Effect of drought stress on flowering and on seed yield and its components in jojoba (Simmondsia chinesis (Link)‎ Schneider)‎ established in western Saudi Arabia

الملخص EN

Atwo year field trial was conducted to assess the effect of drought stress on flowering, seed yield and related traits in a 5 years jojoba plantation (5 to 6 years old) established in Al-Madinah Al- Munawwarah area.

Seven irrigation regimes were created by irrigating the crop at 1, 2, 4, 8, 12, 24 and 36 weeks intervals for only one cycle (i.e.

36 weeks).

Afterwards, the irrigation schedule was relaxed and the crop was maintained at a limited water supply (187 m3/ ha/month) until the end of the trial.

The total amount of water applied in the first 36 weeks of the trial ranged from 35.6 m3/ha/month for the driest treatment to 223.5 m3/ha/month for the wettest treatment.

Collected data through the course of the trial revealed no significant differences between the wettest and driest treatments for each of the studied traits.

Estimates of seed yield per plant, oil and protein contents of seeds, (100-seed weight), shelling percentage and total number of flowers per season, averaged over treatments, were 569 vs.

784 g, 43 vs.

51%, 17.3 vs.

16.7%, 69 vs.

72% and 38 vs.

49 flowers over the two years for the respective traits and are comparable to those recorded in other parts of the world.