Karunarathna, K.D.K., Somaratne, S., Weerakoon, S.R., Weerasena, O.V.D.S.J. and Abeysekera, A.S.K. (2015) Distribution patterns of weedy rice (Oryza sativa f. spontaneae) populations in different climatic zones in Sri Lanka 25th Asian-Pacific Weed Science Society Conference on “ Weed Science for Sustainable Agriculture, Environment and Biodiversity” pp. 11-12