Optimum stratification for yield estimation in cocoa (Theobroma Cacao L.) (Record no. 26522)

000 -LEADER
fixed length control field 02977nam a2200181Ia 4500
003 - CONTROL NUMBER IDENTIFIER
control field OSt
005 - DATE AND TIME OF LATEST TRANSACTION
control field 20220827103359.0
008 - FIXED-LENGTH DATA ELEMENTS--GENERAL INFORMATION
fixed length control field 140128s9999 xx 000 0 und d
082 ## - DEWEY DECIMAL CLASSIFICATION NUMBER
Classification number 630.31
Item number SUN/OP
100 ## - MAIN ENTRY--PERSONAL NAME
Personal name Sunil Kumar G
245 ## - TITLE STATEMENT
Title Optimum stratification for yield estimation in cocoa (Theobroma Cacao L.)
260 ## - PUBLICATION, DISTRIBUTION, ETC. (IMPRINT)
Place of publication, distribution, etc. Vellanikkara
Name of publisher, distributor, etc. Department of Agricultural Statistics, College of Horticulture
Date of publication, distribution, etc. 2000
502 ## - DISSERTATION NOTE
Degree type MSc
520 3# - SUMMARY, ETC.
Summary, etc. Investigation on "Optimum stratification for yield estimation In cocoa
(Theobroma cacao. L)" was carried out in the department of Agricultural Statistics,
College of Horticulture, V ellanikkara during 1997-99 using data on 1025 'F orestro'
variety cocoa trees from the Cadbury-KAU Co-operative Cocoa Research Project
(CCRP), College of Horticulture, Kerala Agricultural University.
Four different stratification rules, viz, cumulative root 'f rule, cumulative
cube root 'f rule, Ekman's rule and an iterative procedure for function minimisation,
were used to arrive at boundary points of strata. For each of these rules stratification
was carried out on average yield of yester years, canopy spread, value of HxG2
where 'H' is height and 'G' is the girth of the trees, the first principal component
derived from these variates and height and girth of the trees and regression estimate
of the study character with the predictor variables mentioned above. Sampling
variance of the estimator of the population mean under Neyman allocation for two to
five strata situations was estimated in each case, assuming a uniform sample size of
200. Different stratification rules and stratification variables were compared using
these estimates.
No single rule was found to be appropriate for all the stratification variables
and for different number of strata. But in most of the cases the cumulative root 'f
rule was found to be good for smaller number of strata followed by the cumulative
cube root 'f rule. For large number of strata, the iterative procedure performed
consistently well compared to all the other methods. In the case of stratification
based on the canopy spread, the Ekman' s method was found to be good for different
numbers of strata.
Regarding the stratification variables, the average yield of yester years was
found to be best followed by the regression estimate in the sense of resulting in
smaller sampling variance of the estimator of the population mean. Stratification
based on value of HxG2 and the first principal component were found to be inferior.

Average yield of yester years or regression estimate of yield could be used as
covariate to perform the analysis of covariance for experiments in cocoa and also
blocking of trees could be done based on these for the conduct of planned
experiments on cocoa.

700 ## - ADDED ENTRY--PERSONAL NAME
Personal name Gopinathan Unnithan V K (Guide)
856 ## - ELECTRONIC LOCATION AND ACCESS
Uniform Resource Identifier http://krishikosh.egranth.ac.in/handle/1/5810103728
942 ## - ADDED ENTRY ELEMENTS (KOHA)
Source of classification or shelving scheme
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          KAU Central Library, Thrissur KAU Central Library, Thrissur Theses 2014-03-18 630.31 SUN/OP 171579 2014-03-18 2014-03-18 Theses
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