What are the key points for pollution-free control of white rust in water spinach?
Symptoms: The lesions appear on the underside of the leaves. On the upper surface of the leaves, pale yellow to yellow spots first appear, then gradually turn brown. The lesions expand, and on the underside of the leaves white raised blister-like spots form, nearly round or oval to irregular in shape, sometimes merging into larger blisters. In the later stage, the blisters rupture and release white sporangia. When the leaves are severely affected, the lesions are dense and the diseased...
Symptoms: The lesions appear on the underside of the leaves. On the upper surface of the leaves, pale yellow to yellow spots first appear, then gradually turn brown. The lesions expand, and on the underside of the leaves white raised blister-like spots form, nearly round or oval to irregular in shape, sometimes merging into larger blisters. In the later stage, the blisters rupture and release white sporangia. When the leaves are severely affected, the lesions are dense, the diseased leaves become deformed, and the leaves fall off.
Key points for control:
(1) Use disease-free seeds or dress the seeds with 0.3% of the seed weight of ridomil-mancozeb.
(2) This disease is limited to infecting vegetables of the Convolvulaceae family. A 2-3 year crop rotation gives good disease control results.
(3) Pay attention to field drainage and thinning plants for ventilation.
(4) At the early stage of the disease, spray 48% metalaxyl-mancozeb wettable powder, 40% metalaxyl-copper wettable powder, or 64% oxadixyl-mancozeb wettable powder at 600 times dilution, or 72.2% propamocarb aqueous solution at 800 times dilution, once every 7-10 days, for 2-3 consecutive applications.