Yields and quality in relation to planting bed management of organically grown strawberry cultivars

A four-year strawberry field trial was conducted under organic production in a North Atlantic coastal climate. Three mulching materials, viz. black plastic film, barley straw and fresh spruce bark, were compared in the cultivars 'Korona', 'Nora' and 'Jonsok'. Runner plants were planted in single rows on elevated beds at plant spacings of 0.20, 0.25 and 0.30 m in rows 1.2 m apart. Plastic mulch gave the highest total and marketable yields in the first three years, while bark mulching gave the highest yield in the fourth year. Of the two organic mulches, bark gave the highest yields and fewest diseased fruits. Straw mulch performed well in the first year of harvest, with higher yields than bark mulch and the lowest number of fruits infected by Botrytis cinerea. In all four years, plastic mulch gave the highest percentage of infected fruits. 'Korona' gave about twice the yield and twice the fruit weight compared to the other cultivars. 'Nora' had the lowest percentage of fruits with B. cinerea. Plastic mulch promoted fruit ripening and straw mulch delayed ripening, but the differences were small.