Examinando por Autor "Lozano Isla, Flavio"

Mostrando 1 - 5 de 5

Azospirillum brasilense as a Bioinoculant to Alleviate the Effects of Salinity on Quinoa Seed Germination
(MDPI, 2025-12-16) Apaza Calcina, Jose David; Muñoz Salas, Milagros Ninoska; Lozano Isla, Flavio; Rezende, Rachel Passos; Santana Silva, Raner José
Quinoa (Chenopodium quinoa Willd.) is valued for its resilience to abiotic stress; however, germination and seedling establishment remain highly sensitive to salinity. While its salt tolerance at later growth stages has been well studied, strategies to improve early development under high salinity are limited, and the role of halotolerant plant growth-promoting bacteria (PGPB) in quinoa has not been systematically investigated. This study assessed the ability of three Azospirillum brasilense strains (BR-11001, BR-11002, and BR-11005) to increase the germination and seedling performance of the cultivar 'BRS Piabiru' under saline stress. A 3 × 4 factorial design with three bacterial treatments and four NaCl concentrations (0, 150, 300, and 450 mM) was conducted in a completely randomized arrangement, with four replicates per treatment. Seeds were surface sterilized, inoculated, and incubated at 18 °C under constant light for 10 days. Elevated salinity (≥300 mM NaCl) drastically reduced germination and seedling vigor in the controls. Inoculation with BR-11002 significantly alleviated salinity-induced damage, sustaining over 84% germination at 450 mM and increasing seedling biomass at 300 mM. These findings highlight the potential of halotolerant A. brasilense, particularly BR-11002, as bioinoculants to promote quinoa establishment in salt-affected soils, supporting sustainable agriculture and food system resilience.
Diversity and Selection of Superior Algarrobos (Neltuma pallida) Phenotypes in the Natural Dry Forests of Peru for Sustainable Conservation and Genetic Improvement
(MDPI, 2025-11-20) Casas Niño, Sebastian; Baselly Villanueva, Juan Rodrigo; Salazar Hinostroza, Evelin Judith; Chumbimune Vivanco, Sheyla Yanet; Nauray , William; Tirabante Terrones, Nery; Ramírez Rojas, Max Augusto; Lozano Isla, Flavio
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 PST, 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 PST 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.
Efficacy of Biological and Chemical Control Agents Against the Potato Psyllid (Bactericera cockerelli Šulc) Under Field Conditions
(MDPI (Multidisciplinary Digital Publishing Institute), 2025-12-03) Cárdenass Huaman, Gabriela; Morocho Romero, Henry Hoseph; Casas Niño, Sebastian; Vilchez Navarro, Sandy Graciela; Velarde Apaza, Leslie Diana; Ramirez Rojas, Max; Cruz Luis, Juancarlos Alejandro; Lozano Isla, Flavio; Morocho Romero, Henry
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.
Harvest index is a key trait for screening drought-tolerant potato genotypes (Solanum tuberosum)
(Springer, 2023-07-04) Lozano Isla, Flavio; Farfán Vignolo, Evelyn Roxana; Gutierrez, Raymundo; Blas, Raúl; Awais, Khan
Drought stress is a significant constraint that affects the yield of almost all major crops. Its impact is expected to worsen due to global climate change and human population expansion. Potato (Solanum tuberosum L.) is the third most important food crop worldwide, but it is highly susceptible to drought stress. In order to understand the effects of drought stress on yield and identify traits for selecting drought-tolerant potato genotypes, we evaluated the response of a range of agronomic and physiological traits in 15 potato genotypes under well-watered (WW) and water deficit (WD) conditions. The harvest index (HI) was found to have a high plot-based heritability (0.98), indicating that it can be used for the indirect selection of drought-tolerant genotypes. In contrast, SPAD was sensitive to detecting early drought stress in potatoes. Drought-tolerant genotypes, including CIP392797.22 (UNICA), CIP397077.16, CIP398190.89, CIP398208.219, and CIP398208.620, were able to allocate limited water towards tuber production rather than biomass. These genotypes showed high tuber production under WW conditions and increased photosynthetic activity and water use efficiency under WD conditions.
Impact of interstock and rootstock on the growth and productivity of mango (Mangifera indica L.) cultivar Kent in the San Lorenzo valley, Peru
(MDPI, 2025-11-24) Casas Niño, Sebastián; Vilchez Navarro, Sandy Graciela; Morocho Romero, Henry Hoseph; Cárdenas Huamán, Gabriela; Nuñez Ticliahuanca, Esdwin Oberti; Montañez Artica, Ana Gabriela; Velarde Apaza, Leslie Diana; Ramirez Rojas, Max; Rojas Llanque, Juan Carlos; Lozano Isla, Flavio
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.