I have a nice row of summer squash this year. However right in the
middle I have two plants that has very green leaves. But the veins of
the leaves are bright yellow. Any ideas?
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One possibility is cucumber mosaic virus, If you planted yellow squash either
straight neck or crookneck and the fruits are mottled green you will know for
sure, It is spread by the cucumber beetle, but I know of no cure once
established.