Pearl Millet Diseases
Fungal Diseases

Myrothecium Leaf Spot

Myrothecium roridum Tode ex Fr

Symptoms: Water-soaked oval spots on leaves rapidly increase in size and turn dirty brown. Necrotic tissue can crack and develop holes.

Pathogen and disease characteristics: In culture, sporodochia are sessile, up to 1.5 mm in diameter, and often confluent. Spore masses are viscous and green at first, later becoming hard and black. No setae in sporodochia. Conidia are cylindrical with rounded ends, colorless to pale olive green to black in mass, and mostly 6-8 × 1.5-2.5 µm (Ellis 1971, Barron 1968).

Host range: Pearl millet guar [Cyamopsis tetragonoloba (L.) Taub], moth (Phaseolus acontifolius Jacq.), black gram (Phaseolus mungo L.), green gram [Vigna radiata (L.) Wilkzee], pigeonpea [Cajanus cajan (L.) Millsp.], cowpea (Vigna sinensis Endl.), pea (Pisum sativum L.), soybean (Glycine max Merr.), peanut (Arachis hypogaea L.), okra [Abelmoschus esculantum (L.) Moench.], cotton (Gossypium hirsutum L. and Gossypium arboreum L.), potato (Solanum tuberosum L.), tomato (Lycopersicum esculentum Mill), eggplant (Solanum melongena L.), wheat (Triticum aestivum L.), maize (Zea mays L.) (Gaikwad 1988).

Geographic distribution: India. A Myrothecium species has been isolated from pearl millet stalks in the United States, but the species appears to be M. verracaria (J.P. Wilson, personal observation).

Nomenclature discrepancies: None.

Seed transmission: Can be isolated from seed (Girisham et al. 1985).

Primary citations: Ellis 1971, Barron 1968.

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United States Department of Agriculture
Agricultural Research Service

The material on this page is in the public domain.

Original posting: June 5, 1999.