EFFECT OF ROTYLENCHULUS RENIFORMIS ON COMMERCIAL TRANSGENIC AND NON-TRANSGENIC COTTON CULTIVARS

摘要

The reniform nematode (Rotylenchulus reniformis) is the number one nematode pest of cotton in Alabama. Currently the only management tools available to producers are nematicides and crop rotation. The identification of varieties that have defined levels of tolerance would be a cost effective management tool to cotton producers. Selected cotton varieties were evaluated in 2002, 2003, and 2004 in a Limestone Co., AL field naturally infested with the reniform nematode. Varieties were tested with and without a nematicide. Seed cotton yields, nematode populations, and early season vigor were parameters measured. Fifty-three commercially available cotton varieties were also evaluated for resistance to the reniform nematode and early season vigor in the greenhouse. Reniform nematode reproduction, shoot length, and root and shoot fresh and dry weights were recorded. Field trials indicated that a small amount of tolerance may be present in DP 451 BR due to a positive performance in plots not treated with anematicide. There was no correlation (P<0.05) between early season vigor and seed cotton yields Greenhouse trials demonstrated that all tested varieties are susceptible to the reniform nematode.