RR soybean seed quality after application of glyphosate in different stages of crop development

Abstract

-In consequence of several studies and speculations concerning the issue of RR transgenic soybean after the application of glyphosate, additional scientific investigations became necessary to clarify the actual viability of the product use when applied in different developmental stages of the soybean crop. Therefore, this study was aimed to evaluate the physiological quality as well as seed health quality of RR soybean subjected to application of the herbicide glyphosate in different phonological stages of the transgenic soybean, cultivar CD 219RR. For this, an experiment with a complete block experimental design with treatments randomly distributed within the block, with four replications, was carried out. The assessed treatments were foliar sprayings of glyphosate in three increasing dosages [0 (control); 1,440 g ha -1 ; and 2,880 g ha -1 ] of acid equivalent, applied in two crop developmental stages: vegetative (V6) and reproductive (R2). The variables assessed were: germination; first count of germination; fresh and dry mass of seedlings, lengths of seedling and root; vigor and viability by the tetrazolium test; and seed health quality. Glyphosate application may adversely affect physiological quality of RR soybean seeds, when applied in dosages varying from 1,440 to 2,880 g acid equivalent per hectare at the stages V6 and R2.Index terms: Glycine max, transgenic seed, performance, herbicide.Qualidade das sementes de soja RR após aplicação de glyphosate em diferentes estádios de desenvolvimento da cultura RESUMO -Em virtude de estudos e especulações envolvendo a questão da soja transgênica (RR) após a aplicação de glyphosate, se fez necessário a busca de informações científicas que permitam diagnosticar a real viabilidade do uso do glyphosate aplicado em diferentes estádios fenológicos da cultura. Deste modo, o objetivo deste estudo foi avaliar a qualidade fisiológica e sanitária das sementes de soja RR após a aplicação do herbicida glyphosate na cultura da soja transgênica, cultivar CD 219RR. Para tanto, foi desenvolvido um ensaio em delineamento de blocos completos com tratamentos casualizados, com quatro repetições, em que os tratamentos avaliados consistiram da pulverização foliar contendo glyphosate, em três doses crescentes (0, 1.440 e 2.880 g de equivalente ácido por hectare), aplicados em dois estádios de desenvolvimento da cultura: vegetativo V6 e reprodutivo R2. As variáveis avaliadas foram: germinação; primeira contagem de germinação; massa fresca e seca de plântulas; comprimento de plântulas e raízes; viabilidade e vigor, pelo teste de tetrazólio; e qualidade sanitária das sementes. A aplicação de glyphosate pode afetar negativamente a qualidade fisiológica das sementes de soja, quando aplicado em doses de 1.440 a 2.880 g do equivalente ácido do produto por hectare, nos estágios fenológicos: vegetativo V6 e reprodutivo R2 .Termos para indexação: Glycine max, semente transgênica, desempenho, herbicida.1

Glyphosate, isolated or in associations, at agronomic performance and seed quality of the RR®2 soybean

“…However, ALBRECHT et al (2012b) observed that the application of glyphosate (g e.a. ha -1 ) may adversely affect the physiological quality of soybean seeds at the V6 and R2 stages.…”

Proteomic Profile of Glyphosate-Resistant Soybean under Combined Herbicide and Drought Stress Conditions

“…Similar to the results of the present study, glyphosate-based herbicides have been associated with impaired metabolic relationships even in crops that express resistant EPSPS. It has been previously shown to have a phytotoxic effect on seeds [68] and to alter carbon flow and oxidation [17]. The expression of stress-related genes has been observed in early GM soybean seedlings sprayed with glyphosate [69].…”

Impact of Late‐Season Herbicide Applications on Winter Canola Yield and Seed Quality

“…On average, glyphosate applications during these periods resulted in a 5.1, 4.2, and 1.3% decrease in oil content during bolting, early flower, and mid-flower, respectively. Although not in canola production systems, the application of glyphosate has been shown to affect seed quality parameters (Zobiole et al, 2010;Albrecht et al, 2012Albrecht et al, , 2014. It is theorized that as glyphosate alters activity of the shikimate pathway for development within the plant (Saltveit and Mencarelli, 1988), the plant has limited ability to synthesize important compounds needed to produce oil in the seed (Herrmann and Weaver, 1999).…”