Inadequate/insufficient pollination (aka fruit abortion). A common problem when grown in greenhouse where insect-vectored pollination is difficult. There is a FAQ here about how to hand pollinate. Some plants will also abort fruit when they become overly stressed. For example you have several cukes there that are clearly ready for harvest if not going past ideal harvest. Leaving fruit like that on the vine stresses the plant. It can only support so many fruit at one time and begins to shut down if not kept picked. Cukes are notorious for shutting down if not kept well picked. In a GH excess heat can also be a problem. Dave

I want to know the answer to this also. Mine products several good sized cucumbers then started shriveling up all the other baby cukes. Now I only have one baby cuke left. What does this plant need in order to begin producing again?

I think this looks like Nitrogen deficiency in the soil. You need to add a Nitrogen fertilizer for dark green leaves. I use a Nitrogen fertilizer till the plants are big enough and have dark green leaves. After that you can switch to a low Nitrogen fertilizer.

I'm in the south part of the penninsula and have had trouble with cucumbers. This year I am having some luck with them because I installed a drip system. So water is definately a key here. They are right that what your describing is a lack of pollination and even though I'm getting fruit this year I'm not getting a lot because of the same reason. But I'm too lazy to hand polinate, next year I plan to plant some flowering plants next to the cukes to attract pollinators. Next year try armenian cucumbers, they are actually a squash I believe, but they taste like cucumbers with a slightly different texture (a bit drier and less seeds). They are very good and grow well here. HTH, Kristi