Exploring the Fertilizing Potential of the Lichen Pseudevernia furfuracea (L.) Zopf. on the Growth of Capsicum annuum L

The nutritional richness of lichens in mineral nutrients and organic metabolites makes them innovative candidates for the development of biofertilisers, contributing to the biostimulation of plant growth. In this context, this work aims to evaluate the effect of the lichen Pseudevernia furfuracea on the growth of Capsicum annuum L. Inductively coupled plasma atomic emission spectroscopy (ICP-AES) and high-performance liquid chromatography (HPLC) analysis were used for the biochemical characterisation of P. furfuracea. The crushed lichen biomass was applied as a soil amendment at doses of 5, 20 and 30 g·kg-1. The morphophysiological and biochemical parameters of C. annuum were evaluated by comparison with a negative and positive control (NPK). The results obtained by ICP showed that P. furfuracea biomass is rich in macro and micro elements essential for plant growth. Thus, HPLC analysis revealed an abundance of indole-3-butyric acid (IBA) (2.49 mg·g⁻¹). The application of 20 g·kg⁻¹ of this lichen resulted in a significant increase in shoot dry weight (+ 21.39%), number of leaves (+ 200%) and internodes (+ 128.8%) compared to untreated plants. In addition, the fruits weighed 167.6% more than those obtained by NPK treatement. This improvement was accompanied by an amelioration of the physiological and biochemical characteristics of C. annuum, resulting in an increase accumulation of pigments and minerals (N, P, Ca, Cl and Fe). This study supports the hypothesis that the application of P. furfuracea lichen improves the productivity of C. annuum plants. However, further research in the field is essential for sustainable agronomic validation.