Full Length Research Paper

Scheduling irrigation for jujube (Ziziphus jujuba Mill.)

Ping Zhang¹, You-Ke Wang¹*, Jing-Wu Zhan², Xing Wang¹ and Peng Wu³

¹Northwest A&F University, Yangling 712100, P.R. China.

²Institute of Soil and Water Conservation, Chinese Academy of Sciences and Ministry of Water Resources, Yangling Shaanxi 712100, P.R. China.

³Graduate School of Chinese Academy of Sciences, Beijing 100049, P.R. China.

*Corresponding author. E-mail: sdauzhangping@yahoo.cn,  gjzwyk@vip.sina.com.  Tel: 13359180956. Fax: 02987010700.

Accepted 4 June, 2010

   Abstract

This study was performed to select suitable indicator for scheduling the irrigation of jujube (Ziziphus jujuba Mill.) grown in the Loess Plateau. The relationships between plant-based indicators and soil matrix potential as well as meteorological factors of jujube under deficit irrigation compared with well irrigation were determined. The results showed that maximum daily trunk shrinkage increased and maximum daily trunk diameter, gas conductance and midday leaf water potential decreased in response to higher and lower soil matrix potential, respectively. However, the maximum daily trunk shrinkage signal intensity to noise ratio was highest in response to higher and lower soil matrix potential. Besides, the maximum daily trunk shrinkage correlated well with reference evapotranspiration and vapor pressure deficit (r2= 0.702 and 0.605 respectively). When the soil water potential was greater than -25kPa or less than –40 kPa, maximum daily trunk shrinkage values showed increasing trend, suggesting that Jujube might be subject to water stress. Based on this, the suitable soil water potential values of pear-jujube in anthesis and setting periods were identified between -40 kPa and - 25 kPa and the values can conduct precise irrigation of jujube in the Loess Plateau.

Key words: Water stress, water status indicators, soil water potential, Jujube (Ziziphus jujuba Mill.), anthesis , fruit setting periods.