A JOINT-PRODUCT ANALYSIS OF THE ADOPTION OF MODERN CEREAL VARIETIES IN DEVELOPING-COUNTRIES

Semi-dwarf wheat varieties have been slow to diffuse in some regions d espite their superior grain yield. We analyze varietal differences in yields of the joint products of grain and straw, the decision to adopt new varieties, and nitrogen demand. The low straw yield of semi-dwarf varieties under low input conditions is shown to be a plausible expla nation for their slow adoption in some regions. First generation moder n varieties induced a large increase in the derived demand for nitroge n, but subsequent varietal development appears to have had little impa ct on nitrogen demand.