The profitable production of cucumbers, cantaloupes and watermelons, collectively known as cucurblts, depends on the selection of varieties, proper soil conditions, fertilizers, and the control of Insects and diseases. Growers generally realize the Importance of the first three, but neglect the diseases because they do not understand them. Diseases of cucurblts (cucumbers and melons) In Iowa have become so serious that these crops have been discontinued by many growers even where soil and other conditions are very favorable. The diseases affecting cucumbers and melons are caused In some cases by bacteria, In others by fungi and one Is due to a virus. These organisms live In the cucumber and melon plants, and require right conditions for good growth. Cool, damp weather Is most favorable for the growth and development of fungi and bacteria. Under such conditions the crop losses Incurred are largely due to the Increased activities of these organisms.