Response of Wheat Genotypes to Different Levels of Nitrogen

A field experiment was conducted using six genotypes of wheat ( Triticum aestivum L.) for response to different levels of nitrogen (N) use.  The experiment was laid out in split plot design with four levels (0, 50, 100 and 150 kg N ha -1 ) as main plots and six wheat genotypes (BL 3623, BL 3629, BL 3872, NL 1008, NL 1055 and Vijay, a check variety) as sub-plots.  Grain yield and other yield components increased linearly in response to N concentrations in both seasons.  Only two parameters: days to heading (DOH) and days to maturity (DTM) varied significantly (p ≤ 0.05) among wheat genotypes in both the years.  None of the parameters showed interaction effects in both seasons. Vijay showed highest grain yield of 3.12 t ha -1 in 2013 with the application of 100 kg N ha -1 , and 3.23 t ha -1 in 2014 with 150 kg N ha -1 . Spike length, productive tillers m -2 , number of spikes m -2 and test weight were greater with higher N rates. The straw yield of wheat fertilized with 150 kg N ha -1 was the highest in Vijay (4.35 t ha -1 ) and BL 3872 (4.33 t ha -1 ), respectively.  Vijay with 100 kg N ha -1 produced the highest number of productive tillers m -2 (276.33) in 2013 and 296.00 with the application of 150 kg N ha -1 in 2014.