Tomato, Squash & Cucumber plants dying out
A gentleman came into our office inquiring about what may have caused his tomato, squash & cucumber plants to die out last summer. He said that it would start from the bottom of the plant and die out upwards into the vine of the plants. He wants to know what would cause this and how to get rid of it so he doesn't have the same problem this coming year. Thanks!
Kalkaska County Michigan horticulture
With virtually no information except "dying from the bottom up," I have to give the Best Guess.
The tomato problem is not related to the squash and cucumber problems. They belong to the curcurbit family. They are unrelated plants. But they are probably both fungal diseases.
The tomato could have had Septoria leaf Spot. The tomato gets spots on leaves and the leaves turn yellow, then brown, dry up and fall off from the bottom og the plant up.. The fruit is unmarked. If this doesn't sound familiar, then disregard the preventative part. This is a fungal disease that you can prevent but not cure...like all of them. Use a fungicide containing chlorothalonil (several vegetable disease control products have it) and begin spraying the plants BEFORE problems, like the end of June or when the tomato produces flowers. Follow the label directions, which usually indicate to repeat every 7-10 days. Do not overhead water plants and respray after a rain. It has to stay on the leaves to effective. Or try to locate an organic product called Serenade manufactured by Agraquest. It may have to purchased online.
The curcurbit problem could be downy mildew. It cause plants to die rapidly but leaves are spotted. You can also get a squash vine borer that destroys the stem of the plant as it comes out of the ground and causes it to wilt. If it is downy mildew, he will have to use two fungicides and alternate them by applying every 7-10 days. One fungicide is chlorothalonil and the other is Mancozeb or dithane. You alterate them weekly...chlorothalonil one week and dithane the next. The problem is that this may hold the disease at bay for awhile, but it eventually gets the cucurbits. But again, if this does not sound like what he has, don't do it.
Go online and show the guy images of septoria and downy mildew. I am guessing he does not go online himself because you are asking. Check and see if what he sees matches his problems. Good luck.