Interactions Between Adjuvants and the Fungicide Azoxystrobin+benzovindiflupyr in Hydraulic Spraying

Abstract

Adjuvants are tools to maximize pesticide spray quality. This study aimed to evaluate the interaction effects between adjuvants and the fungicide azoxystrobin + benzovindiflupyr on the physicochemical characteristics, droplet evaporation time, and spray droplet size. The experiment was carried out using a 26 factorial scheme, in which the first factor was the absence or presence of the fungicide mixture (water or water + fungicide) and the second factor was the presence of different adjuvants (water and five adjuvants). The parameters evaluated were surface tension, pH, viscosity, electrical conductivity, droplet evaporation time, volume median diameter, percentage of droplets smaller than 100 µm, and relative amplitude of the droplet spectrum. The silicone and propionic acid + soy lecithin adjuvants reduced the pH of the spray solution, and the sodium lauryl ether sulfate, propionic acid + soy lecithin, and orange essential oil adjuvants reduced droplet evaporation when mixed with the fungicide. All tested adjuvants improved spray quality related to the characteristics of the droplet spectrum, reducing the percentage of droplets smaller than 100 μm, and allowing more uniform droplet size. The fungicide azoxystrobin + benzovindiflupyr affected droplet evaporation time.

Measuring the photostability of agrochemicals on leaves: understanding the balance between loss processes and foliar uptake

“…The first compound we studied using this method was a polar herbicide with log D of −2.98 at pH 2.5. It is very soluble in water, not soluble in heptane and its SL (soluble liquid) 52 100 formulation is normally co‐applied with sodium lauryl ether sulphate (SLES), which is a synthetic adjuvant containing surfactants, sequestrants and emulsifiers that reduce surface tension, increase adhesion and improve compound uptake 53 …”

“…It is very soluble in water, not soluble in heptane and its SL (soluble liquid) 52 100 formulation is normally co-applied with sodium lauryl ether sulphate (SLES), which is a synthetic adjuvant containing surfactants, sequestrants and emulsifiers that reduce surface tension, increase adhesion and improve compound uptake. 53 The compound showed a very low T50 on glass slides -13 minsuggesting the potential for rapid loss of the compound once it has been sprayed and exposed to sunlight in the field. However, the leaf study (Fig.…”

Mixture compatibility of Anticarsia gemmatalis nucleopolyhedrovirus (AgMNPV) with pesticides used in soybean

“…Only the fungicide (metconazole + pyraclostrobin), caused 40% mortality for A. gemmatalis, the effect is possibly linked to the metconazole molecule, which fits into chiral pesticides, in this class the way of action to other organisms is not yet elucidated, in addition 40% of insecticides belong to the chiral class (BIELSKÁ et al, 2021;JESCHKE, 2018). The fungicide (azoxystrobin + benzovindiflupyr) caused a reduction in mortality of A. gemmatalis after two hours of mixing (69.27%), compared to one hour of mixing (80.60%), it is possible to infer that this reduction is linked to the increase in pH caused by presence of the fungicide in suspension (LANDIM et al, 2019). Thus, exceeding optimal conditions for virus action.…”