GxE interactions on ratooning of genotypes under trash blankets under cool/wet conditions : SRDC final report BS169S

Abstract

This project was established to investigate the magnitude of the genotype by environment interaction effect for ratooning under a trash blanketing under cool/wet conditions. A population of 50 genotypes was deemed necessary for this study but was not manageable in a fully replicated agronomic trial. Hence, it was necessary to assess a population of 50 genotypes and select a representative sub-population of 25. Accordingly fifty genotypes (40 unselected genotypes and 10 cultivars) were planted in the field at Bundaberg BSES station at fortnightly intervals from February to August 1997. Measurements of shoot emergence, stalk elongation and leaf appearance from each planting date were used to calculate base temperatures and thermal times for each parameter for each genotype. Plots of base temperature against thermal time were used to display the range of variation present in the population and to select a sub-population of 25 genotypes (21 genotypes and 4 cultivars) that represented this range. Population means and standard deviations for the selected 25 genotypes were not significantly different from those for the original 50 genotypes.