Adjusting Irrigation Scheduling to Improve Growth, Yield and Quality of Wine Grapes in East-Foot of Helan Mountain in Ningxia

Abstract

【Objective】 Plant growth and its consequence for quality and yield are modulated by many biotic and abiotic factors. Taking grape in east-foot of Helan Mountain in Ningxia as an example, this paper aims to study how growth, yield and quality of grapes of different varieties can be improved by adjusting irrigation scheduling. 【Method】 The field experiment compared five grape varieties: Cabernet Sauvignon (V1), Matheran (V2), Merlot (V3), Syrah (V4), and Pinot Noir (V5). For each variety, we compared five irrigation treatments: Conventional irrigation with irrigation amount of 4 500 m3/hm2 (CK), reducing the irrigation amount to 4 050 m3/hm2 (W2), 3 600 m3/hm2 (W3), 3 150 m3/hm2 (W4), and 2 700 m3/hm2 (W5). In each treatment, we measured the changes in physiological and seed traits of the grapes. 【Result】 Grape varieties affected grape growth and the associated physiological traits the most. On average, V3 had the largest base stem diameter, followed by V1, V2, while V5 has the least. There were significant differences in photosynthetic rate (P<0.01), transpiration rate (P<0.05) and stomatal conductance (P<0.01) between the varieties. Irrigation scheduling affected physiological traits. The stem diameter of V2, V3, V4 and V5 was the greatest when they irrigated with W4, W3, W4 and W1 respectively, with the diameter being 14.62, 11.24, 12.51 and 11.14 cm respectively. The chlorophyll content of V2 was the highest (42.50) under W3, and that of V4 was the least (28.91) under W5. The impact of irrigation on yield and yield traits varied with variety. The yield and phenol content of V1 peaked under W3, being 4 256.7 kg/hm2 and 4.88 g/kg respectively. The content of soluble solids and phenol content of V2 maximized under W3, being 26.6% and 4.43 g/kg respectively. The yield of V3 was the highest under W1, being 4 425.3 kg/hm2. In contrast, V4 was more water demanding and its base stem diameter, photosynthesis, yield and quality under W1 were significantly higher than that under other irrigation treatments. The reduced sugars content and total anthocyanins of V5 was the highest under W3, being 20.81% and 2.83 g/kg respectively. 【Conclusion】 The optimal irrigation was W3 for varieties Cabernet Sauvignon, Matheran, Syrah and Pinot Noir, and W1 for varieties of Merlot and Syrah.

Keywords

• irrigation scheduling
• wine grape
• yield
• quality
• grape variety