Qualidade de sementes de amendoim armazenadas no estado de São Paulo

Abstract

ResumoCom os objetivos de avaliar a qualidade fisiológica e sanitária de sementes de amendoim armazenadas no estado de São Paulo, identificar os principais insetos e fungos que ocorrem nessas condições e as possíveis injúrias causadas que possam prejudicar a qualidade dessas sementes, amostragens de lotes das cultivares IAC 886 e IAC 503, produzidas nas safras 2010/11 e 2011/12, foram realizadas em quatro épocas: antes do armazenamento, antes do beneficiamento, após o beneficiamento e após o tratamento químico. As sementes foram analisadas quanto ao teor de água, germinação, vigor e sanidade. O beneficiamento não melhorou a qualidade das sementes de amendoim. As principais pragas associadas às sementes foram Cyrtomenus mirabilis (Perty) e Corcyra cephalonica (Stainton). Os fungos mais frequentes foram os dos gêneros Aspergillus, Fusarium, Penicillium e Rhizopus. Durante o armazenamento houve aumento na incidência de Aspergillus spp., Penicillium spp. e Rhizopus sp. e redução da ocorrência de Fusarium sp. O tratamento das sementes de amendoim, após o beneficiamento, é imprescindível para serem obtidos padrões aceitáveis à sua comercialização.Palavras-chave: Arachis hypogaea L., germinação, armazenamento, insetos praga, fungos, beneficiamento. Quality assessment of commercial peanut seeds in the state of São Paulo, Brazil AbstractPhysiological and sanitary quality of peanut seeds stored in the state of São Paulo were assessed in seed lots of cultivars IAC 886 and IAC 503 harvested in the 2010/11 and 2011/12 growing seasons. Evaluations also included the identification and damages caused by fungi and insects occurring in these conditions. Seed sampling and evaluations were done in four stages of the seed storing and processing: before storage, before shelling, after shelling and after seed treatment. Seeds were analyzed for water content, germination and vigor, and evaluated for sanity. Shelling did not improve physiological and sanitary quality of the seeds. Cyrtomenus mirabilis (Perty) and Corcyra cephalonica (Stainton) were the main insects found. The fungi most frequently detected were those of genus Aspergillus, Fusarium, Penicillium and Rhizopus. Increased occurrence of Aspergillus, Penicillium and Rhizopus, and decreased occurrence of Fusarium were noted during the storage period. Seed treatment after shelling was proved to be essential for reaching the necessary quality standard of commercial seeds.

Damage caused by fungi and insects to stored peanut seeds before processing

“…In addition, these conditions may favor fungal and insect activity, thus reducing seed quality (Christensen and Kaufmann 1965). Thus, in São Paulo, the occurrence of peanut seed lots with germination percentage is often lower than the standard established for marketing (60%), due to high rates of infection caused by fungi and insects (Santos et al 2013).…”

“…At lower relative humidity, the growth of these fungi is arrested. Among these fungi, those belonging to the genus Fusarium (Thiessen and Woodward 2012;Santos et al 2013) have been reported to cause rot and reduced physiological potential in peanut seeds.…”

“…These fungi cause discoloration and rotting, affecting viability as well as commercial and nutritional value because of increased fatty acid content, oil rancidity and heating of the seed mass, which increases the respiratory rate and accelerates deterioration (Machado 1988;Nóbrega and Suassuna 2004;Bellettini et al 2005;Borém et al 2006;Santos et al 2013). Aspergillus flavus is generally the most destructive species in peanuts (Hocking and Banks 1991).…”

“…Aspergillus flavus is generally the most destructive species in peanuts (Hocking and Banks 1991). In addition, the genus Rhizopus (Ito et al 1992;Santos et al 2013) has been reported to cause rot and reduce seed quality in peanuts.…”

“…The peanut-growing area in the State of São Paulo has experienced a significant increase in soil pests, especially the burrower bug, Cyrtomenus mirabilis (Perty) (Hemiptera: Cydnidae). This insect is not a storage pest, but the damage caused by its burrowing may reduce seed physiological quality and health in the storage environment (COPLANA 2010;Santos et al 2013).…”