Microencapsulation of agricultural defensives with biological active principles and the oil base to increase efficiency and reduce environmental impact

Abstract

There is an intense demand by traditional pesticide companies for new products that have natural and biological active ingredients. These pesticides are being increasingly used by the demanding consumer market, either for environmental sustainability or for more efficiency and economy. However, the susceptibility of these active ingredients to adverse environmental conditions, such as low humidity and high incidence of ultraviolet rays, limits their useful life and efficiency. When developing this research with the interaction of professionals from different areas of knowledge - engineering, microencapsulation, microbiology, agronomy, and entomology - we seek to obtain highly efficient microencapsulated natural pesticides, with low environmental impact and high economic potential. In this context, the objective of this work will be to produce microencapsulated pesticides that protect the actives compounds and have a prolonged action after application. Two pesticides will be produced, one natural (based on mustard oil) and one biological (based on fungus). An encapsulation pilot plant will be set up to produce pesticides in sufficient amount to carry out field tests. The natural pesticide will be elaborated from the encapsulation of mustard oil in two encapsulating systems, a bilayer emulsion, and a combination of bilayer emulsion with the Pickering emulsion. The natural pesticide, which has already proved to be viable in phase 1 of the project, will be encapsulated in the pilot plant and adjustments to the production system will be made to obtain microcapsules with the same characteristics as those obtained in the laboratory. Tests will be carried out to increase the amount of mustard oil in the microcapsules, increasing the effectiveness of the product and allowing smaller doses to be used. It will be evaluated if product formulation will affect microcapsules. The emulsion stability, the droplet size distribution, and the microcapsules morphology will be evaluated. The biological pesticide will be elaborated from the encapsulation of the metarhizium anisopliae conidia by ionic gelation using sodium alginate and pectin. The encapsulant that presents the best cost-benefit will be selected for the next stages of the research. The influence of the encapsulant concentration and the feed flow rate in the encapsulation process will be evaluated on the physical properties of the microcapsules and fungus viability. As metarhizium anisopliae is sensitive to solar radiation, the effect of adding sunscreens to microcapsules will be evaluated. Preliminary tests have shown that encapsulation increases the viability of the fungus, and the use of sunscreens makes this viability even greater. The effectiveness of microencapsulated natural and biological pesticides will be evaluated in tests using insects and in applications in crops. The pesticides obtained from this research are expected to be responsible for 50% of the revenue of Linax Essential Oils, with continuous growth similar or superior to that of the Brazilian pesticide market. The world market for these products has shown an average annual growth of 15.3% and, in Brazil, the trend is for it to grow between 15% and 20% in the coming years. (AU)