| Taking transplanting time and fertilizer topdressing time as factors, the field experiment was carried out, the effects of different treatments on the growth and development, physiological indexes, economic characters, intrinsic chemical composition and physical characters of flue-cured tobacco leaves were studied, the results showed that:1. The growth and development of tobacco plant. As the transplanting period delay, field growth period gradually reduced. Fertilizing earlier, the growth and development stages shorten accordingly. Early transplanting had a little effect on agronomic traits of rosette stage, promoted the fast growing period, the performance was better in the treatments with nitrogen fertilizing earlier in the early stage. As transplanting time delay, the rapid growth of roots, stems, and leaves was ahead of time, growth rate was faster.2. Tobacco physiological indexes. At fast growing period and topping stage, leaves net photosynthetic rate, stomatal conductance, transpiration rate were at high levels. With the advancement of crop growth, root activity reduced gradually, reached the peak at the bottom leaves harvest. The treatment with transplanting by well cellar type, tobacco root activity also keep higher level after the topping stage. Total nitrogen content of stems and leaves was the largest at rosette stage, the root potassium absorption peak was delayed in the treatments with early transplanting, total potassium content of leaves was higher at rosette stage and topping stage.3. Roast tobacco leaves chemical components. Transplanting earlier and fertilizer topdressing earlier had a positive effect on the quality improvement of flue-cured tobacco, overall, the treatment A1B3(transplanting deeply by well cellar type5days in advance and completed nitrogen fertilizer topdressing within25days after transplanting), A2B2(transplanting deeply by well cellar type10days in advance and completed nitrogen fertilizer topdressing within30days after transplanting) and A2B3(transplanting deeply by well cellar type10days in advance and completed nitrogen fertilizer topdressing within25days after transplanting) performanced best, intrinsic chemical composition had the best coordination. 4. Roast tobacco physical properties. Leaf length, leaf width, leaf thickness and equilibrium moisture content of X2F grade flue-cured tobacco leaves were suitable under all the treatments. The physical properties of C3F and B2F grade flue-cured tobacco leaves were optimum under treatment A2B2ã€A2B1(transplanting deeply by well cellar type10days in advance and completed nitrogen fertilizer topdressing within35days after transplanting)5. Roast tobacco economic characters. The yield difference was not obvious among the treatments, the output value, average price, proportion of superior tobacco leaves and secondary superior tobacco leaves were increased with the advance of transplanting time and fertilizer topdressing time, the treatment A2B3and A2B2had a better comprehensive performance.Comprehensive evaluation, the treatment A2B2, namely transplanting deeply by well cellar type10days in advance (this test was the March16) and completed nitrogen fertilizer topdressing within30days after transplanting combination was the best. |
