Performance of Soybeans With the Application of Glyphosate Formulations in Biostimulant Association

Abstract

<jats:p>ABSTRACT Glyphosate is the main herbicide used in the Roundup Ready® (RR®) soybean crop. However, the different salt and herbicide formulations available on the market can lead to crop intoxication. In this scenario, biostimulants appear as a promising alternative to mitigate the possible phytotoxic effects of glyphosate. Thus, the objective of this work was to evaluate the effects of different MC Extra® biostimulant doses associated with glyphosate formulations on the agronomic characteristics of a herbicide-tolerant soybean cultivar. Two experiments were conducted in the 2015/16 and 2016/17 seasons with three doses of MC Extra® (0.35, 0.70, and 1.00 kg ha-1) associated with six formulations of glyphosate: Glyphotal®, Roundup Original®, Roundup Ready®, Roundup WG®, Roundup Transorb®, and Zapp QI®, plus additional treatment without the use of the herbicide. In both experiments, we used 900 g e.a. ha-1 of glyphosate. The results showed that the highest dose of MC Extra®, in combination with the Roundup Original®, Roundup Ready®, and Roundup Transorb® formulations and 0,70 kg ha-1 of MC Extra® with Glyphotal® provided the highest grain yields. When used in conjunction with the herbicide, there is a need to increase the dose of MC Extra® to obtain higher soybean yields.</jats:p>

‘BMX Ativa’ soybean responses after application of biofertilizer associated or not with glyphosate

“…The other treatments showed low intoxications, with rates below 9%. The highest dose of glyphosate caused intoxication that reached 17%, probably overloading the way by which soybean degrades the herbicide through the AMPA -aminomethylphosphonic route (Franco et al, 2012;Andrade et al, 2020). Intoxication is more perceptible close to the application and tends to reduce over time.…”

“…Even if it is a "RR" soybean cultivar, physiological damage caused by the application of glyphosate may occur. The effects will vary according to the cultivar, dose and formulation of the herbicide, environmental conditions at the time and after application (Andrade et al, 2018;Andrade et al, 2020). According to Andrade et al (2018), the biofertilizer is used to minimize these effects, as it promotes plant growth indirectly and assists the growth of meristems in the plant, however, this was not evidenced on the experiment.…”

“…These results are similar to those found by Pinto et al (2016), the authors tested glyphosate doses applied at various stages of the crop and also found no statistical difference between the treatments. Andrade et al (2020) used different glyphosate formulations and did not find differences in grain yield of RR soybean cultivar (TMG 7062 IPRO ® ). Possibly, this result occurred because a glyphosateresistant cultivar was used, so it has the ability to metabolize the herbicide, recovering from the intoxication effects without harming productivity.…”

“…Therefore, there are studies, aiming the reduction of the phytotoxic effects, using some products such as foliar fertilizers or biofertilizers in association with the herbicide (Du Jardin, 2015; Andrade et al, 2018;Andrade et al, 2020). These biofertilizers or biostimulants have varied compositions, usually containing amino acids such as L. glutamic acid, which can indirectly reduce oxidative stress effects, as they are a precursor to other amino acids, such as arginine and proline (Du Jardin, 2015;Andrade et al, 2018).…”

“…Certain biofertilizers have seaweed extracts in their composition that, depending on the concentration, can explain the effects of the stress recovery on plants and improve production aspects due to the presence of hormones and nutrients that can be used by the crop. Some commercial seaweed have high hormonal levels such as cytokinin or betaines, which act in the retention of chlorophyll and, in the case of betaines, involved in resistance to drought (Marques et al, 2014;Du Jardin, 2015;Andrade et al, 2020).…”