Morfologia e efeito inseticida de extrato de fumo, cultivado em diferentes condições hídricas de substrato

Abstract

The study aimed to evaluate plant morphology and insecticide effect of hydroalcoholic and aqueous extracts of tobacco grown in different water conditions substrate on S. zeamais. For this, the water conditions were compared: 100% container capacity (CC), 75% CC, 50% CC and 25% CC in a completely randomized design with four replications. The humidity of the substrate was monitored every 48 hours, in order to adjust the humidity, that proposed by the treatments. At harvest, height and dry weight of plants were measured. The extracts were prepared using emerged leaves in ethyl alcohol 70% (hydroalcoholic) and distilled water (aqueous). These were applied in corn, with subsequent exposure to insects. Then, the dead insect number was counted after 2, 6, 12, 24, 48 and 72 hours of exposure. There was a linear relationship between water condition, height and dry mass. In addition, there was no water condition effect of the substrate in insect mortality for both extracts. However, it was realized a higher mortality in hydroalcoholic extract. Thus, it was concluded that the water condition of the substrate has an effect on the morphology of plants, however, does not interfere with insecticide effect of the extracts.