Effects Of Different Loads After Late Pruning On Fruit And Wine Quality Of 'Beihong' Grapes

In order to improve the late pruning technology for frost protection of 'Beihong' wine grapes in Ningxia,in this experiment The 5-year-old 'Beihong' trees were chosen after delayed pruning at Pingjibu vineyard.Three different loadings were carried out before veraison to exam the effects of the loads on the tree growth,berry size,total soluble sugar,titratable acid,anthocyanin,tannins total phenolic and wine quality.Sugar concentration,anthocyanin,tannin,total phenols in berry were all negatively correlated with yields.It can be seen that the lower-yield treatment is more conducive to the accumulation of sugar,secondary metabolites and the decrease of acidity.The contents and types of volatile aroma substances in 'Beihong' wines with lower load treatment were higher,and also the sensory quality of wine were improved.Appropriate reduction of load can enhance the tree potential.Considering the comprehensive output and quality,the reasonable load of the 5-year-old 'Beihong' is T2(380 kg/mu)under delayed pruning,which could improve the quality of 'Beihong' fruits,wines and help the vines to get through the winter.