Reproductive physiology and sexual compatibility of the Spanish olive variety ‘Arbequina’ cultivated in Montenegro

Abstract

Aim of study: One of the newly introduced olive varieties in Montenegro is the Spanish olive (Olea europaea L.) variety ‘Arbequina’. The aim of this work was to study the changes in the reproductive physiology of the cultivar 'Arbequina' in conditions of Montenegro. Area of study: Comparative experimental plots were established in two areas in Montenegro, the coastal region of Ulcinj and the inland region of Podgorica. Material and methods: The research was conducted at four experimental sites (UL1 and UL2 in Ulcinj; PG1 and PG2, in Podgorica) over four years. Flowering phenophases, inflorescence characteristics, and inflorescence architecture were assessed. Pollination trials consisted of open-pollination, self-pollination, and cross-pollination of ‘Arbequina’ with several olive varieties, resulting in an assessment of fruit set. Main results: A high level of fruit set (6.75%) in ‘Arbequina’ in open-pollination was recorded in the multi-varietal orchard (PG2). A much lower fruit set was found in the mono-varietal hedgerow orchards (0.75% in PG1 and 0.33% in UL2). The fruit set was very low in the mono-varietal orchards in self-pollination trials, ranging from 0.01% (PG1) to 0.06% (UL1). Research highlights: These results confirm that ‘Arbequina’ is a self-incompatible variety, which is crucial both for farmers in establishing new plantations and for scientists in future research. Some of the 11 olive varieties cross-pollinated with the ‘Arbequina’ variety displayed pollinating potential, which needs to be proven with paternity tests. Despite the differences between experimental sites and areas, ‘Arbequina’ exhibited high reproductive potential, confirmed by many perfect flowers.