Mixture performance of phenotypically contrasting barley cultivars

Abstract

There is lack of information on the yield and yield component performance of same-row and alternate-row mixtures (SRM and ARM) of widely contrasting barley (Hordeum vulgare L.) phenotypes. Therefore, four phenotypically contrasting spring barley cultivars, each selected to represent a unique combination of spike type (two-row or six-row), height (short or tall) and days to maturity (early or late) were used in 1991 and 1992 in field experiments at the Elora Research Station in Ontario, Canada, with the objective of determining whether a yield and/or yield-component advantage could be associated with same-row or alternate-row mixtures of barley cultivars. The four cultivars chosen for the study were each grown as monocrops, and in all six possible binary (two-cultivar) mixture combinations as same-row or alternate-row mixtures, in a randomized complete block design. A 13% yield increase of early, short:late, tall SRM over the midcomponent (weighted mean of the components grown in monocrop) yield in 1991, and 14% yield increase of early, tall:late, tall SRM over the midcomponent yield in 1992 was observed. Between the 2 yr, cultivars in ARM produced similar or significantly greater yields than the monocrop yields, except in 1991, when the late, short cultivar in ARM with early, tall cultivar produced significantly lower yields than in monocrop. The spike number m–2 was similar for all mixtures and their midcomponents, except in 1992, when early, short:late, short in ARM produced 7.0% more spikes than the midcomponent. The results of this study indicate a possible yield advantage of phenotypically contrasting barley mixtures compared to monocrops, with early, short:late, tall and early, tall:late, tall in same-row mixtures having the best combining abilities. Key words: Barley, phenotypes; mixture, same row; mixture, alternate-row; maturity; height