Growth Promoting Potential of Phosphate Solubilizing Enterobacter Cloaca and Enterobacter Hormaechei on Maize and Cowpea Seedlings

Phosphorus plays a range of functions in the proper growth and development of plants. Numerous microbial species, including bacteria, fungi, actinomycetes, and even algae have been found to play a crucial role in the solubilization of phosphate. This study was therefore aimed at exploring the growth-promoting potential of phosphate solubilizing Enterobacter species on maize and cowpea seedlings.

Five strains that showed remarkable phosphate solubilization potential were used for the study. The bacterial isolates consist of three strains of Enterobacter cloaca and two strains of Enterobacter hormaechei. Growth promotion studies were carried out under laboratory conditions (in blotters) and green house (soil environment). In the blotter study, percent germination, germination index, germination time, germination rate, and vigor index were estimated, while shoot and root lengths, number of leaves, and wet weight were estimated in the greenhouse study.

In both seedlings, percent germination, germination index, and vigor index showed significantly higher values in seeds primed with the isolates than in the water-treated seeds (p≤ 0.05). Throughout the period of planting, the shoot and root lengths of the isolate-treated seedlings showed significantly higher values than the untreated control setups. This observation was irrespective of the maize and cowpea seedlings. In both seedlings, shoot and root lengths were directly proportional to days of growth. The bacterial strains showed significantly higher growth promoting potential on the seedlings.

Therefore, the availability of these phosphate solubilizing microorganisms in the soil could enhance the growth of the seeds.