滇中高原高产玉米的产量形成

分析了滇中高产玉米的产量形成特点及其与高原气候生态环境的关系。

YIELD FORMATION OF HIGH YIELD CORN IN THE MIDDLE YUNNAN PLATEAU

This paper analyses the characteristics of the yield formation of high yield corn and the relationship between the corn and the climatic ecological environment in the Middle Yunnan Plateau. The yield composition of the high-yielding fields with yields from 13. 5 to 16. 5 t/hm2 is: 67 500-105 000 plants per hm2, 550-670 grains per ear, 250-320 grams per 1000 grains and 0.18-0. 2 kg per ear. The geographic condition of low latitude, high elevation and the impact of monsoon form a unique climatic ecological environment in the Middle Yunnan Plateau, where precipitation is concentrative, the climate is temperate and stable, with no intense heat in summer, and with strong solar radiation and great temperature variation between day and night in the corn growing season. The corn's growth period, especially the reproductive stage, is significantly elongated, which is favorable to the differentiation of florets and the formation of big ears. The compact plant type and even crop stands are also beneficial to the increase of planting density. The grain filling stage occurs in the rainy season of the Plateau with less sunshine and lower temperature. Therefore the rate of photosynthesis and grain filling are at medium level. But the grain filling stage and the stable leaf area stage of the corn are longer in the Middle Yunnan Plateau, and the total dry matter accumulation is comparatively higher, though the grain weight is lower, because the total grain sink per area is bigger.