Cucumber angular leaf spot causes yield loss, how to prevent and control it?
Cucumber angular leaf spot is a bacterial disease, caused by infection with Pseudomonas bacteria. Cucumbers can be infected throughout the entire growth period, with yield losses of 10%-30%. Control methods:
Cucumber angular leaf spot
1. Seed treatment: practice a rotation of cucumbers with non-cucurbit vegetables for more than 2 years. Choose disease-resistant cucumber varieties. Collect seeds from disease-free land or disease-free cucumber plants. Cucumber seeds can be soaked in 55°C warm water for 15 minutes, or soaked in 3000-fold diluted new streptomycin solution for 2 hours, or soaked in 150-fold diluted formalin solution for 1.5 hours.
2. Strengthen management: cultivate disease-free strong seedlings. In protected cucumber cultivation, ventilate in good time to reduce humidity. After the disease appears, control watering. In open-field cultivation, use high ridges covered with film, and remove diseased and dead leaves promptly.
3. Biological control: at the early stage of the disease, use 72% agricultural streptomycin soluble powder, or 4000-fold diluted new streptomycin solution, or 100-fold diluted Nongkang 120 (pyrimidine nucleoside antibiotic) aqueous solution, once every 6-7 days, spraying 3-4 times in succession.
Spraying: at the early stage of the disease, alternately spray 300-fold diluted 12% copper abietate emulsifiable concentrate, 800-fold diluted 38% oxadixyl-cymoxanil-copper fungicide (control efficacy up to 93%!) aqueous solution. If it occurs simultaneously with downy mildew, choose 77% copper hydroxide wettable microparticle powder, 58% metalaxyl wettable powder, 50% metalaxyl-copper wettable powder, 56% azoxystrobin-chlorothalonil emulsifier, 49% kasugamycin-copper wettable powder, 60% baijuntong wettable powder, etc., sprayed at 500-fold dilution, once every 6-7 days, spraying 3-4 times in succession.
Dusting: at the early stage of the disease in protected cucumber cultivation, dust with 5% kasugamycin-copper dust, or 5% antibacterial dust. If it occurs simultaneously with downy mildew, dust with 12% ethirimol-dichlorvos dust, or use 7% meifengling dust + 5% antibacterial dust, applying 1 kg per mu of cucumbers each time, once every 7 days, dusting 3-4 times in succession.