Foliar application of nitrogen at different growth stages influences the phenology, growth and yield of maize (Zea mays L.)

Foliar fertilization has been widely used and accepted as an essential part of crop production. The objective of this study was to investigate the response of maize (Zea mays L., cv. Azam) to foliar application of nitrogen (2%) from different sources viz. urea, ammonium sulphate (AS) and calcium ammonium nitrate (CAN)] and its application time [15, 30, 45, and 60 days after emergence (DAE)]. The experiment was laid out in randomized complete block design (RCBD) with split plot arrangement using four replications at the research farm of the University of Agriculture Peshawar during summer 2010. Phenological development was delayed, while plant height, 1000-grains weight, grains ear(-1), biomass and grain yield as well as harvest index was increased with foliar application of N than water spray (control). Plant height, leaf area, biomass and grain yield was increased when foliar-N was applied late (45 and 60 DAE) than early (15 and 30 DAE) application. It was concluded from the results that late foliar-N application (urea, CAN or AS) about one week before tasseling up to silking could increase maize productivity in the study area.