agridat (version 1.23)

polson.safflower.uniformity: Uniformity trial of safflower

Description

Uniformity trial of safflower at Farmington, Utah, 1962.

Usage

data("polson.safflower.uniformity")

Format

A data frame with 1716 observations on the following 3 variables.

row

row

col

column

yield

yield (grams)

Details

A uniformity trial of safflower at the Utah State University field station in Farmington, Utah, in 1962. The field was approximately 0.5 acres in size, 110 x 189 feet. A four-row planter was used, 22 inches between rows. Four rows on either side and 12 feet on both ends were removed before harvesting.

Yield of threshed grain was recorded in grams.

Field width: (52 rows + 8 border rows) * 22 in = 110 ft

Field length: 33 sections * 5ft + 2 borders * 12 ft = 189 ft

References

None.

Examples

if (FALSE) {

library(agridat)

  data(polson.safflower.uniformity)
  dat <- polson.safflower.uniformity
  
  libs(desplot)
  desplot(dat, yield ~ col*row,
          flip=TRUE, aspect=189/110, # true aspect
          main="polson.safflower.uniformity")

  libs(agricolae)
  libs(reshape2)
  dmat <- acast(dat, row~col, value.var="yield")
  # Similar to Polson fig 4.
  tab <- index.smith(dmat, col="red",
                     main="polson.safflower.uniformity - Smith Index",
                     xlab="Plot size in number of basic plots")
  
  # Polson p. 25 said CV decreased from 14.3 to 4.5
  # for increase from 1 unit to 90 units.  Close match.
  tab <- data.frame(tab$uniformity)

  # Polson only uses log(Size) < 2 in his Fig 5, obtained slope -0.63
  coef(lm(log(Vx) ~ log(Size), subset(tab, Size <= 6))) # -0.70

  # Polson table 2 reported labor for
  # K1, number of plots, 133 hours 75
  # K2, size of plot, 43.5 hours 24
  # Optimum plot size
  # X = b K1 / ((1-b) K2)
  # Polson suggests optimum plot size 2.75 to 11 basic plots
  
}