RESUMODurante o estabelecimento das lavouras de ervilha, a ocorrência de Rhizoctonia solani causando tombamento de plântulas tem sido observada. O presente trabalho teve como objetivo verificar a eficiência do uso de fungicidas no tratamento de sementes de ervilha cultivar Mikado, visando o controle de Rhizoctonia solani e seus efeitos na qualidade fisiológica dessas sementes. Sementes foram tratadas com os seguintes fungicidas: Carbendazim, Carbendazim + Thiram, Captan, Iprodione, Iprodione + Thiram, Metalaxil-M + Fludioxonil, Pencicurom, Procimidone e Tolifluanida. Como testemunha, foi utilizada sementes tratadas com água destilada. A avaliação da qualidade fisiológica das sementes após o tratamento foi realizada pelos seguintes testes: germinação, primeira contagem, envelhecimento acelerado, condutividade elétrica e emergência de plântulas. As sementes tratadas foram semeadas em solo não inoculado e inoculado com R. solani. A emergência de plântulas foi reduzida em solo inoculado, sendo que os tratamentos que apresentaram melhores resultados foram Carbendazim, Pencicurom, Iprodione e Carbendazim + Thiram. O fungicida Captan prejudicou a qualidade fisiológica das sementes tanto em laboratório como no campo. Com relação à germinação, os tratamentos que apresentaram melhores resultados foram Carbendazim, Pencicurom, Iprodione e Carbendazim + Thiram.Termos para indexação: Pisum sativum, germinação, estabelecimento de plântulas, fungicidas, patógenos. IntroductionPea (Pisum sativum L.) belongs to the Fabaceae family, and it is originated from temperate climate regions with a centre of origin in the Middle East, India, Afghanistan and Ethiopia (Couto, 1989). Peas have a high nutritional value and are much appreciated as a legume throughout the world. They may be consumed as seeds (green or dried, rehydrated), used for animal feed and also as green manure (Sharma and Fonseca, 2000).In Brazil, peas were almost entirely imported until the 1980s but today all domestic demand may be supplied by local production. According to IBGE (2009) data, Brazil grows 2,000 ha of peas with a production of around 6,000 tons and a mean productivity of 2,753 Kg.ha-1.One of the main diseases affecting pea production is Rhizoctonia solani Khun causing damping-off (CAB, 1999), in pre or post emergence. In pre-emergence, the seed is infected by the pathogen at the begining of germination, causing seed rotting. When damping-off occurs in post-emergence, the pathogen affects the base of the plant stem, causing tissue softening and constriction so that the stem may often not support the weight of the plant and it falls over (Lopes et al., 2005). Silva et al. (1996) reported that if R. solani is present in the soil or still present on the seeds, besides causing significant seedling losses, it may also serve as an inoculum source for future crops.Among the recommended control measures is the use of healthy seeds, the crop rotation, the pre-incorporation of residues and the control of water during early crop growth (Vieira, 1988). However, the principal and most economic measure adopted until now to minimize the adverse effects of this disease has been fungicide seed treatment (Carvalho et al., 1985; Cia and Salgado, 1997; Wang and Davis, 1997; Goulart and Melo Filho, 2000).According to Henning (2005), the aim of a fungicide seed treatment is to destroy, or lower, the inoculum potential of the fungus, which occurs on the seeds or inside them. The objective of the present study was to evaluate the efficiency of different fungicide seed treatments in peas for controlling damping-off by R. solani and determine their effects on seed physiological quality. Material and MethodsThe study was carried in experimental field and at the seed laboratory of Embrapa Vegetables in Brasília-Federal District, from March to June 2008. Mikado cultivar pea seeds produced in 2006 at Embrapa Horticulture were used.Seed treatment: vegetables seeds were treated with nine fungicides at the dosages recommended for each product (Table 1). Each treatment used 500 g of seeds. Fungicides formulated as dusts (Tolyfluanid, Captan, Pencycuron, Procymidone and Iprodione + Thiram) were diluted in 10 mL of distilled water to give better adherence and uniformity of product coverage on the seeds. The liquid products (Iprodione, Carbendazim, Metalaxyl-M + Fludioxonil and Cardendazim + Thiram) were applied directly to the seeds by placing these in plastic bags, adding the product and mixing for three minutes. Only distilled water was applied to the control. After treatment, seeds were dryed at ambient temperatures.
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