Crop Genebank Knowledge Base

Genebank management strategies & principles

Safe transfer of germplasm

Millets

Finger millet guidelines

Fungi

Fungi - finger millet

Contributors to this page: ICRISAT, Patancheru, India (RP Thakur, AG Girish, VP Rao).

Leaf spot; Black kernel

Scientific name

Cochliobolus lunatus RR Nelson & Haasis.

Other scientific names

Acrothecium lunatum, Curvularia lunata, Curvularia lunata var. lunata, Pseudocochliobolus lunatus.

Importance

High

Significance

Less important in finger millet compared to sorghum.

Symptoms

Leaf spots occur on leaves as small, diffuse, and reddish with grayish centers (Shaw 1921).

Hosts

Poaceae (cereals), Oryza sativa (rice), Pennisetum glaucum (pearl millet), Sorghum bicolor (common sorghum), Zea mays (maize), Eleusine coracana (finger millet), Setaria italica (foxtail millet) and several leguminaceous crops.

Geographic distribution

The pathogen is widely distributed in Europe, Asia and Africa.

Biology and transmission

Colonies are effuse, brown, blackish brown or black, hairy or velvety. Conidiophores are solitary or in small groups, simple or branched, straight or flexuous, sometimes geniculate, pale to dark brown, septate, up to 650 µm long, 5-9 µm wide, often swollen at the base to 10-15 µm. Conidia are acropleurogenous, 3-septate, almost always curved at the third cell from the base, which is usually longer and often darker than the others. Cells at each end are sub hyaline or pale brown while intermediate cells are mid to dark brown, smooth, 20-32 ´ 9-15 µm (Anil Kumar et al. 2003).

Detection/indexing methods at ICRISAT

Pre-export field inspection and blotter test.

Treatment/control

Not known.

Procedures followed in case of positive test at ICRISAT

Incineration of the infected plants/seed samples, and rejection of the seed samples.

References and further reading

Anil Kumar TB, Mantur SG, Madhukeshwara SS. 2003. Diseases of finger millet. All India Coordinated Small Millets Improvement Project, Indian Council of Agricultural Research, University of Agricultural Sciences, GKVK, Bangalore, Karnataka, India. 126pp.

Shaw FJF. 1921. Report of the Imperial Mycologist. Scient. Reports Agric. Res. Inst, Pusa, 1920-21, 34-40pp.


Leaf spot (Cochliobolus lunatus) of finger millet: (A)leaf spots; (B)mycelial growth on seed; (C)conidiophores with conidia and (D)conidia (photos: ICRISAT).