Wilted & Yellow-Spotted Cucumber plants from Straw-Bale Garden
I'm facing some problems with my cucumber plants: The plants of one cultivar, which should produce long cukes have completely wilted leaves - totally limp - and the cukes that are sprouting are thin and stunted and look desiccated. The other cucumber plants are producing abundant fruits - small pickling cukes - but the leaves are yellow-spotted and holey. No bugs as far as I can tell. I chose to do straw bale gardening this year specifically because I had yellow-spotted cucumber leaves last year, so I sheet-mulched the ground thickly, put landscaping cloth over it, and set up my straw bales so my plants would have "clean compost" inside the bales as a growth medium. I am completely mystified to find the same yellow-spot disease showing up this year, and if anything, moving more aggressively. I prepared the bales with Nature Safe Landscape Fertilizer (8-5-5) on alternate days over three weeks, supplemented with Garden Tone and (at the very end) Chickie-Doo-Doo, all well dug in and watered daily. The Straw-Bale Gardening book said to expect mushrooms to show up midway through the prepping process, and I did - grayish cone-headed little ones on toothpick-like stalks, on all of the bales. I have cilantro, dill, and dinosaur kale in with the cukes that have wilted leaves, and Daikon radish with the cukes that have yellow-spotted leaves; these seem to be perfectly fine.
Cucumbers are subject to several fungal (leaf spot) and bacterial diseases. It is too late to spray for these diseases. If you have space in your garden, it is not too late to replant. See our website for information on management. http://extension.umd.edu/growit/fungal-and-bacterial-diseases-vegetables
In the future you can look for resistant varieties http://vegetablemdonline.ppath.cornell.edu/Tables/TableList.htm
Wilt can be due to insufficient moisture or a disease called bacterial wilt. Go to our vegetable website 'Grow It Eat IT' for information on bacterial wilt which is a disease transmitted by cucumber beetles. https://extension.umd.edu/learn/bacterial-wilt
In the future you can look for resistant varieties. You can also replant.