International Journal of Environmental & Agriculture Research (IJOEAR) ISSN:[2454-1850] [Vol-2, Issue-10, October- 2016] Page | 82 Essential oil of Baccharis as a sustainable alternative for small farmers in South America Altemir J. Mossi 1 , Franciele Rambo Lauxen 2 , Rogerio L. Cansian 3 , Natalia Paroul 4 , Camila Â. Zanella 5 , Fernando Scarati Frandoloso 6 , Marcio A. Mazutti 7 , Helen Treichel 8 1,8 Universidade Federal da Fronteira Sul - Campus de Erechim. Rodovia ERS 135, Km 72, n° 200, Erechim, RS, Brazil. 2,3,4,5,6 Universidade Regional Integrada do Alto Uruguai e das Missões – Campus de Erechim. Av. Sete de Setembro, 1621, 99700-000, Erechim, RS, Brazil 7 Universidade Federal de Santa Maria – UFSM. Departamento de Engenharia Química /Laboratório de Engenharia de Bioprocessos. Avenida Roraima, Bairro Camobi, 97105-900, Santa Maria RS, Brazil Abstract— This work aimed at evaluating the insecticidal and repellent effect of essential oils of Baccharis trimera and Baccharis articulate leaves against the maize weevil in maize grains. The essential oil was extracted by hydrodistillation and the chemical composition showed that the major constituent was the carquejil acetate (73.6%) for B. trimera and β-pinene (22.3%) and β-cariofilene (21.5%) for B. articulate. Our results show that B. trimera oil was insecticidal and repellent to maize weevil. About 100% of mortality was achieved using concentrations of 0.32 μL.cm-2, after 24 h of exposure and the lower concentration 0.065 μL.cm-2 obtained similar results in 96 h. The LD50 value for B. trimera essential oil was 8.4 μL/ Petri dishes or 0.05 μL.cm-2. The results obtained indicate that the effect insecticidal of the essential oil of B. trimera is probably because of the presence of carquejil acetate. B. articulate showed low insecticidal activity. The values of the Preference level varied from -0.6 (0.065 μL.cm-2) to -0.9 (0.65 μL.cm-2) for B. trimera oil and -0.4 (0.065 μL.cm-2) to -0.7 (0.65 μL.cm-2) for B. articulata oil, being lower than -0.10. The minimum limit to consider that a plant has repellency activity, demonstrating that the both plants oils presents repellency activity. Although from an economical point of view synthetic chemicals are still more frequently used as repellents, we find the essential oil of B. trimera have potential to be used sustainably as bioinseticide by the small farmers. Keywords— Baccharis trimera, Baccharis articulata, repellency activity, insecticidal activity, small farmer, sustainability. I. INTRODUCTION In the world, pests (especially weeds, pathogens and insects) are the highest competitor of agricultural crops, reducing drastically the production in the range of 25–50% [1, 2]. Among the most important pests, weeds alone are responsible for nearly 34% of reduction in crop yields. Aiming at protecting the agricultural crops, high amounts of synthetic pesticides are used around the world. Nowadays, the maize weevil is the most relevant pest found during maize grains storage, especially in the small properties, where storage conditions are not adequated [2]. Aromatic plants and their essential oils have been used since antiquity in flavor and fragrances, as condiment or spice, in medicines, as antimicrobial/insecticidal agents, and to repel insect or protect stored products [3]. These oils represent effective alternatives to synthetic pesticides without producing adverse effects on the environment [4]. The essential oils of plants have been broadly studied for pest-control including toxic and repellent effects, antifeedant, ovicidal and other properties [5, 6]. The species of the genus Baccharis, belonging to the Asteraceae family, being from South America, probably the Peruvian Andes. Baccharis trimera (Less) DC or "bitter broom" as it is popularly known, is a native shrub of the fields and forests of the southern borders of Brazil, Bolivia, Paraguay, Uruguay and northern Argentina [7]. It has pharmacological actions such as anti-inflammatory and antioxidant [8, 9]. Baccharis articulata (Lam.) Pers. is a shrub much like Baccharis trimera, originally from South America, taking place in Brazil, Paraguay, Uruguay and northern and central Argentina [7]. The essential oil has the L-limonene constituents, alpha-gurjuneno, trans-caryophyllene, Germacrene, bicyclogermacrene, spathulenol, beta pinene, globulol, viridiflorol, among others, being the major compound Beta-pinene [10]. In this context, the aim of this study was to evaluate the bioactivity and repellency effect of essential oil of Baccharis trimera and Baccharis articulata against the Sitophilus zeamais in maize grains.