Soil acidity severely constrains coffee production by reducing nutrient availability and promoting aluminum toxicity and oxidative stress. Foliar zinc oxide nanoparticles (ZnO NPs) have been proposed as redox modulators that can improve nutrient homeostasis under abiotic stress. However, the safe and effective range of Coffea arabica L. remains unclear. In this study, seedlings were grown in acidic soil and sprayed twice with ZnO NPs at 10, 25, 50, and 100 mg L⁻¹. Morphophysiological, biochemical, and ionomic parameters were evaluated fifty days after treatment. Moderate ZnO NPs doses led to intermediate stomatal conductance values, whereas net photosynthesis showed intermediate but non-significant responses only at 10–25 mg L⁻¹, with higher doses (50–100 mg L⁻¹) causing a marked decline. These doses did not significantly modify hydrogen peroxide (H₂O₂) or malondialdehyde (MDA) levels in leaves or roots. In contrast, the highest dose (100 mg L⁻¹) induced a marked increase in H₂O₂ without affecting MDA, indicating a partial oxidative response rather than clear lipid peroxidation. Foliar analysis showed that 50 mg L⁻¹ ZnO NPs significantly increased P compared with the optimal soil, while Ca and K remained statistically similar across treatments. Na in the optimal soil was comparable to the 10–25 mg L⁻¹ ZnO NPs treatments, whereas Na at 50–100 mg L⁻¹ ZnO NPs was significantly reduced and foliar Zn increased markedly with increasing nanoparticle dose. Proline accumulation reflected a dose-dependent osmotic adjustment, and chlorophyll ratios indicated adaptive photoprotection. Overall, foliar ZnO NPs mitigated acidity-induced stress through physiological and ionomic adjustment, with 10–25 mg L⁻¹ identified as the physiologically safe range for C. arabica seedlings grown under acidic conditions.

Glyphosate is widely used for weed control in coffee but can induce physiological alterations due to its lack of selectivity, and indirect spray drift can cause adverse effects, potentially increasing biological impacts upon exposure. In this study, we evaluated the attenuating effect of foliar-applied zinc oxide nanoparticles (ZnO NPs) on C. arabica var. Geisha seedlings exposed to simulated spray concentrations of glyphosate (3.6 and 17.9 g ae L⁻¹). Exposure caused a marked reduction in chlorophyll content, stomatal conductance, and net photosynthesis, while simultaneously promoting an increase in H₂O₂, MDA, and proline accumulation, reflecting a pronounced redox imbalance and oxidative damage associated with the production of reactive oxygen species (ROS). In contrast, the application of ZnO NPs improved photosynthetic efficiency, increased chlorophyll content, stabilized stomatal aperture, and reduced H₂O₂ and MDA levels in both leaves and roots. Moreover, it enhanced nutrient accumulation, ensuring greater membrane integrity and more efficient ion transport systems under glyphosate exposure. Overall, the ZnO NPs exhibited a notable protective effect by reducing glyphosate-induced phytotoxicity and strengthening the physiological tolerance of C. arabica. These findings support their potential as a sustainable tool to protect coffee crops from glyphosate exposure.

Coffee pulp, a by-product of coffee processing and a rich source of bioactive compounds, is a promising raw material for functional beverages. However, the influence of genetic variability among coffee varieties on the functional and sensory properties of pulp infusions remains poorly understood. This study evaluated physicochemical, antioxidant, and sensory properties of infusions from nine Coffea arabica L. varieties. Significant differences among varieties were observed (p < 0.05). The pH ranged from 5.36 to 6.42, and titratable acidity from 0.06 to 0.08 g/100 mL, indicating a mild acidic profile. Antioxidant activity (DPPH) ranged from 460.52 to 1006.03 µmol TE/L, and total phenolic content from 29.47 to 59.27 mg GAE/L. Geisha showed the highest antioxidant activity and phenolic content, while Casiopea exhibited the highest reducing capacity. In contrast, Oro Azteca, Excelencia, and H1 achieved the highest sensory acceptance. Multivariate analysis confirmed clear differentiation among varieties and a separation between bioactive and sensory-related attributes. These findings highlight the role of varietal selection in balancing functional potential and consumer acceptance, supporting the development of functional beverages within a circular economy framework.

