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ARS Home » Southeast Area » Tifton, Georgia » Crop Protection and Management Research » Research » Publications at this Location » Publication #145873

Title: ROOT-KNOT NEMATODE TOLERANCE IN COMMERCIAL COTTON CULTIVARS

Author
item Davis, Richard
item MAY, O - UNIVERSITY OF GEORGIA

Submitted to: Cotton Research and Extension Report
Publication Type: Experiment Station
Publication Acceptance Date: 3/1/2003
Publication Date: 4/1/2003
Citation: Davis, R.F., May, O.L. 2003. Root-knot nematode tolerance in commercial cotton cultivars. 2002 Georgia Cotton Research and Extenion Report. p. 316-317.

Interpretive Summary:

Technical Abstract: The southern root-knot nematode, Meloidogyne incognita, causes significant yield reductions throughout the U.S. cotton belt. Susceptible means the nematode can reproduce freely, and tolerance means that crop yield is affected little by nematode feeding. Virtually all cotton cultivars are susceptible to M. incognita, but their tolerance is not known. We measured the amount of yield suppression caused by root-knot nematodes in high-yielding cotton cultivars that are known or believed to be susceptible to the southern root-knot nematode. Tolerance was measured in 2002 in field experiments with six replications in a strip-plot design. The horizontal factor was genotype and the vertical factor was fumigation treatment (non-fumigated or Telone II at 6 gal/acre). Delta and Pine Land DP5415 was included as an intolerant control treatment, and GA96-211 was included as a tolerant control treatment. Percent yield loss values were subjected to analysis of variance and means separation by LSD (0.05). Yield suppression ranged from 18% for GA96-211, which is moderately resistant and tolerant to M. incognita, to 47% for DP555BR, which was the highest yielding cultivar in this study. It was anticipated that the pounds lost per acre would increase as yield potential increased but the percent yield loss would be similar among most cultivars. However, there was a trend in which cultivars with higher yield potentials also had greater percent yield loss to root-knot nematodes.