CONCLUSION
The incorporation of crop residues help to reduce the effectiveness of barnyard grass. The results revealed that the ability to inhibit germination and growth of barnyard grass differ among the rice varieties used. The inhibitory effect of Ld and Bw varieties are superior than Bg and At varieties. Therefore, isolation and identification of allelochemicals from rice straw and studying the effect of allelochemicals on germination and growth of weeds are important for further analysis of allelopathic characters of rice varieties.
Acknowledgement
The authors wish to acknowledge the financial support from the Transforming University of Ruhuna to International Status (TURIS) project for this experiment.