Sorghum Diseases in India

3. Determine the influence of host, pathogen,
and environment on symptom expression, including
recovery resistance.
4. Study the genetics of host resistance and
pathogen virulence, and the dynamics of virulence
in pathogen populations.
5. Quantify the relationship between DM incidence
and crop yield loss.
6. Strengthen a multilocational network of reliable
resistance screening, especially in Africa.
7. Develop reliable and efficient screening techniques
that are easily integrated with breeding
programs.
8. Increased interaction of breeders and pathologists
in identifying resistance and its use
in breeding.
9. Investigate control measures that complement
genetic resistance.
Foliar Diseases of Pearl Millet
1. Develop reliable rust-resistance screening
procedures; classify taxonomic identities of
reported rust pathogens.
2. Develop techniques for accurately identifying
viral, fungal, and bacterial causal agents on
plants in the field. Publish and distribute bulletins,
handbooks, or compendia listing foliar
diseases and showing photographs of diseased
plants in accurate color.
3. Document epidemics of foliar diseases involving
loss of millet yields.
4. Ascertain the prevalence of false mildew of
pearl millet in southern and eastern Africa.
5. Determine the cause of yellow blotch of millet,
maize, and sorghums.
6. Determine the incidence and severity of bacterial
leaf stripe and bacterial leaf streak of
millet in western Africa. The potential role of
seed in dissemination of the bacterial causal
agents of these diseases needs clarification.
Utilization of Disease Resistance for
Sorghum and Millets
1. Collaboration of breeders and pathologists in
developing screening techniques and identifying
sources of resistance (especially stable
types), particularly for developing disease-resistant
cultivars.
2. Determine the genetic basis for resistance.
Identify sources of resistance continuously so
that the number of different genes for resistance
may be increased.
3. Where there is danger of breakdown, avoid
or use vertical resistance only with extreme
caution in breeding programs.
4. Use a level of disease resistance consistent
with achieving adequate control; using a level
higher than necessary is resource-consuming
and may exert unnecessary selection pressure
on the pathogen.
Priority Diseases
Committees of all delegates attempted to rank
the importance of sorghum and millet diseases
by geographic area: (i) Africa, (ii) Asia, and (iii)
Europe and the the Americas.
Group 1:
Priority diseases in sorghum and infrastructure
for Research in African Countries
Chairperson: L.K. Mughogho
Rapporteurs: M.D.Thomas
Y. Kebede
After several minutes of discussion on appropriate
criteria that would identify the priority
diseases, seven were selected and ranked in the
order of importance. Seventeen diseases were
rated, with 1 designating low priority; 2, intermediate
priority; and 3, high priority. A fourth
(non-numerical) category, indicated by the letter
A, signified a lack of knowledge for a particular
criterium.
The criteria were assigned numerical ranking;
the least value signifying lesser importance
and the highest value signifying greater importance.
The 17 diseases were as follows:
1. Grain mold
2. Downy mildew
3. Charcoal rot
4. Leaf blight
5. Rust
6. Gray leaf spot
7. Anthracnose
8. Sooty stripe
9. Zonate leaf spot
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