RDI Of Drip Irrigation Mode Of Huangguan Pear

In order to improve the irrigation pattern of pear orchards,and achieve the organic combination of drip irrigation and regulated deficit irrigation,wetook Huang Guan Pear as test material and studied the regulated deficit irrigation under drip irrigation mode.The oil moisture,surface evaporation,evaporation of Huangguan pear,pear new slightly and fruit growth,leaf water content,chlorophyll content,chlorophyll fluorescencecharacteristics,fruit quality and yieldwere measured and analyzed.The results showed that:(1)The soil water content of the short term onshoot growing period(mild regulated deficit irrigation)and the whole term between shoot growing period to young fruit stage(severe regulated deficit irrigation)were significantly reduced about 50% and 57% than CK.(2)that mild short-term regulated deficitin the new shoot growing period and long-term and severe long-term regulated deficit in the new shoot growing periodand young fruit stage both reduced chlorophyll a,chlorophyll b,total chlorophyll content and leaf relative water content of pear leaves,while natural saturation deficit increased.After rewatering,chlorophyll a,chlorophyll b,total chlorophyll content,relative leaf water content and natural saturation deficit of mild short-term regulated deficitin the shoot growing period gradually recovered to CK levels,butthose of mild short-term regulated deficitin the shoot growing period was still significantly different from CK.(3)A new speed(LD)long-term short-term deficit irrigation treatment and the new speed slightly long + fruit period(severe deficit)long time without irrigation water deficit will lead to a significant increase of fo,FM,fv/fo,fv/fm value decreased significantly after rewatering,the new speed slightly long(LD)short-term water deficit treatments of fo,FM,fv/fo and fv/fm were gradually restored to the level of CK,and the new speed slightly long + fruit period of long time(severe deficit)long-term deficit is significant higher than CK,indicating severe deficit will be long-term effects of fo,FM,fv/fo,fv/fm.The diurnal variation of chlorophyll fluorescence determination in early fruit enlargement,initial fluorescence(Fo)diurnal variation showed a low high low trend;the maximum fluorescence(Fm),Fv/Fo and Fv/Fm changes are showing high low high trend,which reached the highest level at Fo,16:00 Fm Fv/Fo,Fv/Fm,at the lowest level,that under water stress and strong light will make the optical system of solar energy conversion efficiency and potential of pear leaf activity was inhibited.(4)With the mild regulated deficit irrigation,new growth amount,fruit yield and fruit quality reduction were not significantlydifferent.With the severe regulated deficit irrigation,the new growth rate and fruit yield were significantly reduced.