Enhancing growth of crops with the help of biofertilizers

The authors are investigating the effect of biofertilizers Mykovam and BioGroe on seedling performance in the nursery and their survival and growth in the field. Biofertilizers Mykovam and BioGroe are trade names for mycorrhiza and Plant Growth Promoting Rhizobacterial (PGPR) inoculants that are low-cost, environment friendly and effective alternatives to chemical fertilizers. Six plant species were inoculated with the biofertilizers in the nursery namely: Jatropha curcas, Acacia Mangium, A. neurocarpa, A. crassicarpa, Casuarina equisetifolia and Swietenia macrophylla. These crops are of prime importance due to their impact on global warming as quenchers of the second most abundant greenhouse gas, carbon dioxide, and secondly, as potential fuel source particularly, J. curcas. Massive plantation establishment is on-going in many areas in the country, more commonly in the marginal sites, hence, seedlings need more than the chemical inputs to persist in the site. Inoculation with BioGroe and Mykovam in the nursery either alone or combined generally promoted taller height of all seedlings of the six host species compared to those without the biofertilizers. After three months in the nursery significant increase in shoot, root and total dry matter production was observed in J. curcas, C. equisetifolia and S. macrophylla when inoculated with single biofertilizers or both. Combined Mykovam and BioGroe inoculation significantly prompted longer root length and greater leaf area of J. curcas that translated to significantly greater Phosphorus content and uptake in the shoots but not in the roots. A. crassicarpa, A. mangium and A. neurocarpa seedlings when inoculated with BioGroe or Mykovam or combined had also greater shoot, root and total biomass but was not statistically significantly different than the uninoculated seedlings. These last three host species being leguminous trees need specific Bradyrhizobium strains for them to fix atmospheric nitrogen and convert to usable forms. Monitoring the growth and seedling survival in the field in on-going. Whether the beneficial effects of biofertilizers inoculation will significantly affect J. curcas seed yield or more importantly oil yield remains to be determined.