Abstract: In order to study the effects of water deficit in different growth periods on growth, yield and water use efficiency of pepper with mulched drip irrigation, mild water deficit (65%-75% Field capacity, FC)and moderate water deficit (55%-65% FC)were composed during seedling period and blossom and fruit period, respectively, mild water deficit was composed during full fruit period and later fruit period, respectively, and full irrigation (75%-85% FC)during the whole pepper growth period as the control (CK). Meanwhile, water production function of pepper was modeled and solved by Jensen model. The results showed that the maximum pepper fresh fruit yield was found in the fully irrigated pepper (CK)with fruit yield of 36 203.90 kg/ha. The mild and moderate water deficit during seedling period and mild water deficit during later fruit period had no significant influence (P> 0.05)on total fresh fruit yield of pepper compared with CK, but the other water deficit treatments had significantly smaller total fresh fruit yield by 10.45% to 13.32% than CK. The mild water deficit at the full fruit period and mild water deficit at later fruit period could significantly (P<0.05)decreased pepper fresh fruit moisture content by 5.75, 5.83 percentage points during the stage with water deficit compared to CK, respectively. Pepper irrigation water use efficiency (IWUE)and WUE were similar in each water treatment, the WUE of the water treatments with moderate water deficit during seedling period and mild water deficit during later fruit period were significantly greater than CK by 11.63% and 9.41%, respectively. The water sensitive index at blossom and fruit period was the maximum of 0.517 during the different pepper growth period in Jensen water production function. Therefore, the blossom and fruit period was the critical period of water requirement of pepper, the water deficit in this growth period would lead to serious reduction of pepper yield. In order to get a higher yield, full irrigation (soil moisture was controlled at 75% to 85% of field capacity)should be conducted at this growth period.

Key words: Pepper, Mulched drip irrigation, Water regulated deficit, Yield formation, Water production function

CLC Number: 

• S275