STUDIES ON ANTHRACNOSE ON SORGHUM AMD MAIZE CAUSED BY COLLETOTRICHUM GRAMINICOLA (Ces.) Wils. AND ON A MIDRIB SPOT ON MILLET
STUDIES ON ANTHRACNOSE ON SORGHUM AMD MAIZE CAUSED BY COLLETOTRICHUM GRAMINICOLA (Ces.) Wils. AND ON A MIDRIB SPOT ON MILLET
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Date
1987-12
Authors
ABDULLAHI, BINDAWA ALIYU
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Abstract
Field observations on the anthracnose on sorghum and maize
in Nigeria had shown variations in the type of symptoms and the
location of the symptoms. Confusion existed as to whether a
midrib lesion on millet in Nigeria is caused by anthracnose.
Because it was not known whether these various symptoms were
caused by the one and same fungus, Colletotrichum graminicola,
the causal agent of cereals anthracnose, this project was undertaken
to clear the doubts or confusions.
Isolates of the pathogen(s) were obtained from sorghum,
maize and millet showing the typical various symptoms observed
in the field. To determine extent of similarities and/or
differences
among the isolates morphological features of conidia
and setae were studied with the aid of microscopes,. Cultural
characteristics on artificial growth media were also studied.
Pathogenicity tests of the different isolates using different crop
cultivars under glass house conditions were conducted.
Colletotrichum graminicola was readily isolated from a
maize and sorghum leaf specimens and never at all from the millet
leaf specimens which yielded mainly Curvularia eragrostidis and
Phoma sorghina. Statistical analyses of the morphological
parameters of the conidia and setae of the different isolates
did not show significant differences among the isolates.
Various cultural forms were detected but none being specific
to a particular isolate.
Pathogenicity tests proved that the millet midrib lesion,
a hitherto undescribed millet disease, is not caused by
Colletotrichum graminicola but by Curvularia eragrostidis and
Phoma sorghina. Two formae speciales were identified from the
isolates of C. graminicola; one form specializing on maize and
another specializing on sorghum. Two pathotypes were separated,
based on symptoms produced on sorghum, from the form that
specialises on sorghum.
The work demonstrated that the same fungus species,
Colletotrichum graminicola, is responsible for anthracnose on
maize and sorghum in Nigeria.
Description
A thesis submitted to the Postgraduate School,
Ahmadu Bello University, Zaria, Nigeria. in partial
fulfillment of the requirements for the degree
of Master of Science in Crop Protection
DEPARTMENT OF CROP PROTECTION
FACULTY OF AGRICULTURE
AHMADU BELLO UNIVERSITY
ZARIA, NIGERIA
DECEMBER, 1987
Keywords
STUDIES,, ANTHRACNOSE,, SORGHUM,, MAIZE,, COLLETOTRICHUM,, GRAMINICOLA,, (Ces.) Wils., MIDRIB,, SPOT,, MILLET.