Photosynthetic Physiology Characteristics of Potato （<i>Solanum Tuberosum</i>) at Tuber Initiation Responses to Water Deficit Regulated with Mulched Drip Irrigation
An experiment was conducted to determine the effect of water deficit regulated with mulched drip irrigation on photosynthetic physiology characteristics at potato tuber initiation in an arid environment. The results indicated that potato leaf photosynthetic rate (PR), transpiration rate (TR) and stomatal conductance (SC) at tuber initiation were greatly affected by water deficit regulated with mulched drip irrigation. Daily PR varied with a double-peak curve within a day at tuber initiation. The TR increased sharply after 7:00 and the maximum was marked at 13:00 in all the treatments and CK at tuber initiation, then started to decrease, and TR also decreased with soil water deficit level increase, so was SC performance. Significant positive relations (p&lt;0.01, r=0.310**) was found between leaf water use efficiency (WUE) and PR at potato tuber initiation, but significant negative relation between WUE and TR (p&lt;0.01, r=-0.534**) and that between WUE and SC (p&lt;0.01, r=-0.527**) also occurred. Therefore, proper levels of water deficit regulated with mulched drip irrigation could be used to effectively regulate crop photosynthetic physiology characteristics at potato tuber initiation in an arid environment.