Effects Of Planting Densities And Spatial Distribution Patterns On Canopy Structure And Physiological Characters Of Summer Maize

Planting density is an important agronomic measure to change the yield of corn, too high planting density will affect the uneven distribution of growth factors. The spatial distribution can regulate ventilation, light level at a high density planting conditions. For changing growing conditions, increased organic matter accumulation has some positive effect. In order to increase corn yield potential, rational allocation of planting density and spatial distribution will regulate the rational allocation of sunlight, water, nutrients between plants. In this paper, a split-plot experiment design was used four kinds of planting density(105,000 、90,000、75,000、60,000 plants/ hm2) and three spatial distribution(equal row spacing with one plant per hole, equal row spacing with three plant per hole and wide-narrow alternate pattern with three plants per hole), 12 treatments and three replicates in total and continued for two years. By setting different planting densities and different spatial layout interaction study under the influence of different configurations of the canopy structure, physiological characteristics and yield, in order to provide a scientific basis for the cultivation of high-yielding maizeThe main results were described as follows.Bottom canopy and plant and ear portions PAR and DIFN the same trend, with the increase of planting density PAR substantially increased at first and then decreases and then increases, with the increase of planting density DIFN first increase in reduction, were planting density of 75,000 plants / hm2 reached the maximum; and spatial layout, mainly in flowering and silking have a significant effect on PAR and DIFN, under ER1 favor of PAR interception, and in the more favorable DR3 canopy of translucent. With the planting density increases leaf area index rises, increasing the height, stem diameter thinning, increase in length between the section and the leaf does not increase with the increase of density values to these plant traits were 105,000 plants / hm2 ER1 lower reaches most value.Photosynthetic Characteristics of Pn, Gs, E overall the same trend, photosynthetic efficiency in 75000 plants/ hm2 DR3 at maximum, conducive to the accumulation of dry matter. The planting density and spatial layout no definite trends affecting the ear leaf photosynthetic pigments in. Leaf protein concentration with the change of the first stage of growth and the increase in the reduction, while the opposite change of MDA, SOD, POD, CAT and dynamic changes in protein concentration, firstly decreased and then increased; protein concentration blades 75,000 plants/ hm2, maximum content, MDA and CAT arrivals 105,000 plants/ hm2 maximum, SOD arrivals largest in 90000 plants/ hm2 time.Yield increased with planting density increaseing at 105,000 plants/ hm2 when the maximum spatial layout mode at low planting density on yield significant accumulation increase production under ER1, at a high planting density, spatial layout of accumulation yield no significant effect; and ear weight and cob weight decreases with increasing density, maximum at 60,000 plants/ hm2, spatial layout mode at low planting density on panicle, cobs weight significantly affected under ER1 weight gain at high planting density, spatial layout had no significant effect on the ear weight, cob weight.