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

Table 1. Public sector maize releases in developing countries, 1966-1990 (%) ~
OPVs Hybrids Others E! Total
----------------
Region Conv. Nonconv.
Sub-Saharan Africa 59 25 15 1 100 (295)
West Asia and North Africa 14 68 18 0 100 ( 28)
South, East, and Southeast Asia 62 16 8 14 100 (180)
Latin America 61 32 6 1 100 (349)
All developing countries 59 27 10 4 100 (852)
(503) (230) (85) (34)
Source: CIMMYT varietal database.
~ Values in parentheses are total number of releases in each category.
~ Includes synthetic varieties and other materials not classified under the previous
three categories.
slightly at least in three regions (except WANA) during the 70s and registered an increase again
during the 80s. This variation in variety vs. hybrid releases during different decades perhaps
can be attributed to the following reasons:
1) In 1960s, the public sector maize breeders placed greater emphasis on maize hybrids than
OPVs. This was perhaps triggered by the success story of hybrid maize in the US and Europe.
2) The decline in hybrid releases during the 1970s is reflected by the greater proportion of
OPVs released. This could be attributed to several reasons including a) the scarcity of
germplasm available for hybrid work, b) difficulty and disappointment in obtaining inbred
parents with acceptable yield potential, c) lack of clear-cut superiority of maize hybrids over
OPVs, d) occasionally hybrids were too late and did not fit into farmer's cropping systems, e)
problems in seed production and distribution, f) insufficient public and private seed enterprises,
and g) greater emphasis on population improvement and composite breeding because OPVs
were less expensive to develop and seed was easier to produce.
The 1980s witnessed a shift back toward an increase in emphasis on hybrids. This change
could be the result of: 1) more resources in the national programs to support more sophisticated
hybrid development work, 2) availability of improved germplasm developed by the national programs
themselves and by CIMMYT and IITA, 3) improved and more convincing performance of hybrids over
OPVs in some countries, 4) increasing presence of private companies involved in hybrid breeding,
and 5) initiation of hybrid research related activities at CIMMYT. The renewed interest in
hybrids is however, true for South, East and Southeast Asia and WANA. In Sub-Saharan Africa, the
national programs have consistently released more OPVs than hybrids because of the involvement of
only a few programs in hybrid research. The national programs in Latin America, in general, have
released fewer hybrids during each of the three decades. Declining support by the Rockefeller
and Ford Foundations and the increasing involvement of private seed companies in the region may
have led national programs to deliberately de-emphasize hybrid research.
It may also be pointed out that improved maize germplasm made its greatest impact in the
lowland tropical areas since two-thirds of the improved germplasm released were for these
ecologies. In Latin America, 94.4% of the improved maize germplasm was for l,owland tropical
ecologies compared with 72.8% in Southeast Asia and 49.2% in Sub-Saharan Africa.
III. Growing interest in maize hybrids by the national programs
In the past decade, the national maize programs have demonstrated an increasing interest
in hybrid work. Though the proportion of hybrid releases in relation to total varietal releases
does not always reflect this change in some regions, it should be remembered that unlike OPVs,
several years of hybrid breeding and testing work is required before a hybrid may actually
qualify for a release. Also, depending upon the type of hybrid to be released, this time frame
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