KERNEL AND SPIKE CHARACTER INFLUENCE ON TEST WEIGHT OF SOFT RED WINTER-WHEAT

Although genotype affects test weight in wheat (Triticum aestivum L.), little is known about how physical kernel characteristics affect this quality parameter. The influence of seed and spike characteristics on test weight was investigated in 24 soft red winter wheat (SRWW) culti vars grown in six environments. Seed characters and test weight were m easured using grain samples from which shriveled kernels had been remo ved. Removal of the shriveled kernels increased test weight an average of 36 kg m(-3) and reduced the total variation in test weight due to environment and environment by cultivar interaction. Of the seed and s pike characters measured, only flour protein content and the average n umber of seed within a spike were significantly correlated to test wei ght (r = 0.56 and r = -0.41, respectively) at P = 0.05. Average kernel length and width and the average number of seed per spikelet showed w eak negative correlations with test weight (r = -0.38, r = -0.35 and r = -0.35, respectively) at P = 0.10. Increasing kernel density was wea kly associated with increasing test weight (r = 0.39, P = 0.10). Thous and-kernel weight, diversity of seed size, kernel length to width rati o, spike length, number of spikelets per spike, and spike density were not directly related to test weight. Results of this study indicate t hat among the characters measured, the amount of shriveling and the pr otein content of the grain were the most important determinants of tes t weight in SRWW cultivars.