1 1 10 Z. Poeloengan Additional Author Pusat Penelitian Kelapa Sawit (PPKS) Additional Author Kusnu Martoyo Additional Author W. Darmosarkoro, I.Y. Harahap, E. Syamsuddin Additional Author Syamsul Anwar, Dja\'far, Arsyad D. Koedadiri Additional Author Winarna, Arsyad D. Koedadiri, Edy S. Sutarta Additional Author Eka Nuryanto, Purboyo Guritno Additional Author Dja\'far, Syamsul Anwar, P. Purba Additional Author mixed material 08532141 Medan Pusat Penelitian Kelapa Sawit (PPKS) 2001 cover_warta_vol9no3.jpg