Influence of rice cultivars and nitrogen fertilizer timing on the interference relationships between the crop and cultivar simulating red rice infestation

Planta Daninha

Agostinetto, D.¹  Rizzardi, M.A.¹  Universidade Federal do Rio Grande do Sul¹  Vidal, R.A.¹  Universidade Federal do Rio Grande do Sul, Porto Alegre¹  Costa, E.L.N.¹  Fleck, N.G.¹ 

关键词: Oryza sativa;    competitive ability;    cultural practices;    non linear regression.;   

DOI  :  10.1590/S0100-83582004000200003

学科分类：农业科学（综合）

来源: Sociedade Brasileira da Ciencia das Plantas Daninhas (S B C P D) / Brazilian Society of Herb Science

【 摘 要 】

The objective of this study was to evaluate the effects of flooded rice cultivars and timings of nitrogen fertilizer application during the crop cycle on the competitive ability of this cereal in relation to EEA 406 cultivar, used as a mimicker of red rice. Thus, a field experiment was carried out during the 2001/02 growing season. The treatments were arranged in a factorial design,comprising the rice cultivars (BRS-38 Ligeirinho, IRGA 417, and BR-IRGA 409), nitrogen (N) application timings (100% at sowing, 50% at sowing plus 50% at the beginning of panicle differentiation (BPD), 100% at BPD, and check without fertilizer), and densities of the mimicker cultivar. In order to relate rice grain yield losses to densities of the mimicker cultivar, a retangular hyperbolic regression model was applied, independently adjusted for the factors tested. It was verified that N application timing influenced the competitive ability of rice cultivars. Very early and early maturity rice cultivars showed greater competitive ability with mimicker genotype when N fertilizer was applied at sowing time, whereas medium maturity cultivar took more advantage with N fertilizer fractioning at sowing and BPD.

【 授权许可】

Unknown