Identificação e desenvolvimento de técnica alternativa de controle de fungos em sementes utilizadas no artesanato

Abstract

Amostras de sementes de plantas nativas de matas, cerrado e de campo empregadas para a confecção de artesanato de várias regiões do Brasil foram avaliadas quanto aos aspectos fitossanitários. Realizou–se o levantamento e identificação de fungos associados às sementes, bem como os sintomas nas mesmas. Técnicas de desinfestações superficiais e de tratamento natural com uma solução de óleos vegetais extraídos de essências florestais foi empregada para o controle dos fungos. As sementes de Euterpe oleraceae, E. precatoria var. precatoria, Dipterix alata, Orbignya phalerata, Phytelephas macrocarpa, Socratea exorrhiza, Hymenaea courbaril L. var. stilbocarpa, Leucaena leucocephala, Schefflera morototoni, Astrocaryum faranae, Sapindus saponaria, Ipomoea pes-caprae, Caesalpinia peltophoroides, Heliconia metallica, Cyperus rotundus e Astrocaryum aculeatum, apresentaram – se naturalmente infectadas com uma gama significante de fungos. Os fungos mais freqüentes associados às sementes foram Alternaria alternata, Aspergillus spp., Cladosporium sp., Chaetomium sp., Botryodiplodia sp., Epicoccum sp., Eurotium sp., Fusarium sp., Monilia sp., Nigrospora sphaerica, Penicillium sp., Pestalotiopsis sp., Phialophora sp., Rhizoctonia sp., Rhizopus sp., Syncephalastrum sp. e Verticillium sp. Os danos causados por estes fungos foram deformações, manchas necróticas, podridões moles e deterioração parcial ou total das sementes. O tratamento com a solução de óleos foi bastante eficiente para todos os fungos, com a erradicação da maioria deles. _______________________________________________________________________________ ABSTRACT

Some seed samples of native plants from forestry, cerrado and savannas which are currently employed for the confection of handcrafts from several brazilian regions were valued as far as the phytosanitary aspects are concerned. The fungi overview and identification associated to the seeds as well as their symptoms were accomplished. Techniques of superficial de-infections and natural treatment with appropriate vegetable oil solutions extracted from tree essences were used to the control of fungi studied in the current work. Seeds of Euterpe oleraceae, E. precatoria var. precatoria, Dipterix alata, Orbignya phalerata, Phytelephas macrocarpa, Socratea exorrhiza, Hymenaea courbaril L. var. stilbocarpa, Leucaena leucocephala, Schefflera morototoni, Astrocaryum faranae, Sapindus saponaria, Ipomoea pes-caprae, Caesalpinia peltophoroides, Heliconia metallica, Cyperus rotundus and Astrocaryum aculeatum, have shown themselves naturally infected with a significant range of fungi. The most frequent fungi associated to the seeds were Alternaria alternata, Aspergillus spp., Cladosporium sp., Chaetomium sp., Botryodiplodia sp., Epicoccum sp., Eurotium sp., Fusarium sp., Monilia sp., Nigrospora sphaerica, Penicillium sp., Pestalotiopsis sp., Phialophora sp., Rhizoctonia sp., Rhizopus sp., Syncephalastrum sp. e Verticillium sp. The damages caused by these fungi have been associated to deformations, necrotic spots and soft rotten as well as partial or total decay of seeds. The treatment we propose here was accomplished with the natural oils solution and it has been shown that the proposed technique is very efficient in the control of all the fungi for the complete eradication of them.