Development of Portable E-Nose System for Fast Diagnosis of Whitefly Infestation in Tomato Plant in Greenhouse

Shaoqing Cui,Peter P Ling,Heping Zhu,Lin Cao,Nuris Acosta

doi:10.3390/chemosensors9110297

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 whitefly infestation in tomato plants. Profile changes of volatile organic compounds (VOCs) released from tomato plants under different treatments (i.e., whitefly infestation, mechanical damage, and no treatment) were successfully determined by the developed E-nose system. A rapid sensor response with high sensitivity towards whitefly-infested tomato plants was observed in the E-nose system. Results of principal component analysis (PCA) and hierarchical clustering analysis (HCA) indicated that the E-nose system was able to provide accurate distinguishment between whitefly-infested plants and healthy plants, with the first three principal components (PCs) accounting for 87.4% of the classification. To reveal the mechanism of whitefly infestation in tomato plants, VOC profiles of whitefly-infested plants and mechanically damaged plants were investigated by using the E-nose system and GC-MS. VOCs of 2-nonanol, oxime-, methoxy-phenyl, and n-hexadecanoic acid were only detected in whitefly-infested plants, while compounds of dodecane and 4,6-dimethyl were only found in mechanically damaged plant samples. Those unique VOC profiles of different tomato plant groups could be considered as bio-markers for diagnosing different damages. Moreover, the E-nose system was demonstrated to have the capability to differentiate whitefly-infested plants and mechanically damaged plants. The relationship between sensor performance and VOC profiles confirmed that the developed E-nose system could be used as a fast and smart device to detect whitefly infestation in greenhouse cultivation.

Highlights

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 USD1.22 billion [1]
It is worth noticing that sensor 3 (S3), which was sensitive to the alcohol class of volatile organic compounds (VOCs), showed a significant and continuous increase when the E-nose system analyzed the infested plants, while it showed little response
On the basis of the principal component analysis (PCA) results and the hierarchical clustering analysis (HCA) results, the developed

Summary

Introduction

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 USD1.22 billion [1]. 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 USD. Among the biotic stresses from insects, damage caused by whitefly is a major constraint in the growth and productivity of tomatoes and other vegetable crops. In warm or tropical climates, for example, in greenhouses, whitefly damage presents major problems in crop protection [2]. 25% of yield reduction of fresh tomatoes is caused by insects and virus damage [3,4]. Within the list of 27 arthropod pests causing yield reduction, whitefly is ranked as the most serious one, affecting 90% percent of the acreage grown [5] Whitefly, especially Trialeurodes vaporariorum and Bemisia tabaci, has been found worldwide in greenhouse crops and open-field

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Conclusion