RESIDUE PRODUCTION OF SEMIDWARF AND CONVENTIONAL WHEAT GENOTYPES

Crop residues are important components of conservation tillage systems, but little information is available on genotypic differences in residue production, particularly with regard to the differences between semidwarf and conventional (tall) genotypes. The objective of this research was to determine the influence of genotype and environment on height and non-grain residue production of semidwarf and conventional-height wheat (Triticum spp.). Locally adapted semidwarf and conventional height common (T. aestivum L.) and durum (T turgidum L. var. durum) wheat genotypes were grown in up to three environments (fallow, irrigation, and stubble) during the years 1983 to 1988, and 1991. Residue yields of semidwarf and conventional genotypes, and of short and tall conventional genotypes, were compared within and between wheat classes. Within classes, residue yield of semidwarf genotypes tended to be lower (P < 0.05) than that of conventional genotypes. Residue yield of the semidwarf HY320 from the high yielding Canada Prairie Spring class was similar to that of the conventional Canada Western Red Spring cultivar Neepawa. Within the conventional height group, the tallest genotypes tended to have higher residue yields than the shortest genotypes, although the differences were not consistent. Residue yield differences among genotypes were associated with variation in grain yield, plant height, and harvest index.