Effects of Irrigation Amount on Growth and Fruit Quality of Table Grape

Abstract

【Objective】 Vineyards in north China require irrigation and the purpose of this paper is to experimentally study the effect of irrigation amount on fruit quality of table grape. 【Method】 The field experiment was conducted in Shanxi province in north China, in which the perennial early-ripening Emerald green and the mid-ripening Crimson were used as the model plants. They were both watered using border irrigation. For each variety, we compared three irrigation amounts: 2 570 m3/hm2 (CK), 2 056 m3/hm2 (T1), and 1 542 m3/hm2 (T2). During the experiment, we measured the growth, fruit yield and quality of the grape. 【Result】 Reducing irrigation amount during the shooting stage did not result in a noticeable effect on stem growth and shooting of either variety, but a change in irrigation amount during the fruit expansion stage affected the length and width of both individual fruits and grape clusters, and the ultimate yield. Compared with CK, T1 increased the yield of the Emerald green by 6.89%, while T2 reduced its yield by 16.36%. Reducing irrigation amount also affected nutrient quality and edible quality of the grape, with the contents of total phenols and flavanols both decreasing as the irrigation amount decreased, despite the insignificant difference between T1 and CK. The yield of the Crimson maximized in CK, reaching 22 555 kg/hm2; compared with CK, T1 and T2 reduced its fruit yield by 8.18% and 14.05%, respectively. T1 increased the total phenolic content by 4.55% while increasing the total flavonoids content by 52.83%, compared to CK. The highest total phenol content in T2 was 8.48 mg/g, a 11.91% increase compared to that in CK. Decrease in irrigation amount led to a reduction in the sugar-acid ratio. 【Conclusion】 Change in irrigation amount did not have a significant effect on growth of the fresh grape during the shooting period, but significantly impacted fruit yield and quality of the grape during the fruit expanding stage. Reducing irrigation amount to 2 056 m3/hm2 during the fruit expanding stage of the Emerald green can increase fruit yield and quality, while for the Crimson the optimal irrigation amount is 2 570 m3/hm2.

Keywords

• table grape
• irrigation amount
• soil moisture
• quality