Use of fluorescence indices as predictors of crop N status and yield for greenhouse sweet pepper crops

Abstract To increase nitrogen (N) use efficiency and reduce water pollution from vegetable production, it is necessary to optimize N management. Fluorescence-based optical sensors are devices that can improve fertilization through non-destructive field monitoring of crop variables. The aim this work was compare the performance five fluorescence indices (SFR-R, SFR-G, FLAV, NBI-R, NBI-G) predict variables, as dry matter content, uptake, Nitrogen Nutrition Index (NNI), absolute relative yield, in sweet pepper ( Capsicum annuum ) crops grown greenhouse. Fluorescence measurements were periodically made with Multiplex® 3.6 sensor throughout three cropping cycles subjected application treatments. variables considered calibration validation analyses. In general, strongly related NNI, content yield. best performing NNI at early stages (i.e., vegetative flowering phenological stages) SFR indices, both under red (SFR-R) green (SFR-G) excitation. However, final stage harvest stage), NBI, (NBI-R) (NBI-G) excitation, FLAV. two predicted yield growth stages. Overall, evaluated able status pepper. They have capacity be incorporated into management practices.