Uniformity trial of corn

Uniformity trial of corn at Arkansas Experiment Station, 1925.

Usage

data("mcclelland.corn.uniformity")

Format

A data frame with 438 observations on the following 3 variables.

row

row

col

column

yield

yield

Details

A uniformity trial of corn in 1925 at the Arkansas Experimental Station. Unit of measure not given.

Field width = 66ft * 2 = 132 feet.

Field length = 219 rows * 44 inches / 12 inches/ft = 803 ft.

Note: In the source document, table 2, first 'west' column and second-to-last row (page 822), the value 1.40 is assumed to be a typographical error and was changed to 14.0 for this data.

The source document does not give the unit of measure for the plot yields. If the yield was bu/ac, the value of 12 bu/ac would be very low. On the other hand, a value of 12 pounds per plot * 180 plots per acre / 56 pounds per bushel = 39 bu/ac would be very reasonable yield for corn in 1925, whereas 12 kg per plot would be unlikely too high. Also, in 1925, pound would have been more likely than kilogram.

Source

McClelland, Chalmer Kirk (1926). Some determinations of plat variability. Agronomy Journal, 18, 819-823. https://doi.org/10.2134/agronj1926.00021962001800090009x

References

None

Examples

if (FALSE) { # \dontrun{

library(agridat)

  data(mcclelland.corn.uniformity)
  dat <- mcclelland.corn.uniformity
  
  # McClelland table 3, first row, gives 11.2
  # Probable error = 0.67449 * sd(). Relative to mean.
  # 0.67449 * sd(dat$yield)/mean(dat$yield) # 11.2
  
  libs(desplot)
  desplot(dat, yield ~ col*row,
          flip=TRUE,
          aspect=(219*44/12)/132, # true aspect, 219 rows * 44 inches x 132 feet
          main="mcclelland.corn.uniformity")
  
} # }