Current Status Of Hybrid Development
- The strengthening of hybrid research in 1989 under the special project
on Promotion of Research and Development of Hybrids in Selected Crops
has taken care of many important issues like early maturing kharif
hybrids with emphasis on their suitability to tribal areas
- Cold-tolerant full season hybrids for rabi season for north-west
- Hybrids for rabi cultivation for northeast plains,
- Full season hybrids for both kharif and rabi for peninsular
- Development of homozygous inbred lines through haploidy.
- The gaps in seed technology research including production of nucleus
and breeder seed, and on-farm research and testing on of hybrids, is
also being addressed to.
- A coordinated emphasis on these aspects during the last four years
has yielded encouraging results.
- Three-way hybrids, like Trishulata, DHM 105, DHM 107 and DHM 109 have
already been released for commercial cultivation during 1991-93.
- A single cross hybrid, JH 1121, with about 35 per cent higher grain
yield, low ear placement and resistance to post-flowering stalk rot,
is found promising for kharif season in the Indo-gangetic plain.
- The exercise in development of inbreds for both kharif and
rabi seasons has led to identification of about 25 promising
advance stage inbreds with yield potential from 13.3 to 44.0 q/ha. Out
of these, about 15 inbreds have yield potential of over 30.0 q/ha.
- On-farm demonstrations in Andhra Pradesh with DHM 105 and DHM 105
and DHM 107 conducted during kharif 1993 under rainfed situation gave
grains yields upto 77 and 69 q/ha respectively, with no pest and disease
hazards in both the cases.
- Under protected irrigation, DHM 105, DHM 107 and Trishulata recorded
44-81 percent yield increase over check varieties during kharif 1993
in Andhra Pradesh.
Single Cross Hybrids Programme A thrust area for future
- Maize breeding has gone through many phases and the importance of
single cross hybrids has been re-discovered. Nowadays, the emphasis
has swung to the development of vigorous inbred lines that have good
performance per se and in cross combinations.
- Single cross breeding is also much more effective in terms of time
and cost involved.
- Some short cuts can be made in single cross breeding and many of them
can be easily integrated with population improvement.
- The practical superiority of single cross breeding in terms of higher
gain has been demonstrated in various countries in which maize breeding
- Seed production can also be better-planned and easily handled in single
crosses in comparison to the multi-parent crosses.
- Adoption of single cross hybrid programme on a large scale in India
is bound to accelerate the productivity trend. New high yielding inbreds
developed under the programme will greatly help in this direction.
Collaborative Research Projects
- Since 1989, six ICAR-CIMMYT collaborative projects in various facets
of maize improvement have been in operation. These are :
- Genetic resource exploration, cataloguing and conservation.
- Evaluation of inbred lines for more productive hybrids.
- Cultivation of maize under excess soil moisture and drought conditions.
- Economic studies on maize development.
- Genetic improvement of gene pools for Turcicum leaf blight and sorghum
downy mildew resistance.
- Multiple insect resistance and development of borer resistant maize
germplasm in south and east Asia.
- Hopefully, in the years to come, some good materials possessing tolerance
to important biotic and abiotic stresses would be on the ground.
- Under these projects, stress is contemplated to be laid on banded
leaf sheath blight and post flowering stalk rot, which are of economic
importance not only in India but also in other Asian countries.
Prospects for maize development in India
- The maize prospects have to be looked from a wider angle and also
in cognisance other crops in India as well as status of maize in the
- Presently India is far behind China, where national average productivity
is about 4.5 t/ha. But China is endowed with large maize areas in temperature
climate. Which is a fortunate situations compared to India.
- But India is definitely in a better position compared to other countries
in the region.
- Quality seed production of new improved cultivars and their popularization
is still a grey area in India.
- Since many hybrids with realizable yield potential of around 5 t/ha
are already available, the country can easily hope for achieving at
least 3.5 t/ha productivity (which is twice the present) in the next
5 to 10 years provided basic issued related with hybrid seed production
and popularization could be attend to.
- Maize improvement programme in the country is particularly weak for
drought/water logging affected areas in the states of Rajasthan, Gujarat,
Madhya Pradesh and Uttar Pradesh, which occupy 55 percent of the total
maize area in the country.
- A few options in terms of new hybrids and a number of composites for
these areas are available and greater emphasis on transfer of improved
technologies is considered essential.
- This alone can substantially increase production/productivity form
this major belt as even private sector is not expected to provide greater
thrust for such difficult conditions for obvious reasons.
- For other areas in both north and south India, an intensive maize
popularization programme duly supported by appropriate incentives is
equally essential for large gains in production.
- Obviously, progress in development of single cross hybrids would yield
quick results, but a greater emphasis on basic and strategic researches
would only provide the needed support for this improvement activity.
- The endeavor should be to have a long term perspective planning for
attaining the highest genetic potential possible.
- For this purpose, there is need to identify gene(s) which will increase
the genetic efficiency of a new maize plant in utilizing nutrients,
especially nitrogen, and their efficient partitioning in the grain,
increasing the genetic potential for response to high plant density,
and increasing the desirable chemical component of maize to improve
its value in various industrial uses.
- For winter maize, the efforts for judicious and systematic introgression
of temperature germplasm in tropical maize has to be strengthened to
significantly increase rabi maize area.
- Regarding breeding for early maturity, an important objective, there
is need to understand the physiological and genetic basis of earliness
and to investigate the ways and means to break the linkage, or at least
reduce the adverse effects of earliness on grain yield.
- There is also 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 for making possible the adoption of maize-based
- Serious attention is also required to better understand abiotic stresses
and the integrated stress management systems to increase maize productivity.
- Any long term strategy will not be complete unless the area of cultivar
development for specialized uses is given specific attention to cater
the industrial requirements.
- Cultivars suitable for industrial purposes have tremendous significance
in not only boosting the yields and improving the economics for farmers
and corn million industry, but also for earning valuable foreign exchange.
- Some important areas are high oil content (upto 7%) with maximum concentration
of oil in germ portion for easy recoverability, waxy maize (high amylopectin)
for starch industry and baby corn for domestic consumption and export.