Finger millet


Finger millet is an annual herbaceous plant. It is a tetraploid and self-pollinating species probably evolved from its wild relative Eleusine africana.
Finger millet is native to the Ethiopian and Ugandan highlands. It has the ability to withstand cultivation at altitudes over above sea level and a high drought tolerance. The grain is suitable for decades-long storage. It is widely grown as a cereal crop in the arid and semiarid areas in Africa and Asia.

Taxonomy

Finger millet is under the genus Eleusine Gaertn.

Cultivation

History

Finger millet originated in East Africa. It probably evolved from its wild relative Eleusine africana. It was claimed to have been found in an Indian archaeological site dated to 1800 BCE ; however, this was subsequently demonstrated to be incorrectly identified cleaned grains of hulled millets. The earliest record of finger millet comes from an archaeological site in Africa which is thought to date to the 3rd millennium BCE, although it has not been precisely dated.
By 1996, cultivation of finger millet in Africa was declining rapidly because of the large amount of labor it required, with farmers preferring to grow nutritionally inferior but less labor-intensive crops such as maize, sorghum, and cassava. Such a decline was not seen in Asia, however.

Growing regions

Main cultivation areas are parts of eastern and southern Africaparticularly Uganda, Kenya, the Democratic Republic of the Congo, Zimbabwe, Zambia, Malawi, and Tanzaniaand parts of India and Nepal. It is also grown in southern Sudan and "as far south" in Africa as Mozambique.

Climate requirements

Finger millet is a short-day plant with a growing optimum 12 hours' daylight for most varieties. Its main growing area ranges from 20°N to 20°S, but it is found to be grown at 30°N in the Himalaya region. It is generally considered a drought-tolerant crop, but compared with other millets, such as pearl millet and sorghum, it prefers moderate rainfall. The majority of worldwide finger millet farmers grow it rainfed, although yields often can be significantly improved when irrigation is applied. In India, finger millet is a typical rabi crop. Heat tolerance of finger millet is high. For Ugandan finger millet varieties, for instance, the optimal average growth temperature ranges at about 27 °C, while the minimal temperatures should not be lower than 18 °C. Relative to other species, finger millet has a higher tolerance to cool temperatures. It is grown from about above sea level. Hence, it can be cultivated on higher elevations than most tropical crops. Finger millet can grow on various soils, including highly weathered tropical lateritic soils. It thrives in free-draining soils with steady moisture levels. Furthermore, it can tolerate soil salinity up to a certain extent. Its ability to bear waterlogging is limited, so good drainage of the soils and moderate water-holding capacity are optimal. Finger millet can tolerate moderately acidic soils, but also moderately alkaline soils.

Cropping systems

Finger millet monocrops grown under rainfed conditions are most common in drier areas of Eastern Africa. In addition, intercropping with legumes, such as cowpea or pigeon pea, are also quite common in East Africa. Tropical Central Africa supports scattered regions of finger millet intercropping mostly with legumes, but also with cassava, plantain, and vegetables.
Most common finger millet intercropping systems in South India are with legumes, cereals, or brassicas.

Weeds

Weeds are the major biotic stresses for finger millet cultivation. Its seeds are very small, which leads to a relatively slow development in early growing stages. This makes finger millet a weak competitor for light, water, and nutrients compared with weeds. In East and Southern Africa, the closely related species Eleusine indica is a severe weed competitor of finger millet. Especially in early growing stages of the crop and the weed and when broadcast seeding instead of row seeding is applied, the two species are very difficult to distinguish. Besides Eleusine indica, the species Xanthium strumarium, which is animal dispersed and the stolon-owning species Cyperus rotondus and Cynodon dactylon are important finger millet weeds. Measures to control weeds include cultural, physical, and chemical methods. Cultural methods could be sowing in rows instead of broadcast sowing to make distinction between finger millet seedlings and E. indica easier when hand weeding. ICRISAT promotes cover crops and crop rotations to disrupt the growing cycle of the weeds. Physical weed control in financial resource-limited communities growing finger millet are mainly hand weeding or weeding with a hand hoe.

