Abstract:

The study investigates the effects of nitrogen application rate, organic nitrogen proportion and retained leaf number on the yield and quality of ‘K326’ flue-cured tobacco in Chuxiong region. Through systematic experimentation, we aim to determine the optimal combination of these three key cultivation factors to provide technical support for optimizing the cultivation measures of Chuxiong ‘K326’ and improving tobacco leaf yield and quality. L₉(3⁴) orthogonal experimental design was employed to study nitrogen application rate, organic nitrogen ratio and remained leaf number in Nanhua County of Chuxiong in 2023, and we analyzed the effects of these factors on the agronomic characters, economic characters and chemical composition of tobacco. Results showed that, the nitrogen application rate of 150 kg/hm² had the best performance on comprehensive agronomic characters, and the internal chemical components of tobacco leaves were more coordinated, the nitrogen application rate of 120 kg/hm² had the best performance on economic characters. Organic nitrogen ratio of 30% had the best performance on agronomic characters, and the internal chemical components of tobacco leaves were more coordinated, and organic nitrogen ratio of 10% had the best performance on yield and medium quality leaves ratio, organic nitrogen ratio of 20% had the best performance on output value, average price and high quality leaves ratio. Remained leaf number of 18 had the best performance on agronomic characters and economic characters, remained leaf number of 22 had the best performance on yield, when the number of remained leaves was 20, the internal chemical components of tobacco leaves were more coordinated. Considering the effects of nitrogen application rate, organic nitrogen ratio and remained leaf number, nitrogen application rate of 150 kg/hm², organic nitrogen ratio of 30% and remained leaf number of 20 had the best performance on agronomic characters and chemical quality of flue-cured tobacco; nitrogen application rate of 120 kg/hm², organic nitrogen ratio of 10% and remained leaf number of 20 had the best performance on yield; nitrogen application rate of 120 kg/hm², organic nitrogen ratio of 30% and remained leaf number of 10 had the best performance on output value, average price and high quality leaves ratio. Therefore nitrogen application rate of 120 kg/hm², organic nitrogen ratio of 30% and remained leaf number of 18 was the best combination of this experiment. This can serve as a key cultivation technique for the tobacco variety ‘K326’ in Chuxiong to guide local tobacco production.

Key words: flue-cured tobacco, ‘K326’, nitrogen application rate, organic nitrogen ratio, remained leaf number, agronomic characters, yield, quality