Bollenrevolutie 4.0 : onderzoek Spectracam in tulp: Rapportage werkpakket voorbeeldbedrijven: onderzoek Spectracam

Technature’s Spectracam offers the ability to obtain an accurate and objective picture of crop growth and vitality using spectral imaging. In 2021 and 2022, trials were conducted on bulb farms with the Carola variety to determine the relationship between the reflections measured with the SpectraCam and the crop growth of flower bulbs. The SpectraCam measures reflection in different wavelength ranges and converts it into different indices as a measure of biomass and crop stress. The goal was to get a better picture of the relationship between the SpectraCam’s measurements and the growth, development, and yield of the crop. In 2021, a field experiment was conducted with the SpectraCam on a field sprayer in Noordwijkerhout. In 2022, measurements were taken again with the SpectraCam in the Carola cultivar to validate the results. Two years of research data have nevertheless proved insufficient for calibration and validation of found relationships. The best relationships between crop and SpectraCam measurements were found for N content and reflection of 550 nm, 700 nm, and NDVI. The assumed exponential relationship between crop and SpectraCam measurements turned out to be better described by a linear relationship for some relationships (LAI and Chlorophyll red, NDRE and NDVI; N in crop and Chlorophyll green; N content and reflection 700 nm). Above-ground biomass during flowering and associated SpectraCam measurements are not good predictors of bulb final yield. However, the REIP (stress) measurement value around flowering could possibly serve as an indicator for lower bulb yields.