Jojoba flower buds: effects of preconditioning temperature.

Abstract

The environmental factors which control the reproductive cycle of jojoba (Simmondsia chinensis [Link] Schneider), were studied under controlled conditions. Plants were placed under a warm pretreatment temperature which resulted in the growth of new shoots bearing dormant flower buds. The plants were later moved to lower treatment temperatures which have been shown to break flower bud dormancy. Pretreatment temperature affected the percentage of nodes which produced flower buds. Both the pretreatment and the treatment temperature affected flowering percentage, there being an optimum pretreatment effect at 30/25�_C day/night temperatures. Flowering percentage responded to absolute treatment temperature rather than to the drop in temperature from pretreatment to treatment. Flowering percentage increased with decrease in treatment temperature down to 15/10�_C (male clone) and 12/7�_C (female clone). The lowest pretreatment-treatment temperature combination was associated with the production of female flower parts on the male inflorescences.