Qualidade fisiológica de sementes de milho doce sob diferentes condições de armazenamento

Abstract

The seed of sweet corn is more susceptible to injury in storage that the seeds of common corn. Due to this characteristic, the author of the present study aimed to evaluate the physiological quality of seeds of sweet corn stored under different conditions. The experiments were conducted at the Seed Analysis Laboratory of the Federal University of Lavras/MG, between the months of June/09 and March/10. The seeds used were SwB585 cultivar of supersweet corn classified as flat sieve and round sieve. The seeds were placed to soak in distilled water with GA3 at concentrations of 0, 10 and 20 mg.l-1, after the drying were packed in vacuum plastic and paper packaging, then stored in two environments (cold = 10 °C and room temperature = ± 25 °C). The following determinations were used to evaluate the physiological quality of the seeds: germination test, cold test, electrical conductivity, accelerated aging, emergence speed rate, dry matter weight of aerial part and dry matter weight of root. We used the completely randomized experimental design, in factorial scheme (2x3x5), corresponding to the two environments, three doses of GA3 and five assessment times (0, 60 ,120 , 180 and 240 days) with four replications. Analysis of variance was performed considering the two forms of seed separately and involving the two types of packaging. It was verified by the cold test in flat seeds and electrical conductivity in round seeds that the packages influence the physiological quality; it was found in both types of seeds, which in refrigerated storage at 10 °C was more efficient in maintaining the physiological potential of seeds. Gibberellic acid loses effect on seed performance with the course of time of storage. The vigor of sweet corn seeds decreases linearly with the passage of storage time independently of shape of the seed.