Is Older Better? Maize Hybrid Change on Household Farms in Kenya
IDWP 114. Melinda Smale and John Olwande. 2011. Is Older Better? Maize Hybrid Change on Household Farms in Kenya
Kenya has been recognized globally as maize success story since the 1970s. Released on the
eve of independence, Kenya’s first maize hybrid diffused faster than did hybrids in the U.S
Corn Belt during the 1930s-1940s. In recent decades, policy researchers have lamented that
earlier gains in maize productivity have not lived up to their potential. Claims of stagnating
yields and stagnating adoption are offset here, at least in part, by longitudinal survey data
showing rising yields and adoption rates on farms. Tegemeo survey data confirm that Kenya
has reached its adoption ceiling years ago in the major maize producing zones of the country,
and is near to doing so in other zones. Data show adoption rates topping 80% of farmers.
Multiple explanations of slowed productivity gains have been advanced, including the old
age (the number of years since initially grown by farmers) of hybrids grown on farms. Old
hybrid age contributes to lower yield potential on farms. This paper begins an exploration of
factors affecting maize productivity in Kenya by examining the age of hybrids on smallholder
farms and its determinants, drawing from the nationally representative survey data collected
by Tegemeo Institute in 2009/10. Today, a hybrid released in 1986 (H614) still dominates on
farms in Kenya, despite the dramatic increase in the number of hybrids, breadth of seed
suppliers, and range of hybrids sold as seed markets liberalize. The average age of maize
hybrids grown in Kenya is old (about 18 years overall in 2010).
Applying a double hurdle model to explore the factors that influence adoption, we were better
able to explain the amount of hybrid seed grown (the intensity of use) than whether or not a
farmer chooses to use the seed at all. This outcome is not surprising given the many years of
experience with hybrids in Kenya. Rainfall stress is of no importance in either the decision to
grow hybrids or how much seed to plant. Women widows are no less likely to plant hybrids
than are male households heads, but they plant them on a smaller scale. Factors such as
formal education, experience growing hybrids, and farm land owned have long been
associated with use of improved seed—and still are. These are robust results and are
consistent with the literature.
The larger the farm, the younger is the hybrid planted. Larger, commercially oriented farmers
are able to keep up with the latest releases. When we exclude farmers growing the H611-
614D series, more experienced farmers grow younger hybrids.
We argue that what matters most today for national maize productivity is the dynamic
replacement of older with newer materials, as long as these newer materials truly represent an
improvement on previously released hybrids. There is some suggestion in the data that this
may not always be the case. Given the strong price-responsiveness demonstrated by these
farmers, despite that many remain subsistence-oriented, continued progress in supplying a
range of price- (and trait-) differentiated materials in a competitive seed market is important.