Qualidade fisiológica de sementes de soja cultivada em rotação com milheto
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Data
2006-04-01
Autores
Nakagawa, João [UNESP]
Lemos, Leandro Borges [UNESP]
Cavariani, Cláudio [UNESP]
Penariol, Fernando Guido [UNESP]
Título da Revista
ISSN da Revista
Título de Volume
Editor
Associação Brasileira de Tecnologia de Sementes (ABRATES)
Resumo
Para o sucesso do plantio direto há necessidade de que a cultura antecessora à principal seja boa produtora e mantenedora de cobertura vegetal. O milheto tem-se constituído em boa opção de cultivo no outono/inverno para rotação com soja, porém não há estudos avaliando o efeito do sistema na qualidade das sementes. O objetivo do trabalho foi estudar o efeito de três épocas de semeadura e cinco manejos com ceifas do milheto sobre a qualidade fisiológica de sementes de soja cultivada em sucessão, por plantio direto, na mesma área, por três ciclos de rotação (1999/2000; 2001/2002 e 2002/2003). As épocas de semeadura constituíram três experimentos (E1, E2 e E3), em delineamento experimental de blocos ao acaso com cinco tratamentos (M1 = ceifa a cada florescimento e retirada da massa vegetal; M2 = ceifa a cada florescimento e permanência da massa vegetal; M3 = ceifa no florescimento e retirada da massa vegetal; M4 = ceifa no florescimento e permanência da massa vegetal e M5 = sem ceifa até a produção de grãos, quando foi cortada a panícula, permanecendo o restante da massa vegetal), e quatro repetições. Os experimentos de milheto foram semeados em 1999: E1 = 05/03, E2 = 25/03 e E3 = 19/04; em 2001 = E1 = 17/04, E2 = 07/05 e E3 = 27/05, e em 2002: E1 = 25/04, E2 = 15/05 e E3. = 05/06. em cada ciclo de rotação, a soja foi implantada nos três experimentos na mesma data após o manejo final do milheto com dessecação química; as colheitas foram realizadas na mesma data, também. As sementes de soja, cv. Empresa Brasileira de Pesquisa Agropecuária (EMBRAPA)-48, foram avaliadas quanto ao tamanho, massa de 100 sementes, teor de água, germinação e vigor. Sementes de soja com melhor qualidade fisiológica foram obtidas, nos três ciclos de sucessão, quando cultivada após a primeira época de semeadura do milheto, independentemente do manejo com ceifas do milheto, cujo efeito foi pouco evidente.
A successful no-tillage system requires high mass production in the preceding to the main crop that and its crop residues remain in the soil. Pearl-millet was shown to be a good option as an autumn-winter crop before soybean, in rotation, but there are no studies of this system on soybean seed quality. The effects were investigated of three sowing times and five types of crop cut management of pearl-millet on seed quality of soybean cropped in sucession, in no-tillage system, for three crop rotation cycles (1999-2000, 2001-2002 and 2002-2003). Each pearl-millet sowing time was a trial with five treatments (M1 = cut at each flowering and no residues; M2 = cut at each flowering with residues; M3 cut at flowering and no residues; M4 = cut at flowering with residues; M5 = not cut until mature panicle harvest, then with residues) and four replications, arranged in randomized blocks. The pearl-millet trials were sown in 1999: E1 = 5 March, E2 = 25 March and E3 = 19 April; in 2001: E1 = 17 April, E2 = 7 May and E3 = 27 May; and in 2002: E1 = 25 April, E2 = 15 May and E3 = 05 June. The soybean was sown at the same time for the three trials in each crop rotation cycle, after chemical dessecation of the pearl-millet; the soybean was also harvested at the same time. The soybean seeds, cv. Empresa Brasileira de Pesquisa Agropecuária (EMBRAPA)-48, were evaluated by its size, weight of 100 seeds, water content, germination and vigor. Soybean seeds with better physiological quality were obtained when cropped in sucession on residues of the first pearl-millet sowing for three cycles of crops rotation, regardless of the pearl millet harvest management, whose effect was not clear.
A successful no-tillage system requires high mass production in the preceding to the main crop that and its crop residues remain in the soil. Pearl-millet was shown to be a good option as an autumn-winter crop before soybean, in rotation, but there are no studies of this system on soybean seed quality. The effects were investigated of three sowing times and five types of crop cut management of pearl-millet on seed quality of soybean cropped in sucession, in no-tillage system, for three crop rotation cycles (1999-2000, 2001-2002 and 2002-2003). Each pearl-millet sowing time was a trial with five treatments (M1 = cut at each flowering and no residues; M2 = cut at each flowering with residues; M3 cut at flowering and no residues; M4 = cut at flowering with residues; M5 = not cut until mature panicle harvest, then with residues) and four replications, arranged in randomized blocks. The pearl-millet trials were sown in 1999: E1 = 5 March, E2 = 25 March and E3 = 19 April; in 2001: E1 = 17 April, E2 = 7 May and E3 = 27 May; and in 2002: E1 = 25 April, E2 = 15 May and E3 = 05 June. The soybean was sown at the same time for the three trials in each crop rotation cycle, after chemical dessecation of the pearl-millet; the soybean was also harvested at the same time. The soybean seeds, cv. Empresa Brasileira de Pesquisa Agropecuária (EMBRAPA)-48, were evaluated by its size, weight of 100 seeds, water content, germination and vigor. Soybean seeds with better physiological quality were obtained when cropped in sucession on residues of the first pearl-millet sowing for three cycles of crops rotation, regardless of the pearl millet harvest management, whose effect was not clear.
Descrição
Palavras-chave
Glycine max, plantio direto, épocas de semeadura, manejo de fitomassa, Glycine max, no-tillage, sowing time, phytomass management
Como citar
Revista Brasileira de Sementes. Associação Brasileira de Tecnologia de Sementes, v. 28, n. 1, p. 36-44, 2006.