Study On Quality Of ’Marselan’ Grape And Wine With Different Fruit Load

Grape load is one of the important factors affecting the quality of grape,and reasonable control of load is an important measure to obtain high quality of grape.Based on the demonstration garden of Yantai Academy of Agricultural Sciences and Penglai Guobin winery,6（T1～T6）and 9（T1～T9）different load treatments were set up in 2020 and 2021 respectively to study the effects of different loads on tree growth,fruit quality and wine quality.In order to provide a theoretical basis for the high-quality production of ’Marselan’ grapes in Yantai producing area.The main results were as follows:1.The effect of different load on tree growth: The axillary shoot growth increased with the increase of new shoot density,and the higher the new shoot density,the greater the growth,the lower the storage nutrient content of branches.A reasonable load can reduce the pruning workload in sunmmer and increase branch storage nutrition content,which is beneficial to the cold resistance and overwintering of ’Marselan’.The results of the experiment of comprehensive two-year experiment showed that when the density of new shoots was controlled at 8-10 shoots / m,the growth of axillary shoots was lower,and the storage nutrition of branches was higher.2.The effect of different loads on fruit quality: According to the comprehensive comparison and analysis of the contents of flavor substances and appearance quality of ’Marselan’.With the increase of load,the fruit quality of ’Marselan’ decreased,but in a certain range of load gradient,the fruit quality increased and then decreased with the increase of load.The effect of load on the fruit quality of ’Marselan’ was different under different shoot density:（1）When the shoot density was controlled at 8 shoots /m,with the increase of load,the contents of reducing sugar,sugar-acid ratio,100-berry weight,soluble solids in ’Marselan’ grape decreased,titratable acid content increased and the contents of total phenols,tannins and anthocyanins increased and then decreased.The fruit quality achieved best when the average number of clusters was 1 to 1.5 and the yield per mu is about 330 kg～480 kg.（2）When the new shoot density was controlled at 10 shoots / m,the contents of reducing sugar,soluble solids,100-berry weight,sugar-acid ratio,tannin and total phenols in ’Marselan’ grape decreased with the increase of load,and titratable acid content increased.The fruit quality achieved best when the average number of clusters was 1 and the yield per mu is about 440 kg ～ 485 kg.（3）When the density of new shoots was controlled at 13 shoots / m.with the increase of load,the contens of soluble solids,seed weight,reducing sugar,the content of three phenols in ’Marselan’ grape increased and then decreased.The titratable acid contents in fruits decreased and then increased,and the ratio of juice yield and sugar to acid increased and then decreased.The fruit quality achieved best when the average number of clusters was 1.5 and the yield per mu is about 860 kg.3.The effect of different load on the quality of wine: With the increase of load,the quality of ’Marselan’ wine decreased or increased and then decreased,and the change law of different shoot density was different.The main results were as follows:（1）When the shoot density was controlled at 8 shoots / m,and the alcohol contents and dry extract decreased with the increase of load.The color intensity,anthocyanin content,tannin and total aroma content increased and then decreased.The wine quality achieved best when the average number of clusters was 1 to 1.5 and the yield per mu is about 330 kg～480 kg.（2）When the shoot density was controlled at 10 shoots / m,with the increase of load,the dry extract,alcohol content,hue of wine,total phenols content,anthocyanins content,tannins content,kinds of aroma and total aroma content of ’Marselan’ wine decreased.The wine quality achieved best when the average number of clusters was 1 and the yield per mu is about 440 kg ～ 485 kg.（3）When the density of new shoots was controlled at 13 shoots / m.With the increase of load,the dry extract and alcohol content of wine decreased,the hue of wine,anthocyanins content,tannins content,kinds of aroma and total aroma content increased and then decreased.The wine quality achieved best when the average number of clusters was 1～1.5 and the yield per mu is about 590 kg～860 kg.