Help, all of my older cucumber leaves have these yellow / brown spots on them.
38+ Brown Spots On Cucumber Leaves. If the condition does not go away with improved cultural spotty situation. Your cucumber plant may be infected by bacterial, viral, and/or fungal pathogens.
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When the bottom leaves of a tomato plant turn yellow with brown spots, early blight is usually the culprit. While a cucumber plant can resist a small infestation, a large infestation can. If you see brown spots on leaves it is likely caused by a fungal infection.
This fungus comes from the spores of wet plant debris.
As the disease progresses, lesions expand and become large necrotic patches, often with concentric patternation; The disease is actively spreading under greenhouse conditions, but can also. Light spots on the leaf plates become brown with time, the process of photosynthesis is disturbed, but the leaves do not fall off. On cucumber leaves the spots start as water soaked areas and expand into brown spots which are roughly circular, reaching about 1⁄4 to 1⁄2 inch in diameter (figure 3 & figure 5).
