What chemicals are used to control white rust in water spinach?
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, 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, 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, heavy fog and dew, and sticky, wet soil conditions favor the occurrence and spread of this disease.
III. Control methods
(I) Use disease-free seeds and seed treatment: select a disease-free plot for seed production; soak newly purchased seeds in warm water at 50°C for 25 minutes, then cool and sow.
(II) Strengthen garden 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 plot become too wet. When diseased plants are found, pull them out promptly and bury them. After harvest, thoroughly remove diseased plant residues, dispose of them centrally, and carry out deep plowing to reduce sources of inoculum.
(III) Chemical control: spray in the early stage of the disease, once every 7-10 days, for 3-4 consecutive sprays. Commonly used chemicals 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, M8 wettable powder at 500 times dilution, and 66.5% propamocarb aqueous solution at 700-1000 times dilution.