agridat (version 1.16)

draper.safflower.uniformity: Uniformity trial of safflower

Description

Uniformity trial of safflower in Arizona in 1958.

Usage

data("draper.safflower.uniformity")

Format

A data frame with 640 observations on the following 4 variables.

expt

experiment

row

row

col

column

yield

yield per plot (grams)

Details

Experiments were conducted at the Agricultural Experiment Station Farm at Eloy, Arizona. The crop was harvested in July 1958.

The crop was planted in two rows 12 inches apart on vegetable beds 40 inches center to center.

In each test, the end ranges and one row of plots on one side were next to alleys, and those plots gave estimates of border effects.

Experiment E4 (four foot test).

Sandy streaks were present in the field. Average yield was 1487 lb/ac. A diagonal fertility gradient was in this field. Widening the plot was equally effective as lengthening the plot to reduce variability. The optimum plot size was 1 bed wide, 24 feet long. Considering economic costs, the optimum size was 1 bed, 12 feet long.

Field width: 16 beds * 3.33 = 53 feet

Field length: 18 ranges * 4 feet = 72 feet

Experiment E5 (five foot test)

Average yield 2517 lb/ac, typical for this crop. Combining plots lengthwise was more effective than widening the plots, in order to reduce variability. The optimum plot size was 1 bed wide, 25 feet long. Considering economic costs, the optimum size was 1 bed, 18 feet long.

Field width: 14 beds * 3.33 = 46.6 feet.

Field length: 18 ranges * 5 feet = 90 feet.

References

None

Examples

# NOT RUN {
  
  data("draper.safflower.uniformity")
  dat4 <- subset(draper.safflower.uniformity, expt=="E4")
  dat5 <- subset(draper.safflower.uniformity, expt=="E5")

  require(desplot)
  desplot(yield~col*row, dat4,
          flip=TRUE, tick=TRUE, aspect=72/53, # true aspect
          main="draper.safflower.uniformity (four foot)")

  desplot(yield~col*row, dat5,
          flip=TRUE, tick=TRUE, aspect=90/46, # true aspect
          main="draper.safflower.uniformity (five foot)")

  require(agricolae)
  require(reshape2)
  # Remove border plots at either end and right side
  dat4 <- subset(dat4, row>1 & row<20)
  dat4 <- subset(dat4, col<17)
  dat5 <- subset(dat5, row>1 & row<20)
  dat5 <- subset(dat5, col<15)
  
  s4 <- index.smith(acast(dat4, row~col, value.var='yield'),
                    main="draper.safflower.uniformity (four foot)",
                    col="red")$uni
  s4 # match Draper table 2, p 22
  
  ## s5 <- index.smith(acast(dat5, row~col, value.var='yield'),
  ##                   main="draper.safflower.uniformity (five foot)",
  ##                   col="red")$uni
  ## s5 # match Draper table 1, p 21
  
# }