1. Biology Division; Malaysian Palm Oil Board; 6, Persiaran Institusi Bandar Baru Bangi Kajang Selangor 43000 Malaysia
2. Laboratory of Food Crops; Institute of Tropical Agriculture; Universiti Putra Malaysia; Serdang Selangor Darul Ehsan 43400 Malaysia
3. Department of Plant Protection; Universiti Putra Malaysia; Serdang Malaysia