Diseases and pests

Finger millet is generally seen as not very prone to diseases and pests. Nonetheless, finger millet blast, caused by the fungal pathogen Magnaporthe grisea, can locally cause severe damages, especially when untreated. In Uganda, yield losses up to 80% were reported in bad years. The pathogen leads to drying out of leaves, neck rots, and ear rots. These symptoms can drastically impair photosynthesis, translocation of photosynthetic assimilates, and grain filling, so reduce yield and grain quality. Finger millet blast can also infest finger millet weeds such as the closely related E. indica, E. africana, Digitaria spp., Setaria spp., and Doctylocterium spp. Finger millet blast can be controlled with cultural measures, chemical treatments, and the use of resistant varieties. Researchers in Kenya have screened wild relatives of finger millet and landraces for resistance to blast. Cultural measures to control finger millet blast suggested by ICRISAT for Eastern Africa include crop rotations with nonhost crops such as legumes, deep ploughing under of finger millet straw on infected fields, washing of field tools after use to prevent dissemination of the pathogen to uninfected fields, weed control to reduce infections by weed hosts, and avoiding of high plant densities to impede the pathogen dispersal from plant to plant. Chemical measures can be direct spraying of systemic fungicides, such as the active ingredients pyroquilon or seed dressings with fungicides, such as trycyclozole.
Striga, a parasitic weed which occurs naturally in parts of Africa, Asia, and Australia, can severely affect the crop and yield losses in finger millet and other cereals by 20 to 80%. Striga can be controlled with limited success by hand weeding, herbicide application, crop rotations, improved soil fertility, intercropping and biological control. The most economically feasible and environmentally friendly control measure would be to develop and use Striga-resistant cultivars. Striga resistant genes have not been identified yet in cultivated finger millet but could be found in crop wild relatives of finger millet. Another pathogen in finger millet cultivation is the fungus Helminthosporium nodulosum, causing leaf blight. Finger millet pests are bird predators, such as quelea in East Africa.

Insects

The pink stem borer and the finger millet shoot fly are considered as the most relevant insect pests in finger millet cultivation. Measures to control Sesamia inferens are uprooting of infected plants, destroying of stubbles, having a crop rotation, chemical control with insecticides, biological measures such as pheromone traps, or biological pest control with the use of antagonistic organisms.
Other insect pests include:
  • Root feeders
  • *root aphid Tetraneura nigriabdominalis
  • Shoot and stem feeders
  • *Atherigona miliaceae and Atherigona soccata
  • *Sesamia inferens
  • *stem weevil Listronotus bonariensis
  • Leaf feeders
  • *hairy caterpillars, Amsacta albistriga, Amsacta transiens, and Amsacta moorei
  • *cutworms, Agrotis ipsilon
  • *armyworm larvae of Spodoptera exempta, Spodoptera mauritia, and Mythimna separata
  • *leaf-folder Cnaphalocrocis medinalis larvae
  • *skipper Pelopidas mathias larvae
  • *grasshoppers, Chrotogonus hemipterus, Nomadacris septemfasciata, and Locusta migratoria
  • *beetle grubs of Chnootriba similis
  • *thrip, Heliothrips indicus
  • Sucking pests
  • *aphids, Hysteroneura setariae, Metopolophium dirhodum, Rhopalosiphum maidis, and Sitobion miscanthi
  • *mealy bug, Brevennia rehi
  • *leaf hoppers Cicadulina bipunctella and ''Cicadulina chinai''

    Propagation and sowing

Propagation in finger millet farming is done mainly by seeds. In rainfed cropping, four sowing methods are used:
  • Broadcasting: Seeds are directly sown in the field. This is the common method because it is the easiest way and no special machinery is required. The organic weed management with this method is a problem, because it is difficult to distinguish between weed and crop.
  • Line Sowing: Improved sowing compared to broadcasting. Facilitates organic weed management due to better distinction of weed and crop. In this method, spacing of 22 cm to 30 cm between lines and 8 cm to 10 cm within lines should be maintained. The seeds should be sown about 3 cm deep in the soil.
  • Drilling in rows: Seeds are sown directly in the untreated soil by using a direct-seed drill. This method is used in conservation agriculture.
  • Transplanting the seedlings: Raising the seedlings in nursery beds and transplant to the main field. Leveling and watering of beds is required during transplanting. Seedlings with 4 weeks age should be transplanted in the field. For early Rabi and Kharif season, seedlings should be transplanted at 25 cm x 10 cm and for late Kharif season at 30 cm x 10 cm. Planting should be done 3 cm depth in the soil