Research Of Microclimate Characteristics Of Apricot Orchard In Different Planting Density

Abstract:To master the change characteristics of micro-climate of aDricot orchards in different planting densitv,with Luntai white apricot as the experimental object,we measured and analyzed the tree structure,the diurnal variton of photosynthesis,leaf area index,the daily variation of light,temperature and humidity of different parts of the canopy in different planting density and we also measured and analyzed the yield and fruit quality of apricot orchard,the results are as follows.1. The tree height and the crow of apricot orchard in small planting density were big also.the tree height and crowm of apricot orchard in large planging density was relatively small.The apricot growth deferred from density to density.2.The change curve of net photosynthetic rate (Pn),Stomatal conductance (Gs) and transpiration rate (Tr) of apricot in ditterent planting density was basically the same Tne tirst peak occurred at12:00,and the "midday depression" phenomenon appeared at noon.The second peak appeared at16:00,and the first trough of intercellular CO2concentration(Ci) appeared at1.2o’clock,and then rose again.The second trough appeared at16:00,Apricot net photosynthetic rate of2m×4m and8m×8m had a relatively large difference.While apricot of4m6m and4m×8m and4m×4m had a relatively small different.The Ci of2m×4m of apricot obyviously difference from the other four densities.The Tr had an siginificant difference in deferent densities.3.The results showed that PAR in one day of apricot orchards presented the change rule of ’low-high-low;The PAR of inter-plant,inter-row and canopy center in the apricot orchards from big to small-in turn was:Inter-row>inter-plant>canopy center.4.The LAT value of different parts of apricot had a close relation with the planting density;Determination of apricor leaf area index(LAT) snowed the LAT vaiue of apricot orchards whose planting density were2m×4m,4m×4m and4m×6m were between3.0-5.0,the LAI value of apricot orchards whose planting desity were4m×8m and8m×8m was less than30The TAT value of anricot orchards in different density from big to small in turn was2m×4m>4m×4m>4m×6m>4m×8m>8m×8m.Comprehensive results,showed that the LAl value of apricot orchard with4m×6m planting density is reasonable,which could reach more than3.0, and with this density,the light was well distributed,the light transmittance was better.5.The internal temperature of the apricot orchard is lower than the outer (control) temperature, while the’humidity is higher than the external (control).The change of temperature in a day showed a"low-high-low"rule,while the change rule of the relative humidity is contrary.The temperature of inter-plant, inter-row and canopy center in the aprncot orchards from big go small in turn is inter-low inter>plant>canopy cemer,while the change of relative humidity is just opposite.from3o’clock to4o’clock in the afternon, there was a great difference in temperature among apricot orchards in different densities.The change rule of temnerature from big to small in turn was8m×8m>4m×8m>4m×6m>4m×4m>2m×4m,the vari ation of humidity was just contrary.There was a significant difference between temperature and humidity of apricot orchards in.different densities.In the low desity of apricot orchard,the temperature waa low and humidity was high,while the situation was just opposite in the high density apricot orchard,so the proper densities was (?).6.Planung density had a great imence on orenard yrerd.The Yierd of apncot orcnard whose planting density was2m×4m could reach1843kg,while the8m×8m was only383.207kg,2m×4m fruit weight and Vc content and total sugar content was low.The fruit weight of4m×4m was low.The fruit weight and Vc content and total sugar content of4m×6m was relatively modest,and the eutput could reach mere than500kg.although the production of apriot orchard of4m×8m was not high,the quality was better.When the desity of aprioot orchard was too small,the production would be seriously affectde.In the opposite situation, the frnit quality would be seriously infmnencde and then the economic benefit of apricot orchard would be impacted.Take all into account,the more appropriate density was4m×6m, yield and quality could be unified.