Articles
THE EFFECT OF N-FERTILIZATION ON THE GROWTH OF CHRYSANTHEMUM “WHITE HORIM” IN BARK COMPOSTS AND PEAT
Composted bark from Pine, Spruce and Hardwood was used to formulate five bark-peat (2:1) (v/v) mixtures.
Peat alone was used as a control medium.
Plants were fertilized with three N levels 150, 300 and 450 mg N per litre.
Physical properties of the initial mixtures and both macro and micro nutrients were determined.
At the end of the experiment substrates pH, N-NH4, N-NO3, and extractable Mn and Fe were analysed.
At harvest, plants were chemically analysed, average leaf area measured and the period from short day treatment was started to the flowers showed visible color was recorded.
Peat and Pine substrates behaved in the same way but different to the Spruce and Hardwood bark substrates.
Peat and Pine had high initial ammonium content that was partially nitrificated and affected the pH and subsequently the concentration of extractable Mn.
Plants grown in Peat and Pine showed delay in flowering and plants in Pine a slight manganese toxicity.
There was a positive effect of N-fertilization on plants grown in Spruce and Hardwood which gave the highest dry matter production at 450 mg N per litre.
This was however still below the production by plants grown in Peat.