MSc

This investigation was taken up to determine optimum size of experimental
units for coconut using multivariate approach. Observations on yield, female flower
production, percentage of buttons set and number of functional leaves from 184
coconut palms for two consecutive years were utilised. These palms belonged to two
separate experiments in two locations.
All known systematic effects were eliminated from the observations. The
trees were arranged in the ascending order of the number of functional leaves of first
year of observations. Experimental units of sizes ranging from single tree to ten trees
were formed by combining trees adjacent in the list of ordered trees. Blocks of five
plots, seven plots and ten plots were also formed by combining adjacent plots.
Coefficient of variation in univariate case and determinant of relative
dispersion matrix in multivariate case were the measures of variation used.
Optimum size of experimental units was determined in univariate case for
yield and female flower production in first and second years. Optimum size of plots was
determined in multivariate case for the following character combinations.
1) Yield for first and second year
2) Female flower production for first and second years
3) Yield and female flower production for first and second year
4) Yield, female flower production and percentage of buttons set for the first year
5) Yield female flower production and percentage of bottons set for the second year


Optimum size of plot was determined by three different criteria viz., (i) that
which requires minimal experimental material for a specified precision (ii) that having
maximum efficiency and (iii) that which maximises the curvature of the relationship
between measure of variation and plot size.
Plot size that required minimum number of trees for 5 per cent error was
two tree plots except in the univariate case of yield in first year and multivariate case of
without blocking for characters sets (4) and (5) for which single tree plots were
optimum.
In all univariate determinations single tree plots had maximum efficiency.
Two tree plots had maximum efficiency in multivariate approach except for characters
sets (4) and (5) in the case of no blocking.
Four tree plot was optimum by the method of maximum curvature except for
characters sets (3), (4) and (5) is multivariate case for which three tree plots were
optimum. Though Fair Field Smith's law was a good fit to the relationship between the
measure of variation and plot size, Y = a +b/√x+ c/x gave better fit in most of the
cases.
Two tree plots were recommended for experiments it) established coconut
gardens.