Ontogenetic Evaluation of Grain Yield and Time to Maturity in Barley
1997
Dofing, Stephen M.
High grain yield and early maturity are desirable characteristics in many regions in which barley (Hordeum vulgare L.) is grown. However, negative correlation between these traits makes their joint improvement difficult. Previous research quantifying the contribution of traits to grain yield has not included their effects on time to maturity, and often has not included important developmental traits related to time to maturity. The purpose of this research was to quantify the determination of grain yield and time to maturity in barley, using a model that included developmental traits such as leaf number, phyllochron, and grain fill rate. A genetically diverse group of 24 barley genotypes was grown for three years at Palmer, AK, and significant causal relationships determined using path analysis and stepwise regression. Longer vegetative periods (time to heading) resulted in higher grain yield, but longer heading-to-maturity periods had no effect on grain yield. Faster grain fill rate resulted in higher grain yield and shorter grain filling period. In environments similar to these, the competing objectives of high grain yield and acceptably early maturity were realized by cultivars with relatively long preheading periods and relatively short reproductive periods, without exceeding the critical level of early maturity required by growers. Longer preheading periods appear necessary to develop an adequate number of kernels per spike and sufficient number of leaves to provide photoassimilate during grain fill. These results provide breeders additional insights for decisions involving choice of germplasm and selection criteria in breeding programs. Contribution from the Agric. and Forestry Exp. Stn., Univ. of Alaska Fairbanks.
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