Evaluation of five corn hybrids (Zea mays, L.) at different maturity stages.: 1.: Productivity, morphologic traits and correlations

This study was conducted to evaluate productivity and morphologic traits of five Pioneer corn hybrids: P32R21, P30R07, P3041, P30F33 and P30F80 at different maturity stages. The treatments were assigned to plots of 7 x 8 m in a randomized block design, with four replicates. The samples collected of corn hybrid were adopted trying to estimate five plant maturity stages (30, 34, 38, 42 and 46% of dry matter [DM]). In the first maturation stage, some parameters (plant height, corn ear insertion height, plant weight, stem diameter, average number of corn ears) were evaluated, at harvest. For each maturation stage, the stem + sheath, leaf blade, grain, cob and straw were separated. The hybrid P32R21 and P3041 presented shown weight, diameter stem and plant height. Dry matter (DM) yield, green material, grain, leaf blade, and stem + sheath, in t/ha, at hybrids were different and presented significance at days after seeding (DAS). DM productivity increase, as the maturity stage hybrids advanced, was positively correlated.. with grain production increase (R-2 = 64.3%). DM production positively correlated with corn ear concentration (R-2 = 56.0%) and negatively (R-2 = -56.7%) with stem + sheath concentration (in relation to the whole plant).