hold a young leaf of cucumber seedlings in your fingers. diseases

alternaria angular anthracnose aphids bacterial beetles black blight blossomend blotch crown cucumber cucumbers cucurbit damping diseases downy fingers fruit fusarium green gummy hold leaf mildew mite mites mosaic mottle nematodes pests phytophthora powdery pythium rhizoctonia root rootknot rot scab seedlings soft spider spot stem target thrips twospotted vein virus whiteflies wilt yellowing young