Loader

Abstracts - Luis G. Cuadrado DurangO

DEVELOPMENT OF EXTRACTS OF Azadirachta indica AS INSECTICIDE INTEGRATED WITH HUMIC ACIDS AS FERTILIZER NANOENCAPSULATED/MICROENCAPSULATED TO PROMOTE INCREASED AGRICULTURAL PRODUCTIVITY


Luis G. Cuadrado Durango1, Maria F. das Graças Fernandes da Silva1, João B. Fernandes1, and Moacir Rossi Forim1*


1 Department of Chemistry, Federal University of São Carlos, Rod. Washington Luiz, Km 235, PB 676, São Carlos, SP 13.565-905, Brazil; E-mail: ppgq@ufscar.br
* Correspondence: mrforim@gmail.com
Currently the use of biodegradable nanoparticles in agriculture are being explored for the controlled release of biologically active substances in pest control and increased agricultural productivity1; however, few studies describe the development of nano/microparticles as carriers of pesticides with polymeric matrix with fertilizer capacity2. As the slow release, the protection against thermal and ultraviolet degradation, as well as the low solubility of the insecticide encapsulated the most important characteristics of the polymer nanoformulations, which makes them the first choice for nanoencapsulation3-4. The present work describes the development of a bio-insecticide-fertilizer model for insect-pest control formulated with extracts of Azadirachta indica (Neem), using as polymeric matrix humic acids, precursor in the organic fertilization of plant. The nano/microparticles were formulated in colloidal suspension by prepolymer polymer precipitation technique and powder by Spray-Dryer; evaluating the pH, particle diameter, zeta potential, morphology, absolute recovery percentage and encapsulation efficiency, release kinetics, thermal and photochemical stability, as well as fertilizer capacity. The formulation promoted photochemical, thermal and pH stability gains of approximately 50% by nano/microencapsulated azadirachtin, maintaining its efficient insecticide action in the biological evaluation against the insect pest Spodoptera frugiperda, used as a model. The data obtained in the biological assays presented a mortality higher than 50% in formulated products against the effect of the non-nanoencapsulated neem extract used as control in an average evaluation of 10 days. Finally, the evaluation of the duality of the function of the humic acids in the process of encapsulation and composite action were significantly relevant, presenting a germination in the maize plants an average of 89% efficiency, in the function of the biopolymer in the formulation of the polymer nanoparticles presented yields of 70%.

References
1. Kashyap, P. L., et al., Int. J. Biol. Macromol 77, 36-51, 2015.
2. Forim, M. R., et al., J. Agric. Food Chem, 61(38), 9131-9139, 2013.
3. Das, R., et al., J Biofertil Biopestici, 5(1), e120, 2014.
4. Nuruzzaman, M., et al., J. Agric. Food Chem, 64(7), 1447-1483, 2016.