عنوان مقاله [English]
Simmondsia chinensis (Link) Schneider) commonly known as jojoba (hohoba), is a dioicious evergreen shrub native to dry regions of south west of United States of America and north of Mexico. This species is very tolerant to drought and heat and is of great importance with regard to soil conservation and combat desertification. Moreover, it produces seeds which contain about 50% liquid wax, a unique substance which is of great value in cosmetics, food, pharmaceuticals and in other industries. To study the performance and adaptation of this species at south of Fars province in rain-fed and irrigated conditions, 286 and 225 seedlings were planted in statistical designs in 1993 and 1994 in Jahrom and Larestan, respectively. Growth, mortality and phenological factors including flowering, sex differentiation etc., of the plants were monitored at several irrigation levels. In Jahrom experiment, supplementary irrigation for two rows of plants continued after four years of establishment while the rest of the plants were left rain-fed. In Larestan experiment, four different irrigation regimes (control, 45, 30, 15 day intervals) were applied during the trial period. Jojoba clearly demonstrated the potential and ability to adapt to the climatic and edaphic conditions in Jahrom region. For the first time in Iran, seed production was materialized in this experiment. The mean weight of produced seed/plant from the total 120 female plants in Jahrom in 1998, 1999 and 2000 was 15, 22, and 35 Kg, respectively. Continuation of supplementary irrigation after the fourth year of establishment significantly increased height and crown diameter as well as seed production. The survival of rain-fed plants and the growth and yield in almost all treatments in Larestan experiment were not as satisfactory as they were in Jahrom due to several factors such as different provenance, heavy textured soil, and protection difficulties. However, jojoba generally demonstrated an acceptable adaptation in terms of reaching the stage of seed production. It is too early to recommend any commercial plantations unless more extensive experiments in the context of comparison of provenances and clones in different edaphic and climatic conditions are carried out.