Strategies Used to Improve the Performance of Plant Growth-Promoting Rhizobacteria Under Agricultural Greenhouse and Field Production Scenarios in Semi-Arid Conditions

The utilization of plant growth-promoting rhizobacteria (PGPR) in agricultural production scenarios has the potential to significantly improve the quality and yield of several commercially important crops. The observed benefits stem from the capacity that PGPRs have to alter the biochemistry of their plant hosts to promote growth and/or resist abiotic stress conditions or biotic aggressors. However, a growing body of experimental evidence has demonstrated that the performance of these beneficial microorganisms in the frequently unpredictable real-world conditions of agricultural production is far from satisfactory. Several aspects, from unrealistic laboratory conditions to inefficient distribution networks, contribute to impede the realization of the full potential that PGPRs have to significantly increase production in a much more sustainable manner. The present assay is a compilation of different strategies that have been tested to improve the performance of environmentally resilient PGPRs isolated from the semi-desertic regions of the North–Central state of Coahuila, Mexico, in actual agricultural production scenarios of solanaceous crops, like tomato, chili peppers and tobacco, as well as short-cycle parsley plants. The latter included cultivation in open fields, in addition to the use of protective shading combined, or not, with plastic mulching. The outcome of these working strategies is described, including an ample discussion offering possible explanations for both the positive results and the non-reproducible and/or unexpected poor outcomes. A forward leap into future perspectives to improve the sustainability of the world’s agricultural production is also included.