Characteristics and Control Methods of Garlic Gray Leaf Spot
(1) Symptom characteristics: It mainly affects the leaves. The lesions are long elliptical, initially light brown, later turning grayish white. On both sides of the leaves, the lesions produce fine grayish-black mold-like growth. In severe cases, the lesions merge, causing localized death of the leaves. The disease is severe in weather with warm days and cool nights, heavy fog, and heavy dew. (2) Control methods: ① Promptly remove damaged leaves...
(1) Symptom characteristics: It mainly affects the leaves. The lesions are long elliptical, initially light brown, later turning grayish white. On both sides of the leaves, the lesions produce fine grayish-black mold-like growth. In severe cases, the lesions merge, causing localized death of the leaves. The disease is severe in weather with warm days and cool nights, heavy fog, and heavy dew.
(2) Control methods
① Promptly remove damaged leaves.
② Strengthen field management, maintain rational close planting, drain promptly after rain, and improve host disease resistance.
③ At the early stage of disease onset, spray 75% chlorothalonil wettable powder at 600 times dilution, 50% iprodione wettable powder at 1500 times dilution, 64% oxadixyl mancozeb wettable powder at 500 times dilution, 60% phosethyl-Al wettable powder at 500 times dilution, or 1:1:100 Bordeaux mixture, alternating the chemicals once every 7-10 days, for 3-4 consecutive applications.
Note: Harvest and market after the pesticide pre-harvest interval.