Effects Of Sowing Date And Planting Density On Photosynthetic Characteristics And Yield Of Millet

Millet is very sensitive to environment, We selected ND10as the experimental material, using split block design of experiment, in order to study the effects of sowing date and planting density on photosynthetic characteristics and yield of millet production. The sowing date was the mainly area,(five levels, respectively use B1, B2, B3, B4, B5),and the planting density was the deputy district,(six levels, respectively with M1, M2, M3, M4, M5, M6).the growth period, morphological characteristics, photosynthetic characteristics, yield and yield components were determined and statistical analysis, the main results are as follows:1Effect of sowing date and density on millet growth periodThis study showed that:the average growth period of ND10is121.4days. It is the sowing date that has greatly impact on the growth period while the planting density has little influence. With the sowing date delaying, the growth period was significantly shortened. According to variation coefficient we can see that the effect of sowing date on growth period are jointing stage>heading stage>booting stage>filling stage>seedling stage>mature period.Correlation analysis of the temperature during the growth period and it showed growth period showed that growth period was positively correlated with the accumulated temperature, and the accumulated temperature rose along with the extension of growth period; while growth period is negatively correlated with the maximum temperature, daily mean temperature and the temperature difference between day and night. With development period of the rise of daily maximum and average daily temperature, the growth period were shortened.2Effects of sowing date and density on morphological indexThis study showed that:plant height of different sowing date is "S"type growth over time,As sowing time delayed, time needed for the slow growth of the "S" type growth shortened. At fast growth period, the plant height grow rapidly and fast into the "slowing growth". However, with the sowing date delaying,slow decline period is shortened. High density were higher than low density height in the seeding stage while at the jointing stage and heading stage had no significant difference in plant height, plant height manifested in the low density is higher than the high density of the plant height in grain filling period and mature period.The effect of sowing date on ND10stem diameter reached significant level, and the effect of density on ND10stem diameter reached very significant level. sowing time and density of against each stem diameter, the effects of difference reached significant level. Changes of stem diameter in sowing period was B4>B3>B1>B2>B5. Changes of the density of stem diameter was M1>M2>M3>M4>M5>M6.3Effects of sowing date and density on chlorophyll fluorescence characteristic of milletWith the sowing date delaying,the content of chlorophyll a showed a trend of decrease after the first increase, with the increase of the density also showed a trend of decrease after the first increase. With the increase of density and sowing date decreasing and delaying,the content of chlorophyll b showed a trend of decline. As the sowing date delayed,the content of chlorophyll a+b showed a trend of decrease after the first increase,and the increase of density also gave rise to the content of chlorophyll a+b increasing firstly and then decreasing.And the same to chlorophyll a/b.Based on the multiple comparison is made on the chlorophyll fluorescence indicators, the maximum value of the initial fluorescence Fo appeared in the B5M1,and the Fo value is0.289,the minimum of Fo turned up in B2M4,the value of Fo is0.201.The maximum fluorescence Fm appeared in the B1M4, the minimum value of Fm appeared in the B1M1.The maximum value of Fv/Fm arised in the B2M4, the minimum value of Fv/Fm emerged in B5M2.By the analysis of variance:the initial fluorescence of Fo in sowing date and density had significant differences, while in the sowing time and density interaction were not significant.The maximum fluorescence Fm values were significantly difference in sowing period, the effects of density on Fm were not significantly different, and the effects of sowing date and density interaction on Fm was significantly.The effects of sowing date,density and the interaction on sowing date and density on Fv/Fm reached significant level respectively.Both Fo and Fm value were increased with the delay of sowing time,and the trend is decreased first then increased.The value of Fv/Fm increased with the sowing date postpone and then decreased.Fo and Fm value along with the increase of the density trend to decrease gradually. With the sowing date postpone, the values of Fv/Fm was increased firstly and decreased afterwards.4Effects of sowing date and density on yield components and yield of millet.The correlation analysis of sowing time, density and yield components showed that the sowing date was very significant negative correlation with yield and the density was very significant positive correlation with yield, sowing date’s effect on panicle number reached extremely significant level, correlation coefficient is0.63, the impact on the ear grain number reached significant level, correlation coefficient is0.38, and the yield was very significant positive correlation with panicle number,and the correlation coefficient is0.93,the result indicate that the main indicator is panicles.The regression analysis of yield components showed that the regression equation of the yield,sowing time and the density is:Y=55547.13+886.29X1+886.29X2-3.37X,2-2.86X22-1.39X1*X2. On May5th, we sowed seeds, controlled the density at373800plants/ha,In the experiment,the highest yield reached up to6558.21kg/ha.The regression analysis of panicles showed that the regression equation of the sowing time and density’s effect on panicles is:Y=443.67+6.8974X1+6.8974X2-0.0256X120.0182X22-0.0160X,*X2, we acquired the panicles for the ND10largest number of agronomic traits is X1=120.19, X2=45, on May1, we sowed seeds, controlled the density of420000plants/ha,,the highest spike grain number reached up to5.5million ears/hm2.The regression analysis of spike grain number showed that the regression equation of the sowing time and density of the spike grain number is:Y=23359.29+542.67X1+542.67X2-2.23X12-X22-0.10X1*X2. we acquire the panicles for the10largest number of agronomic traits is, the Xi=123, X2=7.5, we seeded on May5, controlled the density of75000plants/ha, the maximum of the spike grain number is8829grams/ear.The regression analysis of the gain showed that The regression equation of the sowing time and density’s effect on grain is Y=1.4608+0.0641X1+0.0641X2-0.0003X12-X22+0.0006X1*X2. we acquire the agronomic panicles of the highest10gain nongda10is X1=140, X2=22.11, on May20, we sowed seeds, and controlled the density of221100plants/ha, the maximum grain of millet ND10is2.6899grams.