Development of portable E-nose system for fast diagnosis of whitefly infestation on tomato plant in greenhouse

Authors: CUI, S - University Of Tennessee; CAO, L - University Of Tennessee; ACOSTA, N - The Ohio State University; Zhu, Heping; LING, P - The Ohio State University

Submitted to: Chemosensors
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/18/2021
Publication Date: 10/23/2021
Citation: Cui, S., Cao, L., Acosta, N., Zhu, H., Ling, P. 2021. Development of portable E-nose system for fast diagnosis of whitefly infestation on tomato plant in greenhouse. Chemosensors. 9(11). Article 297. https://doi.org/10.3390/chemosensors9110297.
DOI: https://doi.org/10.3390/chemosensors9110297

Interpretive Summary: The U.S. is one of the world leaders in fresh tomato production, with around 2.7 billion pounds of fresh tomatoes produced in 2015 with a market value of about$1.22 billion. However, tomatoes are subject to attack by insect pests especially whiteflies from the time of first emergence as seedlings until harvest. Technologies with accurate diagnosis of infested plants at early stages is advantageous to establish a smart platform for the insect control and pest management. In this research, amounts of volatile organic compounds emitted from greenhouse-grown tomato plants with and without infestation of whiteflies were determined. An interface computer program was developed to real-time record the release of volatile organic compounds for fast diagnoses. As a result, an experimental non-invasive portable E-nose system was designed to diagnose infestations of tomato plants by whiteflies based on an optimized sensor array. GC-MS analysis confirmed the diagnosis of the developed E-nose system and demonstrated its ability as a non-destructive and portable tool. Further investigations are needed to validate the E-nose system reliability and repeatability in large greenhouses.

Technical Abstract: An electronic nose (E-nose) system equipped with a gas sensor array and real-time control panel was developed for a fast diagnosis of tomato plants infested by whiteflies. Profile changes of Volatile Organic Compounds (VOCs) in tomato plants under different treatments, with and without whitefly infestation and mechanical damage, were successfully detected by both the gas chromatography mass spectrometry (GC-MS) and the developed E-nose system. A rapid sensor response and high sensitivity were observed by using E-nose system. Principle Component Analysis (PCA) and Hierarchical Clustering Analysis (HCA) indicated that the E-nose system was able to provide accurate diagnosis of whiteflies-infested plants from health plants, with the first three PCs accounting for 87.4% of the classification. Identification of individual VOCs compounds by GC-MS indicated that compounds (2-Nonanol and Oxime-, methoxy-phenyl, and n-Hexadecanois acid) were generated after infestation by whiteflies, while compounds of Dodecane and 4,6-dimethyl were only found in mechanical damaged tomato plants. Those unique VOCs profiles could be considered as bio-markers of plants under different damages. The relationship between the sensor performance and VOCs compounds showed that the designed sensor array had high sensitivity to VOC biomarkers, demonstrating the capability of the developed E-nose system to diagnose whitefly infestations differing from mechanical damages.