Sorghum Diseases in India

Sorghum Ergot
R. Bandyopadhyay 1
Abstract
Ergot, caused by Sphacelia Sorghi is an increasingly important disease of sorghum in eastern and
southern Africa as well as Asia. The disease reaches economically significant levels particularly in
sterile sorghums. Currently there are no distinct sources of host resistance, and other methods for
control in areas where the pathogen is endemic, have not been established. Management of ergot in
sorghum remains a major concern for the improvement of sorghum in much of the sorghumgrowing
region of Africa and Asia.
Ergot is known to occur in Botswana, Ethiopia, Ghana, Kenya, Mozambique, Nigeria, Rwanda,
Senegal, South Africa, Sudan, Tanzania, Uganda, Zambia, and Zimbabwe in Africa; and India,
Japan, Myanmar, the Philippines, Sri Lanka, Thailand, and Yemen Arabic Republic in Asia. It has
not been reported in the Americas, Australia, or Europe.
Information of the disease is reviewed, gaps in knowledge indicated, and areas for future
research suggested.
Introduction
Ergot causes grain yield reduction because infected
spikelets do not produce grain. Honeydew
exuded from infected florets can smear
healthy grains; saprophytes grow and reduce
the quality of grains. Published data on crop loss
are not available.
Ergot is a serious limiting factor in production
of hybrid seed, particularly if seed-set in
male-sterile lines is delayed due to lack of viable
pollen caused by nonsynchronous flowering of
male steriles and restorers. Moreover, environmental
conditions favorable for disease development
are not congenial for rapid seed-set, thus
making spikelets more vulnerable to ergot attack.
In India, where hybrid seeds are in great
demand but in short supply, the damage is twofold:
directly through loss in seed yield, and indirectly
through rejection of ergot-sclerotia contaminated
seed lots due to poor quality If the
disease strikes in new areas where farmers are
totally dependent on hybrids, the effect would
be devastating. Ergot can also cause widespread
damage of male-fertile cultivars in farmers'
fields when environmental conditions favorable
to the pathogen occur at flowering (Molefe 1975;
Kukadia et al.1982).
Dihydroergosine is the major alkaloid in sorghum
ergot sclerotia and honeydew, but four
clavine alkaloids are also produced (Mantle
1968). The alkaloid spectrum in sclerotia collected
from diverse sources may be uniform, but
their concentrations differ (Molefe 1975). From
rat-feeding trials, Mantle (1968) concluded that
sorghum ergot sclerotia was the least toxic, if
toxic at all, of all alkaloid-containing ergots.
Symptoms
The earliest symptom of the disease may be seen
on the ovary if the glumes are opened 3-5 days
after infection. The infected ovary appears dull
1. Plant Pathologist, Cereals Program, ICRISAT Center, Patancheru, Andhra Pradesh 502 324, India.
Bandyopadhyay, R. 1992. Sorghum ergot. Pages 235-244 in Sorghum and millets diseases: a second world review, (de Milliano,
W.A.J., Frederiksen, R.A., and Bengston, G.D., eds). Patancheru, A.P. 502 324, India: International Crops Research Institute for the
Semi-Arid Tropics. (CP 740).
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