Arroz tolerante a imidazolinonas: controle do arroz vermelho, persistência de herbicidas e fluxo gênico

Red rice (Oryza spp.) is one of the main limiting factors to rice (O. sativa L.) yield. After several decades searching for red rice control tools, it was developed imidazolinone tolerant rice, to selectively control red rice. To better understand this technology it were conducted two experiments in...

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Detalhes bibliográficos
Autor: Villa, Silvio Carlos Cazarotto
Tipo de documento: dissertação
Estado:Versão publicada
Data de publicação:2006
País:Brasil
Recursos:Universidade Federal de Santa Maria (UFSM)
Repositório:Manancial - Repositório Digital da UFSM
Idioma:português
OAI Identifier:oai:repositorio.ufsm.br:1/5081
Acesso em linha:http://repositorio.ufsm.br/handle/1/5081
Access Level:Acceso aberto
Palavra-chave:Sistema clearfield
Imazapic
Imazethapyr
IRGA 422 CL
Only®
Tuno CL
Clearfield system
CNPQ::CIENCIAS AGRARIAS::AGRONOMIA
Descrição
Resumo:Red rice (Oryza spp.) is one of the main limiting factors to rice (O. sativa L.) yield. After several decades searching for red rice control tools, it was developed imidazolinone tolerant rice, to selectively control red rice. To better understand this technology it were conducted two experiments in 2004/05, in Santa Maria, Rio Grande do Sul state, Brazil. The first experiment (Chapter I) had the objective of: 1) evaluate red rice control by imidazolinone herbicides in Clearfield rice; 2) evaluate the imidazolinone herbicide carryover effect on rygrass and non-tolerant rice (IRGA 417) and 3) evaluate the outcrossing rates between Clearfield rice and red rice. The herbicides tested control red rice. Although injury to Clearfield rice was observed, the herbicide did not affected yield. It was observed herbicide carryover to non-tolerant rice, reducing plant stand. There was natural outcrossing between Clearfield rice and red rice, at rates of 0.065%. The second experiment (Chapter II) had the objective of evaluate the herbicide Only® (imazethapyr 75 g L-1 + imazapic 25 g L-1) in different application rates and timing on two genotypes, IRGA 422 CL and Tuno CL, to the imidazolinones herbicides. When compared with the cultivar, the hybrid was more tolerant to the herbicide Only®. It was possible to apply rates of up to 2.0 L ha-1 in the hybrid, without affecting rice yield. Red rice control was total with split application of Only® in PRE and POST, with rates above 1.25 L ha-1. The most efficient treatment was with application of 0.75 L ha-1 in PRE followed by 0.5 L ha-1 in POS, because, it was the lowest rate that promoted 100% control, with relatively low toxicity to the cultivar and without affecting rice yield.