agridat (version 1.23)

ansari.wheat.uniformity: Uniformity trial of wheat

Description

Uniformity trial of wheat in India in 1940.

Usage

data("ansari.wheat.uniformity")

Format

A data frame with 768 observations on the following 3 variables.

row

row

col

column

yield

yield of grain per plot, in half-ounces

Details

An experiment was conducted at the Government Research Farm, Raya (Muttra District), during the rainy season of 1939-40.

"Wheat was sown over an area of 180 ft. x 243 ft. with 324 rows on a field of average fertility. It had wheat during 1938-39 rabi and was fallow during 1939-40 kharif. The seed was sown behind desi plough in rows 9 in. apart, the length of each row being 180 ft".

"At the time of harvest, 18 rows on both sides and 10 ft. at the end of the field were discarded to eliminate border effects and an area of 160 ft. x 216 ft. with 288 rows was harvested in small units, each being 2 ft. 3 in. broad with three rows 20 ft. long. There were 96 units across the rows and eight units along the rows. The total number of unit plots thus obtained was 768. The yield of grain for each unit plot was weighed and recorded separately and is given in the appendix."

Field width: 96 plots * 2.25 feet = 216 feet.

Field length: 8 plots * 20 feet = 160 feet.

Comment: There seems to be a strong cyclical patern to the fertility gradient. "History of the field reveals no explanation for this phenomenon, as an average field usually found on the farm was selected for the trial."

References

None

Examples

if (FALSE) {

  library(agridat)
  data(ansari.wheat.uniformity)
  dat <- ansari.wheat.uniformity

  # match Ansari figure 3
  libs(desplot)
  desplot(dat, yield ~ col*row,
          flip=TRUE, aspect=216/160, # true aspect
          main="ansari.wheat.uniformity") 

}