RA 00110.pdf - OAR@ICRISAT

Introduction
A successful crop improvement program must have
appropriate objectives, however, "appropriate" is
not always easily defined. Knowledge of the physical
and management characteristics of target cropping
systems into which the new cultivars are to fit is
essential so that crop traits attractive to farmers can
be incorporated. However, such targets are multiple,
moving, and complex. Throughout the West African
semi-arid tropics (WASAT), cropping systems
differ widely across farm types and across and within
agroclimatic zones. This means that distinct target
farmers (or "recommendation domains") need to be
identified and evaluated in order to assign priorities
among alternative crop improvement objectives.
Cropping systems—and the broader farming systems
of which they form a part—are also constantly
evolving from demographic changes, infrastructure
development, and changes in the types and availability
of complementary production technologies. Because
breeding programs require years to breed stable,
improved cultivars, the pace and direction of
such changes need to be gauged at the outset in order
to define objectives which will fit the most probable
future adoption conditions.
W A S A T farmers have also diversified cropping
systems with the result that management decisions
on varietal selection, timing of cultural operations,
and input intensity directed at one crop, are rarely
independent—they affect the resources available to
other crops and activities. Crop improvement objectives
based on an assessment of probable returns to
resources, e.g., fertilizer allocated to one crop may
be frustrated by competing demands or returns for
these same resources from the farmers' other cropping
activities.
This paper uses farm-level data from Burkina
Faso to demonstrate how these considerations can
be applied to define millet improvement objectives
for several zones in the W A S A T . Millet's importance
in the major cropping systems and land-use
patterns of Burkina Faso is reviewed. Varietal diversity
in local millets, how farmers perceive and
exploit this diversity, and how breeders can use such
information to set program priorities among maturity
groups is examined. Millet's special role as a crop
grown with low inputs in the W A S A T cropping
systems is considered by comparing management
responsiveness and input-use patterns among the
major cereals. Results from farmers' tests of promising
millet cultivars are reviewed to assess the major
constraints blocking their adoption, followed by
conclusions concerning appropriate millet improvement
objectives and methods.
Data used in the analyses are drawn primarily
from baseline surveys and farmers' tests conducted
by the ICRISAT/Burkina Faso Economics Program
in 1981-1985. Some 150 randomly selected
farmers participated in the on-farm research in six
villages chosen as representative of the three major
agroclimatic zones in the WASAT: the Sahel (380
mm average annual rainfall during the survey period),
the Sudan savanna (560 mm), and the northern Guinea
savanna (780 mm). Drought conditions prevailed
throughout the survey period as annual rainfall
fell below the long-term average for all villages
and all years. Percentages of the zonal long-term
rainfall averages for the survey period were 67% in
the Sahel, 75% in the Sudan, and 80% in the northern
Guinea zones.
Role of Millet in Regional
Cropping Systems
Cropping Patterns
Higher rainfall and longer cropping seasons increase
farmers' options as one moves from the Sahel in the
north to the Sudan savanna and northern Guinea
savanna zones in the south (Table 1). Among the
cereals, millet is more tolerant to arid conditions,
and therefore is the dominant cereal in the Sahel
zone where it occupies more than 90% of the cultivated
area. In higher rainfall environments the proportion
declines to approximately 25% in the Sudan
234