Potencial do isotilcianato de alilo no controle de Sclerotium rolfsii e Sclerotinia sclerotiorum

• Autor(a) principal: Schurt, Daniel Augusto
• Data de Publicação: 2006
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: http://locus.ufv.br/handle/123456789/4447
• topic: Óleo mostarda; Fungo; Controle; Fungi; Control; CNPQ::CIENCIAS AGRARIAS::AGRONOMIA::FITOSSANIDADE::FITOPATOLOGIA

The losses caused by fungi in the nursery of seedling production are high if the planting substrate is not treated for their eradication. Transplanting infected seedlings to field causes disease in the field besides infesting the soil with pathogens transported by the disease seedling, where the disease control becomes economically unviable. The objective of this study was evaluate the effect of the, allyl isothiocyanate (AITC) for the soil treatment, to control Sclerotium rolfsii and Sclerotinia sclerotiorum and also to evaluate its effect on the general soil microbiota. The study about diffusion of AITC vapors in the soil showed that AITC diffused downwards better in dry soils (detected up to 15 cm of depth) than in moist soils, where it was detected up to 10 and 7,5 cm depth at soil moisture of 17 % and 22% respectively. Irrigating soil with water containing AITC to provide 150 µL/kg soil reduced the viability of the scletoria of S. rolfsii and S. sclerotiorum to a depth of 7,5 cm. In vitro, AITC vapors in the concentration of 150 µL/L killed 80% of concentration of AITC, in vitro or in soil, delayed sclerotial germination in the first 48 hours, and full germination potential was observed only after 120 h. The AITC effect on scletoria viality was slightly greater the air-dry soil compared to the soils, however from the practical point of view the soil moisture up to 20% and the high temperature did not affect the influence of AITC on sclerotial viability. In field conditions the used AITC at the rate of 8,86 ml/m2 killed 98% sclerotia of S. rolfsii when the plots were covered with a plastic mulch after the application. Soil treatment with AITC also reduced the microbial activity, changed significantly depending upon the soil conditions, but in general, the populations of actinomycetes, bacteria and fungi decreased.