Sooty Stripe
Sooty Stripe
Sooty stripe is caused by the fungus Ramulispora
sorghi (Ellis & Everh.) Olive & Lefebvre in Olive
et al. Sorghum spp. are the only known hosts
of the pathogen. R. sorghi overwinters as sclerotia on
leaf debris on and in the soil. When leaf tissue remains in contact
with the soil between crops, sporodochia serve as survival structures.
Sclerotia and sporodochia have been shown to produce conidia in
culture and it is assumed that this is the source of primary inoculum.
Plants may be infected at any stage of growth but older leaves
are infected first. Conidia are produced in older leaf lesions
during periods of warm, wet weather and serve as secondary inoculum.
These spores are wind borne or splashed onto nearby plants.
Symptoms
Initial symptoms appear as small water soaked
spots on leaf blades and sheathes. Spots may be circular to elongate
and reddish-brown to tan in color. Spots enlarge in to elongate
to spindle shaped lesions with straw colored centers. The lesions
have a reddish purple to tan border, depending on host pigmentation.
A wide, bright yellow area surrounds the lesions. These lesions
are large, 5-14 cm long and 1-2 cm wide, and may coalesce causing
extensive leaf necrosis. Lesions take on a grayish cast in their
centers when conidia are formed during favorable environmental
conditions. As the disease progresses, small superficial sclerotia
are formed in the lesions. They can be easily rubbed off and adhere
to human flesh, resembling a sooty residue (kind of dramatic but
I didn't want to plagiarize clings to fingers like soot).
Plant Health Management
Plant residue management.
Destruction of plant
debris has been recommended for control of sooty stripe. This
practice may not be possible to a conservation tillage operation.
A more acceptable means of reducing sorghum crop debris is to
rotate to another crop. Rotation is a very good option since the
fungus has a limited host range.
Plant Population
References
Nyvall, R.F. 1989. Field crop diseases handbook,
2nd. ed. Van Nostrand Reinhold, New York. 817 pp.
Odvody, G.N., and Dunkle, L.D. 1973. Overwintering
capacity of Ramulispora sorghi. Phytopathology 63:1530-1532.
Frederiksen,R.A. ed. 1986. Compendium of sorghum
diseases. American Phytopathological Society, St. Paul, MN. 82
pp.
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Caveat
This description is presented for information only and no endorsement is intended for
products listed, nor criticism meant for products not mentioned. Always consult the product
label before purchasing and using any pesticide.
Material contained on the Links from the page are the responsibility of the linked page's author(s).
This page was drafted by:
Jane Christensen,
Department of Plant Pathology, University of Nebraska-Lincoln
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This page is authored and maintained by:
Dr. J.E. Partridge, Department of Plant Pathology, University of Nebraska-Lincoln
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Copyright (C) 2003 J.E. Partridge, University of Nebraska-Lincoln. All Rights Reserved.
