Effect of inoculation with bacteria of the genus Bacillus on the growth of Megathyrsus maximus Jacq, in conditions of water stress

Abstract

In the Colombian dry Caribbean, the forage production is affected, in terms of quantity and quality, by the periods of droughts systematically presented in some periods of the year, causing water deficit, damages in the feeding, in animal productivity and in the producers income. The objective of the research was to evaluate the effect of inoculation with Bacillus and Azotobacter plant growth promoting bacteria on the development of guinea grass Megathyrsus maximus in drought conditions and controlled irrigation. The studies were performed at the Motilonia research center (CORPOICA) located in Agustín Codazzi (Cesar-Colombia). Two simultaneous experiments were implemented applying a completely randomized design with 12 treatments and 11 replicates in experiment 1 and 9 treatments with 13 replicates in experiment 2. Results of the morphological variables measured in the plant, and the analysis of the nitrogen concentration of the foliar tissue and turgidity, showed a significant increase (p < 0.05) in root length, plant height at 62 days, and turgidity among treatments inoculated with Bacillus strains in relation to drought control (without inoculation). The strains XT38, XT13, XT14 and Azotobacter contribute to promote the growth of M. maximus and inoculation and co-inoculation with Bacillus present an ability to counteract the negative effects of water stress.