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

BREEDIt-G COON HYBRIDS F~ VII:rNAM
P. Padmakar Reddy 11
Abstract
Corn is grown in Vietnam in approximately 500,000 ha. The country presents 7 different
ecological zones and corn is grown in most of these zones. However, there are three broad
distinct areas comprising of North, South and the Central highlands. In the North, maize is
grown in approximately 300,000 ha. The area comprising both South the Central highlands accounts
for the remaining 200,000 ha.
Vietnam's corn growing area is between 8-23 0 N lat. Based on latitude and altitude it
appears to be a tropical and subtropical environment. However, close observation of corn growing
conditions in the North makes it clear that subtropical germplasm from other parts of the globe
may not adapt directly. High wind velocity, typhoons, Viruses, maydis and turcicum leaf blights,
waterlogging, low sunshine and continuous rainfall make the northern corn growing area "harsh
subtropical" cl imate for corn. Central and South Vietnam have some similarities with other
tropical - subtropical corn growing areas of the world.
Bioseed in Vietnam has screened 600 inbred lines, 268 single crosses, 300 double crosses,
60 populations and 10,000 segregating materials. We have introduced three hybrids which are
adapted to the local conditions. Hybrids in the pipeline, are based on lines developed in
Vietnam and are expected to perform better than current hybrids being marketed.
Vietnam is predominantly an agricultural country, and most of the nation's economy depends
on the agricultural sector. Maize is the second most important cereal crop after rice and it is
mainly used as a livestock feed, especially in piggeries and poultry industries. It is also
used as a human food in the North mountainous regions and Central highlands.
Vietnam's entire area lies between 8 0 to 23 0 N lat. and corn is grown in all parts of the
country. The corn growing environments in this country are both tropical and subtropical.
However, the country's corn growing areas have been identified in 7 agroclimatic zones (Fig. 1).
Among these, Zone 3 (Red river delta), Zone 5 (Central highlands) and Zone 7 (South eastern Nambo
and Mekong delta) have the most potential for intensive corn cultivation and productivity.
Maize area in 1992 was approximately 457,000 ha (Table 1) with national average yield at
1.7 t/ha. The corn productivity of Vietnam is one of the lowest in the world, mostly because
large areas are still planted with unimproved local varieties and due to the knowledge of hybrids
among the farmers. Corn hybrids were introduced in this country only in 1989-90. It is presumed
that by the end of 1993, hybrids will be planted in