Impact of fruit thinning on fruit properties of Olea europaea 'Kalamata' and 'Manzanilla'

A. Sentouka, C. Sergentani, E. Markakis, G. Koubouris
The main aim of the present two-year study was to investigate the effects of fruit thinning on basic morphometric properties of olive fruits 'Kalamata' and 'Manzanilla'. In the first year, 50% fruit thinning was implemented manually of ten uniform branches of four trees per cultivar in late June, July or August. Fruit harvest was carried out in October, and measurements of fruit size, weight, length, width, moisture and oil content followed. In the thinned branches, fruit load was efficiently regulated and no further fruit abscission was observed. In contrast, in unthinned branches, intense fruit drop resulted in a similar final number of fruits per branch as for the thinned branches. Fruit thinning caused non-significant changes in fruit size, weight, moisture and oil content for both cultivars. Based on the results of the first year, 75% fruit thinning was tested in late June, July or August of the second year. For the thinned branches, significantly lower fruit load was measured during harvest compared with the control. Fruit length, width and weight increased for both cultivars with the thinned branches; however, statistically significant differences were observed only for 'Kalamata'. Date of fruit thinning also had a significant effect on harvested fruit properties. In fact, thinning in late August was more efficient compared with the earlier two dates (June or July) in 'Kalamata'. Selection of the most efficient fruit thinning rate should be customized according to the expected fruit load as assessed by fruit set as well as based on the availability of resources - water and nutrients - and the pest infestation risk. Finally, marketing strategy should also be taken into consideration since maximum fruit size is not always the desired trait, especially in markets with low-income consumers.
Sentouka, A., Sergentani, C., Markakis, E. and Koubouris, G. (2018). Impact of fruit thinning on fruit properties of Olea europaea 'Kalamata' and 'Manzanilla'. Acta Hortic. 1199, 375-378
DOI: 10.17660/ActaHortic.2018.1199.59
fruit drop, fruit size, 'Kalamon', oil content, table olives

Acta Horticulturae