Common Root Rot and Yield Responses in Spring Wheat From Chloride Application to Soil in Northwestern Minnesota. Carol E. Windels, Associate Professor of Plant Pathology, Northwest Experiment Station, University of Minnesota, Crookston 56716. John A. Lamb, and Todd E. Cymbaluk. Associate Professor of Soil Science, and Associate Scientist, Northwest Experiment Station, University of Minnesota, Crookston 56716. Plant Dis. 76:908-911. Accepted for publication 20 March 1992. Copyright 1992 The American Phytopathological Society. DOI: 10.1094/PD-76-0908.

Plots were established at five locations in northwestern Minnesota during 1986–1989 and fertilized with five rates of chloride (0, 13, 27, 40, and 54 kg/ha) using two sources (CaCl₂ and KCl) to determine if Cl affected the incidence and severity of common root rot and grain yield. Locations differed for all variables measured, but there were no significant interactions (P = 0.05) between the rate of Cl fertilization and location. Ratings for common root rot (0–100 scale) for each location during 1986–1989 averaged 81.9, 42.9, 60.2, 51.2, and 73.3 for control plots, respectively, and 74.3, 41.9, 59.5, 49.9, and 66.6 for combined Cl plots, respectively. There were no significant differences in plant populations, whole-plant uptake of Ca or K, or grain yield for Cl-fertilized plots compared with control plots. Fertilization with Cl tended to increase forage yield and decrease grain protein concentration. Test weight of grain was significantly increased by 6–11 g/L for Cl-fertilized plots compared with controls. Overall, soil supplemented with Cl was not effective in significantly decreasing common root rot or in increasing grain yield.

Keyword(s): Bipolaris sorokiniana, Cochliobolus sativus.