烟草漂浮育苗施肥量与电导率关系及对培育健壮苗的影响

Correlation between Fertilized Amount and Solution Conductivity in Floating Pool and Effects on Culturing Robust Seedlings of Tobacco

烟草漂浮育苗的施肥量与漂池溶液的电导率大小有关。分别以专用肥和KCl的浓度梯度水溶液,检测其电导率,获得直线回归方程yF=10037x+498.6和yKCl=15304x+570.6,其相关系数为rF=0.999和rKCl=0.998,表明可通过测定漂池液的电导率,推测肥料浓度的变化。以总施肥量设3个水平、在3个育苗时期施肥、用3个烟草品种培育烟苗、检测漂池液电导率的动态变化和调查烟苗生长状况。结果表明,电导率与施肥量呈正相关;总施肥量2400 g/标池时可满足育苗过程中烟苗所需养分,在适宜时期施肥,可培育健壮烟苗;施肥水平与根腐发生率有关,差异极显著;在试验的烟草品种中,红花大金元对根腐较敏感;肥料浓度约0.32%、电导率约4000μS/cm时,发生根腐的潜在风险最高。

The conductivity value was relative to the fertilized amount in nutrient solution of floating-bed pools. By using the concentration gradient solutions of dedicated fertilizer and KC1 respoctively, their conducfivities were tested, and linear regression equations were obtained as YF = 10037x ＋498.6 and YKCl = 15304x ＋ 570.6. Their coefficient of correlation are rF = 0. 999 and rKC1 = 0. 998. The results showed that the fertilizer concentration could be inferred by testing conductivity value in solution. Three concentration levels of fertilized amount were designed in this experiment. Dedicated fertilized was added at 3 phases of cultivating seedlings. 3 varieties of tobacco were cultured for seed- lings. Conductivity changes were tested in the euhuring course, and the growing state of tobacco seedlings was investigated. The results showed that the conductivities were positive correlative with fertilized amount. The total fertilized amount 2400 g in a standard pool was suffi- cient nutrition for culturing tobacco seedlings, and robust seedlings could be cultured by fertilizing at suitable period. The root rot incidence rate was relative to the fertilized level, and their differences were very significant. Honghuadajinyuan was more sensitive to root rot than other tested tobacco varieties. In the conditions of fertilizer concentration at 0.32 % and conductivity at 4000 μS/cm, the potential risk of occurring root rot would be the highest.