Effects of Crop Management Practices on Common Root Rot of Winter Wheat. S. C. Broscious, Former Graduate Student, Department of Plant Pathology, University Park 16802. J. A. Frank, ARS-USDA, Pennsylvania State University, University Park 16802. Plant Dis. 70:857-859. Accepted for publication 29 January 1986. Copyright 1986 The American Phytopathological Society. DOI: 10.1094/PD-70-857.

Crop management practices were evaluated for individual and interaction effects on common root rot of wheat in Pennsylvania. Four management practices were incorporated into replicated field experiments conducted on four farms located in Centre County and Lancaster County, PA, during the 1981 and 1982 growing seasons. Management variables tested were two planting depths (2 and 4 cm), two row spacings (13 and 18 cm), three seeding rates (101, 168, and 235 kg/ ha), and four spring nitrogen fertilization levels (0, 34, 67, and 101 kg/ ha). The management practices did not interact consistently over the range of values tested to influence the intensity of common root rot, indicating that the effects of a management practice could be considered individually. Planting depth was the only factor that consistently influenced the intensity of common root rot. In all experiments, seed planted 4 cm deep produced plants with longer subcrown internodes with higher disease intensity than those planted 2 cm deep; however, yields were not significantly lower in the deeper planting. Bipolaris sorokiniana and Fusarium spp. were the fungal pathogens most frequently isolated from lesions on subcrown internodes. The frequency of Pythium spp. isolation was higher in 1981, when soil moisture was more uniform throughout the season.