Yield composition of two-rowed and multi-rowed barleys in drilled and single-plant populations in southern and northern Finnish experiments

Abstract

Abstract. Northern location was found to accelerate the development of multirowed barley varieties more than that of two-rowed varieties. In drilled trials tworowed varieties even required longer growing periods in the north than in the south.Single-plant populations developed more slowly than drilled populations and produced larger biological and grain yields per plant. They also produced higher numbers of culms and ears and higher proportions of leaves in the biological yield than the drillsown trials. On the other hand, adventitious shoots were more abundant and the ratio of grain yield to biological yield was lower in the single-plant trials than in the drilled trials.In general, multi-rowed varieties were significantly earlier than two-rowed varieties.In single-plant trials the two-rowed barleys, due to their good tillering capacity, gave a larger biological yield than the multi-rowed barleys. Grain yield in single-plant trials was in the south higher from the two-rowed varieties but in the north from the multirowed varieties. There were no differences due to barley type or locality in the proportions of different plant organs in the biological yield.Correlation coefficients between grain yield and some factors affecting it. is also treated.In breeding of cereal varieties with highest possible yielding potential, various factors of the yield have been under separate consideration ever since the 1920's (Engledow and Wadham 1923). Besides the actual yield components, viz. number of headed culms, number of grains per ear, and grain weight, attention has been directed in the past few decades to various other physiological and morphological factors. The core of the many works published on this subject has been reviewed by Thorne (1966) and Langer (1967). According to Thorne the size of grain yield depends mainly on the flag leaf and the assimilating plant parts situated above it. Langer similarly names assimilation as the prime factor but also emphasizes the importance of dry-matter distribution as well as that of the relationship between environmental and physiological factors in determining the yield.The aim of the present study was to investigate the formation and composition of yield in two-and multi-rowed barley varieties as well as the distribution of biological yield within the barley plants when grown in drill-sown and single-plant populations in southern and northern Finnish experiments.