Yield and agronomic performance of sweet corn in response to inoculation with Azospirillum sp.

Background: Nitrogen is the most common limiting factor for crop productivity and most maize cultivars require fertilizing. Here we report the possibility of partially replacing the nitrogenous fertilizer in sweet corn inoculated with a native strain of Azospirillum. Methods: In this study, we examined an agronomic experiment in a crop field of arid soils under drip irrigation in Huacho (central coast of Peru) using the commercial variety of sweet corn "Pardo". The treatments were two levels of nitrogen (90 and 180 kg N ha -1 ), one or two applications to the foliage of a native strain of Azospirillum sp. (1 x 10 8 CFU/mL) and a control treatment without inoculation (only with nitrogen fertilizer). Eleven agronomic variables related to productive aspects were evaluated, performing statistical analysis and the comparison of treatment means. Results: The inoculation with Azospirillum sp. did not significantly ( p > 0.05) affect the total weight of ears per plot, the number of ears per plant and the number of male flowers, but it significantly ( p < 0.05) influenced the grain yield per hectare, survival of plants at harvest, the weight of grain per plant, diameter and length of the cob; the probable mechanisms underlying this performance are discussed. Conclusion: In some productive characteristics of sweet corn cv "Pardo", a significant effect was found by inoculation with Azospirillum sp., surpassing in grain yield the control only with nitrogen fertilization, suggesting that it is possible to complement the application of nitrogen to the soil through the inoculation of the native strain, replacing up to 50% of the levels of fertilizer application, since the B/C ratio increased with the use of the inoculant.