Effect Of Different Yield On Quality Of Grape And Wine In Weibei Region

The study was in Jingyang County, aiming to explore the effect of different yields on thequality of grape berry and wine in Shanxi province in2012. The objective of this work was tolay a foundation for the reasonable wine grape production in Weibei region. Two winemakingcultivars, Cabernet Sauvignon and Ugni Blanc, were used for the experimental materials. TheCabernet Sauvignon was setted in four different yield levels:8808Kg/hm~2,16998Kg/hm~2,22252Kg/hm~2, and27815Kg/hm~2. The Ugni Blanc was setted in three different yield levels:13019Kg/hm~2,23474Kg/hm~2,33000Kg/hm~2. It systematically studied the effect of differentyields on the main quality indexs of grapes and wine. The primary conclusions were asfollows:（1）Reducing the load increased the maturity of Cabernet Sauvignon and Ugni Blanc.The cluster and berry weight were increasing as the yield dwindled. With the reduction ofyield, the reducing sugar content and sugar-acid ratio of the mature berries increased, whilethe content of total acid decreased.（2）Reducing the load increased the content of phenolics in Cabernet Sauvignon andUgni Blanc. The content of total anthocyanins and quantitative monomeric anthocyanins inCabernet Sauvignon increased observably with the yield decreasing. With the productionincreasing, the content of total phenol content in the skin of Cabernet Sauvignon and UgniBlanc reduced, but there was no significant difference between each output gradient. Thecontent of tannin showed a rising trend with yield lowering. After clusters thinning, thecontent of tannin in Ugni Blanc was significantly greater than ck’s, but there was nosignificant difference in Cabernet Sauvignon between each output gradient. The content ofquantitative monomeric nonanthocyanins in the the Cabernet Sauvignon and Ugni Blancshowed a trend of rise with the decreasing of the yield.（3）Reducing the load increased the content of phenolic compounds of wine made byCabernet Sauvignon and Ugni Blanc. With the reduction of production, the content of totalanthocyanins and quantitative monomeric anthocyanins in Cabernet Sauvignon wines showeda trend of rise. While the production decreasing, the content of total phenolic in wines madeby Cabernet Sauvignon and Ugni Blanc was increasing, there was no significant differencebetween each output gradient. The content of tannin showed a rising trend with yield lowering. The differences between each output gradient in Cabernet Sauvignon all reached asignificant level. After cluster thinning, the content of tannin in Ugni Blanc was much higherthan the ck’s. The content of quantitative monomeric non-anthocyanins phenolic compoundswere getting higher in Cabernet Sauvignon and Ugni Blanc while the production reducing.（4）Reducing the load increased the amount of aroma substance in the CabernetSauvignon and Ugni Blanc berry and the wine made by them. With the reduction ofproduction, the content of aroma substance in two cultivars berry and wine increased. Themian aroma substances in berry were aldehydes, esters and acids. The mian aroma substancesin wine were alcohol, esters and acids. The differences of Aroma substances were lessbetween different production.（5）The optimal yields of Cabernet Gernischet and Ugni Blanc grape in jingyang are8800Kg/hm~2and13019Kg/hm~2respectively.