Preparation and characterization of lignin-based formulations for controlled release applications in agriculture

BUSATTO, CARLOS; MARÍA EUGENIA TAVERNA; LEZCANO, MAIA; NICOLAU, VERÓNICA; ZALAZAR, CRISTINA SUSANA; ESTENOZ, D.

Simposio; XVI Simposio Latinoaméricano de Polímeros; 2018

Pesticides are important chemicals used in agriculture. However, some of these compounds exhibit persistence and mobility in the environment. Atrazine is a moderately toxic triazine, used as a selective pre- and post-emergence herbicide in various crops. The actual concern about the impact of agrochemicals on the environment has increased the use of natural pestices instead of synthetic ones. Among these compounds, azadirachtin, a strong insect antifeedant and growth-regulating substance is widely used for pest control purposes. The use of azadirachtin-based pesticides may be limited by its susceptibility to photodegradation2. The toxicity of atrazine and the photodegradation of azadirachtin can be reduced using polymer controlled release formulations that also increase the effectiveness of pesticides1. In addition, natural polymers are of great interest for controlled release applications in agriculture due to their biodegradability, free availability, cost effectiveness and low toxicity. Lignins are aromatic biopolymers from biomass, the second more abundant after cellulose. The aim of this work is to prepare lignin microparticles and alginate-lignin beads for the encapsulation and controlled release of atrazine and azadirachtin, respectively. The formulations are characterized in terms of particle size and morphology, encapsulation efficiency and controlled release behavior in water.