Abstract: In order to discuss the effect of water demand regulation and yield of pumpkin under different irrigation frequency and irrigation amounts,field experiments using the cultivar of pumkin Tianli as the experimental materials,were conducted to elucidate the effects of irrigation amount and stage on the water requirements characteristics,yield,water use efficiency and fruit appearance of this crop,respectively,in 2014 and 2015.The experiment had five treatments:45 mm irrigation water was applied at seedling stage(represented as T1),45 mm at seedling stage and 30 mm at tendril extending stage (T2),45 mm at seedling stage and 45 mm at tendril extending stage (T3),45 mm at seedling stage,45 mm at tendril extending stage and 30 mm at flowering and fruit setting stage (T4),45 mm,45 mm and 45 mm at seedling stage,tendril extending stage and flowering and fruit setting stage,respectively (CK).The result showed that the fruit diameter size gradually increased with the increased of irrigation amount,the fruit diameter and longitudinal diameter of other treatments were significantly(P<0.05) increased than T1,however,different irrigation frequency had no significant effect on shape index of pumpkin.The water consumption increasing with the increased irrigation frequency and irrigation amount of pumpkin growth period,and different irrigation frequency and irrigation amount had a little effects on water consumption regularity.The water consumption of pumpkin appeared the same laws as follows:First,the flowering and fruit setting stage.Second,tendril extending stage.Third,seedling stage,Forth,sowing stage,and the water consumption rate showed that:First,tendril extending stage.Second,the flowering and fruit setting stage.Third,seedling stage.Forth,sowing stage.The largest water use efficiency were T2 (2014) and T4 (2015) and they were significantly higher than T1 and CK by 14.80%,19.71% (2014) and 25.59%,1.89% (2015),respectively.The yield of T1 was significantly lower than other treatments,which were higher than T1 by 24.59%,29.75%,23.07%,21.20%(2014)and 39.81%,55.22%,71.85%,74.93% (2015),respectively.It was indicated that the critical period of pumpkin water demand was the tendril extending stage and flowering and fruit setting stage,irrigation in the two periods could significantly improve the yield of pumpkin.It would affect the yield and water use efficiency with too much or too less irrigation water.However,irrigation frequency and irrigation amount had little effect on the fruit shape index.Yield and water use efficiency showed a parabola with the change of water consumption in Hexi oasis of irrigation pumpkin.

Key words: Pumpkin, Irrigation amount, Irrigation frequency, Water consumption characteristics, Yield

CLC Number: 

• S274.1