Estimating the degree of coffee rust infection (Hemileia vastatrix) in coffee leaves

Abstract

We estimated the degree of coffee rust (Hemileia vastatrix) infection through photographs of lesions found in coffee leaves. Comparing the manual count and the histogram analysis, we found that the trend of the calculated values using the histogram agrees with the manually estimated values despite differences in the actual values. Moreover, the histogram analysis is easier and better as it limits any form of bias in the measurement and is able to distinguish tiny details. Moreover, it is nondestructive thus allowing successive measurement for the same sample.