# mcleod.barley: Multi-environment trial of barley in South Canterbury with... In agridat: Agricultural Datasets

## Description

Yield and yield components for barley with different seeding rates.

## Format

A data frame with 40 observations on the following 10 variables.

`year`

year, numeric

`site`

site factor

`rate`

rate, numeric

`plants`

plants per sq meter

`tillers`

tillers per plant

`heads`

`surviving`

percent surviving tillers

`grains`

`weight`

weight of 1000 grains

`yield`

yield tons/hectare

## Details

Trials were conducted at 5 sites, 3 years in South Canterbury. (not all sites in every year). Values are the average of 6 blocks. In 1974 there was a severe drought. The other years had favorable growing conditions.

## Source

C. C. McLeod (1982). Effects of rates of seeding on barley sown for grain. New Zealand Journal of Experimental Agriculture, 10, 133-136. https://doi.org/10.1080/03015521.1982.10427857.

## References

Maindonald (1992).

## Examples

 ``` 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29``` ```library(agridat) data(mcleod.barley) dat <- mcleod.barley # Table 3 of McLeod. Across-environment means by planting rate d1 <- aggregate(cbind(plants, tillers, heads, surviving, grains, weight, yield) ~ rate, dat, FUN=mean) # Calculate income based on seed cost of \$280/ton, grain \$140/ton. d1 <- transform(d1, income=140*yield-280*rate/1000) signif(d1,3) ## rate plants tillers heads surviving grains weight yield ## 50 112.12 5.22 4.36 83.95 21.25 46.11 3.97 ## 75 162.75 4.04 3.26 80.89 19.95 45.10 4.26 ## 100 202.62 3.69 2.73 74.29 19.16 44.66 4.38 ## 125 239.00 3.28 2.33 71.86 18.45 43.45 4.41 ## 150 293.62 2.90 2.00 69.54 17.94 42.77 4.47 # Even though tillers/plant, heads/plant, surviving tillers, # grains/head, weight/1000 grains are all decreasing as planting # rate increases, the total yield is still increasing. # But, income peaks around seed rate of 100. libs(lattice) xyplot(yield +income +surviving +grains +weight +plants +tillers +heads ~ rate, data=d1, outer=TRUE, type=c('p','l'), scales=list(y=list(relation="free")), xlab="Nitrogen rate", ylab="Trait value", main="mcleod.barley - nitrogen response curves" ) ```

agridat documentation built on Dec. 20, 2021, 9:07 a.m.