Date of Award:


Document Type:


Degree Name:

Master of Science (MS)


Plants, Soils, and Climate

Committee Chair(s)

Larry Rupp


Larry Rupp


Roger K. Kjelgren


Richard C. Beeson


Jujube (Ziziphus jujuba) is a major fruit crop in China where it has been a favored cash crop and successfully used to address erosion problems in the Loess Plateau region of western China. Further use of jujube in forestry projects and improved agricultural efficiency are very promising. This study sought to repeat a water-use study in two climates: a hot, semi-arid climate in Yangling, Shaanxi, China and a dry-summer, continental climate in Logan, Utah, USA. The study took physiological measurements on the trees with the aim of characterizing the way that jujube uses water. This would help to create an irrigation scheduling tool for the jujube that could be used by smallholder farmers in China and growers in the arid US interested in a promising new fruit crop. Three treatments were applied: (1) would water the trees generously, (2) would restrict irrigation to produce moderate drought stress, and (3) would restrict irrigation heavily to produce severe stress. The physiological measurements included how much water was being used by the trees, the rate at which the water was being transpired by the leaves, the surface temperature of the leaves, and the internal water pressure of the trees. The study in Yangling nearly failed. That study yielded no data that contributed to scientific discussion, but commentary and insights are given as to the value of failed research in the academic process. The study in Logan was completed successfully and found that jujube's responses to the drought stress treatments revealed an interesting phenomenon in the time after the drought treatments ended and were receiving ample water. These findings contribute to the suggestion that jujube maintains normal water usage during drought stress. Because of this, there is a concern for using jujube in agricultural applications where water must be used carefully.