Table 4.

Factors that drive maize varietal replacement in ESA.

Supply-side factors	Demand-side factors
•Speed breeding programs (e.g., doubled haploidy and marker-assisted breeding to accelerate the rate of genetic gain and product development).	•Multi-channel promotional activities: advertisements, demonstrations, seed fairs, product launches, etc.
•Seed regulatory framework and regional harmonization of varietal testing and release process/laws.	•Farmers' affordability and willingness to purchase seed of new varieties
•Seed producibility* (reduced cost of goods sold)	•Farmers' awareness of and availability of new varieties in agro-dealer shops
•Efficient seed systems (e.g., less cumbersome varietal testing and release laws; existence of an effective seed certification scheme that guarantees quality seed to farmers, etc.)	•Farmers' risk appetite
•Competition in the seed industry for market share	•Perceived potential yield advantage/profitability of the new versus old varieties
•Availability of new, improved varieties with demonstrated tolerance/resistance to key stresses	•Farmers' ability/willingness to invest in other inputs (e.g., irrigation, fertilizer) and good agronomic practices required to make investment in improved seed worthwhile
•Prominent display of seed of new varieties in the shelf space of agro-dealer shops	•Intended grain use from production - subsistence versus commercial
•Effectiveness of the interface between breeding institutions, seed companies, and agro-dealer networks	•Farmer's education level
•Cost of launching a new product in a market vis-a-vis the size of the market or market potential	•Existence of structured output markets
•Quality seed production	•Effective extension program by the company or government
	•Increased per capita food consumption
	•Point of sales technical support/varietal information at agro-dealer level
	•Social networks (farmer-to-farmer)
	•Outbreaks of new devastating pests and diseases

*Seed producibility: For hybrids, the ease with which seed of new varieties can be produced is a function primarily of the female parent seed yield, pollen production capacity of male parent, ease of detasseling the female parent, and the difference in the flowering times of the male and female parents, often termed as “production split” or “nicking”.