Study On Growth Process And Increase Yield Mechanism Of Peanut Adapting To Meteorological Condition

This article has studied the relationship among growing process,climate resources (temperature、sunshine、rainfall) and high yield mechanism,setting up six different sowing-dates,including10/4,25/4,5/5,15/5,1/6,15/6,using shanhua8and shanhua9as test materials.1Peanut growth process adapting to climate resourceCompared with sowing date10/4, the average daily temperature of sowing date15/6is5-14℃higher from emergence phase to flowering and pegging phase,the latter benefits for the emergence of peanut seedling. As for the former four sowing dates highest average daily temperature appear in pod-setting phase, whereas it is flowering and pegging phase for sowing date1/6and emergence phase for sowing date15/6.In shanhua8, average daily rainfall of sowing date5/5in pegging phase,respectively, compared with the10/4,25/4,15/5,1/6, and15/6, more than2.46mm,1.43mm and0.37mm and0.93mm and2.19mm and more than1.57mm,1.53mm,0.26mm,1.80mm,2.62mm at pod-setting phase; In shanhua9, average daily rainfall of sowing date5/5is2.83mm,1.73mm,1.03mm,1.67mm,2.24mm, more than10/4,25/4,15/5,1/6,15/6in sequence at flowering and pegging phase andl.23mm,0.95mm,0.50mm,1.62mm,2.88mm at pod-setting phase.At the yield formation stage, on5/5, the planting season sunshine duration and photo synthetic available radiation are higher than the other seedtime,as for sunshine times these hours increase by139.7h,54.6h,18.1h,78.Oh,155.7h respectively in shanhua8and86.2h,31.7h,52.8h,122.2h,171.8h,accordingly;for PAR increase by16.15%,10.68%,5.51%,14.22%,22.55%respectively in shanhua8and20.57%,11.30%,13.65%,14.18%,30.24%accordingly. Path analysis showed that the key meteorological factor affecting yield is the daily mean air temperature at seedling stage, the daily mean rainfall at pegging stage, the photosynthetically radiation at pod bearing stage and sunshine duration at pod producing stage.2Effect of production increasing in appropriate sowing dateIn all of the sowing dates of shanhua8,yield changing greatly from3027.20kg-hm-2to4178.96kg·hm-2, with highest yield appearing in sowing date5/5, there is no significant difference from sowing date15/5, but higher than that of other growing dates, compared with earlier date10/4and the latest date15/6increase by24.51%,27.56%; in shanhua9,at all sowing dates, yields change greatly from3287.40kg·hm-2to4718.18kg-hm-2, with highest yield appearing in sowing date5/5, there is no significant difference from yield of sowing date of25/4, but higher than other dates, compared with earlier date10/4and the latest date15/6increase by28.31%,30.32%.3Dynamic change regulation of peanut growth and development in different growth processWith the delay of sowing time, days are reduced gradually on each growth stage.Taking shanhua8for example,emergence phase,young seedling phase,flowering and pegging phase,pod-setting phase,pod-maturing phase of plant sowed in10/4is longer than that of15/611d、9d、10d、4d、4d respectively. Whereas shanhua912d、10d、12d、7d、6d accordingly.The variation tendency of main stem height and the lateral branch length are consistent, reaching the climax on5/5, the main stem height of shanhua8and shanhua9are57.20cm、62.96cm and lateral branch length are60.50cm,66.45cm respectively.LAI of both the varieties which sowed in5/5is higher than that other sow-dates’from pod-setting phase to pod-maturing phase, LAI reaching a climax at pod-setting phase, there is no significant difference between4.52of5/5and4.46of15/5,but higher than that of3.55of10/4.3.95of25/4,4.22of1/6.3.93of15/6notably in shanhua8;there is no significant difference between4.97of5/5and4.84of25/4,but higher than that of3.91of10/4,4.74of15/5.4.42of1/6,4.23of15/6notably in shanhua9.Each sowing date of peanut yield per plant dry matter accumulation quantity increased to a larger extent at pod-maturing phase, the accumulation of dry matter yield nearly maximized, it is45.55g per plant on sowing date5/5, increased2.74%-29.57%than other sowing dates in shanhua8and they are52.43g per plant and3.95%-24.37%in shanhua9accordingly.In conclusion, appropriate sowing date can make benefit for growth and development of peanut, keep a higher LAI and increase dry matter accumulation, so that improve the yield of peanut.4Physiological characteristics of functional leaves in different growth processChlorophyll content and net photosynthetic rate reach a climax at pod-setting phase, in shanhua8they are2.08mg·g-1,24.92μmol·m-2-s-1at sowing date5/5respectively and there is no significant difference with that of sowing date15/5, but higher than other dates, in shanhua9they are2.09mg·g-1、22.46μmol·m-2·s-1at sowing date5/5respectively and there is no significant difference with that of sowing date25/4,but higher than other dates.Chlorophyll content and net photosynthetic rategradully decrease from pod-maturing to harvest phase, but remain high level in sowing date5/5, so that guarantee the longer functional time and in favor of the accumulation of photosynthetic product.5Determination of appropriate sowing dateDetermination of appropriate sowing date depends on climate resources. Average daily rainfall of flowering and pegging phase is limitation factor of yield, at first we should assure rain season according to meteorological data, then confirm growth process using effective accumulated temperature, so that each growth stage has appropriate meteorological condition, ultimately improve yield. Calculating suitable sowing date of a certain area is scientific. The two years’ experiment result indicate that in tai’an, the suitable seeding-time of shanhua8is5/5～15/5and shanhua9is25/4～5/5.