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Definition
Managed stress is a systematic approach for developing germplasm
that can perform well when grown under both marginal and optimum
growing environments within a given target area. It differs
from more conventional selection approaches in that priority
stresses are incorporated early in the breeding process. During
the screening stage, all materials are subjected to a set
of uniformly managed environments in a given target area (for
example, environment 1= low N , environment 2= drought stress,
environment 3= non-limiting N and water). The breeder chooses
those materials that exhibit the best trait combinations across
this range of environments. During the testing stage, stresses
are applied at locally relevant times and (if different) during
physiological stages that typically have the largest impact
on crop yield (i.e. flowering and grain filling stages). This
germplasm selection approach has generally led to consistently
higher crop yield gains compared to approaches that either
do not consider stress factors at all or do so at a later
point in the breeding process. See the Banziger references
below for further details.
Related topics
General plant breeding
Participatory
plant breeding
Managed stress breeding
Molecular tools to enhance
crop genetic analysis and improvement
Analysis of genotype by environment interactions
Relevant literature
Available in PDF format
 Scientific
references: managed stress breeding
Available on the Internet
Drought and N tolerance in Maize
- Website: CIMMYT
- Reference: Bänziger, M., G.O. Edmeades, D. Beck,
and M. Bellon. 2000. Breeding for Drought and Nitrogen Stress
Tolerance in Maize: From Theory to Practice. Mexico, D.F.:
CIMMYT. 68 pp
- Abstract: "Targeted initially for maize breeders
in sub-Saharan Africa, the content is based on a successful
approach developed at CIMMYT for improving the tolerance
of maize to drought and low nitrogen stress. Intended as
a supplement to a course for breeders and agronomists of
at least BSc level, it deals with the effects of water and
N deficits on the maize plant, the level of yield increases
to be expected from selection, factors that affect the severity
of drought and low N stress in maize, selecting suitable
fields for drought and low N screening, managing uniform
stress in drought or low N experiments, designing effective
experiments and field layouts for stress trials, the choice
and analysis of data, and the use of drought and low N screening
in a normal breeding program."
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