Salinity and olive: From physiological responses to orchard management

Cultivated olives are commonly subjected to salinity stress. This is particularly true when orchards are irrigated with saline, recycled, and other marginal waters. Understanding plant response and mechanisms of salt tolerance in olives is imperative to orchard planning and management. Literature concerning olive physiology, growth, and oil production as a function of salinity is reviewed and emphasizes that, in spite of the olive's general high tolerance for stress, including that caused by salinity, response to salinity and extent of tolerance mechanisms are strongly cultivar-specific. Environmental conditions causing increased root zone salinity can lead to reduced photosynthetic activity, vegetative growth, and fruit and oil production and therefore, salinity is expected to harm production in commercial orchards. Regardless of this, several field studies report that exposure to moderate levels of salinity did not negatively affect yields. Additionally, salinity appears to contribute to positive attributes of olive oil. Proper management of water and salinity, including leaching of salts out of the root zone, can therefore allow optimization of high yields and high oil quality in orchards irrigated with saline water.