The influence of girdling on flower type, number, inflorescence density, fruit set, and yields in three different olive cultivars (Barnea, Picual, and Souri)

Abstract

The influence of girdling on flower type and number, inflorescence density, and fruit set in 3 different olive cultivars (Barnea, Picual, and Souri) under intensive growing conditions using saline irrigation water was studied for 3 years. The density of inflorescences on the branches was not affected by girdling in any of the 3 cultivars during any of the 3 consecutive years studied. Also, no clear relation between the number of flowers and girdling was found in any of the 3 cultivars tested. The percentage of perfect flowers on the girdled scaffolds of cvv. Barnea and Picual increased significantly, except for Picual in 2002 where no differences were observed. However, no such difference between the non-girdled and girdled scaffolds was observed in cv. Souri. Comparison of fruit set on non-girdled and girdled scaffolds showed a similar and generally positive response to the treatment in the examined cultivars. However, in the third year of the study, no significant difference between the non-girdled and girdled scaffolds was observed. A significantly higher yield of the girdled trees was measured in the 3 cultivars during the first year after the winter girdling. Due to the young age of the trees the effect of girdling on yield was not further recorded. Fruit size on the girdled scaffolds was smaller than those from the non-girdled ones, as a consequence a higher percentage of fruit set was observed on the first ones. The results presented in this study point to different varietal responses of olive trees to girdling. However, this might also be due to the young age of the trees in this study as well as the peculiar agronomic condition of the trees.