Water stress pattern for corn (first and second crop) in the Goias State and their consequences for the breeding program

Water stress is a major constraint to crop production and yield stability in many regions of the world. The cultivation of corn (Zea mays L.) in the Brazilian State of Goias, is frequent affected by periods of water stress resulting in yield reduction. During the process of developing new hybrids and cultivated varieties, new genotypes are selected based on their adaptability for a certain environment. In this context, plant breeding programs demand for information regarding as a function of the crop phenological phases. A crop simulation model was used to determine patterns of water stress for 12 locations of the State of Goias and 6 different sowing for both, first and second corn harvest periods. For the first harvest period, yield loss due to water stress was lower than 50%, with higher effects on yield in the beginning of the reproductive period. For corn as a second crop, yield loss is higher than 50% with frequent occurrence of terminal stress, which presented higher intensity during the stage of grain filling.