Data were used to calculate the
McKinney index (McKinney, 1923), expressing the weighted
average of the disease severity as actual percentage in terms of
the maximum disease severity. The index was calculated by the
formula: MI = [S(d
f)/Tn
D]100, where d is the degree of disease
severity assessed on the fruit and f its frequency, Tn is the total
number of fruit examined (healthy and diseased) and D the highest
degree of disease intensity occurring on the empirical scale