Sirisena, D.N.Wickramasinghe, W.M.A.D.B.Ranathunge, R.A.N.D.2020-05-132020-05-132006Annals of the Sri Lanka Department of Agriculture, 8:p.229-238https://dl-doa.nsf.gov.lk/handle/1/2182PLANT NUTRITIONLeaf colour chartsNitrogen responseRiceUse of leaf colour charts to determine nitrogen requirement and yield response of rice varietiesArticle