This study was conducted to evaluate the structural component concentrations of five hybrids of Pioneer corn: P32R21, P30R07, P3041, P30F33 and P30F80, at different maturity stages. The treatments were used in 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 phases of maturity of the plant (30, 34, 38, 42 and 46% of dry matter [DM]). For each maturation stage, was done separation of stem + sheath, leaf lamina, grain, cob and straw. After the weight and with posterior determination of DM crude, it was possible to obtain the concentrations and relations (%) of grain, cob + straw, ear of the corn, stem + sheath and leaf lamina in the whole plant of five hybrids at different maturation stage. For all the evaluated parameters, the hybrids were different and showed significant effect at days after seeding (DAS). It was observed that as the plant maturity stage (DAS) advanced, an increase of ear and grain concentration and a decrease of the structure component (leaf lamina, stem + sheath) in a DM the whole plant were observed.
corn; ear; grain; stages of maturity; vegetative fraction