Efeito do método de colheita e da classificação por tamanho na qualidade de sementes de soja e no desempenho agronômico das plantas

• Ano de defesa: 2006
• Autor(a) principal: Santos, Paulo Marçal dos
• Orientador(a): Reis, Múcio Silva
• Banca de defesa: Araújo, Roberto Fontes , Silva, Fernando Antônio Pereira da
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Viçosa
• Programa de Pós-Graduação: Doutorado em Fitotecnia
• Departamento: Plantas daninhas, Alelopatia, Herbicidas e Resíduos; Fisiologia de culturas; Manejo pós-colheita de
• País: BR
• Palavras-chave em Português: Soja; Sementes; Colheita; Beneficiamento; Qualidade fisiológica; Características agronômicas
• Palavras-chave em Inglês: Soybean; Seeds; Harvesting; Processing; Physiological quality; Agonomic characteristics
• Área do conhecimento CNPq: CNPQ::CIENCIAS AGRARIAS::AGRONOMIA::FITOTECNIA
• Link de acesso: http://locus.ufv.br/handle/123456789/1194

This work was conducted under laboratory conditions in a greenhouse and at Professor Diogo Alves de Mello Experimental Field at the Universidade Federal de Viçosa (UFV), in Viçosa-MG. It aimed to evaluate the effects of mechanically- and manually-harvested soybean seed size on its physiological quality and plant performance in the field. Basic Splendor and Elite cultivar soybean seeds were used, from the seed company Coopadap, produced in the 2001/2002 crop, in São Gotardo-MG. In the mechanical harvest, the work samples were collected from grain tanks while in the manual harvest the plants were collected in the field and sent to the UFV, where pod hulling was also carried out manually. In Vicosa, the seeds used for both harvest methods were classified manually using sieves with round holes. After classification, the cultivars presented seeds in a sufficient amount to allow a study of five size classes (6.75, 6.35, 5.95, 5.55 and 5.16 mm), with a seed sample from the original lot being maintained (control). Each cultivar constituted an assay, with the plots being the harvest methods (mechanical and manual) and the split-plots, the seed sizes. Seed quality was evaluated by the following tests: germination, first germination count, accelerated aging, electric conductivity, tetrazolium, field and sand emergence, field and sand emergence velocity, and weight of a 1.000 seeds. In the field experiment, the following plant agronomic traits were evaluated: lodging degree and plant height, height of first pod insertion, number of nodes per plant at maturation, number of fertile pods per plant, number of seeds per plant, seed weight per plant and grain yield. In both cultivars, seeds of all sizes obtained excellent sand bed emergence, except fo r the Elite cultivar 5.16 and 5.55 mm seeds, with low quality. Elite cultivar intermediary size seeds (5.95 mm) and small size seeds (5.16 mm) showed the best and worst quality, respectively. Mechanically-harvested intermediary size Splendor cultivar seeds (5.95 and 5.55 mm) presented higher vigor and germination potential, compared to seeds size 6.75 and 6.35 mm, of low potential. The tetrazolium test also permitted to visualize that the mechanical damages were greater in the mechanically-harvested seeds in both cultivars. The occurrence of mechanical damage to the crop was higher in the larger seeds (sizes 6.75 and 6.35 mm), for the cultivar Splendor. In both cultivars, the agronomic traits evaluated were not influenced by seed size or by harvest method, with the only exception for the 6.35 mm size seeds of the cultivar Elite, which presented the highest yields. Sowing outside the recommended season may alter some cultivar traits and lead to cultivar yield drop.