Inseticidas químicos e extratos vegetais aquosos no controle de Sitophilus zeamais em grãos de milho sob condições de armazenamento

• Ano de defesa: 2012
• Autor(a) principal: Vilarinho, Marcella Karoline Cardoso
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Mato Grosso; Brasil; Instituto de Ciências Agrárias e Tecnológicas (ICAT) – Rondonópolis; UFMT CUR - Rondonopólis; Programa de Pós-Graduação em Engenharia Agrícola
• Palavras-chave em Português: Inseto; Temperatura; Umidade; CNPQ::CIENCIAS AGRARIAS::ENGENHARIA AGRICOLA; Storage; Corn; Sitophilus spp.
• Link de acesso: http://ri.ufmt.br/handle/1/1117

The Sitophilus spp. is a major pest of stored grain, which is controlled by the use of chemical insecticides, but their indiscriminate use has been causing a lot of undesirable factors to humans and to the environment. And so as a less harmful alternative, natural insecticides come as an option for combating the insects, which simultaneously decrease the risk of damage to the environment. The study was carried at the Institute of Agricultural Sciences and Technology, campus of Rondonópolis at the Federal University of Mato Grosso, in the period of March to September, 2012. The experiment was performed under three different conditions. The experiment consisted of three environments: AI-temperature and humidity, humidity control, AII, and AIII-control humidity and temperature. AIII maintained at ambient temperature was 25.1 ° C and humidity 70 % (average), the latter being also held in the environment variable AII. The aqueous extracts were obtained by addition of post-plant garlic, lemongrass and neem in distilled water at a ratio of 5 g per 100 ml, and dosages of chemical insecticides were 0.04 and 0.15 ml/100 ml water for Deltamethrin and Chlorpyrifos respectively. Treatments were added to the corn grains placed in glass containers of 2.5 L (plots) and mixed by manual agitation until a uniform, being removed the excess product to avoid higher concentration at certain points. Each experimental unit was infested with 20 adults of Sitophilus spp. not sexed. The experiment was maintained without reinfestation of insects. The grains were stored for a period of 90 days in the three storage environments. The variables analyzed were: counting insects, water content in the grains, electrical conductivity and germination test. At the end of the experiment was also evaluated the qualitative loss of grain weight and specific gravity. The variables were analyzed every 30 days of the experiment, with three periods (30, 60 and 90 days). The analyzes were obtained using Tukey at 5 % probability. On day 30 we observed high efficiency of chemical insecticides Chlorpyrifos and Deltamethrin in control of Sitophilus spp. in the three storage environments. But it was noticeable that the natural insecticide were not effective in controlling insects, which can be confirmed in the qualitative evaluation at the end of the experiment. The high number of insects caused further damage to beans and alter the values of electrical conductivity and water content in the grains. The observed relationship between lower bulk density, with the highest percentages of water content in the grains and number of insects Germination was reduced in all treatments in all three environments, and may infer that the adverse storage conditions may have influenced this fall.