Estimation of optimum plot dimensions and replication number for wheat experimentation in Ethiopia
Bread wheat was row and broadcast sown using uniform crop management practices on a research station soil classified as a haplic Nitisol, situated in a major wheat producing region of Ethiopia, during the 1996 and 1997 crop seasons. The harvested area was divided into basic units measuring 1 m by 1 m. Resultant basic unit grain yields were combined to simulate different plot sizes and shapes, and Smith's empirical model and subsequent derivations were used to estimate soil heterogeneity. The broadcast sown trials generally resulted in lower estimates of soil heterogeneity, higher coefficients of variation, and higher values for adjacent plot correlation due to both modified inter-plant competition, and a more variable distribution of wheat plants and basal fertiliser within plots. Parameter estimates from the broadcast sown trials were less consistent over the two year trial period relative to those from the row sown trials. The analyses suggested a marginal superiority for square plot shapes for broadcast sown trials, while for row sown trials rectangular and square plot shapes were equally precise in measuring soil heterogeneity. A comparison of the trial design parameters currently favoured by wheat researchers in Ethiopia with the optimal parameters estimated in the current study suggests that: (a) the design characteristics of broadcast sown wheat agronomic trials appear close to optimal, but (b) the net plot areas harvested from row sown wheat breeding trials are markedly suboptimal.
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Language: | English |
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African Crop Science Society
2000
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Subjects: | AGRICULTURAL SCIENCES AND BIOTECHNOLOGY, Heterogeneity Index, Optimum Plot Size, Plot Shape, Rectangularity, WHEAT, EXPERIMENTATION, OPTIMIZATION METHODS, PLOT DESIGN, REPLICATION, |
Online Access: | http://hdl.handle.net/10883/2321 |
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dig-cimmyt-10883-23212024-03-12T22:55:08Z Estimation of optimum plot dimensions and replication number for wheat experimentation in Ethiopia Girma Taye Awake Amsal Tesfaye Tarekegne Tanner, D.G. AGRICULTURAL SCIENCES AND BIOTECHNOLOGY Heterogeneity Index Optimum Plot Size Plot Shape Rectangularity WHEAT EXPERIMENTATION OPTIMIZATION METHODS PLOT DESIGN REPLICATION Bread wheat was row and broadcast sown using uniform crop management practices on a research station soil classified as a haplic Nitisol, situated in a major wheat producing region of Ethiopia, during the 1996 and 1997 crop seasons. The harvested area was divided into basic units measuring 1 m by 1 m. Resultant basic unit grain yields were combined to simulate different plot sizes and shapes, and Smith's empirical model and subsequent derivations were used to estimate soil heterogeneity. The broadcast sown trials generally resulted in lower estimates of soil heterogeneity, higher coefficients of variation, and higher values for adjacent plot correlation due to both modified inter-plant competition, and a more variable distribution of wheat plants and basal fertiliser within plots. Parameter estimates from the broadcast sown trials were less consistent over the two year trial period relative to those from the row sown trials. The analyses suggested a marginal superiority for square plot shapes for broadcast sown trials, while for row sown trials rectangular and square plot shapes were equally precise in measuring soil heterogeneity. A comparison of the trial design parameters currently favoured by wheat researchers in Ethiopia with the optimal parameters estimated in the current study suggests that: (a) the design characteristics of broadcast sown wheat agronomic trials appear close to optimal, but (b) the net plot areas harvested from row sown wheat breeding trials are markedly suboptimal. 11-23 pages 2013-06-07T21:11:28Z 2013-06-07T21:11:28Z 2000 Article 2072-6589 http://hdl.handle.net/10883/2321 10.4314/acsj.v8i1.27712 English CIMMYT manages Intellectual Assets as International Public Goods. The user is free to download, print, store and share this work. In case you want to translate or create any other derivative work and share or distribute such translation/derivative work, please contact CIMMYT-Knowledge-Center@cgiar.org indicating the work you want to use and the kind of use you intend; CIMMYT will contact you with the suitable license for that purpose. Open Access PDF Ethiopia African Crop Science Society http://www.bioline.org.br/abstract?id=cs00002&lang=en 1 8 African Crop Science Journal |
