Distribution and recycling of canopy nitrogen storage reserves in sweet cherry (Prunus avium) fruiting branches following 15N-urea foliar applications after harvest

AbstractM. Ayala, P. Banados, M. Thielemann, and R. Toro. 2014. Distribution and recycling of canopy nitrogen storage reserves in sweet cherry ( Prunus avium ) fruiting branches following 15 N-urea foliar applications after harvest. Cien. Inv. Agr. 41(1): 71-80. In sweet cherries, accumulated nitrogen (N) stores from the previous fall support early spring growth. To complement the N supply in the soil, Chilean growers use foliar urea applications after harvest. Information on the effectiveness of foliar N applications in sweet cherry is lacking. To study the canopy distribution of N applied as urea foliar sprays, an experiment using a “Bing”/“Gisela ® 6” (“GI®6”) sweet cherry orchard was carried out in 2009/2010 in Chile (35o 09’ 53’’ S, 71o 20’ 43’’ W). The objective was to investigate N distribution and recycling in 3-year-old fruiting branches. A total of 120 branches (one per tree) were labeled using 15 N-urea. 15 N-urea was applied to the whole branch on four separate dates or treatments (TR) after fruit harvest: TR