In the search for new agrochemicals with safe and improved agronomic efficacy in the field, oil dispersion (OD) formulations have been investigated intensively because they are expected to have a better performance on crops than ordinary formulations. This is because the oils and surfactants within the formulation play the role of adjuvants. Therefore, an OD formulation may show a better biological efficacy, making the addition of tank mix adjuvant (regularly used in association with systemic pesticides) optional. The main goal of this work was to develop a new insecticide OD formulation with active ingredients that would be produced as a suspoemulsion (SE), resulting in a better and easier way of formulating a commercial product. These formulations were developed with new surfactants and dispersants and were stabilized using different rheology modifiers, showing appropriate results in stability tests. Rheological assessments were also performed in order to understand system microstructure. The new insecticides' OD formulations also exhibited excellent performance in physical-chemical lab tests and were subjected to field trials with cotton crops at Primavera do Leste, Mato Grosso, Brazil, during the 2012-2013 season. The target insect evaluated in this study was the cotton boll weevil, Anthonomus grandis Boh. (Coleoptera: Curculionidae), which is primarily responsible for damage to Brazilian cotton. The results from using the new OD formulations showed an improved performance when compared to tank mixtures of the same insecticides. Dispersants and rheology modifiers used in this development are promising tools for future OD formulation technology.

Adjuvants are used in or associated with agrochemical formulations in tank mixtures to improve and ensure the performance of active ingredients during crop management. They can modify physicochemical properties, improving the spray solution quality and stability. Adjuvants are able to improve properties such as wettability, adhesion, and spreading of spray droplets, thus contributing to better retention, persistence, and absorption/penetration of the active ingredient into the target species. As a result, an increase in productivity for the farmer can be expected. One of the most common types of adjuvants used to enhance pesticide performance is the oil-based emulsion, commonly known as crop oil concentrate. The oil component of crop oil concentrates can be derived from either mineral oil (petroleum oil concentrate) or soybean/vegetable oil (methylated seed oil). These products also contain an emulsifier system to achieve the emulsion stability necessary upon dilution for application in the spray tank. In recent years, high-load surfactant oil concentrates have been formulated that increase the functions available from the product. Four different oil concentrates were tank mixed with herbicides and fungicides and compared with regard to the following aspects of their physicochemical characterization: static and dynamic surface tension, contact angle on flat and tilted surface, emulsion stability, and adhesion. The spray droplet size distribution and drift potential were also evaluated. Some mathematical correlations were used to estimate spreading and retention. Field trials were conducted with fungicide (strobilurin and triazole mixture) and also with different herbicide combinations (glyphosate tank mixed with tembotrione and glyphosate tank mixed with clethodim). From these studies, this paper tries to connect chemical formulation features to performance results.