Bar-Akiva, A., Volcani Institute of Agricultural Research, Division of Citriculture, Bet Dagan, Israel

The presence of small amounts of apparently physiologically significant nitrate-N in citrus leaves was demonstrated. Nitrate-N and total N were determined and compared in citrus tree leaves receiving different rates of N and, in one case, additional P and K fertilizers. The nitrate-N in the leaves showed a close relationship with the N fertilizer rate. In P and K fertilized trees, nitrate-N content was also affected by these two elements. © 1972, Taylor & Francis Group, LLC. All rights reserved.