Uso de extratos vegetais como alternativa no controle da pinta preta (alternaria solani) na cultura do tomateiro

Abstract

The tomato crop is one of the vegetable crops of great economic importance worldwide. However, the occurrence of pathogens cause great economic losses in production and culture. Early blight caused by Alternaria solani is a major disease of tomato (Lycopersicon esculentum), attacking leaves, stems, petioles and fruit. It is necessary to search for alternatives to control this disease, which have reduced environmental impacts and low toxicity local biodiversity and for people involved in the production process and tomato consumption. Thus, the study evaluated the aqueous extracts of ginger rhizome (Zingiber officinale), the bulb of garlic (Allium sativum L.) and floral dianthus button (Caryophyllus aromaticus L.). the direct effect in vitro on the fungus A. solani, and in vivo in the control of early blight on tomato plants. The in vitro study was conducted at the Universidade Federal da Fronteira Sul, Campus Laranjeiras do Sul-PR on other Phytopathology Laboratory, where the mycelial growth, spore germination and size of germ tubes of A. solani was evaluated. Concentrations were measured 1%, 5%, 10%, 15% and 20% of the plant extracts. Constituted control Bordeaux mixture and distilled water. But the in vivo test was conducted in tomato plants Santa Cruz Kada grown in pots in the greenhouse receiving treatment and inoculation with the pathogen. In this case the plant extracts was evaluated at a concentration of only 20%. We determined the area under the disease progress curve (AUDPC) and the number and weight of fruits produced. The derivative linearly reduced mycelial growth, spore germination and the size of the germ tubes. The clove extracts, garlic and ginger did not affect production but reduced AUDPC by 55.8, 29.5 and 22.5% compared to control water, respectively. These results indicate the potential of plant extracts evaluated in the control of black tomato painting, particularly the clove extract.