The Effect Of Different Row Spacing On Physiological Characteristics And Yield Of Maize

In order to study the effect of different row spacing on yield of maize, the mechanism ofappropriate row spacing to yield improvement, and to seek the optimal row spacing ofhigh-density planting of spring maize, and to provide the theoretical basis and technical supportfor the spring corn efficient, high yield cultivation, the field conditions, canopy structure,photosynthesis, dry matter accumulation and final yield of 2 maize varieties, Xianyu335 andJundan8, was studied, in which 4 row spacing, 70 cm, 65 cm, 60 cm and 50 cm, was planted.The main results of this study are as follows:In late growth stage of corn, the average illumination intensity in small row spacing wasbetter than large row spacing, the light level was optimal when the row spacing was 50 cm.Concentration of carbon dioxide in lager row spacing was higher than smaller row spacing, theconcentration of 70 cm row spacing was higher than others significantly. The upper and middleleaves of maize in 70 cm row spacing was more flat, and its extinction coefficient K wasslightly higher; in 50 cm row spacing, the upper and middle leaves was more erect so that it wasmore conducive to increased sunlight absorption for maize groups.After the milk stage,LAI in 50 cm and 70 cm row spacing was significantly higher than in65 and 60 cm, maintaining a greater photosynthetic leaf area; In addition, chlorophyll andsoluble protein content of leaves in 50 cm and 70 cm row spacing was more than others. Thus,in the two row spacing, leaf senescence and leaf functional period was delayed and extended inlate growth of maize. Accordingly, leaf chlorophyll content, Hill (Hill) reaction activity andphosphoenolpyruvate carboxylase (PEP Case) activity maintained a high physiological level in50 cm and 70 cm row spacing indicating that the original reaction, light and dark reactions ofphotosynthesis maintained a high activity which resulted in higher photosynthetic rate.Therefore, in the late growth stage, large green leaf area and higher photosynthetic activitymade maize group that plant in 50 cm and 70 cm row spacing maintain a high photosyntheticcapacity, which lay a foundation for high yield of maize.In late growth stage, dry matter accumulation of maize planting in 50 cm and 70 cm rowspacing was more than the other two, and it was highest when row spacing was 50 cm, in whichgrain dry weight was higher than others for 10% to 20%. However, economic coefficient wasnot high in 70 cm and 50 cm row spacing, dry matter distribution in the proportion of grainbetween the treatments showed 70cm <50cm <65 and 60 cm. Higher accumulation of grain wasin 50cm and 70cm row spacing due to highest dry matter accumulation. Compared with other treatments, the two treatments had a higher distribution to vegetative organs in late growth stage,indicating that leaves, stems, sheaths and other photosynthetic organs senescence and functionalperiod was delayed and extended respectively. Dry matter of grain transferred from otherorgans was mainly from stems and leaves, but the amount was not large, no more than 6% ofthe total grain, indicating that the main source of grain yield is still photosynthetic products anddirect distribution.At 70, 000/hm~2 planting density, the yield of Xianyu335 in 70 cm spacing was largest,14181 kg/hm~2; at the 60, 000/hm~2 planting density, the largest yield of Jundan8 was in 50 cmspacing, 12963 kg/hm~2. Maize yield was significantly different (α= 0.05) in different rowspacing, yield of Xianyu335 was in highest 70 cm row spacing, higher in 50 cm, lower in 60 cmand 65 cm; yield of Jundan8 in 50 cm was slightly higher than in 70 cm (but the difference wasnot significant), and yield in these two row spacing was significantly than in 65 cm and 60 cm.Factors affecting maize yield followed by bald length> grain number> kernel weight> earlength, in which bald was the main factor affecting the two maize yield differences in differentrow spacing. The maize bald length in 70 cm and 50 cm is shorter than in 65 cm and 60 cm rowspacing.Considering physiological process and yield of maize, 70 cm and 50 cm row spacing isbetter than the other two treatments, but the row spacing was narrow in 50 cm, in which fieldcultivation and management was inconvenient, but also the use of farm machinery was limited.While in 70 cm row spacing, mechanized operation was more easily, so the 70 cm wasrecommended planting spacing in maize production.