Gibberellic acid in the rice seeds treatment under differents temperatures / Efeito do ácido giberélico no tratamento de sementes de arroz irrigado sob diferentes temperatura

AUTOR(ES)
DATA DE PUBLICAÇÃO

2005

RESUMO

Rio Grande do Sul state is the main Brazilian irrigated rice producer, being responsible by around 45% of the total amount harvested. However, the low temperatures frequently observed in the sowing season and the different gibberellic acid concentrations in seeds of the main rice cultivars, are factors that affect severely the rice grain yield. The knowledge about the cultivars better adapted, amount of gibberellic acid required by distinct cultivars and the temperature where the best responses are observed, are technologies not vastly known but of great importance for the rice culture. This study had the objective of to evaluate the shoot and root length, and the initial growth of rice plants cvs. SCS-112, BRS-7 Taim, BR IRGA 410 and IRGA 417 submitted to 0, 50, 100, 150, 300, 450, 600 and 750 mg L-1 of gibberellic acid in seeds treatment, and to analyze the total dry matter of shoots and roots in different temperatures, evaluated at 3, 7 and 21 days after sowing. The results showed that the rice answer differently to GA in the shoot and root length in function of growth temperatures and time of evaluation. The dry matter of shoot, root and seedlings, a variation in GA3 concentration and growth temperatures are different for the cultivars. The BRS-7 Taim shows different behavior with severe endogenous GA3 in the initial seedling growth. The absence of GA3 application in the BRS-7 Taim affects more intensely the roots than the shoot in the dry matter products.

ASSUNTO(S)

growth regulator oryza sativa l. temperatura sementes agronomia initial growth arroz irrigado oryza sativa Ácido giberélico

ACESSO AO ARTIGO

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