| This paper studies the effect of interaction between fertilizer and density on rapeseed growth, biomass accumulation. N〠P〠K elements content, chlorophyll content, photosynthetic characteristics, economic characteristics, yield and quality of constitute factors. The results showed that:1.The best treatment of1613for field planting is fertilizer level1125kg/hm2and density for450000/hm2,because with this treatment rapeseed have good and stable yield, not easy to lodging, and have best benefit.In the stage of before-winter, the plant have about13leaves, average biomass accumulation is about11g, biomass accumulation of root and canopy ratio is about0.25. After the mature, the number of pods per plant is248.3, the number of seeds per pod is15.2, the weight per thousand seeds is3.6g, the height of the plant is about169cm, width of the stem is1.35cm,the number of the frist branch is about6.8.2. Both leaves and pods of rapeseed have double-peak curve of diurnal variation of the photosynthetic rate. Peak appeared in about10:00and15:00, peak appered in the morning is higher than the afternoon, the photosynthetic rate of pod and stem obviously decreased in the afternoon, but the decline range of the leaf is not too much. Valley value appeared in about13:00.The reason of the rapeseed have a clear depression in the noon is that high temperature and strong highlights closed stomata and hinder the CO2into the cells. The photosynthetic rate of leaf in flowering stage is higher that before-winter stage, The reason for this phenomenon appears is there are with different chlorophyll content, temperature, light intensity, and so on. Fertilizer and density on the rape photosynthesis have certain effect, lack of fertilizer will decreased the photosynthesis seriously, rape photosynthesis were effect to different fertilizer treatment in seedling stage and the before-winter stage was not significant, but it is significant in the flowering and mature period. The influence for photosynthesis of density is weaker than the fertilizer. Only the density differences enough between the treatment, the photosynthesis will have significant differences. Density and fertilizers have certain interactions effect to net photosynthetic rate of rapeseed.3. The biomass accumulation of rapeseed were reduced with the increase of the fertilizer level and density level. In the harvest time, there were have the biggest differences.In this time,80%of the treatment had the ratio biomass accumulation of root and canopy between0.1to0.15. In the stage of the seedling〠before-winter〠flowering,chlorophyll content of leaves will be higher as the fertilizer level increased, and be lower as the density level increased. From flowering to maturity, the nitrogen, phosphorus, potassium content of the rape were declined. All of fertilizer level〠density level and two factors interactions were significant or very significant influence for rape N〠P〠K content.4.Both of the two years, the correlation of economic characters to yield were showed that:Plant height>The number of effective pods per plant> Seeds per pod>The number of effective branches>1000-seed weight>Stem width. Path analysis of agronomic traits on yield per plot showed that the order of directly influence was: branch height> Pods per plant>1000-seed weight>The number of secondary branches> The number of first branches>The number of pods on main inflorescence> Seeds per pod> Stem width> Plant height. Plant high directly influence the yield per plot was small.but big through the other of the traits; Because the number of effective pods per plant with a lot of negative effects directly to yeild, and significant negative correlation between density to the number of effective pods per plant, so we should better appropriately increase density level to reduce it. According to related and path analysis,1613had good yield came from suitable Pods per plan〠Plant height and1000-seed weight. Good yield is the result of the interaction between fertilizer and density... |
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