ENVIRONMENTAL STRATIFICATION FOR MAIZE VARIETIES EVALUATION AND RECOMMENDATION IN GOIÁS STATE, BRAZIL

Abstract

The objective of this study was to identify environmental strata for maize varieties recommendation and key locations for this kind of trial in Goiás State, Brazil. Forty-seven trials from the maize varieties evaluation program, carried out at Secretaria da Agricultura, Pecuária e Abastecimento do Estado de Goiás (Seagro-GO), over four growing seasons (2002/2003, 2003/2004, 2004/2005, and 2005/2006) were evaluated. The environmental stratification was performed by using the winner genotypes AMMI approach, which allows, due to the study of genotypes by environment interactions (GxE), the identification of the genotypes most adapted to each environment, as well as the constitution of similar environmental location groups. Two environmental strata showed stability throughout the evaluated growing seasons, mainly for the group formed by the locations of Ipameri, Inhumas and Senador Canêdo, stable along the four years, and the one composed by Porangatu and Orizona, stable throughout three growing years. From that, it is possible to reduce at least 16% of the currently used test locations and/or replace them by other locations, aiming to increase the efficiency of the varietal evaluation in that region. The ALBandeirante cultivar showed high yield potential and adaptability to the maize crop conditions in Goiás.

KEY-WORDS: AMMI analysis; winner genotypes; GxE interaction; adaptability; zoning.