Phyton (Buenos Aires)
versión On-line ISSN 1851-5657
RINCON-TUEXI, Juan Arnoldo et al. High temperature and water stress during flowering in tropical corn populations. Phyton (B. Aires) [online]. 2006, vol.75, pp. 31-40. ISSN 1851-5657.
Effects of water and high temperature stresses, either separately or in combination, over biomass accumulation, grain yield and its direct components grain number per ear and individual grain weight], as well as harvest index were determined in four tropical maize populations. Results indicated that water stress do not significantly affect the studied variables, due to the absence of a severe water stress during flowering. This was the result of the fallen precipitation at this time. The most important factor in this study was high temperature, which significantly reduced all studied variables, except individual grain weight. High temperature stress reduced aerial biomass accumulation in 45%, being the ear the more affected organ (66%). Grain yield was also reduced (74%) mainly due to the high loss of grain number per ear. As a result of the decreased aerial biomass accumulation and grain yield, the harvest index was also reduced (52%). All studied maize populations showed susceptibility to high temperature stress during the flowering phenological stage. This resulted in large grain yield and aerial biomass accumulation losses. This response indicated that selection for improving water stress tolerance in these populations does not necessarily imply obtaining simultaneously a greater resistance to high temperature.
Palabras llave : Zea mays L; Water stress; High temperature stress; Biomass.