EVALUATION OF CORN HYBRIDS UNDER CONTRASTING WATER AVAILABILITY CONDITIONS

ABSTRACT The current study aimed to assess adaptability and stability of corn hybrids regarding grain yields when sown in three different seasons in the Brazilian cerrado. The research was carried out at the Experimental Farm of the IF Goiano, campus in Ceres - GO. Pre-sowing fertilization was made with 20 kg ha-1 of nitrogen, 150 kg ha-1 of phosphorus and 80 kg ha-1 of potassium (04-30-16 formulation). Data were analyzed in a random block experimental design. We assessed tem corn hybrids (Truck, Fórmula, P30F53, P3646H, P30F35H, AGN 30A77H, AGN 30A37H, AG 8088PRO, DKB 390 and DKB Bi9440) in three sowing seasons (Nov. 18, 2011; Jan. 31, 2012 and Feb. 20, 2012) with three replications. Harvests were held on Apr. 4, 2012; Jun. 10, 2012 and Jul. 1, 2012. Each hybrid was assessed on yielding; and a graphical analysis was made to contrast hybrids and sowing seasons regarding stability and adaptability. Results showed a significant effect of the interaction between hybrids and sowing times. Therefore, we may state that the best hybrid in an environment would not be necessarily good in another. Thereby, we can infer that drought and corn genetic variability have diverse behaviors in each season. Over the two-dimensional graphics generated by GGE Biplot method, we observed an increased adaptability of AGN 30A77H when sown on Nov. 18, 2011 and on Jan. 31, 2012, followed by Fórmula; however, for P30F35H, it was on Feb. 20, 2012.