| Ontogeny and radiation use efficiency of old and new grain sorghum genotypes (Sorghum bicolor (L.) Moench) were studied. New genotypes are better adapted to tropical environments. Two temperature-controlled glasshouses (17 and 25;Impacts of these genotpye by environment interactions in field environments were simulated using the sorghum crop model SORKAM with 40 years generated weather data for sites from Nebraska to southern Texas. Development and potential yield were little affected by ontogeny differences between old and new hybrids. Enhanced radiation use efficiency at high temperature increased potential yield 3, 18, 23, 26, and 27% for North Platte, Manhattan, Lubbock, Temple, and Weslaco, respectively. This north-south trend suggested enhanced radiation use efficiency was associated with improved adaptation to tropical environments of new hybrids. However, the trend was not entirely consistent with other field studies.;This study demonstrated that modelling can play an important role in linking physiological research with crop improvement.;Glasshouse and field experiments examined development rates from emergence to floral initiation (GS1) and initiation to anthesis (GS2) for old and new genotypes. The glasshouse experiments indicated similar responses to photoperiod for all genotypes at both temperatures (20 and 25... |
