Conclusion: Results of this study demonstrated
that the growth and yield of rice may be enhanced
with the application of an auxin, lAM· and its
precursor L-TRP. Bioproduction of plant growth
regulators such as auxins in soil as a result of
microbial activity from the added precursor may be
recognised as having a potential influence on plant
growth and development. Further studies are
needed to irivestigate factors affecting the microbial
production of auxins such as their distribution and
stability in soil and their direct uptake by plants