Influence of Small Grain Rotations on Take-All in a Subsequent Wheat Crop. C. S. Rothrock, Department of Plant Pathology, University of Arkansas, Fayetteville 72701. B. M. Cunfer, Department of Plant Pathology, Georgia Station, University of Georgia, Griffin 30223. Plant Dis. 75:1050-1052. Accepted for publication 25 April 1991. Copyright 1991 The American Phytopathological Society. DOI: 10.1094/PD-75-1050.

Wheat (Triticum aestivum), barley (Hordeum vulgare), triticale (× Triticosecale), rye (Secale cereale), and oat (Avena sativa) rotations were evaluated for their influence on take-all in a subsequent wheat crop. Cultivars of each small grain were planted at two locations for two successive years in plots artificially infested with Gaeumannomyces graminis var. tritici at the beginning of the study. Wheat was planted in all plots the third year to estimate inoculum potential of the pathogen following each of the small grains. Take-all was severe on wheat following all susceptible small grains (wheat, barley, triticale, and rye). Yield reductions did not differ following susceptible small grains compared with wheat following the resistant small grain oats, with the exception of no significant yield reduction for wheat following wheat compared to wheat following oats at one location. Data indicated that even rye cultivars, which showed no yield losses attributable to take-all, support inoculum of sufficient potential to result in severe disease and significant yield reductions in the subsequent wheat crop.