Data from 89 fungicide trials on apple scab across Europe 2008-2018

The data set comprises records of disease incidence and yield from untreated and treated plots.

Assessments
The disease infection was expressed as the intensity of attack (=severity) and/or the frequency of attack. Two assessment methods were used:

1.    Visual assessment:
•    P%INF: intensity of attack was obtained as a visual estimation of the percentage of each plant part (leaves or fruits) affected by disease
•    P%FREQ: frequency of attack was represented by the number of infected leaves or fruits. The frequency is expressed as a percentage of the number sampled.

2.    Class assessment
The level of the attack (intensity and frequency) was evaluated and calculated by classing plants into different severity categories ranging from no disease to severe attack.
•    BEFHKT: frequency of disease attack expressed as a percentage, considering 4 damage classes
•    BEFWER: intensity of attack expressed as a percentage, considering 4 damage classes.

BEFHKT = 100*(cl2 + cl3 + cl4)/(cl1 + cl2 + cl3 + cl4)
BEFWER = 100*(cl2 + 2*cl3 + 3*cl4)/(3*N)  (the Townsend-Heuberger intensity of attck)

Table of measures
Measure        Description
P%FREQ        Estimated frequency of attack %
P%INF        Estimated severy of attack %
%ANTK1        Class 1 (%)
%ANTK2        Class 2 (%)
%ANTK3        Class 3 (%)
%ANTK4        Class 4 (%)
BEFHKT        Frequency of attack
BEFWER        Index of attack
INFECT        Infection (F); Infestation (F)
KR%ABB        Diseased (%)
WIRKGR        Percent of untreated

Data format and source
The data is provided as both a tab-separated text file and a binary R data file. The R files provides code to read and plot the data. The plot produced is also provided as a PNG file.

The field trials were conducted by BASF, Germany.