Disease Note.

First Report of Pratylenchus thornei on Dry Land Wheat in Washington State. H. Mojtahedi, Washington State University, Irrigated Agriculture Research and Extension Center (IAREC). G. S. Santo, and J. M. Kraft. Washington State University, Irrigated Agriculture Research and Extension Center (IAREC), and USDA-ARS, IAREC, Prosser, WA 99350. Plant Dis. 72:175. Accepted for publication 12 October 1987. Copyright 1988 The American Phytopathological Society. DOI: 10.1094/PD-72-0175C.

In 1986, Pratylenchus thornei Sher & Allen, 1953, was found on dry land winter wheat (Triticum aestivum L. 'Stephens') near Walla Walla, Washington. Nematode-infected plants were stunted and chlorotic. Two inoculum levels of P. thornei (400 or 4,000 per pot) were added to the roots of 5-day-old Stephens wheat seedlings growing in 600 cm³ methyl bromide-fumigated loamy sand soil in five pots in the greenhouse. Noninoculated plants in pots served as controls. Plants were grown for 3 mo at 18-22 C. The reproductive factors (final population/initial population) for the 400 and 4,000 inoculum treatments were 33.6 and 2.6, respectively. The 4,000 inoculum level significantly (P<0.05) reduced top fresh weight (24 ± 7%) and root dry weight (48 ± 5%). No difference in plant growth was observed at the 400 inoculum level. These results confirm that P. thornei is a pathogen on wheat (1).

Reference: (1) S. D. Van Gundy et al. 1. Nernatol. 6:107, 1974.