种植密度对熟期不同夏玉米群体光合性能及产量的影响

在大田试验条件下,研究3个种植密度(67 500、82 500、97 500株/hm2)对早熟品种登海618和中晚熟品种登海605的群体光合性能及产量的影响。结果表明,随种植密度增加,单叶净光合速率下降,而群体光合速率、叶面积指数及冠层光合能力均增强,保证了群体光合产物的积累,使玉米总产量提高。两个品种均在97 500株/hm2密度下产量达到最大,且在早收获10 d的情况下登海618产量高于登海605,分别为13 840 kg/hm2和13 080 kg/hm2。随密度增大,登海605倒伏率显著提高,使其产量受到影响。

Effects of Planting Densitieson Canopy Apparent Photosynthesis Characteristics of Summer Maize in Different Maturity Periods

Fieldexperimentwereconductedunderthreeplantpopulationdensities(6.75×10⁴,8.25×10⁴,9.75×10⁴ plants/ha) to study the effect of planting densities on grain yield components and canopy apparent photosynthesis characteristics using two summer maize cultivars Denghai618 and Denghai605. The results showed that planting density had a marked improvement on canopy apparent photosynthesis, canopy photosynthesis ability and grain yield which ensure the accumulation of photosynthetic products.Nevertheless net photosynthesis rate decreased along with the density increased. DH618 had a higher grain-yield than DH605 under the condition of 10 days early harvest. Both the two cultivars reached maximum production under the density of 97 500 plant/ha, 13 840 kg/ha and 13 080 kg/ha, respectively. Besides, lodging rate of Denghai605 was dramatically higher than Denghai618, the risk could not be overlooked.