Effects Of Sowing Date And Harvesting Date On Growth And Yield Of Summer Corn (Zea Mays. L)

This study was conducted with three corn hybrids with different growth period to observe the effects of different sowing date on plant morphological indexes, growth process, dry matter accumulation and the grain yield of summer corn. And the relationship between ecological factors with the summer maize growth and yield In order to provide theoretical support for the efficient utilization of the limited light and heat resources and summer maize yield increase in Hebei Province, The results showed as follows:1. Different sowing date resulted in the difference from growth stage of summer maize duration and spike differentiation process. When summer corn sowed early. The grain filling time prolonged. One-day-ahead of sowing date resulted in grain filling time prolonged 0.74 day, The period of duration along with sowing date postpone to appear the regular reduction, panicle initiation stage by the impact of sowing date significantly, along with sowing date postpone that panicle initiation stage reduction, the panicle initiation stage of early sowing treat lengthen 3 day than late sowing. This has provided the time guarantee for the corn later period photosynthesis product accumulation and the grain yield improved.2. Sowing date and dry matter accumulation was significantly negatively correlated. The treat on June 10 single dry matter accumulation which compared to the treat of June 25 increased 9%~21.03%. With the delay of sowing date, the days of MIR Advance, Linear increase period shorten, Biomass accumulation in linear increase period decreased, MIR increased slightly. Therefore ahead of time sowing is the effective way that prolonged dry matter accumulation time and Increased dry matter accumulation.3. When summer corn sowed early. Plant height and ear height decreased, spike position height coefficient increased, stem diameter, population uniformity decreased significantly, coefficient of stem diameter also decreased. When sowing late peak duration become shorter, LAI decrease rapidly after spinning, population LAD significantly lower than sowing early. Along with sowing date ahead of time, total LAD increased 10.21% ~ 16.46%. Phenomenon of premature senescence be serious, lodging percentage been decreased, ability of utilization and interception of light been decreased.4. Grain filling rate had significantly influence on sowing date and harvest date, when summer corn sowed early, grain filling rate increased remarkable, grain dry matter accumulate growth process accords with the Logistic equation, with the delay of sowing date, the days of MIR advance, linear increase period shorten, Biomass accumulation in Linear increase period decreased, MIR increased slightly. Sowing date to the ZhengDan958 influences obviously than other two varieties. Therefore, early sowing and late harvesting can achieve the improvement of grain yield by improving the speed and extend the filling time to achieve.5. Summer corn sowing ahead of time, that is advantageous in enhances the number of fertilization flowers and the number of effective seeds, reduced rate of kernel abortion, increased ear length, kernel numbers per row, and kernel numbers, reduced the barren ear tip. In which grain number per spike is sowing date influence to be most remarkable. Five-days-ahead of sowing date resulted in zhengdan958 grain yield increased 1.03%~8.26%, nongda108 grain yield increased 2.09%~8.23%, DH-3719 grain yield increased 0.06%~7.47%. From DAP 40-DAP 55, five-days-backward of harvesting date zhengdan958 grain yield increased 3.69%~10.54%, nongda108 grain yield increased 3.27%~12.58%, and DH-3719 grain yield increased 3.99% ~ 17.52%. Therefore, sowing early and harvesting late make the period of duration to lengthen, filling stage extension, dry matter accumulation in grain been full, and weight of a thousand seeds remarkable increased. The role of late harvesting increaseing significantly yield larger than the early sowing. Under the condition of limited light and heat resource in Hebei province, sowing date of summer corn should not be later than June 15th; the grain filling period lasted more than fifty days.6. The temperature is the main factor that affects the corn period of duration length. Temperature with the growth period was extremely significant positive correlation; it is the biggest direct action to the period of duration, when the growth period accumulated temperature increased, period of duration extension, otherwise it would be reduced. Temperature difference between the size and length of growing period was assume the negatively correlated, sunshine duration and the growth period was positively correlated, the yield was significantly affected by accumulated temperature, sunshine duration, daily mean temperature difference. The influence of accumulated temperature and the date average temperature were most remarkable, the influence of the daily average temperature difference and the total rainfall amount are not remarkable to the grain yield. Therefore, timely early sowing and late harvesting can increase the accumulated temperature and sunshine hours, in order to increase the grain yield to provide a favorable weather conditions.