Effects Of Delayed Excavation On The Quality Of Red Globe Grape In Heyang, Shannxi Province

Delayed Cultivation is a kind of cultivation which can be helpful to increase the incomeof peasants, and delayed cultivation had not build up in Heyang county. This research put offthe phenology of grape by delaying excavation, and this research was in order to provide newideas to delayed cultivation in Heyang county This research was conducted in2012inSunshine Chateau of Northwest A&F University in Heyang County, Shannxi Province withRed Globe Grape as the research material. Covering straw curtain before grape beingexcavated from soil was used to put off the date of excavating grape. The aim of this researchis to study the effects of delayed excavation on Red Globe grape phenology, the diseaseincidence and growth habit, and mainly tested the effect on berry quality. The outcome of ourresearch is as follows;1．Before excavating grape from soil, covering straw curtains during daytime can reducethe temperature in daytime by3~4℃and slow the increase of earth temperature. Coveringstraw curtain delayed excavation up to11days.2．Delayed excavating grape from soil can put off phenology of Red Globe Grape up to14days. The date of excavation was put off till April9th, and fully ripen till December26th.Those control grapes were excavated on March29th, and ripe on December26th.3．In terms of disease occurrence in2012, the major diseases of Red Globe Grape ofboth delayed excavated and normally excavated were downy mildew and sunscald. Incidenceof downy mildew under the two conditions was similar, but delayed excavated grape sufferedseverely from sunscald, which had a harmful effect on the yield.4．Red Globe grapes excavated later and normally had similar growth habit, such as thesimilar rate of budbreak, fruiting shoot and fruit setting. But because of the higher incidenceof sunscald, the delayed excavated grape had lower cluster weight and yield per vine.5．Delayed excavation did not decrease the quality of Red Globe Grape.Delayed excavation did not have a significant effect on reducing sugar content, titritableacid content, M(sugar/acid) and soluble content, but had a significant effetct on totalanthocyanin content, total phenol content, and tannin content after veraison.As for the mature fruit,the reducing sugar content(151.27～154.04g/L), titritable acid content(4.61～4.65g/L),M(sugar/acid)(31.5～32.5), soluble content(15.8～15.9%) and fruit hardness(3.8～4.3kg/cm2)were similar in excavated in different time. However, delayed excavation grapes hadhigher VC content in berry and more total anthocyanins and total phenols but less tannin inskin.In addition, delayed excavation berries were larger and heavier than those normallyexcavated ones and their skin color was darker and more accordant. As for their lower clusterweight,After veraison, the major types of anthocyanins in berry skin of delayed excavated andnormally excavated were Pn-3-O-Glu, Cy-3-O-Glu and Pn-3-O-(6-O-Acet)-Glu, and totalamount of these anthocyanins made up more than90%of total anthocyanins in berry skins.Grape of delayed excavated and excavated in normal date had the same kind of anthocyanins,but higher amount of anthocyanins were found in grape of delayed excavated.