CAN N-FIXATION BY WOODFIBRE, EITHER AS AN ADMIXTURE TO SUBSTRATES OR AS PAPERPOTS, BE USED FOR GROWTH REGULATION?

Woodfibre is increasingly used either as a substitute for peat in substrates or in the form of paper pots.
Both uses strongly influence the activity of soil microbes and cause the dynamic fixation of nitrogen.
The rapid removal of available nitrogen results in a rapid stagnation of plant growth that could be used for growth regulation.
In several trials pansies (Viol˙a–Wittrockiana–Hybriden), used as a model plant, were cultivated in different substrates containing different contents of woodfibre both in plastic and in paper pots.
The cultural conditions and the late extra fertilization were varied.
The results of the trials indicated that: the induced lack of nitrogen reduced plant height and diameter.
Starting extra fertilization too early resulted in rapid and strong growth that was slightly greater than normal.
When started late, and as a foliar feed, the extra fertilization quickly overcame the chlorosis caused by N-deficiency und resulted in plants of good quality.
The temporary lack of nitrogen also caused a retardation of flower development.
When assesed at the same stage of flowering, plant height was reduced and a true growth regulation was obtained.
The rapid removal of available nitrogen by woodfibre incorporated in the substrate makes it possible to regulate N-nutrition, which can be used to regulate the growth of ornamental plants.

II Workshop on Environmental Regulation of Plant Morphogenesis

S. Wartenberg

Viola–Wittrockiana–Hybriden, pansies, nutrition, control plant height

https://doi.org/10.17660/ActaHortic.1997.435.23