Controlled deterioration test to evaluate the physiological potential of sweet corn seeds

Abstract

The evaluation of the physiological potential of sweet corn seeds is essential in a quality control program and the choice of vigor tests using an adequate analysis methodology is essential to obtain reliable results. In this sense, this study aimed to standardize the methodology of the controlled deterioration test through combinations between time and temperature to evaluate the vigor of sweet corn seeds. Six lots of sweet corn seeds were characterized by the degree of moisture and the initial physiological potential through the following tests: germination, first germination count, cold test, electrical conductivity, accelerated aging, length and dry mass of normal seedlings, seedling emergence in sand, and emergence rate index. Subsequently, these lots had their initial water content adjusted to 20% using the wet substrate method. The seeds from the six lots were subjected to the controlled deterioration test under two temperatures for four periods, obtaining a completely randomized design in an 8 × 6 factorial scheme with eight combinations of time/temperature and six lots. Germination and the first germination count were evaluated after the deterioration test. The data were subjected to analysis of variance with a comparison of means by the Tukey test at a 5% significance. The results of the first count and germination tests after deterioration were subjected to a simple linear correlation study together with the initial characterization data. The combinations 8 h – 40 °C and 8 h – 45 °C in the controlled deterioration test were efficient in distinguishing the vigor of seed lots. The shorter exposure period and the first germination count after deterioration are more suitable for evaluating the vigor of sweet corn seeds.