Influence of controlled deficit irrigation on tomato functional value.

The effect of controlled deficit irrigation (CDI) on the accumulation of carotenoids, polyphenols and l-ascorbic acid was studied in conventional and high lycopene tomato cultivars. Plants were initially irrigated to cover 100%ET and after the fruit set phase, the dose was reduced to 75% or 50% of ET. CDI had no significant effect on the accumulation of carotenoids, while it increased the levels of the hydroxycinnamic acids chlorogenic and ferulic acids, the flavonoid rutin and l-ascorbic acid. Nevertheless, there were important interactions and this effect was highly dependent on the year and site of cultivation. Certain growing areas would be more favorable to supply high quality markets, and, fortunately, CDI would maximize polyphenol (100-75%ET) and l-ascorbic acid (100-50%ET) in these areas. A combination of the best genotype and growing area with CDI would offer high quality products, preserving a scarce resource: water.