Quality changes of merlot grape in different plots in shihezi region during ripening period

In order to analyze the fruit ripening quality of Merlot grapes in the blocks of 5-1, 5-2 and 5-3 in Shihezi region, various physicochemical indexes of Merlot grapes in different blocks were measured from August 23 to September 7, 2017 and 2018, respectively. The results showed that as the grapes maturation, the sugar accumulation showed an upward trend. The total sugar content of the three plots during the ripening period was 194.2-259.1 g/L (measured by glucose), and the total sugar of 5-1 was the highest, 259.1 g/L. The total acid content showed a downward trend, ranging from 9.3 to 4.6 g/L (measured by tartaric acid), the highest value in 5-1 was 5.3 g/L when was harvested, and the fastest decline of total acid belonged to 5-3 plots. PH was generally on the rise from 3.39 to 3.83, meanwhile increase of 5-3 grapes was the fastest compared with other two, with a small difference between 5-1 and 5-2. Tannin continued to decrease with the change range between 6.24 and 1.04 mg/g, and tannin in block 5-2 decreased the fastest with both 2.08 mg/g of 5-1 and 5-3. The content of total phenol decreased after increase. 5-3 grape increased the fastest and also decreased the fastest block from 46.25 mg/L to 104.779 mg/L to 44.118 mg/L. 5-1 total phenol rose in the second place, but decreased in the slowest, and finally remained at 60.662 mg/L. The content of anthocyan in 5-1 had been on an upward trend, rising to the highest level of 111 mg/L eventually, 5-2 and 5-3 rapidly rising and then slightly decreasing. The chroma was also decreased after increase, and the fastest rising belonged to 5-1 from the lowest point of 9.563 to the highest point of 16.186, and fell slowly to 14.363. 5-3 rose to 12.75 with the slowest speed and fall to 11.05 with the fastest rate. Through comprehensive analysis of the indicators of the three plots combined with the growth environment, the fruit quality of the plot 5-1 was relatively good, which was the most suitable growth and ripening of Merlot grapes.