Abstract
Breeding programs for rainfed lowland rice normally use large plot sizes for accurate estimation of yield. Resource requirements are reduced and more genotypes can be tested if a small plot size can be used. A total of 4 experiments was conducted at high and low soil fertility locations in Thailand to determine the influence of plot size and arrangement of tall and short genotypes in small plots on the estimation of yield of genotypes differing in height. Ten to sixteen genotypes were grown in different orders of tall and short genotypes within 2-row plots and also in random arrangements in 4-row, 6-row and 16-row plots. Results showed that taller genotypes tended to suppress the performance of the neighboring shorter genotypes. Consequently the yield results from 2-row plots, in which genotypes were randomly allocated, were unreliable at the high soil fertility location with more vigorous growth, although they were sufficient at the low soil fertility location. Thus plot sizes of 4 and 6-rows appear necessary for accurate estimation of yield across environments. However, when all short genotypes were grouped together and formed a block, and all tall genotypes grouped to form another block, yield results from 2-row plots showed a rather small effect of the competition between the neighbouring genotypes. The yield estimation was improved further by adjusting yield according to the height of each genotype by using covariance analysis. With these modifications, 2-row plots were found to be sufficient for accurate estimation of yield.
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Claims 7
Claim · model-written summary
Taller rice genotypes tended to suppress the performance of neighbouring shorter genotypes.
Verbatim
e0“Breeding programs for rainfed lowland rice normally use large plot sizes for accurate estimation of yield”
e1“Results showed that taller genotypes tended to suppress the performance of the neighboring shorter genotypes”
Claim · model-written summary
Yield results from 2-row plots with random genotype allocation were unreliable at the high soil fertility location.
- Taxon
- rainfed lowland ricee0
- Outcome
- yield results from 2-row plotse2
- Qualifier
- unreliablee2
- Setting
- high soil fertility locatione2
Not reportedDirection
Verbatim
e0“Breeding programs for rainfed lowland rice normally use large plot sizes for accurate estimation of yield”
e2“Consequently the yield results from 2-row plots, in which genotypes were randomly allocated, were unreliable at the high soil fertility location with more vigorous growth”
Claim · model-written summary
Yield results from 2-row plots with random genotype allocation were sufficient at the low soil fertility location.
- Taxon
- rainfed lowland ricee0
- Outcome
- yield results from 2-row plotse2
- Qualifier
- sufficiente3
- Setting
- low soil fertility locatione3
Not reportedDirection
Verbatim
e0“Breeding programs for rainfed lowland rice normally use large plot sizes for accurate estimation of yield”
e2“Consequently the yield results from 2-row plots, in which genotypes were randomly allocated, were unreliable at the high soil fertility location with more vigorous growth”
e3“although they were sufficient at the low soil fertility location”
Claim · model-written summary
Plot sizes of 4 and 6 rows appear necessary for accurate yield estimation across environments.
Verbatim
e0“Breeding programs for rainfed lowland rice normally use large plot sizes for accurate estimation of yield”
e4“Thus plot sizes of 4 and 6-rows appear necessary for accurate estimation of yield across environments”
Claim · model-written summary
Grouping short genotypes into a block gave a rather small effect of competition between neighbouring genotypes on 2-row plot yields.
Verbatim
e0“Breeding programs for rainfed lowland rice normally use large plot sizes for accurate estimation of yield”
e5“when all short genotypes were grouped together and formed a block, and all tall genotypes grouped to form another block, yield results from 2-row plots showed a rather small effect of the competition between the neighbouring genotypes”
Claim · model-written summary
Adjusting yield for genotype height by covariance analysis improved the yield estimation.
- Taxon
- rainfed lowland ricee0
- Treatment
- adjusting yield according to the height of each genotypee6
- Outcome
- yield estimatione6
- Direction
- improvede6
Not reportedComparator
Verbatim
e0“Breeding programs for rainfed lowland rice normally use large plot sizes for accurate estimation of yield”
e6“The yield estimation was improved further by adjusting yield according to the height of each genotype by using covariance analysis”
Claim · model-written summary
With height adjustment, 2-row plots were sufficient for accurate yield estimation.
Verbatim
e0“Breeding programs for rainfed lowland rice normally use large plot sizes for accurate estimation of yield”
e7“With these modifications, 2-row plots were found to be sufficient for accurate estimation of yield”