Vigor tests based on stress tolerance of sunflower seeds

Abstract

This study aimed at identifying procedures based on stress tolerance of sunflower seeds, which would be efficient for testing their physiological quality. Seeds of Catissol and Multissol cultivars, each represented by five lots, were used to meet this objective. Their physiological quality was determined by the following tests: germination, first count of germination, seedling emergence, emergence speed index, accelerated aging and controlled deterioration. The experiment was conducted in completely randomized block design, with four replications for each cultivar and test. The accelerated aging test in chambers containing either water (traditional method) or saturated NaCl solution (modified method) was performed under three temperature-time conditions (42 °C/24 h, 42 °C/48 h, and 42 °C/72 h). The seeds were submitted to aging in a double boiler at 42 °C for 72 h, with seed moisture content adjusted to 20, 22 and 24%. It is concluded that the accelerated aging (traditional method or saturated NaCl solution) and controlled deterioration tests were not efficient in detecting differences among seed lots of sunflower.