Planting Date and Foliar Fungicide Effects on Yield Components and Grain Traits of Winter Wheat

Abstract

In the eastern Great Plains, winter wheat (Triticum aestivum L.) typically is planted from late September through November. However, grain yield and grain quality often are reduced by variable weather conditions in the spring and foliar disease infections. Field studies were conducted in southeastern Kansas from 1990 through 1995 on a Parsons silt loam soil (fine, mixed, thermic, Mollic Albaqualf) to evaluate effects of planting date, with and without a foliar fungicide (propiconazole: (1‐{[2‐(2,4‐dichloro‐phenly)‐4‐propyl‐1,3‐dioxolan‐2‐yl] methyl}‐1H‐1,2,4‐triazole), on grain yield, yield components, and grain quality (test weight and protein) of hard and soft red winter wheats with different maturities and disease resistances. In 2 of 6 yr, grain yields of all cultivars planted in late September were reduced significantly by barley yellow dwarf virus (BYDV) infection. Intermediate planting dates in mid‐ to late October resulted in the best grain yield and quality in most years. Grain yields and test weights of November‐planted wheats were more variable and depended on specific environmental conditions. Grain yield and test weight responses to foliar fungicide depended on severity of specific foliar diseases, cultivar disease resistance, and environmental conditions, but significant yield increase occurred 77% of the time. Planting date had no significant effect on foliar fungicide effectiveness. Foliar fungicide had no effect on grain protein, head density, or kernels per head. Results indicate that a foliar fungicide application could be beneficial in protecting grain yield and test weight potential of both hard and soft winter wheat cultivars when conditions are favorable for foliar disease epidemics in the eastern Great Plains wheat‐growing region.