Uniformity trial of safflower

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 feet = 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 feet = 46.6 feet.

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

Data are from Table A & B of Draper, p. 53-56. Typed by K.Wright.

Source

Arlen D. Draper. (1959). Optimum plot size and shape for safflower yield tests. Dissertation. University of Arizona. https://hdl.handle.net/10150/319371 Page 53-56.

References

None

Examples

if (FALSE) { # \dontrun{

  library(agridat)
  data(draper.safflower.uniformity)
  dat4 <- subset(draper.safflower.uniformity, expt=="E4")
  dat5 <- subset(draper.safflower.uniformity, expt=="E5")
  
  libs(desplot)
  desplot(dat4, yield~col*row,
          flip=TRUE, tick=TRUE, aspect=72/53, # true aspect
          main="draper.safflower.uniformity (four foot)")
  
  desplot(dat5, yield~col*row,
          flip=TRUE, tick=TRUE, aspect=90/46, # true aspect
          main="draper.safflower.uniformity (five foot)")

  # Draper appears to removed the border plots, but it is difficult to
  # match his results exactly
  dat4 <- subset(dat4, row>1 & row<20)
  dat4 <- subset(dat4, col>1 & col<17)
  dat5 <- subset(dat5, row>1 & row<20)
  dat5 <- subset(dat5, col<15)
  # Convert gm/plot to pounds/acre. Draper (p. 20) says 1487 pounds/acre
  mean(dat4$yield) / 453.592 / (3.33*4) * 43560 # 1472 lb/ac
  
  libs(agricolae)
  libs(reshape2)
  
  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
  
} # }