EFFECT OF THE BEARING CONDITION OF THE TREE, CHILLING AND DEFOLIATION ON THE FORCED BUDBURST OF OLIVE CUTTINGS AT DIFFERENT TEMPERATURES

Experiments with leafy and defoliated 3-node cuttings of ‘Manzanilla de Sevilla’ olive were conducted during 1996/97 in growth chambers at 12.5, 20 and 30°C. The presence of the leaves inhibited the growth of the axillary buds until the beginning of winter.
After that period, this effect disappeared progressively, allowing full bud inflorescence development of 1996 non-bearing cuttings by February.
At 12.5°C, some inflorescence development was already recorded by mid autumn.
Nevertheless, it was higher and faster with the accumulation of chilling.
The same pattern was observed at 20 and 30°C, but inflorescences were only evident after mid January or early February, respectively.
Percent of inflorescence development in non-bearing cuttings also increased at all temperatures with the accumulation of natural chilling in the trees.
However, the maximum percent of growing inflorescences was delayed at high temperatures and with defoliation until February.
No significant inflorescence development was observed in bearing trees in 1996. The above results confirm the major role of the bearing condition of the tree in the return of bloom and suggest a relevant role of both high forcing temperatures and defoliation on the progression of normal reproductive bud development until the chilling requirements for bud dormancy release were fully satisfied.

III International Symposium on Olive Growing

A. Ramos, L. Rallo

olive, floral induction, floral initiation, chilling requirements, dormancy release, defoliation, forced budburst, biennial bearing

https://doi.org/10.17660/ActaHortic.1999.474.50