ABSTRACT The experiment to known the affect of age and number of defoliated on yield of corn (Zon mays L.) hibryd of Biei 2 voriety has been carried out since 17 February until 4 Juni 1997, at Sojokerto Village, Lekeono District, Wonosobo Regency, Central Java Province. The soil type is lathosol with pil 6,3 and altitude 505 meters above sea level. The methode is factorial experiment 3 x 3 wi…