COMPONENTS OF YIELD OF RECOVERABLE SUGAR IN RANDOM AND IMPROVED SUGARBEET POPULATIONS

Abstract

Path coefficient analyses indicated that the components of recoverable sugar yield rank differently in relative importance in improved populations of sugarbeet (Beta vulgaris L.) than in relatively unimproved populations. Root weight was a more important yield component than sucrose percentage and over twice as important as purity in unselected populations. Root weight and sucrose percentage contributed about equally in improved populations, but the importance of both to recoverable sugar was substantially greater than in the unselected population. Purity was about twice as important a component in the improved population as it was in the unselected population. Results suggest that the emphasis of breeding programs will need to change with changes in the genetic structure of the improved population. Because of the lack of negative indirect effects in the commercial population, the association of recoverable sugar and sucrose percent was nearly twice as high as compared to the relatively unimproved random hybrid population.