Phenological development of spring barley in a short-season growing area

Understanding the phenological development of barley (Hordeum vulgare L.) g rown under field conditions in its major growing area in the northern Great Plains, the Canadian province of Alberta, is important for the development of a crop model in this area. Five cultivars of barley registered for prod uction on the Canadian Prairies were grown at three locations in Alberta (B otha, Lacombe, and Olds) from 1993 to 1996. Measurements and estimates were made of 12 growth stages, the final leaf number of the main culm, phylloch rons, and leaf area indices (LAIs). The average phyllochron was 69.1 growin g degree days (GDD), and the final leaf number was 9.0. While location-year differences in GDD requirements to reach successive stages could be relate d to environmental conditions, the genotypic effects and genotype x environ ment (g x e) interactions would require that specific genotypic coefficient s he introduced into the model. For instance, 'Manley' required only 129 GD D to emerge and 493 GDD to reach Apex 1 but required 1495 GDD to reach phys iological maturity while Tukwa' required 133 GDD to emerge, 514 GDD to reac h Apex I, and only 1431 GDD to reach physiological maturity. Despite genoty pic differences in reaching specific growth stages, all cultivars had very synchronous growth under the wide range of environments encountered in the 12 location-years of these tests. This should allow for the development of a crop model for barley that will accurately predict growth stages and the allocation of resources to the growth and maintenance of plant structures ( leaves, stems, spikes, and kernels).