1 Introduction

Pesticide treatments are used to protect crops from insects and other agricultural pests. The effectiveness of a treatment may vary depending on several factors, including its location within an orchard.

This analysis uses the OrchardSprays dataset to investigate the relationship between row position and the decrease in concentration. The analysis also compares this relationship across different pesticide treatments.

1.1 Setup

library(tidyverse)
library(knitr)

data(OrchardSprays)
OrchardSprays %>%
  ggplot(aes(rowpos, decrease, color = treatment))+
  geom_point(size = 1, alpha =0.7)+
  geom_smooth(method = lm, se = T)+
  facet_wrap(~treatment)+
  labs(title = "Pesticide Efficiency in Relation to the Decrease of Concentration Volume")
## `geom_smooth()` using formula = 'y ~ x'

1.2 Dataset

The OrchardSprays dataset contains observations from an experiment investigating the effectiveness of different pesticide treatments.

The variables used in this analysis include:

  • rowpos — position of the observation within the orchard
  • decrease — decrease in concentration
  • treatment — pesticide treatment used

1.3 Dataset Summary

summary(OrchardSprays)
##     decrease          rowpos         colpos       treatment 
##  Min.   :  2.00   Min.   :1.00   Min.   :1.00   A      : 8  
##  1st Qu.: 12.75   1st Qu.:2.75   1st Qu.:2.75   B      : 8  
##  Median : 41.00   Median :4.50   Median :4.50   C      : 8  
##  Mean   : 45.42   Mean   :4.50   Mean   :4.50   D      : 8  
##  3rd Qu.: 72.00   3rd Qu.:6.25   3rd Qu.:6.25   E      : 8  
##  Max.   :130.00   Max.   :8.00   Max.   :8.00   F      : 8  
##                                                 (Other):16

1.4 Dataset Structure

glimpse(OrchardSprays)
## Rows: 64
## Columns: 4
## $ decrease  <dbl> 57, 95, 8, 69, 92, 90, 15, 2, 84, 6, 127, 36, 51, 2, 69, 71,…
## $ rowpos    <dbl> 1, 2, 3, 4, 5, 6, 7, 8, 1, 2, 3, 4, 5, 6, 7, 8, 1, 2, 3, 4, …
## $ colpos    <dbl> 1, 1, 1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2, 2, 2, 2, 3, 3, 3, 3, …
## $ treatment <fct> D, E, B, H, G, F, C, A, C, B, H, D, E, A, F, G, F, H, A, E, …