Leaf Canopy as Related to Yield in Barley1

Abstract

AbstractThe purpose of this paper was to examine the relationship between leaf canopy area integrated over time and yield of grain, using mean values from 15 populations of spring barley (Hordeum vulgare L. Emend. Lam.). Mean values of selfed (F7 or BC6) unselected populations were used to minimize the confounding effects of linkages.No significant relationships was found for yield and leaf area canopy but significant relationships were demonstrated (P<0.05) between leaf canopy integrated over time and both fertile tiller number (X) and seeds/head (Y).We have found no relationship between leaf canopy area and yield but yield (W) was associated with (P<0.05). This indicates that the differences between populations were not due to differences in leaf canopy but were in some degree (r for W vs. Y = 0.63) associated with the shape of the yield parallelepiped.If we accept this reasoning, and there are ample data to support it, we arrive at the premise that the components of yield (X, Y, Z) are active participants in determining relative yield through the regulation of photosynthetic activities via a source‐sink relationship. Further the variation in leaf canopy experienced here resulted in part from the triggering mechanism of whether the genetic code called for high or low X, rather than the reverse of leaf canopy determining differences in X or Y.