Effects of Different Irrigation Modes on Internal Quality of Flue-cured Tobacco Leaves

[Objective] This study aimed to investigate the effects of different irrigation modes on chemical constituent and aroma substance contents and sensory quality in flue-cured tobacco leaves. [Method] Field experiments were conduced with two treatments, including watering irrigation and micro-spraying irrigation. In watering irrigation treatment, flue-cured tobacco seedlings were respectively watered by artificial root irrigation once at rosette stage（May 26） and vigorous growth stage（June 18）, 1kg/plant each time; in micro-spraying treatment, flue-cured tobacco seedlings were watered by artificial root irrigation once at rosette stage（May 26）, 1 L/plant. [Result]Compared to watering irrigation mode, micro-spraying irrigation could extremely significantly increase the content of main aromatic substance in middle and upper leaves.Contents of main aromatic substance non-volatile organic acids, volatile organic acids, petroleum ether extracts, neophytadiene and neutral aromatic substances in C3F tobacco leaves were improved by 24.4%, 32.6%, 20.7%, 33.8% and 26.3%, respectively; contents of main aromatic substance non-volatile organic acids, volatile organic acids, petroleum ether extracts, eophytadiene and neutral aromatic substances in B2F tobacco leaves were improved by 16.3%, 6.0%, 6.1%, 10.8% and8.1%, respectively. In addition, micro-spraying irrigation could extremely significantly reduce the nicotine content in middle and upper leaves and improve the aromatic coordination, mellow taste and smoldering property. [Conclusion] In flue-cured tobacco production, micro-spraying technology is an important means to improve the internal quality of flue-cured tobacco leaves, which can be adopted to effectively solve the problem of declining quality of flue-cured tobacco leaves resulted from the dry climate at maturation stage in seasonal frequent-drought areas.