The effect of water deficit on shoot growth and fruit development in jojoba was studied in 8-year-old jojoba [Simmondsia chinensis (Link) Schneider] plants. In both fruiting and defruited nonirrigated plants, shoot growth, which started at the beginning of April, stopped in June when the xylem water potential (ψx) measured at dawn fell to a value below the osmotic pressure at the point of turgor loss. Osmotic adjustment during the summer enabled some resumption of growth in the autumn at low ψx values. Irrigated plants grew throughout the warm season only if defruited: competition for assimilates evidently inhibits growth during the period of fruit filling. Fruit growth was not affected by water deficit, since fruit are apparently highly resistant to water loss.