Examinando por Autor "Torres Chávez, Edson Esmith"

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Caracterización genética de bacterias endofíticas de arroz (Oryza sativa L.) con actividad antimicrobiana contra Burkholderia glumae
(Asociación Argentina de Microbiología, 2020-03-05) Valdez Núñez, Renzo Alfredo; Ríos Ruiz, Winston F.; Ormeño Orrillo, Ernesto; Torres Chávez, Edson Esmith; Torres Delgado, Jorge
El objetivo del presente estudio fue aislar y seleccionar bacterias endofíticas de arroz capaces de inhibir al fitopatógeno Burkholderia glumae THT, así como caracterizarlas por su genética y bioquímica. También se buscó caracterizar la diversidad genética y los factores de virulencia presentes en cepas de B. glumae y de Burkholderia gladioli, otro patógeno de arroz, aisladas de campo. Se colectaron plantas de arroz en 4 departamentos del norte de Perú, y tras la desinfección de tejidos se aislaron bacterias endofíticas por cultivo en agar soya tripticasa (30 °C; 48 h) y en medio selectivo (pH 4,5; 41 °C; 72 h). Se evaluó la actividad antimicrobiana frente a B. glumae THT, la producción de sideróforos y la resistencia a la toxoflavina, toxina producida por este agente. La identificación molecular se realizó mediante BOX-PCR y secuenciación del gen 16S ARNr. Además, se determinó la producción de enzimas extracelulares y se efectuaron ensayos de motilidad y sensibilidad/resistencia a bactericidas. Se aislaron 189 bacterias endofíticas, de las cuales solo 9 presentaron actividad antimicrobiana contra B. glumae THT, sobresaliendo Burkholderia vietnamiensis TUR04-01, B. vietnamiensis TUR04-03 y Bacillus aryabhattai AMH12-02. Estas cepas produjeron sideróforos y al menos el 55,5% fueron resistentes a la toxoflavina. Por otro lado, 17 de las cepas de B. glumae y B. gladioli aisladas se agruparon en 9 perfiles BOX-PCR, 16 de ellas presentaron similitud con B. glumae LMG2196T (100%) y una con B. gladioli NBRC13700T (99,86%). Hubo elevada diversidad de acuerdo al origen geográfico y se encontraron factores de virulencia. En conclusión, se hallaron cepas del género Bacillus y Burkholderia que podrían ser agentes de biocontrol contra B. glumae.
Green manuring and fertilization on rice (Oryza sativa L.): a peruvian Amazon study
(Instituto Nacional de Innovación Agraria, 2024-12-02) Arévalo Aranda, Yuri Gandhi; Rodríguez Toribio, Elmer; Rosillo Cordova, Leodan; Díaz Chuquizuta, Henry; Torres Chávez, Edson Esmith; Cruz Luis, Juancarlos; Siqueira Bahia, Rita de Cássia; Pérez Porras, Wendy Elizabeth
The study was conducted in Juan Guerra district, province and region of San Martin, Peru; it assessed two treatment sets: (1) nitrogen fertilizer dose (FN75, FN100); (2) green manure Crotalaria juncea (CroJ), Canavalia ensiformis (CanE), and without green manure. It was arranged in a split-plot design with four replications. During the experiment, we observed an important fluctuation in soil parameters. Notably, there was a decrease in soil carbon and nitrogen levels, likely attributed to microorganism metabolism. On the other hand, we observed that CanE significantly reduced the diseased tillers through “White Leaf Virus” (RHBV) by 2.82% compared to the control, and significant panicle fertility was achieved by CroJ (91.88%). No significant differences were obtained in yields during this first campaign; however, the highest reported yield was 8.36 t ha-1 with the CanE - FN100 treatment. Additionally, the nutritional quality of the rice was not affected by either green manuring or the application of chemical nitrogen fertilization. These findings allow deeper studies to consider strategic alternatives to reducing dependency on inorganic fertilizers among the poorest communities.
Impact of Green Manuring and Nitrogen Fertilization on Rice Cultivation: A Peruvian Amazon Forest Study in San Martín Province
(Scielo Preprint, 2024-03-12) Arevalo Aranda, Yuri Gandhi; Rodriguez Toribio, Elmer; Rosillo, Leodan; Diaz Chuqizuta, Henry; Torres Chávez, Edson Esmith; Cruz Luis, Juancarlos Alejandro; Siqueira Bahia, Rita de Cassia; Perez Porras, Wendy Elizabeth
Green manuring is an environmentally friendly technology aimed at providing nutrients to plants, enhancing soil fertility, mitigating soil degradation, controlling weeds and pests, and decreasing reliance on inorganic fertilizers. However, it requires dissemination and support to be adopted, especially in the poorest agricultural communities in Latin America. The study was conducted at the El Porvenir INIA in San Martín, Perú; it assessed two treatment sets: (1) green manure Crotalaria juncea (CroJ), Canavalia ensiforme (CanE), no green manure; and (2) nitrogen fertilizer dose (FN75, FN100). It was arranged in a split-plot design with four replications. During the experiment we detected an important fluctuation in soil parameters, however, it is the diminished levels of soil carbon and nitrogen, which were presumably the outcomes of microorganism processes. Otherwise, we observed that CanE significantly reduced the diseased tillers by "White Leaf Virus" (RHBV) by 2.82% compared to the control. The superior outcomes were achieved through CanE, and the highest yield was 8.36 t.ha¯¹ with the CanE - FN100 treatment. Additionally, the nutritional quality of rice was not altered by green manures or chemical nitrogen fertilization doses tested.
