Interaction between shoot growth and reproductive behavior in olive trees

Trabajo presentado en el V International Symposium on Olive Growing, celebrado en Esmirna (Turquía) el 27 de septiembre de 2004.In the olive tree, (Olea europaea L.), bearing status exerts a strong influence on shoot growth as well as on flowering in the following year. Similar to various woody species, a heavy crop load reduces vegetative growth and return-to-bloom. Information is lacking, however, as to the precise nature of the effect of bearing condition on shoot growth, and the relationship between the type of shoot growth and its potential for flowering. We characterized shoot growth architecture in detail for six heavily bearing "on" and six non-bearings "off" trees. Five four-year-old branches were selected on each tree in summer and then detached in the winter dormancy period, at which time all current season shoots were measured and their morphogenetic origin determined. Flowering behavior was then monitored for three similar previously marked branches remaining on the trees, paying particular attention to the characteristics of the shoots on which inflorescences were formed. The bearing condition of the tree influenced both the site of origin and the growth of current-year shoots. A greater proportion of current-year-shoots in "off" trees originated by lateral branching, whereas in "on" trees shoot growth tended to occur by elongation from the shoot apex. Shoot number was three times higher for "off" than "on" trees. The size range and distribution among current-year-shoots, however, was quite similar between "on" and "off" trees, showing only a small trend toward the formation of a higher proportion of short shoots in the "on" trees and a higher proportion of longer shoots in the "off" trees. Flowering behavior was governed by the tree's previous season bearing condition, and was completely independent of shoot type.Peer reviewe