Sugar and organic acid contents of day-neutral and ever-bearing strawberry cultivars in high-elevation for summer and autumn fruit production in Korea

Abstract

This study was conducted to evaluate the contents of sugars and organic acids in the fruits of day-neutral (DN) and ever-bearing (EB) cultivars grown in high-elevation in Korea. Six DN and five EB cultivars were established in bench-top substrate culture system in high tunnel. Plug transplants were planted on 5 May, 2011 and complete nutrition was supplied during the whole experimentation. Fruit harvest started in early June, and lasted until middle of November. The fruits of DN cultivars showed higher organic acid contents but lower sugar contents and total soluble solids than those of EB cultivars. ‘Albion’ showed the highest contents of total soluble solids and sugars, and sugars/acids ratio among DN cultivars. Among EB cultivars, ‘Goha’ possessed mediate contents of sugars, organic acids and total soluble solid without any extreme weakness in qualities. ‘Charlotte’ showed the highest contents of sugars and total soluble solid, and sugar/acid ratio, and the lowest contents of organic acids; the unique character of ‘Flamenco’ was its lowest contents of organic acids among EB cultivars. Fruit total soluble solid contents, sugars, organic acids, and sugar/acid ratio all significantly varied with the progressive seasons and an interactive effects between cultivars and harvest time on above fruit quality parameters were found. Integrated cultural strategy based on contents of sugars and organic acids was discussed according to fresh consumption and process purposes.