P.B.C. Panawala

Department of Plantation Management, Faculty of Agriculture and Plantation Management, Wayamba University of Sri Lanka, Makandura, Gonawila (NWP), 60170, Sri Lanka

D.C. Abeysinghe

Department of Plantation Management, Faculty of Agriculture and Plantation Management, Wayamba University of Sri Lanka, Makandura, Gonawila (NWP), 60170, Sri Lanka

R.M. Dharmadasa

Herbal Technology Section, Industrial Technology Institute, Bauddhaloka Mawatha, Colombo 07, 00700, Sri Lanka