不同播期对烤烟品种产量和品质的影响

Effects of sowing date on tobacco yield and quality

为了探索韶关烟区适宜的播种期和移栽期,以6个优质烤烟品种(品系)为材料,进行分期播种,塑造不同的光温气候条件,以优质中部烟叶化学成分为参考样,用指标赋值法对烤烟(等级为C3F)化学品质进行综合评分,依品质优劣将不同品种排序。结果表明:播期显著影响烤烟品种的产量和品质的形成。产量高低决定产值高低,适当推迟播期有利于提高烤烟产量和产值;但播种过迟会严重降低产量,降低烤后烟叶中上等烟比例,导致产值下降。烟叶化学品质中烟碱含量、总氮含量、淀粉含量、钾含量均受播期影响,随着播期延迟C3F烟叶的烟碱含量、总氮含量、钾含量减小,淀粉含量明显增加,影响烤烟品质;但3个播期中各品种的氮碱比、糖碱比、钾氯比变化因品种而异。在3个播期试验品种中,各品种的C3F品质平均综合评分表现为"云烟100"、"NX208"、"K326"的评分相对较高,C3F烟叶品质较好。适当的播种期使得烟叶化学成分的协调性好,利于提高烤烟的产量和品质。不同播期试验表明,韶关烟区适宜播种期为12月1日—12月10日,适宜移栽期为次年2月25日—3月5日。

Six high quality varieties（lines） of tobacco were sown at different dates to explore suitable times for seeding and transplanting in Shaoguan tobacco fields.Chemical quality of the flue-cured tobacco was comprehensively determined using quality grading（grade C3F） assessment.Results showed that yield and quality of flue-cured tobacco were significantly influenced by sowing time.Tobacco economic value was determined from yield amount.Appropriate sowing date delay improved yield and economic value of flue-cured tobacco.However,yields heavily dropped due to too late sowing date,and the proportion of me-dium-high grade tobacco leaves after baking declined along with economic value.Chemical components such as nicotine,total nitrogen,starch and potassium were influenced by different sowing dates.Nicotine,total nitrogen（TN） and potassium（K2O） of C3F leaves decreased under delayed sowing dates.However,starch increased significantly while flue-cured tobacco leaf quality deteriorated.Changes in the ratios of total nitrogen to nicotine（TN/nicotine）,reducing sugar to nicotine（RS/nicotine） and potas-sium to chlorine（K2O/Cl） under different sowing dates were mainly driven by differences in crop variety.Total scores of C3F leaves of ＂Yunyan 100＂,＂NX208＂ and ＂K326＂ tobacco varieties were relatively high for the three different sowing dates.This suggested that the qualities of three varieties of flue-cured tobacco were better than other varieties.Appropriate sowing dates en-hanced the chemical composition of tobacco leaves,which in turn benefited tobacco yield formation and quality grade.The results suggested that most suitable sowing date of tobacco in Shaoguan tobacco fields was Dec.1 to Dec.10.Similarly,the most suit-able transplanting period was Feb.25 to Mar.5.