RESPONSE OF AGRONOMIC AND BARLEY QUALITY TRAITS TO NITROGEN FERTILIZER

Malting and non-malting barleys fertilized with nitrogen were evaluated for qualitative kernel properties, agronomic performance, cultivar-treatment interactions, and the relationship between malt quality and agronomic performance. Sixty-seven kilograms per hectare of N increased the mean yield of five barley cultivars by 38 and 44% over the checks at Ft. Ellis in 1971 (environment 3) and 1973 (environment 4), respectively; 50 kg/ha of N increased yields over the checks at Aberdeen by 8% in both 1971 (environment 1) and 1973 (environment 2). Doubling the rates at either location did not increase yields further. Nitrogen treatments delayed heading dates at Ft. Ellis in 1971 and height of plants increased at Ft. Ellis but not at Aberdeen. Nitrogen increased barley diastatic power (DP), but decreased barley extracts. Barley protein percent increased significantly with each increment of applied N. A differential response of cultivars to applied N resulted in interactions for barley DP and percent protein. Cultivars × environments interacted for grain yield, heading date, barley DP, barley extract, and grain protein content. Nitrogen rates interacted with environment for plant height, barley extract, and grain protein content. Forty-six of 65 simple correlations between malting and agronomic or kernel traits were significant.