Suitability of Stem Diameter Variations as an Indicator of Water Stress of Cotton

作     者：ZHANG Ji-yang DUAN Ai-wang MENG Zhao-jiang LIU Zu-gui 

作者机构：Farmland Irrigation Research Institute Chinese Academy of Agricultural Sciences Xinxiang 453003 P.R. China 

出 版 物：《Agricultural Sciences in China》 (中国农业科学（英文版）)

年 卷 期：2006年第5卷第5期

页      面：356-362页

学科分类：09[农学] 0901[农学-作物学] 

基　　金：National Food Fertility Project of China, (2004BA520A06-W9) National High Tech R&D Program, (2001AA242081, 2002AA2Z4071) 

主　　题：stem diameter variations water stress atmospheric factors cotton 

摘      要：Water stress effects on stem diameter variations （SDV） were studied in a pot experiment on cotton （Gossypium hirustum L. Meimian99B）. Water restriction was imposed at the flowering stage and were compared with a well-watered control treatment. The volumetric soil water content （0v） and SDV were monitored continuously. The objective was to determine the feasibility of using the parameters derived from stem diameter measurements, including maximum daily stem shrinkage （MDS）, maximum daily stem diameter （MXSD）, and minimum daily stem diameter （MNSD） as indicators of plant water stress. The different behavior of SDV was founded at different growth stages. At stem-maturing stage, MDS increased and MNSD decreased in deficit-irrigated plants compared with the control plants, therefore, it appeared that MDS and MNSD ccould be used as available indicators of plant water status. At stem growth stage, there were no significant differences in MDS values between treatments but MXSD and MNSD responded sharply to soil water deficits. Thus, for rapidly growing cotton, the course of MXSD or MNSD with time offered a consistent stress indicator. SDV was also closely related to atmospheric factors, solar radiation （Rs） and vapor pressure deficit （VPD） were found to be the predominant factors affecting MDS, followed by the relative humidity （RH）, while air temperature （Ta） and wind velocity had the least effect. A good linear relationship was founded （r^2 = 0.921） between MDS and environmental variables （Rs, VPD, RH, and θv）, which can be used to establish a reference value for detecting plant water stress based on the MDS patterns.