水分胁迫及复水对绿洲膜下滴灌辣椒动态生长、产量及水分利用的影响

为了研究水分胁迫对露天膜下滴灌辣椒生长、产量形成和水分利用效率的影响,在辣椒苗期和开花坐果期均分别施加轻度水分胁迫(65%~75%田间持水量)、中度水分胁迫(55%~65%田间持水量)和重度水分胁迫(45%~55%田间持水量),全生育期充分供水处理(75%~85%田间持水量)为对照,分别测定各水分处理辣椒不同生育期末生长指标(株高、茎粗、叶面积指数和单株干物质积累量)以及青果总产量和水分利用效率,并用三次曲线模拟了辣椒各生长指标在全生育期内的动态变化过程。结果表明:三次曲线能够较好地反映不同水分处理下辣椒各生长指标随时间的动态变化。苗期和开花坐果期一定程度水分胁迫能导致辣椒在水分胁迫时段株高、茎粗和叶面积指数显著(P0.05)小于CK组,后期复水后,由于辣椒产生补偿性生长,苗期轻度和中度水分胁迫处理以及开花坐果期轻度水分胁迫处理辣椒,各生长指标增长速率在一定时间内超过CK组,最终辣椒产量和单株结果数均与CK组之间无显著差异(P0.05),且辣椒平均单果重分别比CK组显著高18.48%,22.49%,14.14%。苗期和开花坐果期水分胁迫,均能提高辣椒根冠比和果实干物质分配指数并减少辣椒全生育期灌水量和耗水量,特别是苗期中度水分胁迫处理,在不显著降低产量的情况下,灌水量和耗水量分别比CK组显著低12.36%和11.51%,且水分利用效率、灌溉水利用效率均最高,分别比CK显著高8.61%和9.66%,因此,在苗期施加中度水分胁迫,后期充分灌水是实现绿洲辣椒节水、高产和高效栽培的一种较优灌溉方式。

The Effects of Water Stress and Rewatering on Dynamic Growth,Yield and Water Use of Pepper with Mulched Drip Irrigation in Oasis Region

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.