agridat (version 1.25)

bryan.corn.uniformity: Uniformity trial of corn at 3 locations in Iowa.

Description

Uniformity trial of corn at 3 locations in Iowa.

Usage

data("bryan.corn.uniformity")

Format

A data frame with 1728 observations on the following 4 variables.

expt

experiment (variety/orientation)

row

row

col

column

yield

yield, pounds per plot

Details

Three varieties of corn were planted. Each experiment was 48 rows, each row 48 hills long, .65 acres. A "hill" is a single hole with possibly multiple seeds. Spacing between the hills would be sqrt(43560 sq ft * .64) / 48 = 3.5 feet.

In the experiment code, K=Krug, I=Iodent, M=McCulloch (varieties of corn), 23=1923, 25=1925, E=East/West, N=North/South.

Each experiment was aggregated into experimental units by combining 8 hills, both in East/West direction and also in North/South direction. Thus, each field is represented twice in the data, once with "E" in the field name and once with "N".

References

None

Examples

if (FALSE) {
  library(agridat)
  data(bryan.corn.uniformity)
  dat <- bryan.corn.uniformity
  
  libs(desplot)
  desplot(dat, yield ~ col*row|expt,
          main="bryan.corn.uniformity",
          aspect=(48*3.5/(6*8*3.5)), # true aspect
          flip=TRUE, tick=TRUE)

  # CVs in Table 5, column 8 hills
  # libs(dplyr)
  # dat 
  #   summarize(cv=sd(yield)/mean(yield)*100)
  ##   expt    cv
  ## 1 K23E  10.9
  ## 2 K23N  10.9
  ## 3 I25E  16.3
  ## 4 I25N  17.0
  ## 5 M25E  16.2
  ## 6 M25N  17.2

}