Santa Catarina State farmers in the "Alto Vale do Itajaí" region are using several home-made products to control onion pests, where leaf blight of onion (Botrytis squamosa) is the main nursery disease. This research was carried out during the nursery period in 1993, 94 and 95, in order to evaluate traditional formulations against leaf blight of onion. The formulations studied were alcoholic extracts of Matricaria chamomilla, Mentha glacilis, garlic and propolis; wood ash, lime, solution of B+Zn, KMnO4, NaClO, "silica-gasil", creoline, formalin, Bordeaux mixture, sulphur, camphor, and the antagonist Gliocladium roseum. The formulations were used weekly in concentrations previously tested to avoid phytotoxicity. In the onion cycle 1994/95, G. roseum (108 spores/ml) reduced leaf blight of onion with the effect comparable to the standard fungicide vinclozolin (0.075%). In 1995/96, the survival of onion and the number of plants suitable for transplanting were highest using wood ash, Bordeaux mixture (0.5%) and a mixture of sulphur + Na2SiO4 + propolis extract, when compared to the fungicide used as a standard treatment. No leaf blight control effect was observed with sprays of KMnO4, NaClO, "camphor", sulphur and "sílica-gasil". Organic fertilizer increased the survival of onion seedlings and reduced Botrytis squamosa, irrespective of formulation, during the 1995/97 period.
Allium cepa; biological control; Botrytis squamosa; Gliocladium roseum
