Diagnosing Fungus Infection in Tobacco Crops with Spectrophotometry

Despite the controversy surrounding tobacco and tobacco products, it still remains a very important crop in Northwest Argentina. For many, it provides a source of income and creates an industry that supports many families. Maintaining the health and quality of these crops ensures that these communities are able to survive. Tobacco plants are susceptible to a variety of diseases and ailments, however, that can inhibit their growth or destroy them. Being able to identify pathogens early on helps save these crops and minimizes costs for treatment.

A particularly virulent pathogen is a fungus known as Fusarium oxysporum that can wither and severely damage tobacco plants. Detecting this fungus early is essential to preserving as much of the tobacco as possible. To help with this, scientists have been experimenting with a variety of detection methods, including VIS and reflectance spectroscopy.

Because Fusarium oxysporum fungi emit a reflectance wavelength known as “spectral signature,” scientists were able to identify this harmful pathogen on tobacco plants using a VIS and reflectance spectrophotometer. In one study, one group of healthy Burley tobacco plants and one group of infected Burley tobacco plants were measured and analyzed with these instruments over the course of four weeks. After comparing the results, scientists correctly identified the presence and prevalence of Fusarium oxysporum on the infected group of Burley tobacco leaves with high accuracy. Additionally, they determined which parts of the leaves and plants were most heavily infected due to this noticeable change in the spectral signature.