Oil palm inflorescence sex ratio and fruit set assessment in dura × pisifera biparental progenies on fibric peat soil by Swaray, Senesie, Amiruddin, Mohd Din, Y., Mohd Rafii, Jamian, Syari, Ismail, Mohd Firdaus, Jalloh, Momodu, Eswa, Mazli, Marjuni, Marhalil, Akos, Ibrahim Silas, Yusuff, Oladosu