RA 00110.pdf - OAR@ICRISAT

• those falling into other disciplines, e.g., soil and
water management, where there was some possible
interaction with variety improvement.
Finally, the group identified:
• cooperative needs, and
• operational constraints to research.
General Constraints by Region and
Broad Rainfall Zones
In both zones, "early" (gero, souna) varieties are
grown, but in the drier zone, soil moisture and nutrient
deficits become more dominant (Table 2).
Major Constraints for Breeding Work
First Priority
• Stand establishment (emergence and seedling
survival under low moisture and high temperature
stresses).
• Insect resistance, according to dominant species
(Raghuva and borers in West Africa, and borers
in East and southern Africa).
• Grain production (efficiency of water and nutrient
use) and production stability.
Second Priority
• Diseases, according to region (more severe in the
higher rainfall zone; downy mildew and smut are
the most common diseases).
• Striga (not important in some localities, very
important in others).
Third Priority
• Grain quality (acceptability assumes that in the
normal course of selection an approximation to
local standards can be recovered).
Breeding Objectives
• Good emergence and seeding survival.
• Maturity slightly earlier than existing local material
(in both medium and lower rainfall zones,
e.g., the Sahel, western Sudan, and Botswana).
• Yield increases (which generally reflect increased
water-use efficiency and nutrient-use efficiency
when these are in short supply).
• Yield stability (implies tolerance or adaptability
to drought stress).
During breeding several other objectives are
normally selected to an acceptable level, e.g., disease
Table 2. Breeders aggregate prioritizations of all on-farm constraints to pearl millet production in Africa.
Region
Annual
rainfall
(mm) 2
Soil
moisture
Soil
fertility
Priority 1
Diseases
Insects
Striga
Stand
establishment
Weeds
Grain
quality 5
West Africa
Central/East Africa
Southern Africa
300-600 1
600-900 3 3
300-600 1
300-600 1
600-900 2
1
I
2
3
2
2
1
2
3
2
1
1
2
3
2
2
1
3
2 4
3
1 3
1 2
1 2
1 I
I 1
2
2
2
3
3
1. 1 = high priority, 2 = medium priority, 3 = low priority.
2. Approximate classes. In some regions 500 mm is a more realistic dividing line between classes.
3. A third millet zone in West Africa with rainfall above 900 mm was recognized, where improvement to millet is subsidiary to sorghum or
maize. Any work on millet in this area would be priority 3, and change of maturity type is not recommended.
4. Striga of no importance to millet in some areas.
5. In terms of consumer acceptability.
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