8 papers were presented in the Agronomy Session|.One was a general critique of sustainability/agronomy issues relevant in maize production.|.One was a general review of issues relevant to "winter" maize production in rotation with rice. .One was a review of research in sloping lands networking in SE Asia by msRAM|.The rest presented general descriptive agronomic issues facing maize production in the SE|Asian countries.|In general, the value of hybrids was strongly recognized by speakers, in particular, early- maturing and stress tolerant materials adapted to rotation systems with rice. General recommendations for nutrient inputs were high, over 100 kg N/ha and over 100 kg P/ha as TSP. The need for K + fertilization was recognized given the intensive land-use patterns which typify the region.|Specific issues:|1. The paper on "alley cropping" pointed out the trade-off concerns between costs of establishment of hedgerow crops and the long-run returns to farmers. Obviously, hedgerow crops do reduce rates of soil erosion and runoff, but benefits to maize productivity only accrue in the long-run as soil fertility increases because of fodder green manure additions from the hedgecrop cuttings.|2. Kraokaw's paper pointed out the homoestatic equilibrium in maize, where drought stress also affects N and P nutrition.|3. The paper on nutrient management for maize production in Indonesia pointed out the high input use for maize production. Low production systems used 0-129 kg N/ha whereas high production systems used doses of 225 -400 kg N/ha. Also, P requirements were equally high, with more than 100 kg TSP/ha. Regrettably, most of the data shown was somewhat old, from 10 -15 years ago.|4. The paper on maize cultivation for paddy rice fields in Thailand highlighted the increased emphasis on such system. An interesting point was the high optimum density for production, i.e., near 80,000 pl/ha.|5. The paper on maize production for Nepal hill slopes emphasized the need for an integrated approach in maize breeding, since maize is normally grown as intercrop.|6. The paper on winter maize for Vietnam highlighted the increased importance of such rotation. Incorporating maize increased total system productivity, and the paper recognized the need for early maturing hybrids and tolerance to waterlogging conditions.|Baldos's paper summarized the research needs in winter maize production. It pointed out the need for collaborative research on tillage requirements and crop establishment, nutrient input use efficiency, crop protection and weed control, water-use-efficiency and irrigation management and cultivar development of early-maturing stress tolerant hybrids.

English

0208|AGRIS 0201|AL-Maize Program|R01PROCE

Juan Carlos Mendieta

CIMMYT Staff Publications Collection