Retardamento da polinização : granação e qualidade de sementes de milho

Abstract

Fecundation in maize plants depends, among other factors, on climatic and genetic elements, being of significant importance the viability of pollen and styles-stigma. This way, the objective of this work was to evaluate whether the stages of development of the style-stigma affect grain and seed quality of different maize genotypes. For this, an experiment designed in randomized blocks was installed, in a 6 × 8 factorial scheme, with 6 maize genotypes (L170, L134, L159, L169, 160 e SHL20) and 8 pollination phases, with 3 replications. The pollination phases were: open pollination and pollination varying sequentially from the first to the seventh day after the emission of the style-stigma. The sowing was conducted between 03/02/2022 and 03/12/2022 with the harvest being carried out on 01/07/2022. The number of seeds per ear, number of rows of grains per ear, length of ear, mass of a thousand seeds, percentage of germination, percentage of vigor and moisture content were evaluated. Data were subjected to analysis of variance and comparison between qualitative and quantitative effects by means of contrasts, which was the comparison between open pollination and days of controlled release, using the F test at 5% probability, and regression analysis for the quantitative effects, which was the comparison between the days of controlled release of the styles-stigmas. The results obtained indicate varied trends among the studied genotypes, depending on the evaluated parameters. All genotypes have yield losses per spike in the controlled release of style-stigma. The release of style-stigma until the fourth day does not show difference for all genotypes. For the number of seeds per ear, the number of rows of grains per ear, the length of the ear, moisture content and the mass of a thousand seeds, the L160 genotype was more stable, reducing only the number of seeds per ear. The L170, L159 and L160 genotypes proved to be stable for seed physiological quality and the L134, L169 and SHL20 genotypes were unstable.