ABSTRACT
Monthly variation in some of the plant-nutrient contents were investigated using the guttation fluid samples taken from dieffenbachia (Dieffenbachiae anoena) plants. Guttation-fluid samples were taken between September 1, 2001 and March 31, 2002. Amounts of potassium (K), calcium (Ca), magnesium (Mg), sodium (Na), iron (Fe), zinc (Zn), manganese (Mn), and copper (Cu) were analyzed by atomic absorption spectrophotometer. According to the results of the experiment, plant-nutrient composition of the fluids ranged in the following order during the experimental period: Ca (62.55%–82.91%) > Mg (11.05%–16.52%) > Na (2.70%–13.76%) > K (0.03%–20.53%) > Mn (0.26%–1.10%) > Zn (0.10%–0.31%) > Cu (0.05%–0.16%) > Fe (0.00%–0.55%). It was also observed that macro-cation contents of the samples decreased during winter and increased during the autumn and spring. Meanwhile, percentage microelement content of the fluid samples increased during the winter months, as macro-cations decreased. This result might have been due to the fact that plants had evidently developed a defense mechanism against cold damage during the winter season: by not emitting macro-cations out of their leaves, they were able to increase the pH level of xylem sap.
Notes
**= P < 0.01.
**= P < 0.01.
*= P < 0.05.