IRRIGATION WITHHOLDING EFFECTS ON OLIVE REPRODUCTIVE BUD DEVELOPMENT FOR CONDITIONS WITH INSUFFICIENT WINTER CHILLING

F.J. Castillo-Llanque, H.F. Rapoport, H. Baumann Samanez
In the Mediterranean areas where olive domestication originated, flowering of the tree occurs once florally induced buds receive sufficient chilling during the winter dormancy period, followed by warmer temperatures adequate for budburst and subsequent floral differentiation. In locations such as Tacna, Peru, where winter temperatures provide insufficient cold, flowering is traditionally stimulated by withholding irrigation. As an initial step for determining the specific requirements and potential of this system, we observed morphological and structural aspects of buds during winter dormancy irrigation witholding, and under budburst forcing following non-irrigated periods of different lengths. Buds and flowering were observed on current-year shoots from previously non-bearing trees of ‘Frantoio’ and ‘Criolla’, a prominent local cultivar. Floral budbreak capacity following 5, 6 and 9 weeks water-withholding periods was tested by forcing leafy cuttings from the affected trees in a greenhouse and monitoring morphogenetic changes. In both cultivars dormant buds presented 4-5 nodes and similar internal dimensions, and remained unchanged throughout the irrigation suspension period. Reproductive budburst on the cuttings did not occur following 5 weeks witholding, increased with successively longer periods, and was greater for ‘Criolla’ than ‘Frantoio’. Comparison to buds of the same cultivars in standard winter dormancy conditions (Cordoba, Spain) indicated similar bud morphology and behavior to that observed with the irrigation suspension scenario. Flowering on shoots maintained on the trees confirmed the effectiveness of the irrigation withholding method for both cultivars. Overall, the greater and more rapid floral budbreak in ‘Criolla’ suggests it may be better adapted to the local climatic and cultivation conditions than ‘Frantoio’.
Castillo-Llanque, F.J., Rapoport, H.F. and Baumann Samanez, H. (2014). IRRIGATION WITHHOLDING EFFECTS ON OLIVE REPRODUCTIVE BUD DEVELOPMENT FOR CONDITIONS WITH INSUFFICIENT WINTER CHILLING. Acta Hortic. 1057, 113-119
DOI: 10.17660/ActaHortic.2014.1057.12
https://doi.org/10.17660/ActaHortic.2014.1057.12
Olea europaea L., floral differentiation, budburst, inflorescence, dormancy
English

Acta Horticulturae