Effect of Nitrogen Levels and Application Schedules on Physiological Growth Indices of Maize (Zea mays L.) in Kandahar province of Afghanistan

Abstract

A field experiment was conducted at Research Farm, ANASTU, Kandahar, Afghanistan during
2015 to investigate the effect of nitrogen levels and its application schedules on physiological growth
indices in maize. Four levels of nitrogen (0, 120, 180 and 240 kg N ha–1) and three N application
schedule (1/2 dose at sowing + ½ dose at knee high stage; ½ dose at knee high stage + ½ dose at
tasseling and ¼ dose at sowing + ½ dose at knee high stage + ¼ dose at tasseling stage) were tested
in a factorial randomized block design (FRBD) and replicated three times. The results revealed that
physiological growth indices (LAI, CGR, RGR, and NAR) and yield were higher with application
and 240 kg N ha–1 than other levels of N. These values were also higher when N was applied in
three splits as ¼ dose at sowing + ½ dose at knee high stage + ¼ dose at tasseling stage. Significantly
higher physiological growth indices and yield were also observed when 240 kg N ha–1 was applied
with split application of ¼ dose at sowing + ½ dose at knee high stage + ¼ dose at tasseling stage.