Soil Distribution of Fenamiphos Applied by Overhead Sprinkler Irrigation to Control Meloidogyne incognita on Vegetables. A. W. Johnson, Supervisory Research Nematologist, USDA, Agricultural Research Service, Southern Region, Tifton, GA 31793. W. A. Rohde, Research Chemist, and W. C. Wright, Agricultural Research Technician, USDA, Agricultural Research Service, Southern Region, Tifton, GA 31793. Plant Dis. 66:489-491. Accepted for publication 17 August 1981. This article is in the public domain and not copyrightable. It may be freely reprinted with customary crediting of the source. The American Phytopathological Society, 1982. DOI: 10.1094/PD-66-489.

Fenamiphos applied to squash and cucumber to control Meloidogyne incognita at 4.5, 6.7, 9.0, and 18.0 kg a.i./ha via injection into a sprinkler irrigation system was compared with fenamiphos granules spread on the soil surface at 9.0 kg a.i./ha and incorporated into the top 15 cm of soil. Nematode populations in the soil and root-gall indexes were lower and yields were greater in treated than in untreated plots. Root-gall indexes did not differ between methods of application of fenamiphos at 9 kg a.i./ha on most sampling dates; however, root-gall indexes of cucumber in broadcast and incorporation plots were lower than those in irrigation plots after the final harvest. Based on root-gall indexes, fenamiphos concentrations above 1.5 µg/g of soil in the 0–15 cm soil layer for 10 days appear to be adequate for controlling root-knot nematodes on squash and cucumber. Concentrations of fenamiphos in the 0–15 cm soil layer were below 1 µg/g of soil 30 days after application at all rates.

Keyword(s): Cucumis sativus, Cucurbita pepo.