Is it possible that your drip irrigation is malfunctioning such that it isn't distibuting water to your watermelons as you think?

It may also be possible that the watermelons just have a higher water requirement.

What do yo mean by "watering seems to do no good"? Do you mean that increasing the amount or frequency of water given to the watermelons has no effect on this phenonemon?

Sounds like lack of water to me. Mine do the same. When I flood water they are fine until the soil drys out again.

The Fruitnut

Billy:

I have to agree that it sounds like a problem of water distribution. Your underground system may not be close enough to the root zones of the watermelons, although their root systems are very extensive.

Don't know what your rainfall situation is in West Virginia, but here in East Virginia we are about to dry up and blow away; close to 10 inches below normal. My melon and squash plants also droop when they get dry, especially during a very sunny day, but perk right up when they get some water.

Don Yellman, Great Falls, VA

Thanks for the input and I think everything you say is basically correct. It does sound/look/feel etc. like a water problem but watering one evening does not prevent the same thing from happening the next day even, with 4-5 hours of water on three 40' rows. A problem with the drip irrigation seems logical except that crenshaw melons and pumpkins on half of each of the 3 rows are fine. And since we have had reasonable water in July (likely around 3.5" so far, much more than in May & June combined; I have a number of friends in VA not so lucky)I think I will take as much of the plastic off as I can and see what happens (My guess is, nothing). Thanks again.

billv,
I don't think it is a watering problem. I HAVE HAD THE SAME PROBLEM REPEATEDLY in some areas in many years. A few varieties in some areas seem more immune to the problem...like Summer Flavor #420.
I believe it is somewhat along a disease problem...some sort of mature vine decline. I also beleve it is partially normal after the melons are matured. However, watermelons planted in brand spanking new areas seem fairly immune to the leaf decline you speak of.

As a last word, if you discover a true cure,[besides totally new locations] please let me know.

Thanks for the input Wayne. What you say matches most of the facts here but the situation (as well as the best thing to do) remains a mystery. My melons have been grown in the same location for about five years so it is not new ground but I have never had the problem before. The melons are somewhat mature but should have another 2-3 weeks before fully ripe. As I said earlier, I hope (tonight, weather permitting) to open up the plastic, put some water directly on the rows, and then spray with one or a combination of fungicides. If you are right, the latter may be the most important. Regards.

I just heard on a game show that the largest watermelon grown was 269lbs. I couldn't believe it!!!

That's 100lbs more than me. WOW

Billv, are your pumpkins mingling with your melons? Pumpkins are notorious attractors of squash bugs and if they have migrated into your melons they could be sucking the vines to a slow death. A few weeks ago I noticed a wild melon vine growing from a compost pile and it appeared stressed and somewhat droopy. I hand watered it heavily and to my surprise about 20 squash bugs climbed to the top if it's leaves, where I quickly squashed them. Today that vine is strong and healthy sporting an interesting looking melon.

vgkg:
The answer to your question is "yes, to an extent". About half the bed is watermelon (west side), about 1/3rd is crenshaw melons (northeast) and about 1/6th pumpkins. There was no initial side-by-side planting of watermelons and pumpkins (separated by crenshaws) but certainly pumpkin vines could grow through the crenshaws to the watermelons. This supports your theory but I would wonder why I had no problem in the previous 5 years when they have been planted the same way and why the pumpkins look fine if they are the source of the problem. I spray with sevin before the vines bloom and for the past month or more have been putting down small plastic cups filled with water, sevin and ground cucumber peels and leftovers. I found lots of the squash or cuke beetles floating in the cups for the first several weeks but more recently, mostly flys and other insects. I do plan to water the vines individually as you did and will keep an eye out for bugs to squash.

Goodground:
Try and get some rest.

Again, I think the problem is a mild form of mature vine decline from some kind of disease pressure of unknown indentity. I don't think that even the experts could easily nail down the cause. If you replanted in the same spot next year, you may or may not have the problem. The best answer is to find a new location.

Wayne:
I think you are probably correct. Like most home gardners, I have no problem moving things a few feet. Moving them a meaningful distance is much more difficult but I will work on it. Thanks for the input.