Efeito da época de semeadura nas relações de interferência entre uma comunidade infestante e a cultura do amendoim
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Data
2007-09-01
Autores
Nepomuceno, M.P. [UNESP]
Alves, P.L.C.A. [UNESP]
Dias, T.C.S. [UNESP]
Cardozo, N.P. [UNESP]
Pavani, M.C.M.D. [UNESP]
Título da Revista
ISSN da Revista
Título de Volume
Editor
Sociedade Brasileira da Ciência das Plantas Daninhas
Resumo
A presente pesquisa foi realizada com o objetivo de avaliar o efeito da época de semeadura sobre os períodos de interferência das plantas daninhas na cultura do amendoim-rasteiro (Arachis hypogaea cv. IAC Runner 886). Dois experimentos foram instalados em épocas diferentes - início de novembro e de dezembro de 2005 em áreas vizinhas e provenientes de reforma de canavial, no município de Jaboticabal, SP, num solo de textura média. O delineamento experimental foi de blocos ao acaso, com os tratamentos constituídos por períodos crescentes de convivência ou de controle das plantas daninhas com as plantas de amendoim. As plantas daninhas que se destacaram em importância relativa, na primeira e segunda épocas, foram Ipomoea triloba, Digitaria nuda, Hyptis lophanta e Sida spp. A comunidade infestante e a cultura foram influenciadas pela época de semeadura, modificando suas relações de interferência. Os valores de acúmulo de massa seca da parte aérea das plantas daninhas na segunda época superaram em 23,7% os encontrados na primeira época durante todo o ciclo de desenvolvimento da cultura, refletindo, principalmente, em redução de produtividade de vagens de amendoim. Admitindo 5% de tolerância na redução da produtividade de vagens, verificou-se que o período anterior à interferência (PAI) na primeira época foi de 28 dias após a emergência (DAE), e o período total de interferência (PTPI), de 78 DAE, com redução de produtividade de 53,5%. Na segunda época, os efeitos da convivência da comunidade infestante com a cultura foram mais drásticos, pois afetaram com maior intensidade a produtividade da cultura, reduzindo-a em 86%, com PAI de 33 DAE e PTPI de 93 DAE. Quando no limpo, durante todo o ciclo da cultura, o amendoim semeado mais cedo (início de novembro) apresentou produtividade de vagens maior, superando em 23,7% o semeado um mês mais tarde.
This research was conducted to determine the effect of sowing time on weed interference periods in peanut crop (Arachis hypogaea cv. IAC Runner 886). Two experiments were set at different times, early November and December 2005, at neighboring areas originated from sugar-cane renewal in Jaboticabal, SP. The experiment was arranged in a randomized block design,with the treatments consisting of increasing periods of weed coexistence or weed control in the peanut crop. The main weed species in the area were: Ipomoea triloba, Digitaria nuda, Hyptis lophanta and Sida spp. The weed community and the peanut crop were influenced by sowing time, modifying their interference relations. Weed shoot dry biomass for the second period exceeded in 23.7% those found at the first period throughout the crop development cycle, specially reflecting decreased peanut bean productivity. Assuming a tolerance of 5% for peanut bean production decrease, it was verified that the period before interference (PBI) for the first time was 28 days after emergence, and the entire period of interference prevention (EPIP) was of 79 days after emergence, with a productivity reduction of 53.5%. At the second time, weed interferences in the peanut crop were the worst, with production being affected more intensely and reduced to 86%, with a PBI of 33 and a EPIP of 93 days after emergence. When the peanut crop sowed earlier (November) was kept weed-free, throughout the crop cycle, green bean productivity was higher, 23.7% more than the peanut crop sowed a month later.
This research was conducted to determine the effect of sowing time on weed interference periods in peanut crop (Arachis hypogaea cv. IAC Runner 886). Two experiments were set at different times, early November and December 2005, at neighboring areas originated from sugar-cane renewal in Jaboticabal, SP. The experiment was arranged in a randomized block design,with the treatments consisting of increasing periods of weed coexistence or weed control in the peanut crop. The main weed species in the area were: Ipomoea triloba, Digitaria nuda, Hyptis lophanta and Sida spp. The weed community and the peanut crop were influenced by sowing time, modifying their interference relations. Weed shoot dry biomass for the second period exceeded in 23.7% those found at the first period throughout the crop development cycle, specially reflecting decreased peanut bean productivity. Assuming a tolerance of 5% for peanut bean production decrease, it was verified that the period before interference (PBI) for the first time was 28 days after emergence, and the entire period of interference prevention (EPIP) was of 79 days after emergence, with a productivity reduction of 53.5%. At the second time, weed interferences in the peanut crop were the worst, with production being affected more intensely and reduced to 86%, with a PBI of 33 and a EPIP of 93 days after emergence. When the peanut crop sowed earlier (November) was kept weed-free, throughout the crop cycle, green bean productivity was higher, 23.7% more than the peanut crop sowed a month later.
Descrição
Palavras-chave
Arachis hypogaea, Competition, Control, Arachis hypogaea, Competição, Controle
Como citar
Planta Daninha. Sociedade Brasileira da Ciência das Plantas Daninhas , v. 25, n. 3, p. 481-488, 2007.