Alternative practices to improve ‘Firiki’ apple cultivation

Abstract

‘Firiki’ is a local to central Greece apple cultivar approved as protected designation of origin based on its history and high quality. Its cultivation is not expanding due to its major drawbacks: alternate bearing, strong vegetative growth and bruising susceptibility. Trials were performed in two commercial orchards to manage vegetative growth and increase bruising resistance. Fruiting trees were sprayed 12 days after full bloom with Prohexadione-Ca (Pro-Ca) or repeatedly with a commercial product containing calcium silicate (CaSi) in nanoparticles in combination with summer pruning. Branch girdling was performed around 15 days after full bloom. Leaf, and shoot characteristics were measured in June and September, and fruit quality was evaluated at commercial maturity early October. Pro-Ca resulted in reduced shoot growth and nodal length, negatively affected leaf characteristics (specific leaf mass, chlorophyll content), shoot dry matter, and fruit mass, with minor effects on fruit quality at commercial harvest. Girdling also resulted in reduced shoot growth and leaf chlorophyll content, but increased shoot dry matter, fruit mass and fruit quality (except of decreased flesh firmness). CaSi did not result in a similar pattern on all characteristics measured in the two orchards evaluated, but even more, it was found to accelerate flesh bruising appearance compared to control. Girdling seems a promising method to manage vegetative growth and fruit quality in ‘Firiki’ apple, but alternative methods should be tested to improve fruit bruising resistance. © 2021 International Society for Horticultural Science. All rights reserved.