Potato (Solanum tuberosum L.) is a key staple crop in the Peruvian Andes, but its productivity is threatened by fungal pathogens such as Rhizoctonia solani and Alternaria alternata. In this study, 71 native bacterial strains (39 from phyllosphere and 32 from rhizosphere) were isolated from potato plants across five agroecological zones of Peru and characterized for their plant growth-promoting (PGPR) and antagonistic traits. Actinomycetes demonstrated broader enzymatic profiles, with 2ACPP4 and 2ACPP8 showing high proteolytic (68.4%, 63.4%), lipolytic (59.5%, 60.6%), chitinolytic (32.7%, 35.5%) and amylolytic activity (76.3%, 71.5%). Strain 5ACPP5 (Streptomyces decoyicus) produced 42.8% chitinase and solubilized both dicalcium (120.6%) and tricalcium phosphate (122.3%). The highest IAA production was recorded in Bacillus strain 2BPP8 (95.4 µg/mL), while 5ACPP6 was the highest among Actinomycetes (83.4 µg/mL). Siderophore production was highest in 5ACPP5 (412.4%) and 2ACPP4 (406.8%). In vitro antagonism assays showed that 5ACPP5 inhibited R. solani and A. alternata by 86.4% and 68.9%, respectively, while Bacillus strain BPP4 reached 51.0% inhibition against A. alternata. In greenhouse trials, strain 4BPP8 significantly increased fresh tuber weight (11.91 g), while 5ACPP5 enhanced root biomass and reduced stem canker severity. Molecular identification confirmed BPP4 as Bacillus halotolerans and 5ACPP5 as Streptomyces decoyicus. These strains represent promising candidates for the development of bioinoculants for sustainable potato cultivation in Andean systems.

Potato (Solanum tuberosum L.) is the third most important food crop worldwide and a cornerstone of food security across the Andean region. However, its production is increasingly threatened by the potato psyllid Bactericera cockerelli (Šulc), the vector of Candidatus Liberibacter solanacearum, the causal agent of the purple-top complex associated with zebra chip disease, which severely reduces both tuber yield and quality. This study was conducted from September 2024 to February 2025 in the province of Huancabamba, Peru, to evaluate the efficacy of biological and chemical control agents against B. cockerelli under field conditions. A randomized complete block design was implemented with five treatments and four replicates, totaling 20 experimental units, each consisting of 20 potato plants (S. tuberosum L.), of which 10 plants were evaluated. Treatments included an untreated control (T0), a chemical control (thiamethoxam + lambda-cyhalothrin, abamectin, and imidacloprid) (T1), and three biological control agents: Beauveria bassiana CCB LE-265 (>1.5 × 10¹⁰ conidia g⁻¹) (T2), Paecilomyces lilacinus strain 251 (1.0 × 10¹⁰ conidia g⁻¹) (T3), and Metarhizium anisopliae (1.0 × 10¹⁰ conidia g⁻¹) (T4). Foliar applications targeted eggs, nymphs, and adults of the psyllid. Results indicated that B. cockerelli mortality across developmental stages was lower under biological treatments compared with T1, which achieved the lowest probability of purple-top symptom expression (46%) and a zebra chip incidence of 60.60%. Among the biological agents, M. anisopliae (T4) reduced incidence to 56.60%, while P. lilacinus (T3) demonstrated consistent suppression of nymphal populations. In terms of yield, T1 achieved the highest tuber weight (198.86 g plant⁻¹) and number of tubers (7.74 plant⁻¹), followed by T3 (5.08) and T4 (4.24). Nevertheless, all treatments exhibited low yields and small tuber sizes, likely due to unfavorable environmental conditions and the presence of the invasive pest. Overall, chemical control was more effective than biological agents; however, the latter showed considerable potential for integration into sustainable pest management programs. Importantly, vector suppression alone does not guarantee the absence of purple-top complex symptoms or zebra chip disease in potato tubers.

Neltuma pallida (algarrobo) is a keystone species of the Peruvian dry forest whose persistence is threatened by overexploitation and habitat degradation, making its conservation and genetic improvement a national priority. This study aimed to identify outstanding phenotypes of N. pallida through phenotypic characterization in the regions of Piura and Tumbes in northern Peru. A stratified random sampling design was applied, establishing forest plots in 13 localities and evaluating 631 adult individuals. Dendrometric and phenotypic traits were recorded together with physiographic, climatic, and edaphic variables obtained from soil analyses and geographic information systems. Phenotypic differentiation among populations was assessed using the index $P_{ST}$, which quantifies between- and within-population variance components. High morphological variability was detected across populations, with significant differences in tree height, diameter, and fruit production, largely explained by environmental heterogeneity, particularly soil fertility and organic matter. The $P_{ST}$ values, ranging from 0.83 to 0.98, revealed strong phenotypic divergence among populations, suggesting adaptive differentiation rather than neutral variation. Eight superior individuals were identified as potential candidates for inclusion in a germplasm bank to support breeding and restoration programs. This study provides a scientific basis for the sustainable management and conservation of N. pallida in the arid ecosystems.

