Effects of organic vs. conventional farming system on yield and quality of strawberry grown as an annual or biennial crop in southern Italy

Organic foods represent a significant market segment within the global food industry, since these prod-ucts are often believed to be safer and more nutritious than their conventional counterparts. Due to the growing importance of organic strawberry cultivation for several agricultural areas in Italy, we carried out a four year research (2008–2011) on Fragaria × ananassa grown under tunnel in Campania (southern Italy), with the purpose of assessing the effects of two farming systems (organic or conventional) combined with propagation material (fresh or cold stored plants) and crop duration (annual or biennial) on yield and quality. The experimental treatments were randomized in a split-plot design, assigning the farming systems to the main plots and the propagation material in factorial combination with the crop duration to the subplots, with three replicates. The conventional system produced the highest yield, as a consequence of the higher fruit number per plant, while the organic management resulted in increased berry mean weight. Organic fruits showed higher values of dry and optical residue and higher content of glucose, sucrose, vitamin C and ß-carotene but lower nitrate. Fresh plant crops produced a lower yield than the cold stored ones; moreover, the fruit production of fresh plants was higher when grown as an annual crops compared with a biennial cycle, independently on the farming system. In the case of cold stored plants, no yield differences were recorded between annual and biennial cultivations under conventional management, whereas organic crops from cold stored plants showed higher yields as annual crops compared with the biennial cycle. Fruit dry residue as well as sucrose, malic acid and mineral element content attained higher values in the fruits harvested from biennial crops than from the annual ones. The choice of organic system as an alternative to the conventional practice could be justified by the better fruit quality, lower environmental impact and higher market prices. Moreover, the biennial crop duration could be a cost effective option when the crop is started from cold stored plants under organic management.