Controle de Alternaria alternata, Colletotrichum acutatum e Phyllosticta citricarpa com os produtos Duque® , Flavon® E Straike® em Citros

Abstract

The cultivation of citrus is responsible for the development of regions and municipalities Brazilians, standing out worldwide for the production of oranges and the export of your juice. Phytosanitary requirements for export, as well as the loss of effectiveness of certain agricultural pesticides are factors that make the search for management programs and alternative control measures for crop diseases. The objective of this work was to analyze the effect of organomineral fertilizers Flavon® and Straike® and Duque® non-ionic adjuvant in the control of pathogens Alternaria alternata, Colletotrichum acutatum and Phyllosticta citricarpa, as well as evaluate the selectivity of products to citrus culture. For this, were carried out three experiments. In the first, the in vitro fungal inhibition of the Duque® product was tested in relation to the three pathogens. The second experiment evaluated the effectiveness of Duque®, Flavon® and Straike® products in the control of Alternaria alternata, through product applications in Ponkan mandarin orchards grafted on Rangpur lemon. In the third trial, the efficacy of the Duque® and Flavon® products in the control was evaluated of Colletotrichum acutatum through the application of the products in acid lime orchard Tahiti grafted on Flying Dragon trifoliate. Field experiments had randomized block design, consisting of 4 treatments and 4 replications, whose plots had 10 plants of which 4 central plants were evaluated. The results were submitted to analysis of variance by the F test, comparing the means using the Scott-Knott test (5%). The results obtained demonstrated that the Duque® product controlled the mycelial growth of the three pathogens in tests in vitro, highlighting the dose of 1.5 L ha-1 with greater inhibition of mycelial growth in P. citricarpa and C. acutatum. It was observed that Duque® and Flavon® products showed significant control of the incidence of Alternaria alternata on the leaves, however, they did not differ from the control in the results for severity in the leaves and in the fruits, and incidence in the fruits. Duque® products (1.0 and 1.5 L ha-1 ) and Flavon® (1.0 L ha-1 ) proved to be superior to the control in controlling the incidence of Colletotrichum acutatum in flowers, as well as the reduction of retained calyxes. already in evaluation of fixed fruits, only the doses of Duque® showed increments in the fixation of the fruits. The three products promoted increases in the productivity of the Tahiti acid lime. Furthermore, Duque®, Flavon® and Straike® proved to be selective to Ponkan mandarin, as well as Duque® and Flavon® did not show symptoms of phytotoxicity to Tahiti lime plants.