扩行距、缩株距对春玉米冠层结构及产量的影响

In order to explore the physiological and ecological mechanisms of expanding line spacing and shrinking row spacing for close planting and yield increasing of corn in Xiliaohe Plain, the study was conducted with two corn varieties compact density-enduring Nonghua 101 and semi-compact maize variety Weike 702 as materials in densities of 6104 plantshm-2 (D1)7.5104 plantshm-2 (D2) and 9104 plantshm-2 (D3). With the contrast of conventional cultivation (CK, the row distance was 60cm, D1D2 and D3 of plant distance were 27.78 cm22.22 cm and 18.52 cm) and plantation of expanding line spacing and shrinking row spacing (KH, the row distance was 100cm, D1D2 and D3 of plant distance were 16.67 cm13.33 cm and11.11 cm), the leaf area index, angle of stem to leaf, leaf orientation value, light transmittance, yield and component factors of maize canopy in spinning stage, milk-ripe stage and full ripe stage were determined; leaf area attenuation rate was calculated. Then the effects of plantation of expanding line spacing and shrinking row spacing on spring corn yields and canopy structures were studied. The results showed that the yield of KH was significantly higher than that of CK, in which yield increase was the most obvious in D2 density; and the yield of Nonghua 101 was 7.8% (2015) and 7.0% (2016) higher than CK; the yield of Weike 702 was 5.6% (2015) and 5.9% (2016) higher than CK. The leaf area index of KH was higher than that of CK in late growth stage, and reached the highest level at milk-ripe stage, in which the variance was the most obvious in D2 density. The yield of Nonghua 101 was 13.7% (2015) and 11.1% (2016) higher than CK; the yield of Weike 702 was 11.4% (2015) and 15.8% (2016) higher than CK. The angle of stem to leaf of the upper leaves was smaller and the leaf orientation value was larger, while the angle of stem to leaf of the middle leaves and the lower leaves were larger and the leaf orientation value was smaller in KH plantation of 2 varieties.The translocation rates of canopies were higher than that of CK in KH plantation of 2 varieties; under the D1 density, Weike 702 all showed as the difference of the top layer> spike layer> bottom layer except 2015; under the D2 and D3 densities, Weike 702 all showed as the difference of spike layer> the top layer> bottom layer under the D3 density, and the differences were the most obvious under the D2 density except 2016. Nonghua 101 was 5.1% (2015) and 5.0% (2016) higher than CK; Weike 702 was 5.0% (2015) and 4.9% (2016) higher than CK. In conclusion, the canopy structure of KH planting pattern is more reasonable under a higher density, and the yield was higher, and the response of different varieties to KH planting pattern was different. The leaf area index and the angle of stem of Nonghua 101 are less than Weike 702. The leaf aspect value and canopy transmittance of all horizons were greater than those of Weike 702; the measured yield under different densities were greater than Weike 702, the yield was the highest under the 7.5104 planthm-2 .Moreover, the yield of Nonghua 101 was more obvious than that of Weike 702.