Solanum tuberosum is one of the most widely cropped plant species worldwide; unfortunately, drought is one of the major constraints on potato productivity because it affects the physiology, biochemical processes, and yield. The use of arbuscular mycorrhizal fungi (AMF) has exhibited beneficial effects on plants during drought. The objective of this study was to analyse the effect of AMF inoculation on two genotypes of potato plants exposed to water stress, and the photosynthetic traits, enzymatic antioxidant activity, and exudation of low-molecular-weight organic acids (LMWOAs) of potato plants inoculated with two strains of AMF, Claroideoglomus claroideum (CC) and Claroideoglomus lamellosum (HMC26), were evaluated. Stomatal conductance exhibited a similar trend in the CC and HMC26 treatments for both potato genotypes; moreover, the photosynthetic rate significantly increased by 577.9% between the 100% soil humidity (S0) and 40% soil humidity (S2) stress levels for the VR808 genotype under the CC treatment. The activities of the enzymes catalase (CAT) and ascorbate peroxidase (APX) showed similar trends. In this study, there were different responses among genotypes and treatments. Inoculation with CC under S2 stress levels is a promising potential approach for improving potato growth under drought conditions.

The presence of engineered nanoparticles (ENPs) in soil systems can modify their properties and the availability of nutrients. This study evaluated the effect of 1% CuO or ZnO ENPs on the physicochemical properties and on the phosphorus (P) adsorption–desorption processes of a volcanic ash soil (Lautaro; LAU). The dynamics of P were conducted through kinetic and isotherm batch experiments. The results showed that LAU soil with 1% CuO or ZnO ENPs increased pH_H2O (from 5.67 to 6.03 and 6.82, respectively), electrical conductivity (from 0.119 to 0.143 and 0.150 dS m⁻¹, respectively), Zn availability (597.7 times higher for LAU with 1% ZnO ENPs in relation to soil without ENPs), and Cu availability (41.8 times higher for LAU with 1% CuO ENPs in relation to soil without ENPs). Moreover, the presence of ENPs decreased Brunauer, Emmett, and Teller specific surface area. The adsorption kinetic studies of P on LAU soil without and with 1% ENPs fitted well to the Elovich model (r² ≥ 0.923), which indicated a chemiadsorption mechanism, whereas the adsorption isotherms were described by Langmuir–Freundlich model (r² ≥ 0.939). The desorption percentage was LAU > LAU + 1% CuO–ENPs > LAU + 1% ZnO–ENPs, demonstrating an increased stability of the P–soil surface binding with 1% ENPs. Co–existing NO₃⁻, SeO₄²⁻, and SO₄²⁻ anions did not generate a steric hindrance between P and LAU soil binding. Finally, both ENPs could alter the quality of the soil due to changes in their physicochemical properties and decrease the availability of P in volcanic ash soils.

Potato has great nutritional and economic importance in agriculture. However, Rhizoctonia solani represents a significant risk, reducing the yield and quality of potato production. Flesh-colored potato (FCP) extracts show in vitro inhibitory effects against R. solani, although environmental factors may reduce their stability. Solid lipid nanoparticles (SNLs) offer a solution by encapsulating these compounds, preventing degradation, and improving delivery, positioning solid lipid nanoparticles as a promising technology for sustainable extract application. A greenhouse potato assay at two phenological stages under R. solani inoculation was used to evaluate the photosynthetic response (photosynthetic parameters and pigments) to two doses of the nanoencapsulated extract (SNL + FCP). During inoculation and commercial fungicide application, stomatal conductance, the photosynthetic rate, and the internal CO₂ concentration increased compared with those of the non-inoculated control (NT), whereas the nanoencapsulated extract maintained levels similar to those of the NT, suggesting the possible regulation of the photosynthetic defense system. In terms of photosynthetic pigments, SLN + FCP maintained chlorophyll concentrations, unlike those in inoculated plants, which significantly decreased. Component analysis revealed that a lower dose primarily increased chlorophyll B synthesis, whereas a higher dose increased chlorophyll A compared with the inoculated control. These findings suggest an improved response from SLN + FCP to commercial fungicides, particularly with respect to photosynthetic pigments. However, further research is needed, and the results indicate promising potential for the eco-friendly control of phytopathogenic fungi in agriculture.