I have a problem with my cucumber plants. I have attached a picture. It appears the leaves are turning yellow and big holes are appearing. I would like to know what is happening and how I can prevent this issue from spreading to my other cucumber plants. Thanks,
Thank you for contacting Delaware Cooperative Extension. You may receive a short survey after the answer to this question.
It is difficult to tell for sure, without looking at your cucumber plants, especially the undersides of the leaves. It looks like you have some insect damage, most likely beetle feeding, but we cannot see the insect involved. The variation in green to yellow color also suggests a fungal leaf spot, but again I cannot tell for sure. You may want to trim off the worst affected leaves. Avoid overhead water on the leaves, instead water with a hose around the base of plants.
You could spray with a household liquid dish soap solution, insecticidal soap purchased, or neem oil to help control insects and fungi.