Squash Leaf Discoloration ID?

[GoDawgs]

Something's going on with the spaghetti squash. I've looked at a bunch of disease photos and I can't match it up. Maybe it's nutritional? Shout it out if you know what's going on or even have an idea I can chase down! I've never had this particular problem with cucurbits before.


Oh, and ignore those two small squash bug egg masses. They're gone now, along with two bugs I found doing the nasty under an adjacent leaf!

[RayR]

Hard to say for sure, with the yellowing between the veins and the curling of the leaves I would first suspect aphids or some other insect or mite on the underside of the leaves. Maybe a closeup photo of the underside of a leaf like in the second photo could identify if there is insect damage or not.

[Wi-sunflower]

The leaves look a bit wilted like they need water, or possibly too much water. I grow several varieties of winter squash that will get a yellow discoloration when small then out grow it. But spaghetti is not 1 that usually does that. So I would suspect they need some nitrogen. I think you have gotten a lot of rain in your area lately so I would suspect possible wet wilt and fertilizer all washed out.

Carol

[GoDawgs]

In just two more days the whole plant was pretty yellow. I dug it up and found the evidence of my old nemesis... nematodes. Mystery solved.

[b54red]

I was going to say nematodes but didn't see the post til just now. It is a far too familiar look. I have quit growing cantaloupes because they are so susceptible to nematodes. Nematodes are usually guilty when cucumbers, okra and squash start failing early. Of course with squash you can also add the squash vine borer to the list of things that can take out squash early.

Those nematodes don't look bad enough to wilt a plant much so you may also have a borer in the plant stem.

Bill

[GoDawgs]

Originally Posted by b54red

I was going to say nematodes but didn't see the post til just now. It is a far too familiar look. I have quit growing cantaloupes because they are so susceptible to nematodes. Nematodes are usually guilty when cucumbers, okra and squash start failing early. Of course with squash you can also add the squash vine borer to the list of things that can take out squash early.

Those nematodes don't look bad enough to wilt a plant much so you may also have a borer in the plant stem.

Bill

I checked for a borer after I pulled the plant and there wasn't any. Usually with a borer I won't see the yellowing. It will be that first leaf drooping like it's thirsty. Then another and another. This problem started out with the yellowing and I forgot about how nematodes will do that. Quickly reminded!

BTW, I've been doing a little nematode experimenting. There was a bed where cukes had gotten 'toded up Spring '18. Then I let the bed be fallow until Spring '19 to starve the little buggers and reduce the population. Then I planted an early corn in that bed April '19 (they don't like corn) to starve them some more. Having read that brassicas other than mustard also deter nematodes, I planted broccoli and cauliflower there fall '19. They did really well. This spring I planted peas (very susceptible) in that bed and they did fine. No 'todes on the roots when I pulled them up. I wonder how long it will stay that way.

I'm not sure what's going in that bed this fall as I don't have the fall garden rotation planned yet. Maybe fall squash or cukes or carrots to test how long the population stays reduced? Maybe turnips. Gotta think some more on that.

[b54red]

Dawg I have no idea. After dealing with them for over 40 years I guess I'll never figure out why some years in some beds they seem to be a minor problem and other years they are do catastrophic damage. I have learned a few things that help a little and sometimes a lot. Mulch heavily and keep the soil moist. If the soil is sandy add a lot of organic matter to build it up because the thrive in dry sandy soil. If possible rotate susceptible crops. And the one that has benifitted me the most is grafting tomatoes.

Bill