day.wheat.uniformity.Rd
Uniformity trial of wheat in 1903 in Missouri.
data("day.wheat.uniformity")
A data frame with 3090 observations on the following 4 variables.
row
row
col
col
grain
grain weight, grams
straw
straw weight, grams
These data are from the Shelbina field of the Missouri Agricultural Experiment Station. The field (plat) was about 1/4 acre in area and apparently uniform throughout. In the fall of 1912, wheat was drilled in rows 8 inches apart, each row 155 feet long. The wheat was harvested in June, in 5-foot segments. The gross weight and the grain weight was measured, the straw weight was calculated by subtraction.
Field width: 31 series * 5 feet = 155 feet
Field length: 100 rows, 8 inches apart = 66.66 feet
James Westbay Day (1916). The relation of size, shape, and number of replications of plats to probable error in field experimentation. Dissertation, University of Missouri. Table 1, page 22. https://hdl.handle.net/10355/56391
James W. Day (1920). The relation of size, shape, and number of replications of plats to probable error in field experimentation. Agronomy Journal, 12, 100-105. https://doi.org/10.2134/agronj1920.00021962001200030002x
# \dontrun{ library(agridat) data(day.wheat.uniformity) dat <- day.wheat.uniformity libs(desplot) desplot(dat, grain~col*row, flip=TRUE, aspect=(100*8)/(155*12), # true aspect main="day.wheat.uniformity - grain yield")# similar to Day table IV libs(lattice) xyplot(grain~straw, data=dat, main="day.wheat.uniformity", type=c('p','r'))# cor(dat$grain, dat$straw) # .9498 # Day calculated 0.9416 libs(desplot) desplot(dat, straw~col*row, flip=TRUE, aspect=(100*8)/(155*12), # true aspect main="day.wheat.uniformity - straw yield")# Day fig 2 coldat <- aggregate(grain~col, dat, sum) xyplot(grain ~ col, coldat, type='l', ylim=c(2500,6500))dat$rowgroup <- round((dat$row +1)/3,0) rowdat <- aggregate(grain~rowgroup, dat, sum) xyplot(grain ~ rowgroup, rowdat, type='l', ylim=c(2500,6500))# }