agridat (version 1.12)

bridges.cucumber: Cucumber yields in Latin Square design.

Description

Cucumber yields in Latin Square design at two locs.

Format

A data frame with 32 observations on the following 5 variables.

loc

Loc factor

gen

Cultivar factor

row

Row position

col

Column position

yield

Weight of marketable fruit per plot

Details

Conducted at Clemson University in 1985. four cucumber cultivars were grown in a Latin Square design at Clemson, SC, and Tifton, GA.

Separate variances are modeled each location.

Examples

# NOT RUN {
data(bridges.cucumber)
dat <- bridges.cucumber
dat <- transform(dat, rowf=factor(row), colf=factor(col))

desplot(yield~col*row|loc, data=dat, text=gen, cex=1,
        main="bridges.cucumber")

# }
# NOT RUN {
require(asreml)
## Random row/col/resid. Same as Bridges 1989, p. 147
m1 <- asreml(yield ~ 1 + gen + loc + loc:gen,
             random = ~ rowf:loc + colf:loc, data=dat)

require(lucid)
vc(m1)
##             effect component std.error z.ratio constr
##  rowf:loc!rowf.var     31.62     23.02     1.4    pos
##  colf:loc!colf.var     18.08     15.32     1.2    pos
##         R!variance     31.48     12.85     2.4    pos

## Random row/col/resid at each loc. Matches p. 147
m2 <- asreml(yield ~ 1 + gen + loc + loc:gen,
             random = ~ at(loc):rowf + at(loc):colf, data=dat,
             rcov = ~at(loc):units)
vc(m2)
##                          effect component std.error z.ratio constr
##  at(loc, Clemson):rowf!rowf.var     32.32    36.58     0.88    pos
##   at(loc, Tifton):rowf!rowf.var     30.92    28.63     1.1     pos
##  at(loc, Clemson):colf!colf.var     22.55    28.78     0.78    pos
##   at(loc, Tifton):colf!colf.var     13.62    14.59     0.93    pos
##            loc_Clemson!variance     46.85    27.05     1.7     pos
##             loc_Tifton!variance     16.11     9.299    1.7     pos

predict(m2, classify='loc:gen')$predictions$pvals
##     loc      gen Predicted Std Err    Status
## Clemson   Dasher     45.55   5.043 Estimable
## Clemson Guardian     31.62   5.043 Estimable
## Clemson Poinsett     21.42   5.043 Estimable
## Clemson   Sprint     25.95   5.043 Estimable
##  Tifton   Dasher     50.48   3.894 Estimable
##  Tifton Guardian     38.72   3.894 Estimable
##  Tifton Poinsett     33.01   3.894 Estimable
##  Tifton   Sprint     39.18   3.894 Estimable
# }