MAIZE GRAIN YIELD POTENTIAL AT TWO ENVIRONMENTS AND FIVE PRODUCTION SYSTEMS

Abstract

The determination of maize yield potential under different environmental conditions is important to identify limiting factors to improve crop productivity. This experiment was conducted aiming to determine the effects of the environment on maize grain yield at five production systems. The trials were conducted in Eldorado do Sul (30º05' S, 46 meters above sea level) and Lages (27º52 S, 930 meters above sea level). Both experimental sites were located in Southern Brazil. Five cropping systems (S) were tested at each place. S1, S2 and S3 corresponded to low, medium and high input management systems, respectively. S4 and S5 were systems established to maximize maize productivity. Grain yield ranged from 3.0 to 15.0 t.ha-1 in Eldorado do Sul and 3.2 to 15.9 t.ha-1 in Lages. No difference in grain yield between experimental sites was observed for S1 and S2. Conversely, maize productivity was 0.9 ton ha-1 higher in Lages than in Eldorado do Sul for S4 and S5. The environment effect on maize agronomic performance is more important when growers use management practices that allow them to accomplish high grain yield. Under these conditions, Lages presents greater potential to reach high yield plateau than Eldorado do Sul, due to its larger relation between the available radiation per thermal unit during maize early grain filling.