of the disease, the diseased leaves were removed and sprayed for prevention and treatment. Use 1000-fold solution of 70% methyl topiramate or 65% Dysenz 600x solution or 1mer 1mer 160Mel 200x Bordeaux solution, spray once every 10ml 15 days, for a total of 2mi 3 times.

Third, lotus root rot. Also known as Fusarium wilt, infects the underground stem, causing rot, when serious, the whole field is withered and yellow, like a fire. Prevention and treatment: seriously diseased fields, 2-3 years of rotation. Spray the seeds with 1000 times of methyl topiramate or 75% chlorothalonil, cover the agricultural film for 24 hours, dry and plant. Turn the lotus root field deeply and apply 150 kilograms of lime per mu. When you get sick, mix well with 0.5 kg 75% chlorothalonil and 30 kg dry soil and sprinkle it into a shallow paddy field.

Fourth, lotus root streak virus disease. The damaged lotus leaves and underground stems can show symptoms, with large polygonal to irregular light brown spots on the leaves and dark brown anthrax spots on the rhizome epidermis. Prevention and treatment: select disease-resistant varieties, timely control aphids (transmission vector), at the initial stage of the disease, spray 1.5% Zhishanling emulsion 1000 times.

Fifth, Fusarium wilt of lotus leaf. The damaged lotus leaves were scorched and withered, which affected the growth of lotus root and reduced yield. Prevention and control: keep the lotus root field clean and prevent oil pollution. Sewage and soapy water can also cause lotus leaves to wither. Lotus root is sensitive to herbicides and herbicides should never be used in lotus root fields.

6. Common diseases and insects. There are aphids, large coir moth, pear green moth, brown thorn moth, harmful to standing leaves and buds. Spray with 90% trichlorfon 800ml 1000 times or 40% dimethoate 2000 times. Water maggots suck the juice from the roots, stems and leaves of lotus roots, causing lotus leaves to turn yellow. once found, they can be killed with lime at a dosage of 10 Mu and 15 kg per mu.