The response of Hongda, a flue-cured tobacco cultivar, to nitrogen fertilizer rate

ABSTRACT

Nitrogen fertilizer is essential for the yield and quality of flue-cured tobacco. Honghuadajinyuan (i.e. Hongda) is a special flue-cured tobacco variety in Yunnan, which differs in nitrogen application rates from other varieties. In 2016 and 2017, different nitrogen application rates were established in Yunnan to compare, with other varieties, Hongda’s agronomic, economic, chemical indicators and soil residual nitrogen. As nitrogen fertilizer rate increased, the ratio of fresh weight to dry weight (RFD) and the proportions of inferior tobacco (PIT) initially decreased and then increased in contrast to the proportions of superior tobacco (PST) and average price. Total sugar and reducing sugar contents in flue-cured tobacco leaves decreased as nitrogen fertilizer rate increased, while total nitrogen, nicotine, and protein contents increased. The highest sensory evaluation scores were obtained with 45 and 60 kg N ha⁻¹. Soil nitrate contents increased with increasing nitrogen fertilizer rate and significantly increased when nitrogen application rate exceeded 60 kg N ha⁻¹. A quadratic model was suitable for Hongda’s response to nitrogen fertilizer rate and 60 kg N ha⁻¹ can meet the needs of the growth of this flue-cured tobacco variety.

Abbreviations: Hongda: Honghuadajinyuan; RFD: ratio of fresh to dry weight; PIT: proportion of inferior tobacco; PMT: proportion of medium tobacco; PST: proportion of superior tobacco; SPAD: soil and plant analyzer development.

KEYWORDS:

• Tobacco quality
• quadratic model
• sensory evaluation
• economic value
• residual nitrogen

Acknowledgements

The authors are thankful to M.S. Coyne for his valuable assistance and advice in the preparation of this paper.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This study was financially supported by several projects from the National Natural Science Foundation of China [No. 41601330]; Yunnan Science and Technology Innovation Project [2019HB068]; Yunnan Ten Thousand People Program [2018-73]; Yunnan Applied Basic Research Projects [No.2017FB074] and Tobacco Monopoly Bureau China [2016 YN28, 2016YN31, 2019530000241012, 2019530000241019 and 2017YN09].