HYV in the Philippines, progress of the seed - fertilizer revolution

Major objectives are a description of fertilizer response of HYV in the Philippines, description of fertilizer response of HYV in the Philippines, comparison with varieties, contribution of HYV to rice production, and a perspective on the exploitation of the potential of major technological advances. About half of the lowland rice area in the Philippines was planted to high yielding varieties (HYV) in the crop year 1969-70. Yields averaged 20percent higher for HYV than for other varieties in the irrigated area and about 10 percent in the non-irrigated lowlands. However, one-fifth of the HYV growers in the irrigated area obtained high yields -- more than 75 cavans (3.3 metric tons) per hectare and averaged 97 cavans (4.3 tons) per hectare, or nearly twice the mean for the whole group.