Geretharan, T.Sangakkara, U.R.Arulnandhy, V.2020-12-022020-12-022020Agrieast, 14(1):p.11-26https://dl.nsf.gov.lk/handle/1/25118Logistic and Gompertz equationsNitrogen application rateTropicsWeed-free periodInfluence of nitrogen fertilizer and duration of Purple Nutsedge (Cyperus rotundus) interference on Onion (Allium cepa) growth and yield in minor seasons in Batticaloa, Sri LankaArticle