Effect of Nitrogen Rate and Cultivar on Burley Tobacco Yield and Leaf Quality

Nitrogen fertilizer management for burley tobacco is necessary to achieve optimum yield. Improper N application can reduce growth and produce poor leaf quality. Current N recommendations for burley tobacco are based on older cultivars. Cultivars (TN 90, KT 204, NC 2000, and NC 7) with improved yield and disease resistance have recently been developed. These cultivars were compared to a high yielding older cultivar, Clay's HY 403, that is susceptible to various diseases. All cultivar treatments received four N treatments (broadcast plus side-dress) of 112, 168, 224, and 280 kg N per ha. Experiments were conducted in 2005, 2006, and 2007 at the Upper Mountain Research Station, Laurel Springs, NC, and two sites at the Mountain Research Station, Waynesville, NC. Nitrogen rate affected tobacco height, time of flowering, and yield at each location, with the 224 kg N per ha rate adequate for optimum burley tobacco yield. Highest yields were produced with the 224 kg N per ha rate on seven of nine location/years, and the 280 kg N per ha rate in two of nine location/years. Leaf quality was not influenced by N rate. Recently developed burley cultivars (TN 90, KT 204, NC 2000, and NC 7) with enhanced disease resistance produced yields equivalent to an older cultivar (Clay's HY 403), and increased yields greater than Clay's HY 403 when blue mold (Peronospora tabacina) was present.