The fate of lateral buds in the olive (Olea europaea L. ssp. europaea var. europaea). A first report. (Special Issue: Integral mechanical harvesting of oil olives and the influence of growing systems.)

摘要

In 2007 tests were carried out to determine the meristems which give rise to the different types of shoots and the basic factors affecting the evolution of the apical meristem and their lateral buds. The tests were conducted on potted plants in fertigation in two extremely different environmental conditions for light intensity (with shading to 50% and with addition of artificial light). In May, one-year-old self-rooted plants of cvs. Arbequina IRTA-i18, Koroneiki and Frantoio were introduced in fertigation and at the end of June were selected for uniformity of growth, distributed in the two zones and subjected to treatments: intact plants reared upright; plant topped at the first internode distinguishable with stem reared erect; plant cut at the base on the oldest wood. Four plants were used per treatment and cultivars distributed by blocks for each area. Similarly, four-year-old 'Coratina' plants (three plants per treatment), raised on a single stem and acting on individual shoots (intact or topped) throughout the canopy, were utilized. The remarks focus on the origin of the shoots from the different meristems and the growth and behavior of their lateral buds in the following season. Observations led to identification in the same bud complex of a vertical succession of two different types of buds: the "principal" bud and, in upper position, the "accessory" bud, the former with a reproductive role, the latter specialized in environmental exploitation (vegetative role). Starting from the primordia of an accessory bud, the apical meristem became "mature" growing in the time with important differences between the cultivars, acquiring only in the second year of growth for 'Arbequina' and 'Koroneiki' (early bearing cultivars) the capability to produce principal lateral buds able to develop in the inflorescences: with 'Frantoio' the "aging" of two years is not enough to move the principal buds to develop inflorescences. In the "mature" shoots the principal lateral buds can develop only as panicles, and the production of new bearing vegetation is limited to the central leader; all branches coming from accessory buds are dedicated to burst new vegetation.