Symptoms: Seedlings can be stunted and chlorotic. Leaf lesions measure approximately 5 × 2.5 mm. Lesions are generally parallel sided with dark brown margins and light brown necrotic centers. Coalesced lesions usually result in tattered leaf tissue. Leaf margins are frequently necrotic. Pycnidia form in necrotic tissue.
Pathogen and disease characteristics: Pycnidia average 75.8 µm in diameter. Conidia are hyaline, single celled, biguttulate, elliptical, and approximately 6.2 × 2.8 µm.
Host range: Pearl millet, possibly napiergrass.
Geographic distribution: Chad, Niger, Senegal (Spegazzini 1914), continental United States. A Phyllosticta sp. was reported on napiergrass in Hawaii (Raabe et al. 1981). A Phoma sp. was isolated from seed in India (Mathur et al. 1973) and possibly Tanzania (Mbwaga et al. 1993).
Nomenclature discrepancies:Synonyms or similar pathogens: Reference to Phoma spp. on seed (Mathur et al. 1973) and Phoma sorghina (Sacc.) Boerema on foliage (Mbwaga et al. 1993) may be P. penicillariae.
Seed transmission: Can be isolated from seed (Wilson et al. 1993). Seedling infection from contaminated seed has not been demonstrated.
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Original posting: June 5, 1999.