Is chilling a prerequisite for flowering and fruiting in 'Arbequina' olives?

Abstract

It is generally thought that olives (Olea europaea) require several days (over 80 days) of chilling temperatures ( 7.2°C) for flower induction; minimum nighttime temperatures between 2-4°C and maximum daytime temperature of 15.5-19°C are considered optimum for flower and fruit production. Environmental chamber studies were conducted on potted olive trees for the purpose of defining flowering conditions for 'Arbequina.' We repeatedly observed that good flower and fruit production in 'Arbequina' can be achieved even when the plants are not subjected to "chilling" temperatures or any chilling criteria that had previously been described necessary for flower and fruit production in olives. This phenomenon could be of great practical value because the results obtained can be exploited to cultivate olives in subtropical climates (e.g., southern and coastal Texas) where typical "chilling" temperatures are not commonly observed for prolonged periods of time.