Yield components of dryland winter wheat genotypes and response to seeding rate

Abstract

AbstractSeeding at the optimum rate is among many decisions considered crucial for crop production. The main objective of this research was to evaluate seeding rate responses for popular dryland winter wheat (Triticum aestivum L.) varieties and determine if variety specific seeding rates were warranted. The study was conducted from 2015 through 2018 at Colby, Garden City, and Tribune, KS. The response of four winter wheat varieties Byrd, T158, TAM 111 or TAM 114, and Winterhawk at five seeding rates (34, 50, 67, 84, and 101 kg ha−1) were studied. The main effects of seeding rate and variety affected grain yield in all 12 environments with only one exception. The lowest yielding seeding rate was 34 kg ha−1 with seeding rates of 84 and 101 kg ha−1 producing the greatest yields in all years and locations. Averaged across site‐years, there was a 17% yield advantage from selecting seeding rates 67 kg ha−1 and greater compared with the lowest seeding rate (34 kg ha−1). A combination of two or more yield components was a good predictor for wheat yield response to increased seeding rate. Lower than optimum seeding rates reduced grain yield while no agronomic penalty was observed to seeding rates above the optimum. We concluded a seeding rate of 67 kg ha−1 or more and variety selection are important factors for dryland winter wheat yield in the central Great Plains region. Results of this study do not support the necessity of variety specific seeding rate for dryland wheat production in the central Great Plains.