Physiological potential of soybean seeds treated with thiamethoxam and submitted to storage

Abstract

Bio-activators such as thiamethoxam have been used to increase the productive potential of plants, by means of metabolic and plant morphology modifications. Nevertheless, very little is known regarding the effectiveness of this insecticide when incorporated into lower quality level soybean seeds, particularly during storage. The objective of this work was to assess the influence of thiamethoxam on the physiological potential of soybean seeds with different initial vigor levels during four storage periods. Three vigor levels of cultivar Anta —low (35%), medium (70%) and high (85%) vigor—of soybean seeds were utilized in this experiment. The experimental design was completely randomized in a 3 × 2 × 4 factorial scheme—3 levels of vigor (low, medium and high); 2 seed treatments (with and without thiamethoxam) and 4 storage periods (0, 30, 60 and 90 days). The analyzed variables were: germination, first germination count, accelerated aging test, seedling length and emergence speed index. Thiamethoxam-treated soybean seeds benefit the physiological potential of both medium and high vigor seeds during storage up to 30 days. Whereas, the use of thiamethoxam was shown to be ineffective in improving the physiological quality of initial low vigor seeds.