Proceedings of the Fifth Asian Regional Maize Workshop - Search ...

excess soil moisture and drought conditions iV) economic studies on maize development, v)
genetic improvement of gene pools for resistance to turcicum leaf blight and sorghum downy
mildew, vi) multiple insect resistance and development of borer resistant maize genmplasm in
south and East Asia. The progress made so far under these projects has been more than satisfactory.
Hopefully in the years to come some good materials possessing tolerance to important
biotic and abiotic stresses will come out. CIMMYT's Asian Regional Maize Program has almost
agreed for two more new projects in the field of maize pathology. under these projects, if
finalized, stress would be laid on banded leaf and sheath blight and post flowering stalk rots
which are of economic importance not only in India but also in other Asian countries.
POOOOCTI~ POTENTIAL ~ FlJTlflE 1lftJSTS.
The production potential of maize should be looked at from a wide perspective in comparison
to the other crops in a country and maize in the neighboring countries. Since a higher
genetic potential is not easily attained due to stress environments and difficulties in obtaining
an ideal genotype, there is need to identify gene(s) which will increase the genetic performance
of a new maize plant more efficient in utilizing nutrients, specially nitrogen, and efficiently
partitioning it in the grain; increase the genetic potential for response to high plant density;
and increase the desirable chemical component of maize to increase its value in various industrial
uses. Also for winter maize, the efforts for judicious and systematic introgression of
temperate germplasm into tropical maize must be strengthened.
Breeding for early maturity is one of our important objectives. Therefore, there is a
need to understand the physiological and genetic basis of earliness and to investigate the
procedures to break the linkage, or at least reduce the adverse effects of earliness on grain
yield. There is need to take up studies on economic threshold injury by pests and diseases,
durable resistance, and integrated pest management for developing appropriate technologies with
judicious use of chemical fertilizers and pesticides, and in the possibility of adopting maizebased
cropping systems. More serious attention may be paid to better understanding various
abiotic stresses and the integrated stress management systems to increase the productivity of
maize.
Questions to the author:
FROM: M. saleem
Q 1) Do you think tolerance to inbreeding depression improves combining ability in maize
inbred lines or facilitates seed production?
2) Indian Maize Program has released a number of improved varieties and hybrids. What
is the yield increase per hectare from these releases?
A Tolerance to inbreeding depression helps to breed seed parent viable enough to go for
single cross hybrid seed production without altering the combining ability.
FROM: C. De Leon
Q What is the demand of extra early maize germplasm. for what regions in India, and what
are you doing to breed for this germplasm?
A The extra early maize germplasm is required for "Diara" land in U.P. and Bihar and tribal
areas of Gujarat, Rajasthan and Madya Pradesh. This is about 10% of area of total maize growing
area in the country.
FROM C. Chutkaew
Q 1) You have done an excellent job on composites and Hybrids. How much of the yield
increase occured in the last one or two decades as compared to the total time spent on maize
improvement?
2) How much of investment you put on Biotechnology in the past and how more you expect
to put on it in the future?
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