Submitted to: New Ag International Magazine
Publication Type: Popular Publication
Publication Acceptance Date: 4/11/2015
Publication Date: 4/15/2015
Citation: Centofanti, T., Banuelos, G.S., Wallis, C.M., Ayars, J.E. 2015. Deficit irrigation: is it impacting yield and nutritional quality of fruits?. New Ag International Magazine. March/April 54-56.
Technical Abstract: Water scarcity, impaired water quality, and decreased soil quality threaten agricultural production in many regions of the world. Farmers’ responses to water shortage and recurrent droughts will ultimately result in the reduced application of water, designated as deficit irrigation (DI). DI may result in various advantages such as: maximizes water productivity (the ratio of marketable yield to the amount of water consumed by the crop), reduces the risk of diseases and pest attacks, reduces nutrient losses through leaching, and enhances fruit nutritional quality. The net effect of DI strategies on plant responses to water stress and their consequences on fruit nutritional quality has not yet been studied for pomegranate. Moreover, very little is known about effects of drought and reduced irrigation on pomegranate fruit nutritional value, especially its impact on levels of antioxidants. The goal of this study was to evaluate the physiological response of pomegranate trees to deficit irrigation strategies relative to fruit yield and quality (antioxidants, such as phenolic compounds). The experiment was carried out on three-year-old pomegranate (Punica granatum L.) trees using the variety ‘Wonderful’. Four DI treatments were applied: 35%, 50%, 75% and 100% of evapotranspiration (ETlys) based on pomegranates grown in a lysimeter located at USDA-ARS San Joaquin Valley Agricultural Sciences Center in Parlier, CA. Fruits were harvested in 2012 and 2013. Yield was recorded and fruit juice was analyzed for concentration of antioxidants: total phenolics and polyphenols. Our 2-year study has shown that application of DI strategies does not affect yield and fruit nutritional quality of pomegranate within the tested years. Long-term studies are essential to better predict physiological responses to water deficit irrigation in pomegranates relative to nutritional quality and productivity.