烟草湿润托盘苗技术研究与应用Ⅱ苗期管理——施肥和空气整根对烟苗素质的影响

STUDY AND APPLICATION OF TOBACCO TRANSPLANT PRODUCTION TECHNOLOGY OF WET-TRAY WITH MEDIA Ⅱ SEEDLING MANAGEMENT-EFFECTS OF FERTILIZATION AND AIR-ROOT-PRUNING ON THE QUALITY OF TOBACCO TRANSPLANTS

通过 6种肥料浓度处理和育苗盘底部不同处理育苗试验证明 :①在营养液纯氮浓度为 5 0mg/kg～ 5 5 0mg/kg(NPK比例为 1∶1∶2 )范围内 ,没有出现肥害现象 ,除个别处理 (4 5 0mg/kg)外 ,烟苗地上部分鲜重随施肥浓度的增加而增加 ,干重则随肥料浓度的增加而降低 ,根系的鲜重及干重也随肥料浓度增加而减少。综合分析各处理烟苗农艺性状 ,烟草湿润托盘育苗营养液浓度以 15 0mg/kg～ 2 5 0mg/kg为宜。②空气整根可有效切断烟苗主根顶端且不留伤口 ,从而促进侧根生长 ,其根系鲜重和干重比对照增加 43.5 9%和 5 0 %。

Tobacco seedlings were nursed on wet-trays supplied with six different concentrations of fertilizer in the range of 50～550 mg/kg,the ratio of NPK being 1∶1∶2.No fertilizer toxicity was observed. The fresh weight of the tobacco shoots increased and their dry weight decreased as the fertilizer rate increased, except the treatment of 450 mg/kg.The fresh and dry weight of the roots dropped with the increase in fertilizer rate. Taking into consideration all the agronomic indexes concemed, 150～150 mg/kg seemed to be the desirable nutrient concentration in the solution. Air root-pruning was effective for cutting the tap-root of the tobacco plants without wound left, thus promoting the growth of the side roots. As a result, the fresh weight and dry weight of the root system increased by 43.59% and 50%, respectively, as compared with the control.