Phytoparasitic nematodes associated with three types of blueberries in arkansas.

Research and commercial blueberry plantings were sampled in October 1991 to determine the population densities and species of phytoparasitic nematodes associated with rabbiteye (Vaccinium ashei), southern highbush (Vaccinium sp.), and highbusb (V. corymbosum) blueberry cultivars and the sod middles between the blueberry rows. In the research planting at Clarksville, Arkansas, samples from the highbush cv. Bluecrop, the southern highbush cv. Cooper and Gulf Coast, and the sod middles had similar numbers of total vermiform phytoparasitic nematodes (125-451/250 cm(3) soil), whereas the samples from rabbiteye cv. Climax and Tifblue had significantly lower numbers (4/250 cm(3)). The major nematode species associated with blueberries and sod was Xiphinema americanum. In a research planting at Bald Knob, Arkansas, which contained Bluecrop and rabbiteye cultivars only, samples from Bluecrop and the sod had similar numbers (288 and 334/250 cm(3)), and the rabbiteye samples had significantly lower numbers (6-14/250 cm(3)). Xiphinema americanum was the major species found in the blueberry samples, whereas Mesocriconema ornata was the major species in the sod. Nematode population densities and species distribution in commercial rabbiteye plantings in nine counties in central and southwestern Arkansas varied greatly. The average population density for rabbiteye samples was 129/250 cm(3) and for sod was 577/250 cm(3). Weed infestations in the blueberry rows in the commercial plantings probably increased the population size and species distribution.