Phytotoxicity of mineral, vegetable oils and foliar fertilizers in coffee seedlings

Abstract

The objective of this study was to evaluate the toxicity in coffee seedlings caused by mineral oil, vegetable and foliar fertilizer, applied in different radiation intensities. In the first experiment not observed symptoms of phytotoxicity in the control plants and sprayed with foliar fertilizer. Two experiments to study the phytotoxic action of oils and foliar fertilizers were performed. The first was evaluated phytotoxic effects of mineral oil, vegetable oil and foliar fertilizer in different application times. In the second experiment evaluated the intensity of radiation in the occurrence of toxicity symptoms caused by both oils. At the end of the second experiment samples were taken to perform scanning electron microscopy. Plants sprayed 12:00 h had higher incidence and severity of injuries to both oils in relation to others (9:00 and 17:00h). In the light intensity experiment proved that the increase of light intensity from 80 to 320 μmol/m2/s promoted an increase in symptoms of phytotoxicity. In the analysis of lesions by scanning electron microscopy, deformations on the leaf surface caused by mineral oil and also for vegetable oil were observed.

Objetivou-se, neste trabalho, avaliar a fitotoxidez em mudas de cafeeiro causadas por óleo mineral, vegetal e adubo foliar, aplicados em diferentes intensidades de radiação. No primeiro experimento não se observou sintomas de fitotoxidez nas plantas da testemunha e nas pulverizadas com o adubo foliar. Foram realizados dois experimentos para o estudo da ação fitotóxica de óleos e adubos foliares. No primeiro foram avaliados os efeitos fitotóxicos do óleo mineral, óleo vegetal e de adubo foliar em diferentes horários de aplicação. No segundo experimento foi avaliada a intensidade da radiação na ocorrência de fitotoxidez causada por ambos os óleos. Ao final do segundo experimento amostras foram retiradas para realizar microscopia eletrônica de varredura. As plantas pulverizadas às 12:00h apresentaram maiores incidência e severidade das lesões para ambos os óleos em relação as demais (09:00 e 17:00h). No experimento de intensidade luminosa verificou que o aumento da intensidade luminosa, de 80 para 320 μmol/m2/s promoveu aumento nos sintomas de fitotoxidez. Na análise das lesões através da microscopia eletrônica de varredura, deformações no limbo foliar causadas por óleo mineral e também por óleo vegetal foram observadas.