Pathogenicity and Control of Nematodes Affecting Sunflower in North Central Florida. J. R. Rich, Agricultural Research Center, Department of Entomology and Nematology, University of Florida, Live Oak 32060. R. A. Dunn, Department of Entomology and Nematology, University of Florida, Gainesville 32611. Plant Dis. 66:297-298. Accepted for publication 4 June 1981. Copyright 1982 American Phytopathological Society. DOI: 10.1094/PD-66-297.

In 1978, two sunflower (Helianthus annuus) field trials were conducted, one in early spring and the other in late summer. Soil in the spring trial was infested with Belonolaimus longicaudatus, Trichodorus christiei, Meloidogyne incognita, and Pratylenchus brachyurus and was treated with the soil fumigant DD at 67 kg a.i./ha. The treatment did not significantly increase sunflower yield but reduced populations of all nematodes except T. christiei. Soil in the summer test was infested with M. incognita, T. christiei, and Pratylenchus zeae and was treated with aldicarb, carbofuran, or fenamiphos at 3.0 kg a.i./ha. Aldicarb significantly increased seed yields, whereas fenamiphos was phytotoxic and reduced plant emergence. All nematicide treatments reduced populations of one or more of the three nematode species. Most plant-parasitic nematodes in both tests reproduced well on sunflower.

Keyword(s):