Grain yield and kernel crude protein content increases of maize hybrids with late nitrogen side-dressing

Scientia Agricola

Paulo Regis Ferreira Da Silva²  Mércio Luiz Strieder²  Rúbia Patrícia Da Silva Coser²  Lisandro Rambo²  Luís Sangoi¹  Gilber Argenta¹  Everton Leonardo Forsthofer¹  Adriano Alves Da Silva² 

[1] ,UFRGS Depto. de Plantas de Lavoura Porto Alegre RS ,Brasil

关键词: Zea mays;    nitrogen;    fertilization timing;    productivity;    Zea mays;    nitrogênio;    época de aplicação;    produtividade;   

DOI  :  10.1590/S0103-90162005000500014

来源: SciELO

【 摘 要 】

Physiological changes incorporated into current maize hybrids suggest the occurrence of modifications in the nitrogen uptake dynamics, improving plant ability to uptake N during grain filling. This may justify late N side-dressing whenever environmental constraints prevent adequate nitrogen supply during crops vegetative development. This study evaluates effects of nitrogen fertilization at booting and silking on grain yield and kernel crude protein contents of commercial maize hybrids. Two experiments were set up in Eldorado do Sul, RS, during the 2001/2002 and 2002/2003 growing seasons. In 2001/2002, treatments were composed of two hybrids (Agroceres 303 and Pioneer 32R21), three nitrogen rates applied during maize vegetative development (30, 80 and 130 kg ha-1) and three nitrogen rates applied at silking (0, 50 and 100 kg ha-1). In 2002/2003, four hybrids (Agroceres 303, Pioneer 32R21, Dekalb 215 and Syngenta Penta) and four nitrogen rates side-dressed at booting (0, 50, 100 and 150 kg.ha-1) were assessed. There were significant increments in grain yield and kernel crude protein content with nitrogen fertilization at booting and silking. Grain yield response to late N side-dressing differed among cultivars. The impact of nitrogen fertilization at silking was higher at the smallest rate of N during the plant vegetative development. Enhancements in grain yield with late N side-dressing resulted from increases in grain weight. Modern hybrids can uptake nitrogen during silking, contradicting the hypothesis that late N side-dressing is not efficient to improve maize grain yield.

【 授权许可】

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