EFFECT OF FERTILIZER LEVELS AND PLANT DENSITIES ON YIELD AND PROTEIN CONTENTS OF AUTUMN PLANTED MAIZE

A field experiment was conducted during 2006 and 2007 to determine the effects of different fertilizer levels and plant densities on yield of autumn planted maize. Maize hybrid Pioneer 30-Y-87 was selected as test. The treatments comprised of six fertilizer levels (150-0, 150-15, 200-0, 200-15, 250-0 and 250-15 kg N-Zn ha^-1) and three plant densities (57100, 71400 and 99900 plants ha^-1). The highest plant height and grain yield was recorded from those maize plots which were fertilized at 250 kg N ha^-1 and 15 kg Zn ha^-1 and the crop was sown at plant density of 99900 plants ha^-1against the significantly minimum plant height and grain yield where fertilizer was applied at 150 kg N ha-1and 0 kg Zn ha^-1 and crop was sown at plant density of 57100 plants ha^-1. Increasing fertilizer levels and plant densities linearly increased plant height and grain yield. Application of Zinc accelerated tasseling and silking of maize crop, however the application of nitrogen had no significant effect on tasseling and silking. The fertilizer levels and plant densities also significantly affected protein contents of maize grain. Application of nitrogen at higher levels improved protein contents of grain however, opposite was true for protein contents of grains collected from the crop sown under higher plant densities. It was concluded that application of fertilizer at 250 kg N ha^-1 and 15 kg Zn ha^-1 and the sowing of crop at plant density of 99900 plants ha^-1 showed the best results.