Definitions of common terms used in the DTMA Project

PDF version: DTMA Definitions 2009

These definitions are:


 Adoption is the uptake of a technology by a farmer; the uptake and continuous use of a technology.

Drought tolerant (DT)

Among maize varieties that have similar maturity and similar grain yield under good conditions, a drought tolerant maize variety has a relative higher yield than others when drought occurs. To generate and disseminate such varieties is the focus of the DTMA project.

An early maturing maize variety may escape drought and has therefore a higher yield under drought. It however yields less when conditions are good.

Mega environments vs agroecologies/agroecological zones

Maize mega environment describes the geographic area within which maize varieties show similar ranking for grain yield due to similar growing conditions (rainfall, temperature, soil type). Mega environment cover more extensive areas than agroecologies/agroecological zones.

A maize agroecology/agroecological zone refers to a specific geographic region, usually covering a few countries in which the interactions of maize varieties with the environment (rainfall, temperature, soil type, altitude) are studied. Agroecology (as a study) provides an interdisciplinary framework with which to study the activity of agriculture.

Seed business vs seed merchant

A maize seed business is an organization that produces and markets maize seed.

A maize seed merchant is an organization that markets seed, without producing the seed: i.e., a buyer and seller of seed, like a retailer.

Seed demand vs production

Seed demand means wanting/needing seed and being able to pay for it. Demand is market driven; it is what the consumer (in this case the farmer) is requesting and is willing to pay for.

Production of seed involves area and yield. Production is what a supplier to that market is responsible for, he/she produces seed in order to address demand at a price he/she is willing to sell for.

Seed distribution

Seed distribution is the dissemination of seed from a producer to a farmer via formal or informal markets; the system of delivering seed from the production point to farmers.

Unmet market demand vs excess capacity

Unmet market demand means that demand is greater than supply while excess capacity means supply is greater than demand.

Unmet market demand: a situation whereby a consumer is unable to source material at a price they are willing to pay for a commodity or service.

Excess capacity: the ability to generate more produce than is currently being demanded.

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by the Consultative Group on International Agricultural Research (CGIAR)
The Drought Tolerant Maize for Africa Initiative
International Maize and Wheat Improvement Center (CIMMYT)
ICRAF House United Nations Avenue, Gigiri PO Box 1041 Village Market-00621,
Nairobi, Kenya

The DTMA Project is funded
by the Bill & Melinda Gates Foundation.

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