Variation in the chemical composition and test weight of barley and wheat grain grown at selected locations throughout Manitoba

Abstract

Cultivars of wheat (n = 8) and barley (n = 6) were grown at 12 locations throughout Manitoba over 3 consecutive years. Test weight (TWT = weight of whole grain per volume), and the concentrations of protein, starch, fat, NDF and ADF in the grain from wheat and barley differed (P < 0.05) among cultivars of each grain. Correlation coefficients between measurements were calculated for barley: TWT vs. starch, r = 0.43; TWT vs. NDF, r = −0.66; TWT vs. ADF, r = −0.51; starch vs. NDF, r = −0.49; and they were also calculated for wheat: TWT vs. protein plus starch, r = 0.26; TWT vs. NDF, r = −0.44; TWT vs. ADF, r = −0.31; protein vs. starch, r = −0.50. Variation for TWT and the concentrations of protein, starch, fat, NDF and ADF in the grain from barley and wheat were due both to differences among cultivars and the effect of environment (location and year of growth) on those differences among cultivars. Effects of environment differed among measurements. Variance due to the interaction between cultivar, and location and year of growth (cultivar × environmental variance) was 7.5 and 14.0% of total variance (total variance = environmental variance plus cultivar × environmental variance) for protein in barley and wheat, respectively. Cultivar × environmental variance was also low and ranged from 24.0 to 35.4% of total variance for starch, NDF and ADF in barley and for ADF in wheat. The lower the percentage of cultivar × environmental variance the more predictable were the differences for a measurement among cultivars of a grain across environments. Key words: Grain, wheat, barley, composition, test weight, Manitoba