Coffee leaf rust (Hemileia vastatrix) is a major constraint on coffee production, while reliance on chemical fungicides raises environmental concerns and may become less sustainable over time. This review critically analyzes the available evidence on the potential of Lecanicillium uredinophilum as a biological control agent against H. vastatrix, with comparative consideration of other microbial agents evaluated for coffee leaf rust management. A structured literature review was conducted using searches in Scopus and PubMed, complemented by manual searches and reference screening. The available evidence indicates that L. uredinophilum shows affinity for urediniospore structures and exhibits mycoparasitic activity against rust fungi under controlled conditions. However, direct evidence against H. vastatrix remains limited and is still concentrated mainly in laboratory and greenhouse studies. In comparison with more established biocontrol agents, L. uredinophilum should be regarded as a promising but still early-stage candidate whose practical relevance has not yet been validated. Future progress will depend on robust field-based studies, improved understanding of its mechanisms of action, evaluation of its environmental stability, and the development of viable formulations compatible with integrated disease management strategies.

Adventitious rooting remains a major constraint for the clonal propagation of Coffea arabica, limiting the large-scale multiplication of elite genotypes. This study evaluated the effects of genotype, auxin treatment, and their interaction on adventitious rooting and basal callus formation in coffee cuttings under controlled nursery conditions, while morphophysiological traits were assessed as complementary indicators of cutting performance. A completely randomized 3 × 3 factorial design was used, including three hybrids (H3, Excelencia, and Milenio) and three plant growth regulator (PGR) treatments: control, indole-3-butyric acid (IBA), and a commercial auxin formulation (RH; NAA + IBA). Rooting probability and root number were significantly affected by PGR treatment, whereas the longest root length was influenced by hybrid, PGR treatment, and their interaction. Model-estimated rooting probability increased from 4.76% in the control to 17.05% under IBA and 35.73% under RH. Similarly, the estimated number of roots per cutting increased from 0.14 in the control to 0.99 under IBA and 1.85 under RH. Although the hybrid × PGR interaction was not significant for rooting probability, the highest observed rooting percentage was recorded in H3 under RH (52.38%), followed by Milenio under RH (33.33%). For the longest root length, the strongest responses were observed under RH, particularly in Milenio (71.15 mm) and H3 (70.08 mm). Callus formation varied among treatments, but its association with rooting performance was weak and inconsistent. Morphophysiological traits provided complementary information on cutting status but were not interpreted as direct mechanistic drivers of rooting. These findings indicate that adventitious rooting in C. arabica was more closely associated with genotype-dependent responsiveness to exogenous auxin than with the extent of callus formation. However, anatomical studies are needed to determine the developmental origin of root primordia and their possible relationship with callus tissue.

Physalis peruviana L. is an Andean crop of high nutritional and commercial value; however, the limited availability of uniform planting material restricts its large-scale propagation. Indole-3-butyric acid (IBA) is widely used to promote adventitious rooting, although its concentration and application methods influence the response observed throughout the different stages of root development. This study evaluated how IBA concentration and explant origin influenced rooting-related traits and early vegetative growth of in vitro-regenerated P. peruviana shoots during a 30-day ex vitro acclimatization phase. The evaluated variables included rooting percentage, root number, longest root length, root fresh and dry mass, shoot length, leaf and node number, stem diameter, shoot fresh and dry mass, leaf area, and photosynthetic pigment contents. The experiment followed a completely randomized design with a 2 × 4 factorial arrangement consisting of two explant origins (cotyledon and hypocotyl) and four IBA concentrations (0, 400, 800, and 1600 mg L⁻¹), with five biological replicates per treatment combination. All shoots formed at least one visible root, resulting in 100% rooting across all treatment combinations. IBA concentration significantly affected root fresh and dry mass and several shoot-growth traits, whereas root number and longest root length were not significantly affected. Among the concentrations tested, 800 mg L⁻¹ produced the highest root biomass and favorable responses in selected shoot-growth traits, whereas 1600 mg L⁻¹ was associated with lower values for some growth variables. Hypocotyl-derived shoots had more leaves and nodes, greater stem diameter, and higher shoot dry mass than cotyledon-derived shoots. These results indicate a concentration- and trait-dependent response to IBA and identify 800 mg L⁻¹ as the most favorable concentration among those tested for increasing root biomass and selected shoot-growth traits under the evaluated acclimatization conditions.