Hi Deborah –
Various fungal diseases and blights attack squash foliage. From your description, I have come up with a couple possible plant problems and listed symptoms and treatments for each.
Fusarium Crown and Foot Rot
Symptoms:
• Wilting of leaves
• Plant dies within a few days
• Dead tissue of the crown and upper taproot
• Infected plants break off below the soil line
Treatment:
• Purchase pathogen free seed
• Rotate crops on a 3 to 4-year rotation
• Don’t plant melons following a barley crop
• If the disease persists, it is best to remove infected plant debris and solarize the soil before planting again
Bacterial Wilt
Symptoms:
• Severe wilting, especially during the heat of the day
• Symptoms appear at all stages of plant development
• Leaves may yellow
• Dead tissue may appear around leaf margins
• Plants die within two weeks
Treatment:
• There is no control for bacterial wilt once plants become infected
• Plant resistant varieties when available
• Use an organic insecticide to control cucumber beetles, which are known to spread the disease.
Various fungus and blights attack squash plants. In most cases, a dilute solution of copper spray will help control the problem. However, we do not offer a product that will work on the two conditions mentioned above.
Hope it helps!