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AGRICULTURAL SCIENCES AND BIOTECHNOLOGY Heterogeneity Index Optimum Plot Size Plot Shape Rectangularity WHEAT EXPERIMENTATION OPTIMIZATION METHODS PLOT DESIGN REPLICATION AGRICULTURAL SCIENCES AND BIOTECHNOLOGY Heterogeneity Index Optimum Plot Size Plot Shape Rectangularity WHEAT EXPERIMENTATION OPTIMIZATION METHODS PLOT DESIGN REPLICATION |
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AGRICULTURAL SCIENCES AND BIOTECHNOLOGY Heterogeneity Index Optimum Plot Size Plot Shape Rectangularity WHEAT EXPERIMENTATION OPTIMIZATION METHODS PLOT DESIGN REPLICATION AGRICULTURAL SCIENCES AND BIOTECHNOLOGY Heterogeneity Index Optimum Plot Size Plot Shape Rectangularity WHEAT EXPERIMENTATION OPTIMIZATION METHODS PLOT DESIGN REPLICATION Girma Taye Awake Amsal Tesfaye Tarekegne Tanner, D.G. Estimation of optimum plot dimensions and replication number for wheat experimentation in Ethiopia |
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Bread wheat was row and broadcast sown using uniform crop management practices on a research station soil classified as a haplic Nitisol, situated in a major wheat producing region of Ethiopia, during the 1996 and 1997 crop seasons. The harvested area was divided into basic units measuring 1 m by 1 m. Resultant basic unit grain yields were combined to simulate different plot sizes and shapes, and Smith's empirical model and subsequent derivations were used to estimate soil heterogeneity. The broadcast sown trials generally resulted in lower estimates of soil heterogeneity, higher coefficients of variation, and higher values for adjacent plot correlation due to both modified inter-plant competition, and a more variable distribution of wheat plants and basal fertiliser within plots. Parameter estimates from the broadcast sown trials were less consistent over the two year trial period relative to those from the row sown trials. The analyses suggested a marginal superiority for square plot shapes for broadcast sown trials, while for row sown trials rectangular and square plot shapes were equally precise in measuring soil heterogeneity. A comparison of the trial design parameters currently favoured by wheat researchers in Ethiopia with the optimal parameters estimated in the current study suggests that: (a) the design characteristics of broadcast sown wheat agronomic trials appear close to optimal, but (b) the net plot areas harvested from row sown wheat breeding trials are markedly suboptimal. |
format |
Article |
topic_facet |
AGRICULTURAL SCIENCES AND BIOTECHNOLOGY Heterogeneity Index Optimum Plot Size Plot Shape Rectangularity WHEAT EXPERIMENTATION OPTIMIZATION METHODS PLOT DESIGN REPLICATION |
author |
Girma Taye Awake Amsal Tesfaye Tarekegne Tanner, D.G. |
author_facet |
Girma Taye Awake Amsal Tesfaye Tarekegne Tanner, D.G. |
author_sort |
Girma Taye Awake |
title |
Estimation of optimum plot dimensions and replication number for wheat experimentation in Ethiopia |
title_short |
Estimation of optimum plot dimensions and replication number for wheat experimentation in Ethiopia |
title_full |
Estimation of optimum plot dimensions and replication number for wheat experimentation in Ethiopia |
title_fullStr |
Estimation of optimum plot dimensions and replication number for wheat experimentation in Ethiopia |
title_full_unstemmed |
Estimation of optimum plot dimensions and replication number for wheat experimentation in Ethiopia |
title_sort |
estimation of optimum plot dimensions and replication number for wheat experimentation in ethiopia |
publisher |
African Crop Science Society |
publishDate |
2000 |
url |
http://hdl.handle.net/10883/2321 |
work_keys_str_mv |
AT girmatayeawake estimationofoptimumplotdimensionsandreplicationnumberforwheatexperimentationinethiopia AT amsaltesfayetarekegne estimationofoptimumplotdimensionsandreplicationnumberforwheatexperimentationinethiopia AT tannerdg estimationofoptimumplotdimensionsandreplicationnumberforwheatexperimentationinethiopia |
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1794797606021365760 |