How do you tell between cucumber mosaic virus versus downy mildew? My cucumber leaves are becoming discolored with blotchy/mottled looking leaves (lighter green and yellow in spots). Still producing lots of male and female flowers and there are about 7 cucumbers growing on my 3 plants right now. I pruned a bunch of the lower leaves, where the discoloration was the worst but it seems to be creeping up the whole plant. Newer leaves and still nice and green. Also, the actual cucumbers start out dark green and then get lighter in color, a very pale green halfway through growth. So, I’m not sure if I should just pick them early or wait until the grow more. When I left some to grow bigger, they seem to have a more bitter flavor. Smaller ones were sweeter. I tried to upload a photo but it’s saying that the size is too large and I don’t know how to make it smaller.
I checked the backs of the leaves and I don’t see any spider mites. They took over my green beans last fall, so I’m double checking everyday to make sure they never come back!
You may not be able to see them because they are very, very tiny, but their little webs may be visible. I have had them in my greenhouse a couple of times. Here is an old foto of mine that I used in an earlier posting here: You can tell by the enormous size of the leaf portion that the foto was enlarged quite a bit. The location of the webbing is typical here; however, if you look on the internet you will see many “horror shots” of giant spider mite webs. I have never seen huge areas of the webbing, rather subtile, almost invisible webs in the typical plant locations. The mites absolutely can be found on the backs of leaves but they usually do their walking about on the webbing that they have laid down. It may be that you have a different cause of your leafy changes. Things like this are interesting to all gardeners, so I hope that you will keep inspecting your plants and trying to discover the aetiology of the leaf damage, and let us know the result.
