Abstract: In order to study the effects of mulched drip irrigation under water stress (WS) on growth,yield formation and water use efficiency of pepper,mild WS(65%-75% Field capacity,FC),moderate WS(55%-65% FC)and severe WS(45%-55% FC)were composed at both seedling stage and flowering and fruit setting stage of pepper,and full water supply(75%-85% FC)during the whole pepper growth stage as the control group. Growth indices (plant height,stem diameter leaf area index (LAI) and dry matter accumulation per plant) were measured at different growth pepper stages and total fresh fruit yield and water use efficiency at the whole stage in each water treatment were measured respectively. Besides,cubic curve was used to simulate the dynamic variations of growth indices during different pepper growth periods. The results showed that the variations of pepper growth indices with time would be represented compatibly by cubic curve. The certain extent of WS both at seedling period and flowering and fruit setting period made growth indices of pepper significantly less than control group. But due to compensation growth after rewatering in later period,the growth rates of pepper growth indices under mild and medium WS at seedling period and mild WS at flowering and fruit setting period exceeded the control group within a certain period time and the yield and fruit setting number of pepper with mild and medium WS at seedling period and mild WS at flowering and fruit setting period weren't significantly different from control group,but the average single fruit weight were significantly higher by 18.48%,22.49%,14.14% than control group,respectively. Compared with the control group,both WS at seedling period and WS at flowering and setting period could reduce irrigation water amount and water consumption and increase fruit dry matter partitioning index whole pepper growth period,especially under the medium WS at seedling period,which made the irrigation water amount and water consumption in the whole pepper growth period significantly decreased by 12.36% and 11.51% than control group,respectively,with the maximum water use efficiency (WUE) and irrigation water efficiency (IWUE) among all treatments,and the WUE and IWUE were significantly higher by 8.61% and 9.66% than control group,respectively. Therefore,applying moderate water stress during seedling period and full irrigation at later period is a better irrigation way to achieve water-saving,high-yield and high-efficient,pepper cultivation in oasis region.

Key words: Pepper, Water stress, Rewatering, Dynamic growth, Mulched drip irrigation, Water using efficiency

CLC Number: 

• S641.01