Pearl millet [Pennisetum glaucum (L.) R. Br.] is the world’s hardiest warm season cereal crop. It can survive even on the poorest soils of the driest, hottest farming regions. A close second to sorghum in scale of production, pearl millet is grown on 32.3 million hectares across the semi-arid tropical and sub-tropical regions of Africa and Asia. Pearl millet is the staple food of more than 90 million people who live in these driest farming areas of the world.
West and Central Africa contains the largest regional area under pearl millet cultivation (15 million hectares). The millet area in this region has increased by more than 90% since 1982 and average yields have risen by 12% (from 800 to 900 kg/ha). Production has increased by about 130% (from 6.1 to 14.1 million tons), most of which has come from increases in cultivated area. Pearl millet improvement research in WCA has emphasized open-pollinated variety (OPV) development due to hybrid seed production constraints. Eight OPVs developed by ICRISAT in partnership with NARS have been released and adopted in nine countries in the region.
In Eastern and Southern Africa, pearl millet is cultivated on about 2 million hectares. Sixteen OPVs have been released in 10 countries in the region, and in a few of them – such as Eritrea, Namibia, Tanzania and Kenya – smallholder adoption has been strong. Nevertheless, as in West and Central Africa, seed production and distribution continues to be a major bottleneck in the spread of improved OPVs.
India boasts the largest national area of cultivation (9.3 million hectares) and of production (8.3 million tons) of pearl millet. The area declined by 19% since the 1980s, yet yields rose by 64% (from about 450 kg/ha to 870 kg/ha in 2005-07), resulting in a net production gain of 28% over the period. The production gain is largely due to the adoption of high-yielding hybrids in areas receiving more than 400 mm of rainfall annually. During the past ten years, 33 hybrids developed both by public and private sector breeding programs, and 13 open-pollinated varieties (OPVs) developed by the public sector have been officially released in India.
In more favorable pearl millet production regions, the private sector is now a dominant force in pearl millet hybrid development and seed delivery. Besides official releases, the private sector also markets what is called ‘truthfully labeled’ hybrid seed, and there are now more truthfully-labeled hybrids under cultivation than the officially released hybrids. A survey conducted in 2006 found that of the more than 82 hybrids marketed by private seed companies and cultivated on about 4 million hectares, at least 60 hybrids were based on ICRISAT-bred male-sterile lines, or on proprietary male-sterile lines developed from ICRISAT-bred materials.
Besides being highly adapted to abiotic stresses such as heat, drought, high levels of soil aluminum saturation and low levels of soil macro- and micronutrients, pearl millet is highly responsive to improved management. For instance, when cultivated as an irrigated summer season crop under intensive management conditions in parts of India, hybrids of 80-85 day duration give grain yields as high as 4-5 t/ha of grain yield.
Pearl millet is highly nutritious. Its grains are high in protein (11-12%) and feature a better amino acid profile for the human diet than maize, sorghum, wheat or rice. They are also high in iron (60-65 ppm in improved varieties and more than 80 ppm iron in landrace germplasm and breeding lines). High levels of dietary fiber, gluten-free and higher content of antioxidants (phenolic compounds) also add to its health value. The stover of pearl millet is also valued by poor smallholder farmers as fodder to sustain their livestock.
Constraints and opportunities
Major constraints to pearl millet production include diseases such as downy mildew and blast, the parasitic weed Striga and abiotic stresses such as drought, soil salinity and high temperatures during seedling establishment and flowering time.
Opportunities for further gains include: Hybrids in Africa; increasing micronutrient content (iron and zinc); increased use for alternative food products, feed and fodder; new genetic and genomic tools leading to biotic and abiotic stress tolerance/resistance and increased nutritional value of grain, stover and green fodder.