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.

Agrochemicals and storage times on soybean seed vigor

“…The results obtained for seed germination and the GRI indicated that all pesticides, except thiamethoxam, significantly reduced seed germination during storage of '97Y07RR' soybean seeds, in comparison with the control. However, Dan et al (2013) reported that thiamethoxam, applied at 90 days of storage, reduced seed vigor of ' Anta 82 RR' soybean. This shows that the tolerance of the genotype to the insecticide at different storage times is an intrinsic factor for seed vigor.…”

“…However, the environmental conditions of storage, without temperature and humidity control, as well as the application of pesticides on seeds, may reduce germination and seedling survival, due to potential phytotoxic effects (Dan et al, 2010(Dan et al, , 2013. It should be noted that pesticide use associated with a long storage period is also harmful to seed vigor (Krüger et al, 2016).…”

“…2017 DOI: 10.1590/S0100-204X2017000200007 be retarded by controlling temperature and moisture conditions in the environment or by preventing pest attacks using chemical treatment (Deuner et al, 2014). Despite this, the use of agrochemicals on seeds during prolonged storage periods significantly reduces seed germination and vigor (Dan et al, 2010(Dan et al, , 2013Deuner et al, 2014). The results obtained for seed germination and the GRI indicated that all pesticides, except thiamethoxam, significantly reduced seed germination during storage of '97Y07RR' soybean seeds, in comparison with the control.…”

Physiological and sanitary quality of soybean seeds under different chemical treatments during storage

“…Hence, Brzezinski et al (2015), evaluating the effect of anticipated treatment of soybean seeds with different combinations of chemical products, concluded that they damage crop performance. Likewise, Dan et al (2013) observed reduction in the emergence of seedlings derived from soybean seeds treated with the insecticide thiamethoxam after three months of storage.…”

Seed treatment and pre-inoculation of soybean: effect of storage period and agrochemicals on the physiological quality of seed and yield

“…Seed treatment with carbendazim + thiram + thiamethoxan, fludioxonil + metalaxyl-M + imidacloprid + thiodicarbe, fludioxonil + metalaxyl-M + thiamethoxan also reduced seed vigor compared to the control after 51 days of storage of the seeds (Table 3). Previous studies did not observe a negative effect of application of imidacloprid only (Castro et al, 2008;Dan et al, 2013Dan et al, , 2012, however, the association of imidacloprid + thiodicarb reduced vigor and germination of soybean seeds (Dan et al, 2012;Bortoletto et al, 2017). Sometimes when products are combined, there can be modification in some characteristics of the mixture that become more toxic to the seeds compared to the product alone.…”