Caldas alternativas no controle de mancha-deestenfílio (Stemphylium solani) em tomateiro sob manejo orgânico na Baixada Fluminense, RJ

Abstract

The tomato (Solanum lycopersicum L.) is the second most cultivated vegetable in Brazil. It is a culture where more than 100 diseases have already been reported causing different levels of reduction in productivity, or the quality of the commercial product, thus requiring large amounts of agrochemicals. Among these diseases is Stemphylium leaf blight (Stemphylium solani), whose reports indicate increased frequency of productivity, losses as well as greater difficulties in tomato cultivation in agroecological systems due to the restriction on the use of agrochemicals. In view of the problems reported, the present study aims to evaluate the use of mixture and plant extracts on alternative control of Stemphylium leaf blight (Stemphylium solani) on tomato under organic management. In tomato plants carried out three experiments, being the first, in the period from August to December 2012, the second, from August to November 2013 and the third from October/2013 to January/2014. Experiments 1 and 3 were conducted on the Experimental Field of the State Center for Research in Organic Agriculture - CEPAO Company of Agricultural Research in the State of Rio de Janeiro - PESAGRO-RIO and the second, in the Experimental Field of Horticulture Department of Phytotechnic of UFRRJ, being all experimental areas located in the municipality of Seropédica, RJ. Five treatments were tested, namely, Viçosa mixture 1 %, Bordeaux mixture 1 %, Lime sulfur in Emulsion 1.5 %, Garlic Extract 8% and Witness with application of water, with five with five replicates, totaling 25 experimental plots. The tomato cultivar used was Perinha White Water susceptible to disease. Disease severity was quantified with the aid of diagrammatic scale in six useful plants of the experimental plot. From the progress of the data we calculated the areas under the curve (AUDPC). In the 1st test, the Viçosa mixture 1% and 1% Bordeaux were the best controls Stemphylium leaf blight and not differing from each other. On 3rd test, the Viçosa mixture 1% was the best control. As for the production of total fruits, non-commercial and commercial there was no significant difference between treatments.