Effect of Graded Nutrient Levels and Timing Nitrogen Application on Yield and Quality of Sweet Corn (Zea mays L.)

Abstract

A field experiment was conducted during the rabi seasons of 2005 and 2006 at S.V.Agricultural college farm, Tirupati to study the effect of four graded levels of NPK and split application of N at different times on yield and quality of sweet corn. The experiment was laid out in split plot design with three replications. Four graded NPK levels viz.,- NPK @ 90:50:40; 120:60:45; 150:70:50 and 180:80:55 kg ha-1 were assigned to main plots and split application of N at different times viz.,- 1/2 basal + 1/2 at knee high stage, 1/2 basal + 1/4th knee high + 1/4 th tasseling; 1/ 3 rd basal + 1/3 rd knee high + 1/3 rd tasseling and 1/4th basal +1/2 at knee high + 1/4th tasseling were alloted to sub plots. The results revealed that increasing the nutrients level of NPK from 90:50:40 to 150-70-50 kg ha-1 significantly increased the yield attributes, green cob yield with husk, green fodder yield and benefit : cost ratio during both the years. It also brought significant improvement in the quality of kernels (higher content of protein, reducing and non-reducing sugars) and of green fodder (higher crude protein and lower crude fibre contents).The yield attributes, yield and quality of sweet corn obtained with NPK @ 150-70-50 kg ha-1 were on par with the highest level of NPK @ 180-80-55 kg ha-1. Application of nitrogen in three splits-1/4th basal + 1/2 at knee high + 1/4th tasseling had substantially increased the green cob weight, kernel number cob-1, green cob and fodder yield of sweet corn as compared to the application of nitrogen in two splits-1/2 basal + 1/2 at knee high stage. Time of nitrogen application did not exert any significant effect on the quality of sweet corn.