Cantaloupe is grown on a wide variety of irrigated soils in southern California. Of the root-knot nematodes, Meloidogyne incognita, is the most common species which attacks this crop. This nematode, as well as other species of the genus, is generally a problem on coarsertextured soils in the southern valleys. When M. incognita is present at planting time it stunts the young plants soon after emergence and causes severe galling of the roots (photo). Plants infected in the very early stages of growth remain stunted and unproductive and seldom bear marketable melons (photo). Localized infestations in a field range in size from a few square yards up to several acres. Sometimes entire fields are uniformly infested with the nematode and, if proper preplant control measures are not taken, the entire field may be unproductive.