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

Irrigation depth and harvest date in sweet potato for conversion to biofuels

Cicero Urbanetto Nogueira
  • Cicero Urbanetto Nogueira
  • Center of Rural Science, Federal University of Santa Maria, Campus Camobi, Santa Maria, RS-Brazil.
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Helena Maria Camilo de Moraes Nogueira
  • Helena Maria Camilo de Moraes Nogueira
  • Polytechnic School, Federal University of Santa Maria, Campus Camobi, Santa Maria, RS-Brazil.
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Richard Alberto Rodríguez Padrón
  • Richard Alberto Rodríguez Padrón
  • Water Department, CENUR, North Littoral Regional, University of the Republic, Uruguay.
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Sérgio Luiz Jahn
  • Sérgio Luiz Jahn
  • Department of Chemical Engineering, Federal University of Santa Maria, Brazil.
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Marcio Antonio Mazutti
  • Marcio Antonio Mazutti
  • Center of Rural Science, Federal University of Santa Maria, Campus Camobi, Santa Maria, RS-Brazil.
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  •  Received: 26 September 2016
  •  Accepted: 08 November 2016
  •  Published: 22 December 2016

Abstract

This study aimed to evaluate the effect of different irrigation depths and harvest dates in sweet potato for conversion to biofuels. Irrigation treatments were 0.25, 0.50, 0.75, and 1.0 of crop evapotranspiration rates and a control treatment (without irrigation). Harvest dates were: 90, 120, 150, 180, and 210 days after planting (DAP). The sweet potato cultivar BRS Cuia (RNC-27.315) was utilized. The experimental design was a randomized block in factorial arrangement (irrigation depths combined with harvest dates) with four replications. Reference crop evaporation was calculated based on the method of FAO Penman-Monteith. Drip irrigation system was used and irrigation frequency was every seven days. The highest and lowest yield were at 90 and 210 DAP, respectively. The lowest yield variation was between 120 and 150 DAP. Control treatment had highest yield in all harvest dates. Efficient water use was greater with irrigation of 0.25 of ETc with 116.9 and 218.8 m3 ha at 90 and 210 DAP, respectively. Starch content, crude protein, length and diameter of the root, and yield were influenced by different irrigation depths and harvest dates.

Key words: Ipomoea batatas, irrigation management, ethanol feedstock, drip irrigation, water deficit, efficient irrigation strategies.