Answer: Without seeing the problem, I'd suspect that your squash plants have a virus. Viruses are small transmissible pathogens that use components of their host plant cells to multiply. In the process of infecting their host, they often damage or disrupt the plant's normal growing pattern, causing such visible symptoms as leaf mottle, leaf distortion, plant stunting and flower color break. Less visible problems caused by virus infection may include slower growth of plants, inefficient use of nutrients and less tolerance to other stresses, leading to overall failure to thrive.
Viruses may be spread vegetatively (in corms, bulbs or cuttings), mechanically (on tools or through movement of equipment, people and animals), by insect vectors (thrips, aphids or whitefly), aerially by pollen, in soil by fungi, or by parasitic nematodes.
The potential for disease to spread from weeds, through the growing season, is serious. It is important that weeds are controlled since they may harbor the virus as well as the aphid vectors.
Viruses cause mosaic patterns (light green, dark green) in leaves, puckering, leaf distortion, stunting, shortened internodes and misshapened fruit. Cucurbit viruses generally overwinter in weed hosts. Avoid late season planting and control weeds around gardens.
You may want to take a sample of the problem to your local Cooperative Extension for positive identification. Contact Utah State University Cooperative Extension at the Courthouse in Fillmore. Phone (801) 743-5412.
Q&A Library Searching Tips