Determinar el efecto de la inoculación de cuatro cepas bacterianas sobre el comportamiento agronómico de tres cultivares comerciales de papa (Solanum tuberosum L.) en la provincia de Cañete. Metodología: Fue utilizado el Diseño de Bloques Completos Aleatorizados con 3 repeticiones. Se dispuso un arreglo jerárquico de parcelas subdivididas en el que los genotipos de papa (3 variedades comerciales) se asignaron a parcelas completas y los tratamientos de inoculación (4 cepas bacterianas y 1 control) a sub-parcelas, evaluándose el efecto promotor del crecimiento de las cepas bacterianas: Bacillus sp., Azotobacter sp. y Pantoea sp. sobre características agronómicas de la papa. Resultados: La inoculación con las cepas bacterianas en las variedades de papa Canchán, Perricholi y Única, afectaron significativamente (p<0,05) el vigor vegetativo, porcentaje de inflorescencias, peso de follaje por planta y el peso de la biomasa total por hectárea en el cultivo por lo que se puede recomendar utilizar la inoculación de algunas de estas cepas que tuvieron un efectoestimulador del desarrollo en estas variedades comerciales, destacando la cepa AZO 16 M2 (Azotobacter sp.) para promover el incremento del peso de follaje y de la biomasa total, así como para estimular la floración en la variedad Perricholi y la cepa BAC 15 MB (Bacillus sp.) para regular el grado de senescencia del follaje, específicamente en la variedad Canchan. Conclusiones: La inoculación con las cepas bacterianas en las variedades Canchán, Perricholi y Única, influenciaron algunos caracteres agronómicos importantes en el cultivo de papa, aunque su efecto específico fue dependiente en cada variedad de papa.Palabras clave: Solanum tuberosum, PGPR, inoculación, interacción genotipo-cepa.

Agronomical performance of potato (Solanum tuberosum L.) cv. ´Unica´ under inoculation with native rhizobacteria and application of acetyl salicylic acidDesempenho agronômico da batata (Solanum tuberosum L.) cv. ´Unica´ sob inoculação com rhizobacterias nativas e aplicação de ácido acetil salicílico

Abstract:To study the effect of interaction of plant genotypes and populations of microorganisms in the rhizosphere may be an important factor to assess the effectiveness of PGPRs on crop production. The objective of this research was to determine the effect of inoculation of four bacterial strains on the agronomic performance of three commercial cultivars of potato in the province of Cañete, Peru. A randomized complete blocks design with three replications on a split plot arrangement was used, in which potato genotypes (three commercial varieties) were assigned to complete plots and inoculation treatments (bacterial strains and control) were allocated to sub-plots, then evaluating the effect for growth promotion related to bacterial strains: Bacillus amyloliquefaciens, B. simplex, Azotobacter sp. and Pantoea sp. on potato agronomic characteristics. As result of inoculation with bacterial strains in potato cultivars Canchán, Perricholi and Unica, significant differences were showed (p<0.05) for vegetative vigor, percentage of inflorescences per plant, foliage weight per plant and weight of the total biomass per hectare with use of inoculation of some of these strains, having a stimulatory effect on development in these commercial varieties, highlighting strain AZO16 M2 (Azotobacter sp.) to promote increased weight of foliage and total biomass and flowering in cv. Perricholi and strain Bac15MB (Bacillus amyloliquefaciens) to regulate the degree of senescence of foliage, specifically in cv. Canchan. Concluding that inoculation with bacterial strains in potato cultivars Canchan, Perricholi and Unica influenced some important crop agronomic characters, although its specific effect was dependent on each potato variety.

Peru is center of origin of potato and its wild relatives, so it is convenient to develop new technologies of agronomical management with less impact on the ecosystem, as in the use of pesticides and chemical fertilizers in potato is increasing in developing countries. The objective of the work was to evaluate the agronomic performance of potato cv. ´Unica´ under inoculation with PGPR rhizobacteria isolated from the rhizosphere of Andean potatoes and on the effect of the application of acetylsalicylic acid in field conditions of the Peruvian coast. Inoculation of four bacterial isolates were evaluated: Bacillus simplex B13, Bacillus amyloliquefaciens Bac 15Mb, Azotobacter sp. Azo 16M2 and Pantoea sp. DZ22, as well as a dose of 0.4 mM acetyl salicylic acid as promoter treatments for plant growth versus a control with no inoculation. A randomized complete block design was used in a sandy loam class soil, slightly alkaline, with low organic content and free of salts. There was a relative humidity between 54 and 71%, while the average air temperatures ranged between 13 and 21 °C in San Vicente de Cañete, Lima (coordinates UTM 18L3540788550372). Inoculated plants with bacterial strains at sowing time and control were evaluated at flowering in plots of 40 plants with three replications for several physiological and productive parameters. Means were separated statistically through Duncan's multiple range test and processed with Infostat software. Inoculation with strain Azotobacter sp. Azo 16M2, showed significant differences (p<0.05) with respect to control without inoculation, increasing tuber yield and commercial tuber weight per hectare and with less damage by the leafminer fly (Liriomyza huidobrensis) vis-à-vis the control. Also application of acetyl salicylic acid showed higher percentage of inflorescences (p<0.05) compared to the control, while statistical differences were not found between bacterial strains for this character. It was concluded that the application of inoculant strain Azotobacter sp. Azo 16M2 improved the agronomic performance of potato cv. 'Unica', under subtropical conditions of the valley of Cañete in terms of production of tubers and commercial quality, and less foliage damage by the leafminer fly compared to non-inoculated plants. KEYWORDS:Azotobacter, agroecology, PGPR, potato-associated bacteria, plant-microbe interaction, salicylic acid. RESUMOPeru é o centro de origem da batata e seus parentes silvestres, por isso é conveniente desenvolver novas tecnologias de gestão agronômica com menor impacto no ecossistema, como o uso de pesticidas e fertilizantes químicos em batata está aumentando nos países em desenvolvimento. O objetivo do trabalho foi avaliar o desempenho agronômico da cv. ´Unica´ sob inoculação com rizobactérias PGPR isoladas da rizosfera de batata andina e pelo efeito da aplicação de ácido acetilsalicílico nas condições de campo da costa peruana. Avaliou-se a inoculação de quatro isolados bacterianos: Bacillus simplex B13, B. amyloliquefaciens Bac 15Mb, Azotobacter sp....