Agronomic characteristics of maize hybrids (Zea mays, L.) at different maturity stages

The objective of this study was to evaluate the production and physical composition of three maize hybrids (Zea mays, L.) for silage production at six maturity stages. The hybrids evaluated were Maximus VIP3, Defender VIP and Feroz VIP. The experiment was conducted in a completely randomized block design with four replicates. The mean plant heights observed at harvest time (2.33 m, 2.45 m and 2.40 m) demonstrated that all materials were medium-sized hybrids. A positive correlation was observed between plant height and height of the ear insertion, varying from 0.86 for the Feroz VIP hybrid to 0.88 for the Maximus VIP3 hybrid, but these two variants had no correlation with the productivity data. There was a significant difference for the production of fresh biomass at the R1, R2 and R5 stages, with Maximus VIP3 obtaining the highest yields. The proportion of grains in the physical composition of plant varied between hybrids, where Maximus VIP3 and Defender VIP (482.2 and 461.7 g kg(-1), respectively) were superior to Feroz VIP (429.7 g kg(-1)). With the advancement of maturity, there was a decreasing linear behavior for stem and leaf participation, with reductions of 3.8 g kg(-1) and 4.5 g kg(-1), respectively, per day (R-2 = 0.79 and 0.80, respectively), quadratic behavior for bracts and corncob and a linear increase in grain participation in the plant structure, with an increase of 7.7 g kg(-1) per day (R-2 = 0.88). In general, the three hybrids present good characteristics for silage production and permit harvesting in the hard grain stage, allowing the addition of starch in relation to the farinaceous grain stage.