Effects Of Planting Density On Yield Formation Characteristics Of Hybrid Millet

Experiment was conducted in Xuanhua experimental station of Zhangjiakouacademy of agriculture science, in2012~2013. Zhangzagu5was selected as material,and6plant densities were set at240000,270000,300000,330000,360000and390000/ha, respectively. Plant photosynthesis, morphological characteristic and grainyield were systematically studied. This paper aims to make clear the effect of densityon yield formation, and it provided theoretical and technical basis for yieldimprovement. The main result showed as follows:1. Planting density on the influence of the biological traits of hybrid milletWith the advance of the growth process, leaf area index and photosyntheticpotential of hybrid millet showed the first increase after reduction trend. Fromseedling to jointing stage, leaf area index and photosynthetic potential were graduallyincreased with increasing density, net assimilation rate decreased with increasingdensity. From heading to maturity, leaf area index and photosynthetic potential arethen presented a single peak curve, net assimilation rate increased with the densityincreasing trend after the first cut was. And its dry matter accumulation with plantingdensity increases significantly reduced.2. Planting density on the influence of the field ecological traits of hybrid milletMillet hybrids with canopy height from low to high, the leaf area index increasedand decreased, the transmittance gradually increases; with planting density increases,leaf area index also showed a trend of increase or decrease after the first, thetransmittance gradually reduced. Changes in diurnal variation of photosynthetic ratebroadly consistent trend, reducing the photosynthetic rate showed an increase with thepassage of time before the increase of the density decreased. Flag leaf chlorophyllcontent is presented with growth promotion decreasing trend and decreased withincreasing density. Density240000/ha photosynthetic rate and chlorophyll contentremains relatively higher level.3. Planting density on the influence of the yield traits of hybrid millet From the density24-390000/hm2processing, hybrid millet mature late in earlength decreased from25.57cm to23.74cm, ear diameter fell from3.3cm2.96cm,single spike weight dropped from23.3g to17g. Grain weight trend is not obvious,single grain number and yardage were lower valley. Economic factors and economicoutput is unimodal curve. Reaches its maximum when handling330000/ha.4. Planting density on the influence of the water utilization of hybrid milletWith the increase of planting density, water consumption growth period and the dateof hybrid millet overall water consumption increases, but after the first increase wateruse efficiency to reduce the processing330,000/ha can significantly promote thephotosynthetic rate is too late fertility and transpiration rate decreased, andsignificantly improve the photosynthetic water use efficiency.5. Planting density on the influence of the morphological traits of hybrid milletWith the increasing density of planting hybrid millet plant height increased from133.45cm to from144.78cm, elevated center of gravity height from63.8cm to71.68cm, between the base of the section becomes slender stalk, stem wall thinning.Section3of the stem between the base of the wall thickness decreased120.34um, alarge number of vascular bundles in the same area fell9. Stalk stalk-type index,puncture strength, mechanical strength and lodging index were significantly reduced..6. Planting density on the influence of the nutritional content of hybrid milletThe NPK accumulation of hybrid millet is gradually decreasing with increasingdensity in leaves, The largest accumulation of NPK appear in heading, accounting forthe total percentage of nitrogen also appeared with reduced fertility trends. Differentplanting densities on nitrogen and phosphorus accumulation of hybrid millet grainsimpact of changes in the same trend, with the ever-increasing growth process, but theopposite trend of potassium accumulation. Appropriate treatment for improving thedensity and grain accumulation in leaves NPK, which increase the distribution ratio ofNPK, reducing the transfer rate of NPK leaves play an important role. In addition,because potassium can promote the development of vascular stem, increasing thethickness and mechanical tissue stem wall thickness, so the stem potassium content isone of the important factors affecting stem traits.