Determination of Value of Evapotraspiration and Plant Coefficient of IR64 Rice Variety (Oryza sativa L.) in the Faculty of Agriculture, University of Sumatera Utara Green House - Nasution, Yunidar; Program Studi Keteknikan Pertanian Fakultas Pertanian Universitas Sumatera Utara (Universitas Sumatera Utara, 2015)