Mango (Mangifera indica L.) is a key fruit crop in Peru; however, its reliance on chemical fertilizers raises concerns regarding fruit quality and environmental sustainability. This study evaluated the effects of soil-applied compost and foliar-applied biol on the quality of ‘Kent’ mango fruits at physiological and commercial maturity stages. Conducted during the 2022–2023 season, the experiment used a 3 × 3 factorial design with compost applied at 0, 5, and 15 t/ha and biol at 0, 5, and 10%, plus a chemically fertilized control. Results revealed significant compost–biol interactions. At physiological maturity, treatments 5-10, 15-5 and 15-10 improved pulp color, soluble solids, titratable acidity, and dry matter content, achieving a desirable yellow pulp (2.0 on the scale), 9.29 °Brix, 1.23% acidity, and 20.96% dry matter—surpassing the control. At commercial maturity, these treatments also enhanced fruit firmness (0.42 MPa), reduced acidity (0.47%), increased pulp pH (4.69), and intensified orange pulp color. Overall, organic fertilization, particularly higher compost and biol doses, significantly improved fruit quality parameters compared to conventional chemical management. These findings highlight the potential of integrating organic amendments to promote sustainable mango cultivation while maintaining or enhancing fruit quality, thus providing a viable alternative for eco-friendly nutrient management in mango orchards.

Key lime (Citrus aurantifolia (Christm.) Swingle) is an important fruit crop in northern Peru; however, inadequate canopy management can limit productivity and fruit quality. This study evaluated the effects of different pruning systems on vegetative growth, flowering, yield, and fruit quality of key lime under the growing conditions of the Piura region. The experiment was conducted during the 2024 and 2025 growing seasons in two commercial orchards using a randomized complete block design with four pruning systems, namely maintenance pruning (MP), thinning pruning (TP), maintenance pruning combined with thinning pruning (MP + TP), and no pruning (NP), with four replicates per system. Vegetative growth, flowering, yield, and fruit quality variables were evaluated. Data were analyzed using analysis of variance (ANOVA), Tukey’s honestly significant difference (HSD) test (p < 0.05), principal component analysis (PCA), hierarchical cluster analysis, and correlation analysis. Pruning significantly affected vegetative growth, flowering, yield, and fruit physical attributes, whereas juice soluble solids, vitamin C content, and titratable acidity were not significantly affected. MP, TP, and MP + TP were associated with higher yields than NP, while MP also showed greater values for several fruit physical attributes. Some responses varied with growing season and/or study site. Overall, pruning modified vegetative and productive responses in key lime, and MP combined relatively high yield with greater values for several fruit physical attributes under the edaphoclimatic conditions of the studied orchards in Piura.

Mango (Mangifera indica L.) is a tropical fruit tree characterized by vigorous growth and high fruit production, making it one of Peru’s main export crops. However, its extensive vegetative development requires substantial space, limiting productivity per unit area. This study evaluated the effects of rootstock and interstock combinations on agronomic traits and fruit biometrics, highlighting the potential of interstocks to modulate tree vigor in mango orchards of Peru’s dry forest region. A total of 216 trees were established using ‘Chulucanas’ and ‘Chato’ as rootstocks and ‘Chulucanas,’ ‘Chato,’ ‘Irwin,’ and ‘Julie’ as interstocks, apically grafted with the ‘Kent’ cultivar, with a spacing of 6.0 m × 6.0 m. Tree performance was assessed after 10 years during the 2017–2019 growing seasons in Piura, Peru, under a randomized complete block design (2 × 4 factorial). The combination of the ‘Chulucanas’ rootstock with ‘Chulucanas’ and ‘Julie’ interstocks reduced tree height by 10.94% and 11.70%, respectively, facilitating orchard management and potentially increasing planting density. Yield varied significantly among growing seasons, with a 15% reduction in 2017 attributed to El Niño–Southern Oscillation (ENSO)-related increases in temperature and rainfall that affected flowering and fruit set. These results underscore the importance of cultivar selection and climate-adaptive strategies to sustain mango productivity in regions prone to climatic variability.