RA 00110.pdf - OAR@ICRISAT

eaching an aggregate production level which at
least meets family food needs, but not to maximize
the yields or even the production of any particular
crop. Due to its better suitability to poorer soils, and
its lower response to inputs, farmers cultivate millet
in low-input systems on their least productive land
as a low-cost, low-risk means of increasing their
overall food security. Under conditions of input
scarcity, they rationally apply inputs primarily to
those crops which give them substantially higher
response, sorghum and maize, with only marginal
levels of inputs applied to millet.
This is the paradox facing millet improvement
programs in the transition zone. It is clear that major
increases in millet yields can only occur through
higher input management systems. However, it is
not clear that breeding for quantum yield increases
within high input systems is a relevant or even realistic
objective in this zone under current and foreseeable
conditions. For farmers to justify applying
inputs to millet, it is not sufficient that their use on
millet be profitable, but that they be as profitable at
the margin as when applied to other crops, such as
sorghum or maize, which are substantially more
responsive. Marginal improvements in the response
of new millet cultivars will not be enough. Moreover,
as sorghum and maize improvement programs succeed
in producing improved cultivars with even
higher response to inputs, the minimum target
response rate will increase accordingly.
In short, unless transition zone breeders judge
that it is possible to increase response rates to levels
competitive with current and future sorghum and
maize cultivars, then they should consider low-input
management on marginal land types as the most
probable adoption conditions for new millet cultivars
in the foreseeable future. In this case, the major
objective should be to improve yield stability by
incorporating improved resistance to the major
causes of yield loss at the farm level. It is not a
coincidence that such a strategy corresponds best to
farmers' own goals of including millet in their transition
zone farming systems.
Implementing these objectives for both the Sahel
and the Sudan and Guinea savanna demands a reassessment
of present screening and selection methods
on the research station, as well as giving greater
accent to on-farm research. Priority now given to
selecting for yield potential under high input management
alone needs to be reconsidered. Only by
screening at several input levels can cultivar differences
in response to inputs be identified. Screening
should also be conducted primarily on land types
considered appropriate for millet cultivation in various
regions. To achieve this, screening of advanced
lines in well-controlled, researcher-managed onfarm
trials may well need to be expanded. The major
farm-level stress factors which contribute to the
yield gap and to yield instability also need to be
measured on farmers' fields, and systematically
introduced on the research station at an early stage
of selection.
Finally, it should be clear that this strategy for
millet improvement requires a close interdisciplinary
effort involving specialists in physiology, plant
protection, agronomy, and economics, as well as
breeding. The role of the physiologist is particularly
important since crop mechanisms for tolerance or
resistance to the major stresses, and interactions
among environmental stresses, are not yet adequately
understood. Knowledge in both of these
areas is needed in order to develop reliable and
efficient screening techniques. This approach also
requires greater work with farmers themselves at
several stages of the breeding and selection process,
not simply at the final stage of pre-extension screening.
An early and continuing interactive relationship
with farmers to define appropriate breeding objectives
and to test concepts and materials will substantially
reduce the time necessary to arrive at improved
cultivars which are well adapted to our clients'
needs.
References
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