Sensibilidade do mamoeiro (Carica papaya L.) a fungicidas

Abstract

Sensibility studies of the papaya (Carica papaya L.) to various fungicides were developed to select those with high degree of safety to control fungal diseases of the culture. The investigation was carried out on the Horticultural Sector of the Agrarian Science Center of the Federal University of Ceará in a ca., half-shaded shelter, in Fortaleza, State of Ceará, Brazil, from April to July, 1995. A completely randomized design was arranged in a 2 x 3 x 10 factorial experiment to assess plant reactions lo the fungicides. Treatments were made up of eight commercial flingicides and ‘manipueira’ (a liquid extract from cassava roots, Manihot esculenta) plus the control which was sprayed with tap water. Potted seedlings of two papaya cultivars, v.g., Formosa and Hawaii were sprayed four times at a 7-days interval. Phytotoxicity of the compounds was thoroughly checked by evaluating the following parameters, ten days alter the last spraying: plant height, plant trunk diameter, leaf number and presence of foliar necrotic symptoms. Tebuconazole was phytotoxic to papaya specially to cv. Formosa. This cultivar has also experienced a leaf number reduction. Hawaii cultivar was much more tolerant to the fungicides than the Formosa one.