ENVIRONMENTAL STRATIFICATION OF THE CORN SECOND SEASON ON THE WEST AND MID-WESTERN OF PARANÁ

Maize is the main crop of Parana State second season, however the heterogeneity of the environmental conditions creates a challenge for the selection of adapted superior genotypes. The objective of this study was to stratify the environments of the Western and Mid-western mesoregions, to identify the environments that are essential for the selection of genotypes to ensure yield and crop moisture. Data sets regarding the yield and crop moisture of 16 commercial hybrids were used, sourced from Cooperativa Central de Pesquisa Agricola (COODETEC) Value for Cultivation and Use ("VCU"), testing in a randomized complete block design with two replicates, of crops grown in the interim-harvests of 2014 and 2015 in the west of Parana, in the Cascavel, Toledo and Foz do Iguacu microregions, the Mid-western Campo Mourao microregion and Mariluz, constituting the Caiua sandstone formation. The evaluation of the representativeness of the environments was carried out over one year of study, through environmental stratification analysis, using the factor analysis methodology. The results of the environmental stratification demonstrated that trials in the same environment provide redundant results, both for yield and for crop moisture. There were no gains for the selection of superior genotypes and the positioning in the different microregions yielded complementary data, aiding the selection. As such, for the West and West Central regions of Parana, the Cascavel, Palotina, Mariluz, Campo Mourao and Sao Pedro do Iguacu municipalities are indispensable for selection for yield and the Campo Mourao, Cascavel, Mariluz, Santa Terezinha do Itaipu, Palotina and Sao Pedro do Iguacu municipalities are indispensable for selection for crop humidity.