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Activity Number:
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314
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Type:
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Contributed
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Date/Time:
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Wednesday, August 11, 2004 : 9:00 AM to 10:50 AM
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Sponsor:
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Biometrics Section
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| Abstract - #300614 |
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Title:
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Temporal-spatial Covariance Structure of Water Use Efficiency of Lentil in Rotation with Wheat
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Author(s):
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Murari Singh*+ and Theib Oweis and Mustafa Pala and Ashutosh Sarker
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Companies:
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International Center for Agricultural Research in the Dry Areas and International Center for Agricultural Research in the Dry Areas and International Center for Agricultural Research in the Dry Areas and International Center for Agricultural Research in the Dry Areas
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Address:
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ICARDA, ALEPPO, International, POBOx 5466, Syria
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Keywords:
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spatial ; temporal ; water ; covariance ; lentil
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Abstract:
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Supplemental irrigation in a crop in dry areas facilitates an efficient use of water and is used as a mechanism for achieving higher and sustainable levels of crop productivity, particularly in crop rotation system. To model water use efficiency of lentil, a grain legume rich in protein, split-plot experiments were conducted at ICARDA station using lentil/wheat rotation system from 1997-2000. The statistical issues addressed are spatial variability in the fields and correlated response over year. Yearwise data were modeled with plot-errors following first-order autocorrelation with/without linear trends in the field, and combined with a constant correlation over time. AIC was used to select the best covariance structure. Spatial correlation with linear trend was detected in several cases. Compared with the standard split-plot analysis, AIC-best models gave stronger significance and higher precision of the main effects and interaction of supplemental irrigation and planting date on lentil water use efficiency. Extraction and use of most appropriate temporal-spatial covariance structures is recommended for estimation of effects of the agronomic factors.
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