Journal of Agricultural Science and Food Research
Open Access

Abstract

Potential Growth Enhancement of Crops Using Pure Culture of Rhizobium Spp.

Josiah Asime Lennox

Background: The quest for increased food production for ever-increasing population growth is a continuous venture. This has necessitated this research to use cheaply available resources, microorganisms in the production of biofertilizer.
Methods: A soil sample was obtained from a potato farm and a ten-fold dilution prepared up to 10-8. One milliliter from dilutions 10-4, 10-5 and 10-6 was pipetted and transferred into 3 Petri dishes labeled accordingly. Molten Rhizobium agar medium was carefully poured into the plates, swirled gently to mix and incubated at 37oC for 24 hours. The discrete colonies were characterized. The broth culture of these colonies were prepared in nutrient agar. Seeds such as corn, beans, groundnut, and pumpkin were treated with broth cultures and planted in soil contained in plastic buckets. These were observed for 14 days at an interval of 2 days.
Results: A total of 5 strains of Rhizobium sp were identified but only 2 showed growth enhancement properties. These 2 were identified as Rhizobium phaseoli and Rhizobium meliloti but only Rhizobium phaseoli was used for the treatment of the seeds. After 2 days of planting, all the seeds treated with the Rhizobium phaseoli germinated except pumpkin. After 7 days of planting, all the seeds germinated and grew but the control for beans, soil treated and control for pumpkin did not germinate. After 14 days, the same pattern of growth as at 7 days except that the pumpkin germinated grew very fast and with impressive leaves. Conclusion: Based on these results it can be stated that the Rhizobium strain used for this research enhanced the growth of maize and groundnut, beans and pumpkin effectively and therefore can be used as biofertilizer for the cultivation of these crops. Rhizobium meliloti can be improved upon and also used to enhance crop growth.
Keywords: Biofertilizer; Rhizobium spp; Growth enhancement; Crops

Published Date: 2020-09-23; Received Date: 2020-06-29