Sensitivity of Stemphylium solani to plant extracts and syrups and disease control in tomato at greenhouse

Abstract

The aim of this work was to evaluate the effect of extracts of cinnamon (12%), garlic (8%), pepper (16%) and tobacco (6%) and viçosa mixture, bordeaux mixture, lime sulfur and sulfur emulsion (all 1%) on five isolates of Stemphylium solani and their efficiency in disease control of tomato in greenhouse. In tests in vitro, chlorothalonil (1800 mg.L^-1) and water were used as controls and the mycelial growth, germination and the production of conidia were evaluated. At greenhouse, the treatments effect on the area under the disease progress curve (AUDPC) and production of fruits was evaluated, altering the fungicide control to mancozebe (3 g.L^-1). There was high variability among isolates concerning sensitivity to treatments. Treatments did not affect spore production, except lime sulfur emulsion, which stimulated it in all isolates. Viçosa and bordeaux mixtures inhibited completely the mycelial growth and reduced significantly the conidial germination in most isolates. The extracts and mixtures decreased the AUDPC compared to water control, mainly bordeaux mixture. The treatments did not affect the fruits production.