Alternate bearing in olive initiated by abiotic induction leading to biotic responses

Abstract

Alternate bearing of olive trees is one of the most troublesome characteristics of this commodity, impacting its economy due to labor distribution, fruit and oil availability, oil mill capacity and marketing. The metabolic changes leading to alteration in fruit production are generally considered of direct genetic nature. In the present review, this approach is challenged, showing that all the biotic-metabolic changes in olive leading to ‘on’ and ‘off’ years are the results of initial abiotic effects on the trees. The nature of the metabolic changes induced by the abiotic regional and annual conditions described are, no doubt, genetically controlled but initiated only as a result of adverse environmental abiotic conditions such as seasonal temperatures, water stress, and soil nutrition conditions.