SEED PRODUCTION OF SINGLE CROSSES OF MAIZE HYBRIDS IN TLAXCALA, MÉXICO

Abstract

The Instituto Nacional de Investigaciones Forestales, Agrícolas y Pecuarias (INIFAP) of México produces seed to attend the demand of certified seed producers of maize hybrids (Zea mays L.), and also develops technology for the identification of the optimal location for seed production and agronomic management. In this study yield and physical quality of seed of female single crosses of commercial maize hybrids were evaluated in two population densities (63 000 and 83 000 plants ha^-1) at two localities of Tlaxcala State (Espíritu Santo, 2480 masl; Francisco Villa, 2540 masl). A randomized complete blocks design with three replications was used in each location, and a combined statistical analysis with factorial arrangement of seven single crosses and two plant densities was applied. We found significant differences (P ≤ 0.05) among locations, single crosses and location x population density interaction for seed yield and seed size. Differences were also present between plant densities for seed size. Seed yield of the single crosses of hybrids ‘H-64’, ‘H-66’ and ‘H-68’ (7.0, 6.4 and 6.2 t ha-1) was higher (P ≤ 0.01) that yield of the single cross of ‘H-50’ (4.4 t ha^-1). No differences (P ≤ 0.05) were detected between plant densities for seed yield, although at 83 000 plants ha^-1 seeds were smaller in size and weight, compared to the density of 62 000 plants ha^-1. The high yield and good physical quality of seeds of single crosses from maize hybrids ‘H-64’, ‘H-66’ and ‘H-68’ shows that it is feasible to produce their seeds in these two localities of Tlaxcala State.