Uniformity trial of potato in Africa 2001

Uniformity trial of potato in Africa in 2001

Usage

data("obsi.potato.uniformity")

Format

A data frame with 2569 observations on the following 4 variables.

loc

location, 2 levels

row

row

col

column

yield

yield, kg/m^2

Details

Data collected from potato uniformity trials at Hollota (L1) and Kulumsa (L2). Each field was 0.15 hectares.

In each field, 75cm between rows and 60cm between plants. The basic units harvested were 1.2m x 1.5m. It is not clear which way the plots are oriented in the field with respect to the rows and columns.

At location L1, plot (10,7) was 22.5 in the source document, but was changed to 2.25 for this electronic data.

Hollota:

Field width: 26 * 1.2 m

Field length: 63 rows * 1.5 m

Note the horizontal banding of 8 or 9 rows at location L1.

Kulumsa

Field width: 19 * 1.2 m

Field length: 49 * 1.5 m

Source

Dechassa Obsi. 2008. Application of Spatial Modeling to the Study of Soil Fertility Pattern. MS Thesis, Addis Ababa University. Page 122-125. https://etd.aau.edu.et/handle/123456789/3221

References

None.

Examples

if (FALSE) { # \dontrun{

library(agridat)
data(obsi.potato.uniformity)
dat <- obsi.potato.uniformity

  # Mean plot yield according to Obsi p. 54
  # libs(dplyr)
  # dat <- group_by(dat, loc)
  # summarize(dat, yield=mean(yield))
  ##   loc   yield
  ##   <fct> <dbl>
  ## 1 L1     2.54 # Obsi says 2.55
  ## 2 L2     5.31 # Obsi says 5.36

libs(desplot)
desplot(dat, yield ~ col*row, subset=loc=="L1",
  main="obsi.potato.uniformity - loc L1",
  flip=TRUE, tick=TRUE)
desplot(dat, yield ~ col*row, subset=loc=="L2",
  main="obsi.potato.uniformity - loc L2",
  flip=TRUE, tick=TRUE)
} # }