Studying Quality Attributes of Grafted Specialty Melons using Both Consumer Sensory Analysis and Instrumental Measurements

Grafting is an effective approach to controlling soilborne diseases and alleviating abiotic stresses in cucurbits. Previous research revealed mixed results regarding rootstock impacts on fruit quality. However, few studies evaluated fruit quality attributes using both consumer sensory analysis and instrumental measurements. In grafted specialty melon production, the rootstock effect on fruit quality deserves more attention as specialty melons are marketed for outstanding taste and unique fruit flavor. In this field study conducted during the 2012 spring season in Citra, FL,  galia melon ‘Arava’ (Cucumis melo var. reticulatus) and honeydew melon ‘Honey Yellow’ (C. melo var. inodorus) were grafted onto commercial rootstock ‘Strong Tosa’ (Cucurbita maxima x C. moschata) (Ar/St and HY/St) and root-knot nematode resistant Cucumis metulifer (Ar/Cm and HY/Cm). Ar/St and HY/St were grown in fumigated vs. non-fumigated conventional fields, while Ar/Cm and HY/Cm were grown in organic vs. non-fumigated conventional fields. Non-grafted (NAr and NHY) and self-grafted (Ar/Ar and HY/HY) melons were used as controls. At harvest, eight to ten melon fruit with similar size and ripeness were selected for both consumer sensory analysis and instrumental assessment. Two consumer taste tests (96–100 panelists) were conducted for each melon cultivar at two harvest dates. A 1–9 hedonic scale (1 = dislike extremely, 9 = like extremely) was used in evaluating all the sensory attributes. Regardless of the production systems, Ar/St received significantly lower scores in consumer overall acceptability, flavor, and firmness liking compared to NAr. Reduced total soluble solids (TSS) content and flesh firmness of Ar/St were detected by the instrumental measurements. Grafting with Cucumis metulifer significantly decreased consumer overall acceptability and flavor liking for organically grown ‘Arava’ fruit, but the difference between grafted and non-grafted treatments was not detected in melons produced from the non-fumigated conventional filed. Interestingly, the instrumental measurements did not show any significant differences in TSS and flesh firmness between Ar/Cm and NAr from either field. However, more consumers detected off-flavor in Ar/Cm than in NAr. Across different production systems, few differences were detected from the instrumental assessment between non-grafted and self-grafted ‘Arava’ fruit, whereas inconsistent results were observed in the consumer sensory analysis. Different from ‘Arava’, grafting did not exhibit any significant effect on TSS, flesh firmness, and consumer perceived sensory attributes of ‘Honey Yellow’ melons. The influence of scion-rootstock interactions on fruit quality in relation to consumer perceived sensory properties of grafted melons deserves more comprehensive studies.