Desempenho agronômico e fisiológico de plantas e sementes de milho sob influência do alagamento temporário do solo

Abstract

This work consists of two experiments and aimed to evaluate physiological attributes plant growth, physical characteristics and vigor expression of maize seeds under the influence of temporary flooding. For this, we used a corn genotype from the city of South Amethyst - RS, and the experiments were conducted at the Federal University of Pelotas. The first study was conducted in experimental design of randomized blocks in a factorial 4x6 (four periods of flooding and six seasons collection) with four replications. We evaluated the total dry matter, the dry matter production rate, relative growth rate and net assimilation, leaf area index, the ratio of area and leaf mass, assimilated partition, harvest index, emergence and seedling emergence speed index. The second study was conducted in experimental design of randomized blocks with four treatments and four replicates, and evaluated the weight of a thousand seeds, number of seeds per head, the number of rows per corn cob, the electrical conductivity in seeds, the length of the part air and dry matter of shoots. The growth and partitioning of assimilates were adversely altered when plants were exposed to periods of 48 and 72 hours of flooding, while the expression of seed vigor is reduced when plants were exposed for 72h to flooding period. The weight of one thousand seeds, seed number per corn cob, number of row per corn cob and electrical conductivity seeds were reduced when plants were exposed to 72h period of flooding. The flooding for 72h, adversely affects the growth, physical characteristics and the expression of vigor of maize seed.