Why are my acorn squash and pumpkins withering on the vine?

Question

I watered them religously through a dry month, and I could understand them not producing then in spite of all my efforts then/ But we have had good rain the last two weeks, and still they are not producing.

I have bees every morning. and my vines are so healthy that it is scarry. My Pumpkin is growing across a 40 foot strech of woven wire fence, and the Squash is spread for about 10 feet around a dead tree then trained up poles leaning on the tree. They are not having any problems other than the young fruit starts to shrivle up after a couple days. I have gotten some fruit from bolth vines, but it seems to early in the year for them to quit.

The female flowers are not opening before the bud withers.I have tons of male flowers.

Answer 1

The heat & even the rain can affect pollination. Bees are not active when it rains, or when it's too hot.
Even when they are pollinated, the squash, pumpkins & cucumbers can abort frm the heat. Also, the hot temperature may cause the plants to form only male flowers; hence no fruit will be produced. When it gets cooler, that won't be a problem.

You can hand-pollinate the female flowers on your plants. Simply remove a male flower and touch its anther to the stigmas of the female flowers present. One male flower produces enough pollen to fertilize a number of female flowers.
Here's a picture & instructions:
http://www.pumpkinnook.com/howto/pollen.htm

Keep them elevated off the ground. Make sure you don't water before 10 a.m. so your plants will have a chance to get pollinated, & don't water overhead because that could wash off the pollen on the short-lived male flowers. Replacement flowers do not open then until the following morning.

If plants have all the conditions for good growing -- plenty of sunlight, water, and nutrients, and a rich soil with neutral pH --and are not being affected by the weather, then the wilting may be caused by a disease called bacterial wilt. The disease is spread by beetles as they feed. To test for bacteria, cut a wilted stem near the base of the plant and squeeze out the sap -- look for a milky white substance. Touch the tip of a knife to the ooze, and if, as you withdraw the knife, it pulls out in a fine thread, the plants have a bacterial infection. You have to control the beetles with pesticides, or grow resistant varieties. If your beetle problem is severe, you might consider growing your plants under "all-season" lightweight fabric row covers to exclude the pest insects.

Also, borers can invade the stems, causing plants to wilt. If borers are the culprit, you'll find small holes and sawdust-like. "This productive vegetable could quickly wither away if careful attention is not given to the plants, especially during early July. The squash vine borer will make its appearance as the females lay their eggs near the base of the plants. Soon after, hills that resemble sawdust are evident, and it is at this point that the larvae have already entered the vine of the plant. To prevent this, I'll use a rotenone dust every few days for the next three weeks on all of the squash plants. A light dusting is all that is required, but to be effective the dust must get under the leaves at the base of the plant."
http://www.connpost.com/garden/ci_6312761
"Vine borers! To prevent, simply wipe the stems of your squash with a damp cloth every morning--you'll destroy the eggs (laid by a moth) before they can hatch into destructive, 'boring' caterpillars. If you can already see holes with 'frass' (bug poop) outside, carefully slit the vine with a razor blade, capture and dispose of the beast ("hahaha! I've got you NOW!"), then cover the damaged part of the vine with soil."
http://www.whyy.org/91FM/ybyg/pests.html

There are other diseases that can affect the plants. Here's illustrations & disease management solutions:
http://www.ag.ndsu.edu/pubs/plantsci/hortcrop/pp656w.htm

It's most likely the hot weather & the rain that's delaying production. I just included the other probabilities to give you a heads up on other possible causes for future reference.
Good luck! Hope this is helpful.

Answer 2

It sounds as though they are not getting pollinated. You will need to get a round, cosmetic-type brush and dust the center of the male flowers, and then move to the female flowers. The female flowers generally have a small rounded ovary just under the petals; it may even resemble a miniature squash or pumpkin, but it will not develop much further without pollination. The male flowers generally open up a couple of days before the female flowers. The site is a good one on how to tell the difference between the flower sexes.

Answer 3

Wither On The Vine

Answer 4

They could be under attack by a stem borer. Those larva chew their way into the stems and just work their way down (or up) the stem, choking off the nutrients to the gourds (acorn squash and pumpkins are gourds). There are some chemicals that you can put on the vines but they really do not penetrate in time to save the plants if that is the cause. That's why I do not grow gourds any more. It turned out to be cheaper to buy.