First Report of the Reniform Nematode Rotylenchulus reniformis on Cotton in Virginia.

ABSTRACT

In Virginia during September 2002, the reniform nematode, Rotylenchulus reniformis Linford and Oliveira (1), was found for the first time following a grower's concern about poor growth and yield of cotton (Gossypium hirsutum L.) cv. Fiber Max 989BR. The infested field was planted with cotton each year for the last eight growing seasons. The field was located on Hall Road in Southampton County, Virginia at coordinates 77°16'28.8926″W, 36°37'10.6428″N near the town of Branchville. The soil was loamy sand, which is typical of sandy textured soils in the region. Rainfall from May to September at a nearby weather station was nearly 50% below normal, which may have contributed to the suppression of plant growth. The vermiform nematodes were extracted with a North Carolina State University model semiautomatic elutriator and centrifugation/sugar flotation. Populations were 30 to 150 per 500 cm3 of soil in areas with noticeable stunting. Cultures were established on cotton cv. Delta Pine 64 and tomato (Lycopersicon esculentum Mill. cv. Rutgers) and were maintained in a greenhouse. Reproduction was moderate on cotton and high on tomato. Identifications were based on morphology and measurements of vermiform females and males immature female length (L) = 407 ± 22 (376 to 418) µm, stylet L = 18.5+1.7 (17.0 to 21.3) µm; and male L = 351 ± 17 (339 to 367) µm. Voucher specimens were placed and are maintained in the Virginia Tech Nematode Collection. Reference (1) M. B. Linford and J. M. Oliveira. Proc. Helminthol. Soc. Wash. 735, 1940.