Growth promotion of chickpea and barley by a phosphate solubilizing strainof Mesorhizobium mediterraneum under growth chamber conditions

The efficacy of a strain of Mesorhizobium mediterraneum to enhance the grow th and phosphorous content in chickpea and barley plants was assessed in a soil with and without the addition of phospates in a growth chamber. The re sults obtained show that the strain PECA21 was able to mobilize phosphorous efficiently in both plants when tricalcium phosphate was added to the soil . In barley and chickpea growing in soils treated with insoluble phosphates and inoculated with strain PECA21 the phosphorous content was significantl y increased in a 100 and 125%, respectively. Also, the dry matter, nitrogen , potassium, calcium and magnesium content in both plants was significantly increased in inoculated soil added with insoluble phosphate. These results show that the inoculation of a soil with rhizobia should not be based only on the effectiveness of the strains with respect to their nitrogen fixatio n potential, since these microorganisms can increase the growth of plants b y means of other mechanisms, for example the phosphate solubilization. (C) 2001 Elsevier Science Ltd. All rights reserved.