甘肃民勤地区'慕合怀特'葡萄最佳采收期的确定OA北大核心

In order to determine the best harvest date of'Muhe White'grape in Minqin area of Gansu province,the local experience harvest date(September 15)was taken as the harvest limit,and different harvest dates were set.The 100 grain weight,longitudinal diameter,transverse diameter,soluble solid matter,soluble sugar and titrable acid of ripe wine grapes with different harvest dates were measured,and the fruit qualities were comprehensively evaluated.The results showed that,based on the appearance and intrinsic quality of the fruit,the harvesting dates were divided into 2 categories,September 21,September 25,September 29 as the class Ⅰ,and September 9,September 13,September 17 as the class Ⅱ.Comprehensive analysis of appearance and internal quality indexes showed that the best harvest period was from September 21 to September 29.The principal component analysis indicated that total sugar,vitamin C,pH and acid in the fruit were the core quality indexes of'Muhe White 369',and solid acid ratio,sugar acid ratio,vitamin C,total sugar were the core quality indexes of'Muhe White 234'.In addition,the composite scores of'Muhe White 234'and'Muhe White 369'reached the highest on September 25,with 0.82 and 0.73,respectively.To sum up,under the meteorological conditions of this study,the best harvesting periods for the fruit quality of'Muhe White 234'and'Muhe White 369'wine grapes in Minqin area of Gansu province were from September 21 to September 29,and September 25 was the best harvesting period,which provided a theoretical basis for timely harvesting of'Muhe White'grape.