Techniques for mitigating the symptoms of injury of glyphosate in RR and RR2 soybean

Abstract

The use of high doses of glyphosate, even if tolerant (RR) technology, can cause leaf insults, such as the yellow flashing effect, which is characterized by a yellowing of the leaves, which can lead to loss of productivity. The present study aimed to increase doses of glyphosate in tolerant soybean. Tests were conducted in greenhouse 2015/2016 and 2016/2017, in Palotina, western region of Paraná in a completely randomized arrangement. The first assay was conducted in a 3x8 factorial set (products x cultivars) with four replicates mixed with glyphosate with growth regulator, one compound of amino acids and one source of manganese, and in the second a factorial scheme 6x3 (products x cultivars) using glyphosate, a growth regulator, a source of manganese and the glyphosate associated to the other products, besides a control without application. A phytotoxicity, chlorophyll index, shoot dry mass and root mass were evaluated visually. A variation of response to cultivar was observed due to characteristics of each genotype. The differences between the products were not observed. A cultivar ‘M6210’ presented greater symptom of phytointoxication while cultivating ‘BMX Ponta’, presenting greater tolerance. No phytotoxic effect was observed for the test.