摘要

To increase summer maize grain yield in North China Plain, we conducted field experiments with three densities (3, 6, and 9 plants m(-2)) on two plant types (a flat type, LD981, and a compact type, LD818) during 2010 and 2011 summer maize growing seasons to study leaf area index (LAI), above ground dry matter accumulation, grain filling rate, and grain yield. The results indicated that with the density increased, the LAI in the both varieties enhanced; however, plant density at the rate of 9 plants m(-2) significantly (LSD, P < 0.05) increased LAI in LD818. Increasing densities enhanced the above ground dry matter of LD818, but not of LD981. With the density increased, the grain filling rate in the both varieties declined, but during the later growing season, the grain filling rate in LD818 was higher than that in LD919. Irrespective of plant density at the rate of from 3 to 6 or 6 to 9 plants m(-2), the grain No. per ear, 1,000-kernel weight, and ears No. per m(2) in LD981 were all lower than those in LD818; this was the main reason why with the increased density, the population yield in LD981 was lower than that in LD818. These results indicate that in North China Plain, increasing plant density could enhance the grain yield of compact type summer maize.