Potential of Different Optical Methods in Estimating Chili Pepper Growth Under Field Conditions

Monitoring the chili pepper growth under organic farming is a key aspect for ensuring a sustainable and high-quality production. While the acquisition of biometric parameters, such as stem diameter and plant height, can be laborious and time-consuming, the use of optical methods represents a reliable alternative, making the growth monitoring easier and faster than using conventional measurements. The aim of this study was to identify the best optical indices from portable optical tools (Dualex, Multiplex, GreenSeeker, Canopeo) for the growth monitoring of fourteen cultivars of Capsicum spp. in an open-field cultivation under Mediterranean conditions. Among the indices acquired on one hundred plants at two growth stages during 2023 season, the combination of the flavonoid index provided by Dualex [Flav(tot)] × the Nitrogen Difference Vegetation Index (NDVI) of GreenSeeker resulted the most promising parameter to describe the plant growth (Pearson r = 0.72;p <0.001).