The effect of source and rate of sidedress nitrogen on yield and quality of burley tobacco

Two field experiments were conducted during the growing seasons of 1983 and 1984 at the University of Tennessee Tobacco Experiment Station, Greeneville, Tennessee, to study the effect of source and rate of sidedress nitrogen on yield and quality of hurley tobacco (Nicotiana tabacum L.). The 1983 experiment consisted of two tests, namely sod tobacco (tobacco following sod) and continuous tobacco (tobacco following tobacco). Only sod tobacco was planted in the 1984 season. Three rates of sidedress nitrogen at 33, 100, and 165 pounds per acre, and nitrogen sources in the forms of sodium nitrate, ammonium nitrate, and urea were used. All treatments received a preplant broadcast application of 450 pounds of 9-18-27 per acre.

No significant differences were found for yield, grade index, and crop index among the nitrogen rates and sources. Notably higher values were obtained for the sod tobacco over the continuous tobacco.

There were significant differences among rates of nitrogen for percent contents of nitrogen, potassium, and calcium in the cured leaves. Percent nitrogen and calcium contents increased with increasing nitrogen rates. While percent potassium showed inconsistent response, percent phosphorus and magnesium contents were not significantly affected by the treatments. Nitrogen sources had no significant effect on the percent contents of nitrogen, phosphorus, calcium, and magnesium. However, sodium nitrate produced significantly higher percent potassium content than either ammonium nitrate or urea.