# little.splitblock: Split-block experiment of sugar beets In agridat: Agricultural Datasets

## Description

Split-block experiment of sugar beets.

## Usage

 `1` ```data("little.splitblock") ```

## Format

A data frame with 80 observations on the following 6 variables.

`row`

row

`col`

column

`yield`

sugar beet yield, tons/acre

`harvest`

harvest date, weeks after planting

`nitro`

nitrogen, pounds/acre

`block`

block

## Details

Four rates of nitrogen, laid out as a 4x4 Latin-square experiment.

Within each column block, the sub-plots are strips (across 4 rows) of 5 different harvest dates.

The use of sub-plots a s strips necessitates care when determining the error terms in the ANOVA table.

Note, Little has yield value of 22.3 for row 3, column I-H3. This data uses 23.3 in order to match the marginal totals given by Little.

## Source

Thomas M. Little, F. Jackson Hills. (1978) Agricultural Experimentation

None.

## Examples

 ``` 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29``` ```data(little.splitblock) dat <- little.splitblock # Match marginal totals given by Little. ## sum(dat\$yield) ## with(dat, tapply(yield,col,sum)) ## with(dat, tapply(yield,row,sum)) # Layout shown by Little figure 10.2 if(require(desplot)){ desplot(yield ~ col*row, data=dat, out1=block, out2=col, col=nitro, cex=1, num=harvest, main="little.splitblock") } # Convert continuous traits to factors dat <- transform(dat, R=factor(row), C=factor(block), H=factor(harvest), N=factor(nitro)) if(FALSE){ library(lattice) xyplot(yield ~ nitro|H,dat) xyplot(yield ~ harvest|N,dat) } # Anova table matches Little, table 10.3 m1 <- aov(yield ~ R + C + N + H + N:H + Error(R:C:N + C:H + C:N:H), data=dat) summary(m1) ```

agridat documentation built on May 2, 2019, 4:01 p.m.