Inoculation of bacterial consortium increases rice yield (Oryza sativa L.) reducing applications of nitrogen fertilizer in San Martin region, Peru
(El Sevier, 2020-04-09) Ríos Ruiz, Winston F.; Torres Chávez, Edson Esmith; Torres Delgado, Jorge; Rojas García, José Carlos; Bedmar, Eulogio J.; Valdez Núñez, Renzo Alfredo
Rice feeds more than 50% of the population worldwide, representing a great energy contribution in low-income families. The exaggerated use of synthetic chemical fertilizers to maintain high levels of yield causes alterations in the physical, chemical and biological quality of the soils. A sustainable alternative is the use of beneficial microorganisms that promote plant growth in crops. The objective of the study was to isolate and evaluate the Plant Growth Promoting (PGP) traits of rhizospheric rice bacteria in soils of the San Martin region, evaluate the effect of promoting growth in rice under pot experiments conditions and finally evaluate the effect of selected strains on the yield under different doses of nitrogen fertilizer under field conditions. Initially, 27 strains were selected for their diazotrophic characteristics and characterized by PGP traits. Through a multivariate analysis of main components, five strains were selected and evaluated in pot experiments. In this stage, the rice seeds were inoculated with the five selected strains at the rate of 109 CFU g−1 and were evaluated at 135 days. The strains showed that the parameters such as Shoot Dry Weight (SDW), tillering and grain quality were superior and even similar between inoculated treatments receiving doses of 50% Nitrogen (N) (75 kg N ha−1) and treatment receiving full dose (150 kg of N ha−1). For the field experiments, Burkholderia ubonensis la3c3, Burkholderia vietnamiensis la1a4 and Citrobacter bitternis p9a3m were selected, which were inoculated in a consortium at a rate of 109 CFU mL−1 in the nursery stage and at the time of transplantation. Grain yield was higher but not significant between 2.5 and 13.5% in inoculated treatments receiving 75% and 100% (150 kg N ha−1) of the nitrogen fertilizer dose compared to the treatment without inoculation and without fertilization. Grain quality was superior in inoculated treatments versus non-inoculated treatments, reaching specific increases of 32.8% (N), 45.5% (P) and 27.9% (K) in inoculated treatments receiving low doses of N fertilizer (25%) versus treatment receive a full dose of fertilizer, also a significant increase of 2.5% in the percentage of whole grain, with respect to mill quality. The rentability (14.7–88.6%) and the utility (17.7–94.1%) were also higher in inoculated treatments. It is concluded that the use of selected native bacterial consortiums reduces the use of nitrogen fertilizer by up to 25%, increasing the productivity of rice cultivation in the San Martín region.
Intermittent Rainfed Rice var. INIA 516 LM1: A Sustainable Alternative for the Huallaga River Basin
(MDPI, 2025-04-23) Flores Marquez, Ricardo; Siqueira Bahia, Rita de Cássia; Arévalo Aranda, Yuri Gandhi; Torres Chávez, Edson Esmith; Guevara, Jonathan; Antezana, Abner; Carranza, Antoni; Lao, Ceila; Solórzano Acosta, Richard Andi
Climate change is projected to increase global temperatures and alter rainfall patterns. In Peru, these changes could adversely affect the central basin of the Huallaga River by increasing pest and disease incidence, evapotranspiration, and water consumption. This basin is one of the country’s main rice-producing regions, where the crop is traditionally cultivated using inefficient practices, such as continuous flood irrigation. This study evaluated the effects of different irrigation management strategies on the growth and yield of rice (Oryza sativa var. INIA 516 LM1-La Union 23), the water footprint as an indicator of water use efficiency, and the incidence of pests and diseases associated with irrigation regimes. Three irrigation treatments were implemented: Traditional flooding T1 (maintenance of a 0.15 m water layer with replenishment every 4 days), Optimized flooding T2 (replenishment every 7 days), and Intermittent rainfed irrigation T3 (replenishment every 14 days). Although no significant differences were observed in biometric parameters, yield, or pest and disease incidence, a trend of decreasing yield with longer irrigation intervals was noted: traditional flooding (7.91 t・ha−1) > reduced flooding (7.82 t・ha−1) > intermittent rainfed (7.14 t・ha−1). The incidence of white leaf virus and Burkholderia glumae was highest in the intermittent rainfed treatment, followed by optimized flooding, with the lowest incidence in traditional flooding. Yield reduction and the use of rainwater to cover water requirements resulted in a lower total water footprint for traditional flooding (834.0 m3・t−1), followed by optimized flooding (843.6 m3・t−1) and intermittent rainfed (923.9 m3・t−1). This reflects an improvement in rainwater use efficiency. The findings suggest intermittent rainfed irrigation enhanceswater use efficiency without significantly compromising rice yield or increasing disease incidence in rice var. INIA 516 LM1-La Union 23 in the central basin of the Huallaga River.
Plant-Growth-Promoting Microorganisms: Their Impact on Crop Quality and Yield, with a Focus on Rice
(MDPI, 2025-01-09) Ríos Ruiz, Winston Franz; Jave Concepción, Henry Giovani; Torres Chávez, Edson Esmith; Ríos Reategui, Franz; Padilla Santa Cruz, Euler; Guevara Pinedo, Nelson Elías
This article presents a systematic review of the ecophysiological mechanisms underpinning the essential role of plant-growth-promoting microorganisms (PGPMs) in improving rice yield and quality. The scientific literature is thoroughly reviewed, highlighting how PGPMs positively influence the growth, development, and health of rice plants. Key aspects, such as nitrogen fixation, nutrient solubilization, hormone production, and disease resistance induction, are emphasized. Additionally, technological advancements related to PGPM use are analyzed, including the identification of effective strains, the formulation of enhanced biofertilizers, and genetic engineering. The article concludes that PGPMs represent a promising tool with which to boost the sustainability and productivity of rice cultivation, providing a robust foundation for future research and practical applications in a field crucial to global food security.