|Porch, Timothy - Tim|
Submitted to: Bean Improvement Cooperative Annual Report
Publication Type: Research notes
Publication Acceptance Date: 3/1/2008
Publication Date: 3/31/2008
Citation: Ramirez, V.H., Porch, T.G., Harmsen, E.W. 2008. Evapotranspiration and water use efficiency for common bean genotypes under non-stress and drought stress conditions. Bean Improvement Cooperative Annual Report. 51:82-83. Interpretive Summary: Drought stress causes the largest reductions in yield in common bean of any environmental stress. In this study, two common bean varieties were evaluated during two years under drought stress and non-stress conditions. Evapotranspiration was determined using two methods, one was based on actual water use and the second estimated evapotranspiration using weather data from field-based weather stations. Drought stress in the field was more severe in 2007 than in 2006, causing an average reduction in seed yield of 76% in variety ‘Morales’ and 67% in variety ‘SER 16’, as compared to 33% for Morales and 29% for SER 16 in 2006. Over the whole season, the cumulative evapotranspiration was similar for Morales and SER 16 under non-stress, while SER 16 showed a tendency toward higher efficiency of water use under drought stress conditions. The elucidation of common bean response to drought will allow for more efficient and sustainable use of limited irrigation water and improved production under drought stress conditions.
Technical Abstract: Drought stress is the most important abiotic constraint in common bean production worldwide and results in significant yield reductions. In this study, two common bean genotypes were evaluated, including ‘Morales’, a small white cultivar, and a small red germplasm developed at CIAT (Colombia), SER 16, during two years under drought stress and non-stress conditions. Crop evapotranspiration was measured using 12 drainage type lysimeters and estimated using the general Penman-Monteith method, based on 4 field-based weather stations, and variable aerodynamic and surface resistance. Drought stress in the field was more severe in 2007 (Drought Intensity Index, DII=0.72) than in 2006 (DII=0.31), causing an average reduction in seed yield of 76% for Morales and 67% for SER 16 in 2007, as compared to 33% for Morales and 29% for SER 16 in 2006. The cumulative evapotranspiration (ET) in the field was similar for Morales and SER 16 under non-stress, while SER 16 showed a tendency toward higher water use efficiency (WUE) under drought stress conditions.