sunflower {PASWR}

Sunflower Defoliation

Description

Seventy-two field trials were conducted by applying four defoliation treatments (non defoliated control, 33%, 66%, and 100%) at different growth stages (stage) ranging from pre-flowering (1) to physiological maturity (5) in four different locations of Navarra, Spain: Carcastillo (1), Melida (2), Murillo (3), and Unciti (4). There are two response variables: yield in kg/ha of the sunflower and numseed, the number of seeds per sunflower head. Data are stored in the data frame sunflower. Data used in Case Study: Sunflower defoliation from Chapter 11.

Format

A data frame with 72 observations on the following 5 variables:

location

a factor with levels A, B, C, and D for locations Carcastillo, Melida, Murillo, and Unciti respectively

stage

a factor with levels stage1, stage2, stage3, stage4, and stage5

defoli

a factor with levels control, treat1, treat2, and treat3

yield

sunflower yield in kg/ha

numseed

number of seeds per sunflower head

Source

Muro, J., et. al. (2001) “Defoliation Effects on Sunflower Yield Reduction.” Agronomy Journal, 93: 634-637.

References

Ugarte, M. D., Militino, A. F., and Arnholt, A. T. (2008) Probability and Statistics with R. Chapman & Hall/CRC.

Examples

summary(aov(yield ~ stage + defoli + stage:defoli, data = sunflower))