How does the Adoption of Modern Variety increase Productivity and Income? : A Case of the Rice Sector in Tanzania

Although high yielding modern rice varieties (MVs) have been gradually disseminating over Sub-Saharan Africa, little is known on how the adoption of MVs influences agriculture productivity and household income. To fill this research gap, we analyze two kinds of data sets in Tanzania: a national representative cross section data and a two-year panel data of irrigated farmers in one district. The most important finding is strong complementary relationship between MVs and water control; high yield is achieved when MVs are grown with improved bund in paddy fields in irrigated area. We also find that the use of chemical fertilizer and the practice of transplanting in rows increase yield and income of both the adopters and non-adopters of MVs in the irrigated area. In rain-fed area, we observe limited impact of MVs. These findings suggest that introducing MVs as a package of technologies including other agronomic practices is effective in order to fully achieve their potential. In the long run, development of irrigation would be important to realize a rice Green Revolution in Sub-Saharan Africa