Capim capivara: tratamentos pré-germinativos, superação da dormência de sementes e sensibilidade a herbicidas

The West Indian Marsh Grass is a native grass to tropical areas of Central and South America, which grows in wetlands, supporting intermittent periods of flooding. Their forms of propagation by fragments of rhizomes, rooting of lower nodes of stem and the high seed production facilitates population...

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Detalhes bibliográficos
Autor: Silva, Keli Souza da
Tipo de documento: dissertação
Estado:Versão publicada
Data de publicação:2011
País:Brasil
Recursos:Universidade Federal de Santa Maria (UFSM)
Repositório:Manancial - Repositório Digital da UFSM
Idioma:português
OAI Identifier:oai:repositorio.ufsm.br:1/5043
Acesso em linha:http://repositorio.ufsm.br/handle/1/5043
Access Level:Acceso aberto
Palavra-chave:Hymenachne amplexicaulis
Arroz irrigado
Sementes
herbicidas
Flooded rice
Seeds
Herbicides
CNPQ::CIENCIAS AGRARIAS::AGRONOMIA
Descrição
Resumo:The West Indian Marsh Grass is a native grass to tropical areas of Central and South America, which grows in wetlands, supporting intermittent periods of flooding. Their forms of propagation by fragments of rhizomes, rooting of lower nodes of stem and the high seed production facilitates population growth and dispersal of the weed to new areas. In Brazil, beyond natural pasture in the Amazonia and Pantanal regions, has been reported as invasive flooded rice in Rio Grande do Sul. So, this study aimed to evaluate the efficiency of pre-germinative treatments on overcoming dormancy of seeds (Chapter I), determine the viability of their seeds, by adapting the methodology of the tetrazolium test (Chapter II) and finally determine the control and reduction of biomass, caused by different doses of selective herbicides and total control in young and perennial plants (Chapter III). Seed exposure to potassium nitrate 0.2%, immersion in water for 48 hours and removal of the glumes, promoted the overcoming dormancy and accelerated the germination process. The seeds analyzed had high viability (89%), and six hours of hydration of seeds without glumes, with subsequent longitudinal slitting of the embryos and immersed in tetrazolium solution at 0.5% for four hours at a temperature of 23 ± 1 ° C, was appropriate for the species. As to chemical control, young plants, showed greater sensitivity to lower doses of herbicides cyhalofop-butyl and ammonium glufosinate, however, in the doses tested, only the glyphosate and the formulated mixture de Imazapic and imazapir caused the death plants. In perennial plants, control and reduction of biomass, caused by both herbicides were unsatisfactory.