VIEW ARTICLE

Yields of Six Soybean Cultivars Following Fumigation of Soil Infested With Root Knot Nematodes. N. A. Minton, Research Nematologist, Agricultural Research Service, U.S. Department of Agriculture, University of Georgia, Coastal Plain Experiment Station, Tifton 31794; M. B. Parker, Assistant Agronomist, Department of Agronomy, University of Georgia, Coastal Plain Experiment Station, Tifton 31794. Phytopathology 64:219-221. Accepted for publication 31 August 1973. DOI: 10.1094/Phyto-64-219.

Nematode control, plant height, and yield of six soybean cultivars were compared in Meloidogyne incognita-infested soil with and without 1,2-dibromo-3-chloropropane (DBCP) fumigation. Yield differences among soybean entries grown in nonfumigated soil were closely related to root knot indices indicating a wide range of susceptibility to nematode attack and effects on yield. Cultivars tested were classified as follows: very tolerant — ‘Hutton’, ‘Coker 68-41’ and ‘Hampton 266A’; tolerant — ‘Bragg’; and susceptible — ‘McNair 800’ and ‘Davis’. Two-year mean yields of Hutton and Coker 68-41 in nonfumigated plots were significantly greater than yields of McNair 800. Yield of Hutton was also significantly greater than those of Bragg and Davis. Yields of all entries except Hutton and Hampton 266A were significantly increased by fumigation. Differences in yield among entries in fumigated plots were not significant. Root knot indices were more accurate indicators of plant damage than larval populations. Differences in plant height between fumigated and nonfumigated plots were closely related to root knot indices.