ISHS Acta Horticulturae 807: International Symposium on Strategies Towards Sustainability of Protected Cultivation in Mild Winter Climate
EFFECTS OF NUTRIENT SOLUTION EC ON YIELD, QUALITY AND SHELF-LIFE OF LETTUCE GROWN IN FLOATING SYSTEM |
| Authors: | D. Scuderi, F. Giuffrida, G. Noto |
| Keywords: | soilless system, hydroponic, salinity, fresh-cut, nitrate, leafy vegetables, Lactuca sativa L. |
| Abstract:
Leafy vegetables can be profitably grown in floating system to obtain fresh-cut products. This system allows to enhance quality (e.g. low nitrate content) as well hygienic characteristics of raw material. Different researches investigated the effect of salinity on yield and quality of leafy vegetables, while scarce attention was addressed to the influence of nutrient solution EC on quality parameters during fresh-cut storage. For this purpose a trial was carried out to evaluate the effect of different nutrient solution EC on yield, quality and shelf-life of fresh-cut lettuce. Plants of Lactuca sativa var. acephala (‘Simply’) and var. longifolia (‘Duende’ and ‘Xanadu’) were grown in floating system. Three nutrient solution EC levels (2.8, 3.8 and 4.8 mS cm-1) were compared. At harvest (45 days after sowing) plants (5-6 leaves) were weighed and processed using standard commercial practices (cutting, washing, centrifugation and packaging) to obtain fresh-cut product stored at 5°C. Some quality parameters to evaluate the shelf-life were determined after 1, 4 and 9 days of storage. At the increasing nutrient solution EC from 2.8 to 3.8 mS cm-1, the yield decreased significantly from 6.1 to 5.8 kg m-2 in all cultivars. Further increase of salinity level did not determine yield reduction, but modified some quality characteristics (increase of dry matter percentage and reduction in leaf nitrate content). In relation to storage, the respiratory process at 9th day was lower for lettuce grown with 3.8 mS cm-1 that also showed an increase of firmness at the end of period considered. With regard to shelf-life of the cultivars, ‘Simply’ showed a better suitability to fresh-cut processing than mini-romaine lettuces in relation to small variations of studied quality characteristics (nitrate content, firmness, dry matter and colour) during the storage period. | |
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