DETERMINATION OF THE UPPER AND LOWER LIMITS OF WATER STORAGE PIT IRRIGATION THROUGH PRINCIPAL COMPONENT ANALYSIS

作者：Guo, Xianghong^*; Lei, Tao; Sun, Xihuan; Ma, Juanjuan

来源：Fresenius Environmental Bulletin, 2018, 27(10): 6618-6627.

• water storage pit irrigation
• root growth
• photosynthesis
• yield
• quality
• principal component

The effects of different upper and lower limits of irrigation (50%-80% of the field capacity W1, 60%-90% of the field capacity W2 and 70%-100% of the field capacity W3) on the root growth, photosynthesis, yield and quality of apple trees were investigated through field experiments to determine the high-quality and high-yield water management pattern under water storage pit irrigation. The correlation degree between indices was examined through grey correlation analysis, and the most suitable upper and lower limits of irrigation were identified through principal component analysis. Results indicated that the different irrigation treatments significantly influenced the root growth. The length density, surface area, weight density, water content and vigour of the roots under each treatment showed the following trend: W3 > W2 > W1. The treatments also significantly affected the photosynthetic characteristics. The stomatal conductance, intercellular carbon dioxide and net photosynthetic rate of the trees under each treatment exhibited the following trend: W2 > W3 > W1. The respective patterns of the transpiration rate and the water use efficiency of the leaves were as follows: W3 > W2 > W1 and W1 > W2 > W3. The significant influence of the irrigation treatments on the fruit yield and quality was also found: W3 > W2 > W1 for the fruit yield, shape index and hardness of the trees under each treatment; W3 > W1 > W2 for the titratable acid; and W2 > W3 > W1 for soluble solid and sugar acid ratio. Grey correlation analysis revealed that the representative physiological indices of the apple trees under water storage pit irrigation included fruit hardness, root water content, stomatal conductance, net photosynthetic rate, fruit shape index, photosynthetically active radiation, titratable acid and soluble solid. Multiple-index comprehensive principal component analysis suggested that the most suitable upper and lower limits of water storage pit irrigation were in a range of 60%-90% of the field capacity.

• 出版日期2018
• 单位太原理工大学; 晋中学院