Foliar application of nitrogenous compounds and elicitors to Tempranillo grapevines: Microbiological implications

This study was aimed to analyze the effects of the nitrogen foliar application, and elicitation used on microbial populations of musts. The nitrogenous compounds were raw and treated wastewater from mushroom industry and a commercial yeast derivate; the elicitors were methyl jasmonate, chitosan and one commercial elicitor from a yeast source. Those six products were sprayed as pre-harvest treatment over the leaves of Tempranillo grapevines for improving quality and maturity of grapes. The applications of raw and treated wastewaters from mushroom industry, chitosan and methyl jasmonate elicitation did not cause changes in microbial diversity of must samples. In contrast, spraying commercial yeast derivate products made the must microbiota reach a high richness of species that would be positive in ecological terms. This research succeeded in establishing the impacts of foliar applications in the grapevines on the microbial community, and in any case, negative impacts were observed so that, presumably, these foliar applications can be perfectly implemented as agronomic practice.