African Journal of
Agricultural Research

  • Abbreviation: Afr. J. Agric. Res.
  • Language: English
  • ISSN: 1991-637X
  • DOI: 10.5897/AJAR
  • Start Year: 2006
  • Published Articles: 6576

Full Length Research Paper

Rice development and water demand under drought stress imposed at distinct growth stages

Germani Concenço
  • Germani Concenço
  • Rodovia BR-392, Km 78, 9º Distrito, Monte Bonito, Cx.P. (ZIP) 403, CEP: 96010-971 - Pelotas, RS, Brazil.
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José Maria Barbat Parfitt
  • José Maria Barbat Parfitt
  • Rodovia BR-392, Km 78, 9º Distrito, Monte Bonito, Cx.P. (ZIP) 403, CEP: 96010-971 - Pelotas, RS, Brazil.
  • Google Scholar
Kelly Downing
  • Kelly Downing
  • Valmont Industries, Irrigation Division, Omaha, NE, USA.
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Jacob Larue
  • Jacob Larue
  • Valmont Industries, Irrigation Division, Omaha, NE, USA.
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Jaqueline Trombetta da Silva
  • Jaqueline Trombetta da Silva
  • Fedaral University of Pelotas, Pelotas, RS, Brazil.
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  •  Received: 19 August 2016
  •  Accepted: 15 September 2016
  •  Published: 13 October 2016

Abstract

This study aimed to establish a comparison for theoretical water demand between rice plants grown under flooding and under different levels of water stress, imposed at distinct crop stages, in terms of plant morpho-physiology and phenology. The experiment was installed in a greenhouse, using complete randomized design and factorial scheme 3 × 4 + 1, with four replications. Factor “A” was defined as the growth stage when water stress was imposed on the treatments, these stages being (1) vegetative, (2) reproductive 1, and (3) reproductive 2; factor “B” was composed of four levels of water stress (0 to 200 kPa). The additional treatment consisted of a flooded check. Water was replenished back to saturation every time the threshold stress level was reached. There is damage to rice growth and development in water tensions greater than 30 kPa when applied between tillering start and anthesis. Main damage was observed as reduced rates of culm growth; leaf area tended to be maintained. Water luxury consumption by rice plants grown under flooding seems to be about 23% of the total demand, compared to the other irrigated treatments. The rice field should be irrigated back to saturation when soil water tension is between 10 kPa and 30 kPa. Overall, theoretical crop coefficient (Kc) for rice under sprinkler irrigation is about 20% lower than that observed for the flooded check.

Key words: Water consumption, planting system, Oryza sativa.