Effect of regulated deficit irrigation on quality parameters, carotenoids and phenolics of diverse tomato varieties (Solanum lycopersicum L.)

- Marked differences in some of the parameters studied were found across varieties.
- Regulated deficit irrigation (RDI) can enhance carotenoids and phenolics levels.
- Overall RDI and cluster position had no major impact in the fruit commercial quality.

This study aims to evaluate the effects of regulated deficit irrigation (RDI) and of cluster position (CI: first and second cluster; CII: third and fourth cluster; CIII: fifth and sixth cluster) on fruit quality parameters, carotenoids and phenolics in tomatoes. Three common ('Tigerella', 'Palamós' and 'Byelsa') and two cherry varieties ('Lazarino' and 'Summerbrix') were studied. The results showed that the regulated deficit irrigation with reduction of 40 and 50% in the leaf water potential in common and cherry tomatoes did not affect greatly the organoleptic quality of common tomatoes and ʽSummerbrixʼ, while cherry varieties were significantly affected with the cluster position. In most case, significant changes in the levels of carotenoids were observed depending on the treatment and the cluster position in all varieties. Significant changes with the treatment and no change with the cluster position were observed in phenolic compounds. Thus, in general, increased total carotenoid levels and reduced the content of phenolic compounds were observed. Considering the significance of changes in the levels of these groups of compounds it was concluded that ʽLazarinoʼ was more susceptible to water deficit, whereas ʽSummerbrixʼ and ʽPalamósʼ were more resistant. On the other hand, the organoleptic and functional quality changed with the variety.

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