SUNFLOWER {PASWR2}

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 Navarre, 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.

Usage

SUNFLOWER

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. 2015. Probability and Statistics with R, Second Edition. Chapman & Hall / CRC.

Examples

summary(aov(yield ~ stage + defoli + stage:defoli, data = SUNFLOWER))
ggplot(data = SUNFLOWER, aes(numseed, yield, color = defoli)) + geom_point() + 
geom_smooth(method = "lm", se = FALSE) + facet_grid(location ~ .)