Strip-split-plot experiment of rice — gomez.stripsplitplot • agridat

A strip-split-plot experiment with three reps, genotype as the horizontal strip, nitrogen fertilizer as the vertical strip, and planting method as the subplot factor.

Format

yield

grain yield in kg/ha

planting

planting factor, P1=broadcast, P2=transplanted

rep

rep, 3 levels

nitro

nitrogen fertilizer, kg/ha

gen

genotype, G1 to G6

col

column

row

row

Details

Note, this is a superset of the the 'gomez.stripplot' data.

Used with permission of Kwanchai Gomez.

Source

Gomez, K.A. and Gomez, A.A.. 1984, Statistical Procedures for Agricultural Research. Wiley-Interscience. Page 155.

Examples

# \dontrun{

library(agridat)
data(gomez.stripsplitplot)
dat <- gomez.stripsplitplot

# Layout
libs(desplot)
desplot(dat, gen ~ col*row,
        out1=rep, col=nitro, text=planting, cex=1,
        main="gomez.stripsplitplot")


# Gomez table 4.19, ANOVA of strip-split-plot design
dat <- transform(dat, nf=factor(nitro))
m1 <- aov(yield ~ nf * gen * planting +
          Error(rep + rep:nf + rep:gen + rep:nf:gen), data=dat)
summary(m1)
#> 
#> Error: rep
#>           Df   Sum Sq Mean Sq F value Pr(>F)
#> Residuals  2 15289498 7644749               
#> 
#> Error: rep:nf
#>           Df    Sum Sq  Mean Sq F value  Pr(>F)   
#> nf         2 116489166 58244583   36.62 0.00268 **
#> Residuals  4   6361491  1590373                   
#> ---
#> Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
#> 
#> Error: rep:gen
#>           Df   Sum Sq Mean Sq F value Pr(>F)  
#> gen        5 49119270 9823854   3.676 0.0379 *
#> Residuals 10 26721828 2672183                 
#> ---
#> Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
#> 
#> Error: rep:nf:gen
#>           Df   Sum Sq Mean Sq F value Pr(>F)  
#> nf:gen    10 24595731 2459573   2.575 0.0344 *
#> Residuals 20 19106733  955337                 
#> ---
#> Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
#> 
#> Error: Within
#>                 Df   Sum Sq Mean Sq F value   Pr(>F)    
#> planting         1   723079  723079   1.715   0.1986    
#> nf:planting      2  2468132 1234066   2.927   0.0664 .  
#> gen:planting     5 23761441 4752288  11.271 1.37e-06 ***
#> nf:gen:planting 10  7512072  751207   1.782   0.1000 .  
#> Residuals       36 15179354  421649                     
#> ---
#> Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1

# There is a noticeable linear trend along the y coordinate which may be
# an artifact that blocking will remove, or may need to be modeled.
# Note the outside values in the high-nitro boxplot.
libs("HH")
interaction2wt(yield ~ nitro + gen + planting + row, dat,
               x.between=0, y.between=0,
               x.relation="free")

# }