QUALIDADE FISIOLÓGICA DAS SEMENTES DE GIRASSOL SUBMETIDAS A SECAGEM E AO ARMAZENAMENTO

Abstract

Several aspects, such as deteriorating processes, can promote degenerative changes in the physiological potential of seeds during storage. With this, the drying method appears as an alternative to allow conservation during storage. The objective of this work was to study changes in the physiological quality of sunflower seeds as a result of drying and storage. The seeds were submitted to drying at temperatures of 40, 50, 60, 70 and 80°C, being later stored in a laboratory environment for 8 months and the analyzes occurred every two months. The characterization of the quality of the seeds was through the analysis of water content, electrical conductivity, germination, average germination time, normal seedlings, germination speed index, seedling emergence in sand and emergence speed index. The water contents showed oscillation for both parameters. The electrical conductivity at 40ºC showed higher values. The percentage of germination at time 0 showed extremely low values, but during storage its potential was expressive, with the lowest values found for the temperature of 80 °C. For normal seedlings, there were low averages in relation to temperatures and storage time. The storage period did not influence the loss of seed vigor. High drying temperatures (70 and 80 ºC) affect seed quality negatively, and are not recommended for vigor maintenance.