Cross-Pollinated Crop Variety Adoption Studies and Seed Recycling: The Case of Maize in Tanzania

  • Ephraim Nkonya Research Fellow, International Food and Policy Research Institute, Kampala, Uganda


A survey of 126 maize farmers was conducted in northern Tanzania with the objective of examining adoption of cross-pollinated seeds among farmers who recycle improved seeds. In this study, an improved variety is defined as any variety that has been bred using formal plant breeding methods. Formally bred cultivars that have been recycled but still maintain some of their characteristic attributes were also categorized as “improved.” About 91% of sample maize farmers used improved seeds. Heckman's two-step procedure was used to examine the factors that affect the probability to adopt and the intensity of adoption of improved maize seed and chemical fertilizer use. Most factors included in the model did not have a statistically significant impact on the adoption of improved maize varieties. The determinants of adoption did not have a significant impact probably due to the high rate of adoption of improved maize seed (91%). Researchers conducting studies in areas where seed recycling is common need to use a more restrictive definition of “improved seeds” than the one used in this study. In the case of studies examining factors influencing intensity of adoption, researchers need to determine the intensity of adoption by using scaling factors that are based on loss of genetic potential (yield) due to seed recycling. Such scaling factors may be determined empirically since they vary from one maize variety to another. About 64% of the moderate rainfall zone (800 – 1200 mm per year) respondents used chemical fertilizer, as compared to 44% in the low rainfall zone (500 - 800 mm per year). The level of fertilizer applied was well below recommended rates, hence the need to research on and promote extension efforts in organic fertilizers that will complement the expensive chemical fertilizers.

Eastern Africa Journal of Rural Development (2001) 17, 25-34

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eISSN: 0377-7103