Tomato Plant Health Monitoring

Electric noses (e-noses), taking their inspiration from the human olfactory system, have been extensively used in food quality control and human disease monitoring. This chapter presents the e-nose as a potential candidate for health monitoring and disease and pest detection on tomato plants. Two common problems in greenhouse tomatoes, namely powdery mildew and spider mites, are considered. An experimental arrangement is described based on a commercial 13-sensor e-nose where tomato plants are grown in an isolated, controlled environment inside a greenhouse. Attention is paid to the preliminary results of data post-processing using two different techniques. First, Principal Component Analysis is employed and demonstrates clear evolution of the components as the plants develop disease or infestation. Subsequently, Grey System Theory enables the identification of clear groupings in the sensor responses and thus the reduction of the model, producing stronger trend differences in the Principal Component between healthy and unhealthy plants. The results, although preliminary, show that the e-nose with appropriate data post-processing is a promising approach to monitoring the development of tomato plant diseases and infestations.