How to prevent and control angular leaf spot of winter melon? First, recognize the disease symptoms
Symptoms: It mainly affects leaves, petioles, and fruit. It can be affected from the seedling stage to the mature plant stage. When true leaves are infected, bright green water-soaked spots appear first, gradually turning light brown; the lesions are restricted by leaf veins and become polygonal, yellow-brown, and when humidity is high, milky white cloudy water-drop-like bacterial ooze exudes from the underside of the leaves, and the diseased tissue is brittle and easily perforated. When stems and petioles are infected, ...
Symptoms: It mainly affects leaves, petioles, and fruit. It can be affected from the seedling stage to the mature plant stage. When true leaves are infected, bright green water-soaked spots appear first, gradually turning light brown; the lesions are restricted by leaf veins and become polygonal, yellow-brown, and when humidity is high, milky white cloudy water-drop-like bacterial ooze exudes from the underside of the leaves, and the diseased tissue is brittle and easily perforated. When stems and petioles are infected, small water-soaked spots appear at the infection sites and extend longitudinally along the stem grooves, forming short streaks, and bacterial ooze is also seen when humidity is high. When fruit is infected, small water-soaked spots appear, and after expansion they become irregular or merge into patches; a large amount of dirty white bacterial ooze exudes from the diseased area, and the pathogen invades the seeds, causing seed contamination.
Control methods: In the early stage of the disease, spray with copper hydroxide suspension concentrate or copper oxychloride wettable powder or agricultural streptomycin diluted with water, once every 7-10 days, for a total of 2-3 sprays.