agridat (version 1.23)

robinson.peanut.uniformity: Uniformity trial of peanuts

Description

Uniformity trial of peanuts in North Carolina in 1939, 1940.

Usage

data("robinson.peanut.uniformity")

Format

A data frame with 1152 observations on the following 4 variables.

row

row

col

column

yield

yield in grams/plot

year

year

Details

Two crops of peanuts were grown in North Carolina in 1939 and 1940. A different field was used each year.

A block of 36 rows 3 feet wide and 200 feet long were harvested in 12.5 foot lengths.

Field length: 36 plots * 12.5 feet = 200 feet

Field width: 16 plots * 3 feet = 48 feet

Widening the plot was not as effective as increasing the plot length in order to reduce error. This agrees with the results of other uniformity studies.

Assuming 30 percent of the total cost of an experiment is proportional to the size of the plots used, the optimum plot size is approximately 3.2 units.

References

None

Examples

if (FALSE) {

library(agridat)

  data(robinson.peanut.uniformity)
  dat <- robinson.peanut.uniformity

  # Mean yield per year. Robinson has 703.9, 787.3
  # tapply(dat$yield, dat$year, mean)
  #     1939     1940 
  # 703.7847 787.8125 
  
  libs(desplot)
  desplot(dat, yield ~ col*row|year,
          flip=TRUE, tick=TRUE, aspect=200/48,
          main="robinson.peanut.uniformity")
  
}