Girdling olive trees, a partial solution to biennial bearing. I. Methods, timing and direct tree response

SummaryThe effect of scaffold girdling on the productivity of olive trees was studied on four cultivars grown under intensive irrigated conditions. Girdling increased the yield when done in midwinter (December-February) and to a lesser extent in April. A girdling width of 10–15 mm covered with PVC tape was most effective and promoted rapid healing. Uncovered girdling wounds healed very slowly, with a resultant decline of the scaffold. Girdling increased both inflorescence formation and fruit set. With cv Manzanillo young scaffolds were more responsive than old ones. The responses of different scaffolds on the same tree to girdling were independent of each other. The degree of response of a scaffold to girdling depended on the potential yield of the scaffold in the year of treatment. No direct prevailing effect of the girdling on of the following year’s yield was noted.