Selection of half-sib maize for second crop condition in south Tocantins state

Abstract

The objective of this work was to select progenies of half-sib of maize under conditions of second crop in the south of the State of Tocantins. For this, 169 families of half-sib were evaluated in an experiment in the municipality of Gurupi, TO. These families are derived from the "Robusto" variety from the maize breeding program of Pioneira Ltda. The selection of the respective families was performed based on the main characteristics related to yield potential of corn grains. High correlations (above 90%) were observed between the characteristic grain yield and spike weight and stalk diameter. The negative correlation between grain yield and the male and female flowering interval suggests that shorter intervals between male and female flowering are associated with higher yields. In the indirect gains estimates, what attracted attention was the gain in the order of 23.96% in yield when the selected characteristic was DC. In the direct selection, the highest total gain was found in the characteristic grain yield (108.1%). The study allowed to conclude that the proposed selection index allows the identification of superiors families of half-sib for multi characteristics of interest in maize improvement in the second harvest. The progenies selected for future recombination and lineage extraction are 32, 73, 12, 51, 62, 52, 50, 122, 128, 117, 133, 42, 47, 21, 107, 5, 74, 101, 139 , 8, 85, 33, 155, 118, 7, 96, 146, 55, 49, 143.