TABLE 3.
Contents of chemical compounds during bulk curing of flue-cured tobacco with different salicylic acid concentrations.
| Treatment | Sampling temperature (°C) | Curing time (h) | Total sugar (%) | Reducing sugar (%) | Total nitrogen (%) | Nicotine (%) | Potassium oxide (%) | Water soluble chlorine (%) | Starch (%) | Protein (%) | Ratio of sugar to alkali (%) | Ratio of nitrogen to alkali (%) |
| Control | Fresh tobacco | – | 6.32Ab | 4.55Ab | 1.69Aa | 2.26ABb | 1.58Aa | 0.24Ab | 41.36Aa | 8ABa | 3.01Ac | 0.77Aa |
| 38 | 23.5 | 37.04Aa | 24.53Aa | 1.74Ba | 1.84Bb | 1.68Aa | 0.49Aab | 8.86Abc | 5.83Bb | 22.48Aa | 1.16Aa | |
| 42 | 16.5 | 36.45Aa | 25.85Aa | 1.69Ba | 2.14Bb | 1.42Ca | 0.29Bb | 9.58Ab | 6.17Ab | 18.44Aab | 0.83Aa | |
| 48 | 15 | 34.06Aa | 22.6Aa | 2.04Aa | 3.23Aa | 1.77Aa | 0.41Aab | 5.19Ac | 6.49Ab | 10.58Abc | 0.64Aa | |
| 54 | 22.5 | 34.77Aa | 20.99Aa | 1.75Aa | 2.2Ab | 1.92Aa | 0.62Aa | 7.81Abc | 6.11Ab | 15.95Aab | 0.8Aa | |
| Primary tobacco leaf | – | 33.61Aa | 23.52Aa | 1.94ABa | 2.59Aab | 1.7Ba | 0.46Aab | 7.95Abc | 6.44Bb | 13.04Aab | 0.76Aa | |
| SA-1 | Fresh tobacco | – | 7.62Ac | 4.98Ac | 1.62Ab | 1.66Bb | 1.45Ac | 0.31Ab | 41.91Aa | 6.9Ba | 4.89Aa | 0.98Aa |
| 38 | 23.5 | 32.07ABa | 19.75ABa | 1.94Bab | 2.85Aa | 1.8Abc | 0.56Aab | 8.61ABb | 6.13Ba | 11.37Ba | 0.68Ba | |
| 42 | 16.5 | 20.75Bb | 12.9Bb | 2.2Aa | 3.1Aa | 3.06Aa | 0.87Aa | 3.07Bcd | 7.04Aa | 7.08Ba | 0.71Aa | |
| 48 | 15 | 35.25Aa | 21.95Aa | 1.87Aab | 3Aa | 1.58Abc | 0.55Aab | 4.02Acd | 5.88Aa | 11.85Aa | 0.63Aa | |
| 54 | 22.5 | 32.62Aa | 18.41Aab | 2.01Aab | 2.84Aa | 2.16Ab | 0.52Aab | 1.79Bd | 5.79Aa | 12.05Aa | 0.72Aa | |
| Primary tobacco leaf | – | 31.72ABa | 22.01ABa | 1.92Bab | 2.4Aab | 2.12ABb | 0.59Aab | 6.97Abc | 6.64Ba | 13.21Aa | 0.8Aa | |
| SA-2 | Fresh tobacco | – | 4.39Ac | 2.42Ab | 1.98Aab | 2.65Ab | 1.43Ab | 0.36Aa | 35.94Ba | 8.9Aa | 1.64Ab | 0.75Aa |
| 38 | 23.5 | 28.03Bab | 16.79Ba | 2.59Aa | 3.59Aa | 1.95Aab | 0.68Aa | 4.32Bb | 7.9Aabc | 7.92Bab | 0.72Ba | |
| 42 | 16.5 | 27.63Bab | 19.48Aa | 2.31Aab | 3.18Aab | 2.07Bab | 0.54ABa | 5.03Bb | 7.28Aabc | 8.83Bab | 0.73Aa | |
| 48 | 15 | 34.19Aa | 20.49Aa | 1.93Ab | 2.96Aab | 1.81Aab | 0.53Aa | 3.68Ab | 6.11Ac | 11.71Aa | 0.65Aa | |
| 54 | 22.5 | 33.13Aa | 21.35Aa | 1.96Aab | 3.08Aab | 1.91Aab | 0.48Aa | 3.62ABb | 6.72Abc | 12.91Aa | 0.67Aa | |
| Primary tobacco leaf | – | 25.35Bb | 16.82Ba | 2.35Aab | 3.08Aab | 2.34Aa | 0.68Aa | 4.41Ab | 8.28Aab | 8.28Aab | 0.76Aa |
Different capital letters indicate significant differences between treatments at the same stage (P < 0.05). Different lowercase letters indicate significant differences between the same treatments at different curing stages. Values represent the averages of three biological replicates.