Abstract:
Last two decades, there has been a general decline in the yields of major
crops because of the collapse of beneficial soil microbial communities under
conventional agricultural practices. Chemical inputs like fertilizers and
agrochemicals have been responsible to this microbial depletion. Use of
Plant Growth Promoting Rhizobacteria (PGPR) for the benefits of
agriculture is gaining worldwide acceptance and appears to be the trend for
the future. Inoculation of crop plants with certain strains of beneficial, free living bacteria enhance emergence, colonize roots, stimulate growth and
enhance yield. A study was conducted to evaluate the beneficial effect of
fungal and bacterial monoculture inoculations on yield enhancement of
potato under greenhouse conditions. Microbial isolations were done using
the top loamy soil samples obtained from abandoned potato crop land in
Agriculture Research Center, Bandarawela. The isolated microbial strains
(PCM1, PCM4, PCM5, PCM8, PCMrg, PCMry, PCMrw and PCMB) were
applied directly around the root zone of the potato plants grown in pots under
the greenhouse conditions. Each pot contained three disease free potato seed
tubers with sterilized sand medium. Effect of the microbial monocultures on
the growth performance of the potato was measured using number of tuber
initiation, dry weights of tubers, shoots and the roots. Potato plants without
any microbial treatment were considered as the control experiment. The
results of ANOVA revealed that all the bacterial monocultures except
PCMrg and PCM4 significantly enhanced the tuber dry weight of potato (p=
0.001). Thus, it can be concluded that the bacterial isolations enhance the
growth promotion through the development of tuber.
