agridat (version 1.16)

kulkarni.sorghum.uniformity: Uniformity trial of sorghum

Description

Uniformity trial of sorghum in India, 3 years on the same plots 1930-1932.

Usage

data("kulkarni.sorghum.uniformity")

Format

A data frame with 480 observations on the following 4 variables.

row

row

col

column

yield

grain yield, tolas per plot

year

year

Details

The experiment was conducted in the Sholapur district in India for three consecutive years in 1930-1932.

One acre of land (290 ft x 150 ft) was chosen in the midst of a bigger area (plot 13 on the Mohol Plot) for sowing to sorghum. It was harvested in plots of 1/160 acre (72 ft 6 in x 3 ft 9 in) each containing three rows of plants 15 in. apart. The 160 plots were arranged in forty rows of four columns, and the yields were measured in tolas. The plot division was kept intact for three years, and the yields of the 160 plots are available for three consecutive harvests. The original data are given in Appendix I.

Field width: 4 plots * 72.5 feet = 290 feet

Field length: 40 plots * 3.75 feet = 150 feet

Conclusions: "Thus, highly narrow strips of plots (length much greater than breadth) lead to greater precision than plots of same area but much wider and not so narrow."

Correlation of plots from year to years was low.

References

None.

Examples

# NOT RUN {
  data(kulkarni.sorghum.uniformity)
  dat <- kulkarni.sorghum.uniformity
  
  # match means on page 462
  # tapply(dat$yield, dat$year, mean)
  #     1930     1931     1932 
  # 116.2875  67.2250 126.3688 

  require(reshape2)
  require(lattice)
  dmat <- acast(dat, row+col ~ year, value.var="yield")
  splom(dmat, main="kulkarni.sorghum.uniformity")
  cor(dmat)

  require(desplot)
  desplot(yield ~ col*row|year, dat,
          flip=TRUE, aspect=150/290,
          main="kulkarni.sorghum.uniformity")
  
# }

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