High-Yielding Varieties of Rice in the Philippines, Progress of the Seed-Fertilizer Revolution

About half the lowland rice area in the Philippines was planted to high yielding varieties (HYV's) in crop year 1969/70.The national average yield for all farmers was 1.7 metric tons per hectare.Yields averaged 20 percent higher for HYV's than for other varieties in the irrigated area and about 10 percent higher in the nonirrigated lowlands.However, one-fifth of the farmers growing HYV's in the irrigated area obtained high yields of more than 3.3 metric tons per hectare, averaging 4.3 tons per hectare.One-third of all HYV growers used no commercial fertilizer, and one-third used no chemicals for weed, pest, or disease control.Those using fertilizer applied an average of 32 kilograms per hectare of nitrogen plus phosphorus, about one-third the recommended rate.