Evaluation of maize top crosses in southern Tocantins

Abstract

The objective of this study was to evaluate maize top crosses in southern Tocantins, Brazil. The experiment was carried out in the municipality of Gurupi  in December 2008 using 81 maize genotypes. The experimental design used was 9x9 lattice with two replications, and the plant height, ear height, ear length and diameter, 100 seeds weight, hectoliter weight and grain yield were evaluated. The ear length and diameter showed no significant differences for the genotypes. The variation coefficients in all analyzed variables indicate a good experimental accuracy. The productivity showed three statistical groups, with 43 genotypes forming the highest means group, with genotype T-118-1-2 presenting the highest yield (8382 kg ha^-1), higher than all evaluated commercial hybrids. The inbreed lines T-VERM F1, T-29-1-2, T-113-1, T-65-2-1, T-38-1-1, T-12, T-134-4-2, T-29-1-1, T-73-1-2, T-55-1-3, T-111-1-9, T-73-1, T-118-1-2, T-134-1-1, T-68-1-2, T-68-2-1, T-65-1-2, T-118-1-1 and T-12-PVHIB showed a set of favourable characteristics for the development of  commercial genotypes for grain production in southern Tocantins.