Imaging spectroscopy for monitoring the crop status of tomato plants

The increasing complexity of greenhouse production systems requires the step to a more data-driven approach that is based on robust, intelligent sensors. Whereas climate sensors are widely available in greenhouse systems, control based on crop data is still in its infancy. There is a clear need among growers to monitor the status of the crop in the greenhouse in real time and non-destructively compared to current practice of cumbersome, expensive and slow laboratory measurements. This project aimed to use visible and near infrared imaging spectroscopy to determine the contents of sugars and starch, dry matter percentage, chlorophyll, and nutrient composition in both leaves and fruits of tomato plants. The results were promising, with Q2 values up to 0.97 for dry matter content in leaves, 0.86 for sugar and 0.99 for chlorophyll-a. The results also showed that pigments have a better correlation to the visible spectrum, while water content, sugars and nutrients showed a better correlation in the near infrared part of the spectrum.