False Mildew
Beniowskia sphaeroidea (Kalchbr. & Cke.) Mason
Symptoms: Small, white, cushion-shaped sporodochia,
circular to elongate (1.5 mm long), are formed singly and in clusters
on leaves. Infected leaves become chlorotic and necrotic from
the point of infection to the apex of the leaf.
Pathogen and disease characteristics: A network of aerial
hyphae culminate in spirally twisted, corkscrew apices at the
periphery of the sporodochium. Hyphae are hyaline to very light
tan. Conidia are hyaline and spherical, averaging 10 µm
in diameter. Spores may have imperceptible roughenings and may
be borne in short chains.
Host range: Andropogon marginatus Steud., Chaetochloa
poiretiana Hitchc. [=Setaria poiretiana (Schult.) Kuntz.],
Panicum palmifolium Willd. (=Setaria palmifolia
(Willd.) Stapf.), Pennisetum japonicum Trin., P. nepalense
Spreng., P. purpureum Schumach, Setaria aurea Hochst.,
S. geniculata, S. verticillata (L.) Beauv., and
Sorghum vulgare Pers.
Geographic distribution: On pearl millet: Malawi (Wiehe 1953), Tanzania (Mbwaga
et al. 1993), Zimbabwe (Mtisi and
de Milliano 1991). On other hosts: Japan, Java, Malawi, South
Africa, Sudan, Trinidad, Uganda, United States, Zimbabwe.
Nomenclature discrepancies: Synonyms or similar pathogens:
Albugo sp., Beniowskia penniseti Wakefield, B.
sphaeroideum Kalchbr. & Cke., Ceratium sphaeroideum
Kalchbr. & Cke.
Seed transmission: Not known to be transmitted by seed.
Primary citations: Taber et
al. 1978, Brown and Hanlin 1982.
United States
Department of Agriculture
Agricultural
Research Service
The material on this page is in the public
domain.
Original posting: June 5, 1999.
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