APPLICATION OF SPATIAL ANALYSIS TECHNIQUES TO ADJUST FOR FERTILITY TRENDS AND IDENTIFY INTERPLOT COMPETITION IN EARLY STAGE SUGARCANE SELECTION TRIALS

摘要

Sugarcane breeding programs in Australia use large unreplicated trials to evaluate clones. Commercial varieties, which are replicated, provide a method of local control of soil fertility. Although such methods may be useful in detecting broad trends in the field, variation often occurs on a much smaller scale. Methods such as spatial analysis have been successfully applied to cereals and have resulted in increased accuracy and precision in the estimates of variety effects. In this paper, spatial analysis methods are applied to unreplicated sugarcane selection trials. Competition in tonnes cane per hectare and trend in sugar content were substantial in many of the trials and often there were large differences in the selections between the spatial andcurrent method. A joint modelling approach for tonnes sugar per hectare in response to fertility trends and interplot competition is recommended.