BEHAVIOR OF EARLY CORN VARIETIES IN THE SEMIARID AND ARID CENTRAL-NORTHERN REGION OF MEXICO

Abstract

Twenty early corn (Zea mays L.) varieties were evaluated under the rainfed conditions prevailing in the northern highland region of México (250-500 mm of rain, 60 to 100 d of growing season, and mean temperature from 16 to 21°C), and at Etla, Oax. with similar environmental conditions (645 mm of rain in 80 to 100 d, and mean temperature of 20.6 °C). The study was carried out from 1997 to 1999. A randomized complete blok design with four replications was used for all locations. The corn yield was analyzed by combinig years and varieties, and localions and varieties. The combination of years, localitions and varieties was not evaluated because of the variable number of traits through years and locations. The late varieties were more productive in locations with higher precipitation and longer growing season. Intermediate and early varieties over yielded the late varieties when growing under deficient rainfed conditions. The mean yield of landraces varieties used as controls, was higher than most of the other varieties, thus suggesting a delailed evaluation of these landraces taking into account traits such as plant sanity and uniformity, and yield potential.