Crescimento e absorção de fósforo do feijoeiro comum ‘Xodó’ sob efeito de subdoses de glyphosate

Abstract

It was evaluated the effect of glyphosate reduced rates on growth and phosphorus (P) uptake of 'Xodó' common bean (Phaseolus vulgaris L.) genotype. The experiment was conducted in factorial scheme 4 x 2, in randomized blocks design with four replications, with the first factor constituted by reduced doses of 0, 4.32, 8.64 and 12.96 g ha-1 equivalent acid (e.a.) of glyphosate and the second factor consisted of soil P rates (50 and 250 mg dm-3). Evaluations were conducted 30 days after glyphosate application (DAA). The reduced dose of 12.96 g ha-1 stimulated common bean cv. Xodó growth as well as increased P concentration in stem and P content in shoot dry mass plants.

Hormetic effect of glyphosate persists during the entire growth period and increases sugarcane yield

“…In the early stage of development, there is intense meristematic activity because of the development of the root system, the tillering, and the emission of the new tillers; P is essential for this cell division, because of its role in the structure of nucleic acids . Rabello et al . observed an increase the aboveground DM, number of leaves, and shoot P content in common beans ( Phaseolus vulgaris L.) after application of glyphosate in the low dose range of 4.32 to 12.96 g a.e.…”

“…Previous research showed that low doses of glyphosate can have a positive effect during the early development stages of different plants, specifically by promoting plant height and increasing the biomass or the development of shoots and roots . The stimulus detected does not only vary according to the species and glyphosate dose; the time point in the phenological phase at which glyphosate is applied can also influence plant response .…”

“…Plant growth is strongly linked with phosphorous (P) supply, but P absorption is a complex process that requires numerous carriers . Some research has shown that subdoses of glyphosate lead to the induction of P‐carrying genes in the plant . Thus, an assessment of the crop's leaf P concentration becomes essential to verify the influence of low doses of glyphosate on biomass production…”