Competitive Abilities of Oat and Barley Varieties

Competitive ability of a plant genotype reflects its capacity to yield well and compete successfully for light, moisture, and nutrients when grown with similar or dissimilar genotypes. This trait is important to plant breeding because most breeding populations are propagated in mixed or competitive stands. The objective of this study was to assess the competitive abilities of oat and barley genotypes. Two sets of oat and barley genotypes were evaluated for competitive ability. Set I consisted of five oat varieties, and Set II consisted of two barley and three oat varieties. Neither set, when averaged, showed over- or under-compensation with respect to competitive ability. Genotypes within a set were highly variable fur mean competitive ability, and the effects of competition were even more variable for individual pairs. In the set with barley and oats, a competitive advantage or disadvantage shown by an entity tended to be consistent across competitors. Competitive advantages or disadvantages displayed by oat and barley genotypes for biomass and grain yield usually could be related to components of biomass or grain yield, respectively. Increases in biomass and grain yield were reflected in significant increases in numbers of spikelets, primary and secondary florets, and tillers per plant. Competitive advantages and disadvantages were greatest in the interspecific comparisons