What to Do When Water Spinach Gets White Rust? A Detailed Guide to Prevention and Control Methods
First, implement a 2-to-3-year crop rotation with other vegetable varieties. Second, before sowing, dress the seeds for sterilization at a ratio of 300 g of 35% metalaxyl per 100 kg of seeds; third, in the early stage of the disease, spray with 50% copper metalaxyl wettable powder at 6000 to 7000 times dilution, or with 72.2% propamocarb aqueous solution at 8000 times dilution, applying once every 7 to 10 days...
First, implement a 2-to-3-year crop rotation with other vegetable varieties.
Second, before sowing, dress the seeds for sterilization at a ratio of 300 g of 35% metalaxyl per 100 kg of seeds; third, in the early stage of the disease, spray with 50% copper metalaxyl wettable powder at 6000 to 7000 times dilution, or with 72.2% propamocarb aqueous solution at 8000 times dilution, applying once every 7 to 10 days. Reinfection. Rainwater and insects can also spread it; whether seeds can transmit it remains to be studied. Cool and humid nights, warm days, dense fog and heavy dew, and sticky, wet soil conditions are favorable for the occurrence and spread of this disease.
III. Prevention and Control Methods
(I) Select disease-free seeds and treat seeds: select a disease-free plot for seed production; soak newly purchased seeds in 50°C warm water for 25 minutes, then sow after cooling.
(II) Strengthen garden and field management: choose a plot with high terrain, good drainage and good ventilation for planting. Apply sufficient fertilizer and increase the application of phosphorus and potassium fertilizers. Irrigate reasonably and do not let the onion field become too wet. If diseased plants are found, pull them out and bury them promptly. After harvest, thoroughly remove diseased plant residues, dispose of them in a centralized manner, and carry out deep plowing to reduce sources of the pathogen.
(III) Chemical control: spray pesticides in the early stage of the disease, once every 7-10 days, for 3-4 consecutive sprays. Commonly used pesticides include 1:1:240-300 Bordeaux mixture, 40% fosetyl-aluminum wettable powder at 200-300 times dilution, 25% metalaxyl wettable powder at 500-1000 times dilution, 75% chlorothalonil wettable powder at 500-600 times dilution, 65% zineb wettable powder at 500-700 times dilution, 64% oxadixyl + mancozeb, M8 wettable powder at 500 times dilution, and 66.5% propamocarb aqueous solution at 700-1000 times dilution.