The production potential of yams cv. Binugas and Gunung was determined by using three planting dates and two planting systems. The yams were planted in March, May and July 1990 on raised and flat rows without vine support at the close spacing of .91 by .30 m. Regardless of planting date and planting system, these cultivars performed similarly with respect to marketable and premium weights, tuber size and non-marketable weight. Planting system has no significant effect on cultivar performance. The best planting date was March, with a marketable production of 70,590 kg/ha. About 88.2% or 62,254 kg/ha was highly graded tubers. The delay in planting from March to July significantly reduced yields by 44.8%.