| The grape is popular with consumers worldwide due to its colorful appearance,delicious taste and various nutrition.Moreover,grapes has strong adaptability to the different environments.And its cultivation area and total yield are both the biggest of all fruit tree.Also,it is one of the most important economic tree in the world.In recent years,the grape industry in Shaanxi has developed rapidly,especially in Guanzhong area,which has achieved considerable economic benefits through greenhouse cultivation.However,there are still some problems in the process of production management,such as excessive fruit load,high yield,blind pruning and so on.These problems affect the fruit quality and restrict the growth of economic benefits seriously.This experiment was conducted in 2016-2018 in the greenhouse of Northwest A&F University of Yangling,Shaanxi Province,taken the’Hutai No.8’grape widely planted in Shaanxi Province as the test material and designed gradient contrast trial on the basis of preliminary test results in previous years.The aim of this experiment is to study the effects of different summer pruning intensity and fruit load on fruit maturity and quality of greenhouse grapes.Furthermore,it can provide reference for the production of high quality table grape in Shaanxi and improve the economic benefits of grape.The main conclusions are as follows:1.Summer pruning intensity can significantly affect the quality of the first berry(fruiting at bearing shoot)and the secondary berry(fruiting at axillary shoot).In the case of fruiting the first and secondary berry,the first berry quality obtained by the middle-long shoot pruning(nodes 8 and 9)on the bearing branch was better,but the corresponding secondary berry quality was poor.And the secondary berry quality obtained by the short shoot pruning(nodes 5)on the bearing branch was better,but the corresponding first berry quality was poor.In the case of prohibiting secondary fruiting,the first berry quality obtained by the long shoot pruning(nodes 9 and 10)on the bearing branch was better.In the case of prohibiting first fruiting and producing high-quality secondary berry,the secondary berry quality obtained by the short(nodes 4)and extremely short(nodes 2)shoot pruning on the bearing branch was the best.The flavor of secondary berry is generally poor,while the value of health care is generally higher.2.Summer pruning intensity can significantly affect the fruit maturity period.In the case of prohibiting secondary fruiting and producing high-quality first berry,the maturity period of the grape was delayed due to the increase of the summer pruning intensity,while in the case of prohibiting first fruiting and producing high-quality secondary berry,the maturity stage of the grape was advanced by the increase of the summer pruning intensity.In the case of fruiting the first and secondary berry,there was no obvious regularity in the maturity of the secondary berry,but the first berry obtained by the short shoot pruning was later.3.fruit load can significantly affect the fruit quality.On the basis of optimizing field management technology,the highest quality was obtained when the fruit load was 8 and 10clusters per plant with a planting density of about 1.7 m~2(about 380 plants per 666.7 square meters)at the age of six years.However,considering the yield,it is suggested that 10clusters per plant is the most suitable for production,which can not only maintain high quality,but also maintain certain economic benefits.For seven-year-old grape plants with planting density of about 5.5 m~2 per plant(about 120 plants per 666.7 square meters),the fruit quality with fruit load of 40 clusters per plant was the highest.4.Fruit load affect fruit maturity.Maturity period of the fruit under less fruit load was earlier than that under more fruit load.In summary,summer pruning intensity and fruit load can have a significant impact on the fruit maturity and quality of greenhouse grape.In view of the actual production management,in the case of fruiting secondary berry,the first berry quality obtained from the summer pruning of the 8th and 9th nodes was better and matured earlier.In the case of prohibiting secondary fruiting,the first berry quality obtained by the long shoot pruning(nodes 9 and 10)was better and matured earlier.If the goal is to produce high-quality secondary berry,it is suggested that summer pruning should be carried out in the 5th nodes while retaining the first berry.In addition,in the case of prohibiting first fruiting,the secondary berry quality obtained by the short(nodes 4)and extremely short(nodes 2)shoot pruning on the bearing branch was better.However,the measures of removing the first berry and retaining only the secondary berry should be carefully adopted.In the study of fruit load,the optimum fruit load of six-year-old grape is 10 clusters per plant,and the optimum fruit load of seven-year-old grape is 40 clusters per plant. |
