Automatic identification of peanut‐leaf diseases based on stack ensemble

Abstract

Peanut is an important food crop, and diseases of its leaves can directly reduce its yield and quality. In order to solve the problem of automatic identification of peanut‐leaf diseases, this paper uses a traditional machine‐learning method to ensemble the output of a deep learning model to identify diseases of peanut leaves. The identification of peanut‐leaf diseases included healthy leaves, rust disease on a single leaf, leaf‐spot disease on a single leaf, scorch disease on a single leaf, and both rust disease and scorch disease on a single leaf. Three types of data‐augmentation methods were used: image flipping, rotation, and scaling. In this experiment, the deep‐learning model had a higher accuracy than the traditional machine‐learning methods. Moreover, the deep‐learning model achieved better performance when using data augmentation and a stacking ensemble. After ensemble by logistic regression, the accuracy of residual network with 50 layers (ResNet50) was as high as 97.59%, and the F1 score of dense convolutional network with 121 layers (DenseNet121) was as high as 90.50. The deep‐learning model used in this experiment had the greatest improvement in F1 score after the logistic regression ensemble. Deep‐learning networks with deeper network layers like ResNet50 and DenseNet121 performed better in this experiment. This study can provide a reference for the identification of peanut‐leaf diseases.