Management and breeding approaches to alleviate the effect of drought on maize in Vietnam
1997
Ngo Huu Tinh
Vietnam is traditionally a rice-eating country and favorable irrigated land is reserved for rice production. Maize is planted mostly as an upland crop where drought is more common. Average rainfall is 1,500 - 2,000 mm per year but rainfall distribution is irregular in some regions and seasons, leading to drought. The National Maize Research Institute's research has led to the adoption of new management practices and varieties to alleviate the effect of drought on maize. Widely adapted early-maturing maize varieties are used to escape periods of low moisture availability during critical development stages. Early- maturing open-pollinated varieties (OPVs) 'TSB-2', 'MSB-49', and 'MSB-49B' are widely grown, and new OPVs are being developed. intercropping maize with legumes (soybean, groundnut and mungbean) appears to reduce evaporation from the soil surface, increases profits and improves soil condition and water holding capacity. Transplanting winter maize takes advantage of adequate temperatures, humidity and sunlight during the early stages of plant development and helps avoid drought and low temperatures that are common at the end of the rainy season. Crop duration in the field is being reduced by harvesting the maize for fresh consumption as glutinous, sweet, or baby corn, thereby avoiding late season drought. Another focus is the development of short-stature erect-leaf hybrids for planting at high densities and in intercropping systems. A few such hybrids-'LVN-20', 'EE-1', and 'HTD-5'-have been widely disseminated. Prolific maize is being selected to reduce drought-induced barrenness, and is being used in an effort to develop more prolific baby corn hybrids. 'NN-1' is one such promising hybrid.
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