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

winter season.
Formerly, farmers only obtained 8 to 9 t/ha of rice when only planting two rice crops each
year. Now, there is an additional winter maize crop per year, and they can get 12-13 t of food
per year.
At present, we are establishing models to produce 20 t/ha/yr of food in tenns of paddy.
2. Tectvlique of IIl.Iltiplying the maize crop on lM'ltilled wetland after floating rice crop in the
Mekong river delta:
In the Mekong river delta of South Vietnam there are about 70-100,000 ha of arable land.
Every year, deep water rice is sown in May during the early rainy season, and plants grow at a
water level of 1.5 to 2.5 m. Deep water rice is harvested in December. After harvest of this
rice crop, an early maturing maize is planted in January on untilled wetland and harvested in
Apri 1.
This model was first developed in An Giang and Hau Giang provinces, and it has spread to
thousands of hectares. In these conditions average yields of OPVs are 3.0-3.5 t/ha, wutg a
maximum of 5 t/ha by skilled farmers. The crop rotation is as follows:
Jun.
Maize
Apri 1
+
May
Deep water rice
Dec.
3. TecMique of increasing yields by using early llI8turing drought tolerant .ize varieties in
land previously planted with only one rice crop:
In the six northern provinces of Vietnam, there are about 140,000 ha of arable land.
Formerly, only one summer-autumn rice crop was planted in June during the early rainy season, and
harvested in November. After that planting the land was left fallow until the rainy season in
the following year.
This model increases maize hectarage, i.e. after harvesting rice in November, land is
ploughed to keep moisture during winter. Then, maize is directly sown in February and harvested
in early June. The crop rotation is as follows:
Spring maize
Feb.
Jun.
+
Jun.
Autumn-summer rice
Nov.
In this system, the varieties TSB-2, MSB-49 , and