Oat Grain β‐Glucan Content as Affected by Nitrogen Level, Location, and Year

Abstract

β‐Glucan is a hypocholesterolemic water‐soluble fiber component of oat (Avena sativa L.) grain. Despite beneficial physiological effects associated with β‐glucan, few data are available on the effects of environment on β‐glucan content. The objective of this study was to examine the effect of N fertilizer, location, and year on oat grain β‐glucan concentration. Plantings were made at East Lansing and Caro, MI, in 1987,1988, and 1989. The experimental design was a split plot with three replications. Whole plots consisted of each of three N levels (0, 37, and 74 kg ha−1), and subplots consisted of five oat cultivars (Heritage, Korwood, Ogle, Pacer, and Porter). Increased levels of applied N tended to increase groat β‐glucan content. No significant differences in mean β‐glucan concentration were found between locations or among cultivars used in the study. β‐Glucan concentration was affected by year, with lowest mean values in 1988, intermediate concentrations in 1987, and highest values in 1989. Cultivar × year and cultivar × location interactions were significant. Correlations between β‐glucan content and test weight, hull percentage, grain yield, or groat weight were mostly small or nonsignificant. Correlations between groat protein and groat β‐glucan were significant, relatively large and positive in 1987 and 1989, but were non‐significant in 1988. The results of this research indicate that environment, especially soil N and year‐to‐year climatic variability, is important in determining oat grain β‐glucan concentration.