Diseases that cause brown spots on the leaves of cucumber flora also afflict other member of the Cucurbitacae plant family ; these plants , called cucurbits , admit melon , watermelon vine , pumpkins and squashes . Both fungous and bacterial diseases can cause spots on cucumber plants . method for preventing and treating brownish blot vary with the nature of the disease .

Bacterial Disease

Angular leaf spot , Pseudomonas syringae pv . Lachrymans , infects the cucumbers and their leaves and halt . Angular , water - soaked spots on the leaves transude bacterium . The bacteria is borne by seeds and is pass around by rainwater splash during wet natural spring . The bacterium can outlive for up to two years in junk or soil contaminated by diseased plants . There are cucumber vine cultivars that resist angular leaf smear .

Fungal Diseases

Anthracnose , collectotrichum lagenarium / glomerella cingulata , is a fungous disease that causes yellow or reddish - brown , water - soaked fleck on the leaves . The spot can turn a pinkish color in during wet weather when the spots ooze spore . Alternaria leaf blight , alternaria cucumerina , is a fungal disease that can cause spots on the leave-taking of Cucumis sativus plant life . These tiny spots produce up to ½ in wide , developing hoop that make them wait like targets . Infections come during extended menstruation of spicy , humid atmospheric condition . Symptoms of ulcocladium leaf spot normally appear on Cucumis sativus leafage in August . The spots , sometimes confused with angulate foliage spot , are beige or brown , but are also white fence in by a dour browned ring and a brown aura . These lesion get out the farewell open to infections by angular foliage dapple . The symptoms of the airborne downy mold fungus , pseudoperonospora cubensis , come out very quick . They produce yellow spots and spores that seem like brownish flecks on the leave .

Preventing Disease

Plant goodly seed of disease resistant varieties . If you’re able to avoid it , do not plant cucumbers in soil that has been growing cucurbits within the last three years . Give your cucumbers a two - and - a - half- workweek head start indoors or plant them in well - drain stain that has reached at least 65 point . Do not ferment with your cuke while they are blind drunk or after the vine are 18 inches long . Remove and bury morbid plants and harvest pass up in the fall .

Identifying Disease

The most likely disease that cause brown spotlight on parting are alternaria leaf blight , angular leaf spot and anthracnose . To take the best treatment , you first necessitate to identify the correct disease . There are website and gardening books with photo of fungous and bacterial spots on cucumber leaves or you’re able to consult your biotic community ’s conjunctive extension office or a gardening expert .

Treating Diseases

Your local agricultural extension service can give you a lean of USDA approve antimycotic for these disease . These are antifungal agent proven to shape for a particular disease and that do not cause environmental damage .

References

…