THE INFLUENCE OF THE PROCESSING STAGE ON THE SUITABLE AMOUNT OF COIR DUST IN GROWING MEDIA

M. Emmel
Coir dust might be interesting as a peat alternative, because several properties make it comparable to peat. However, suitability as a growing medium constituent depends on the conditioning of the material. Coir dust of four different processing stages (raw material, washed with fresh water, buffered conventionally and buffered for use in organic farming) from India was included in an experiment with Euphorbia pulcherrima. Each coir dust was mixed with peat in different ratios (0%, 20%, 40%, 100% (v/v)). In addition the chemical properties were determined. The raw material contains a considerable quantity of potassium (1,566 mg K2O/L), sodium (712 mg Na/L) and chloride (1,936 mg Cl/L). The concentration of these elements as well as phosphate and consequently salinity decrease significantly after washing with fresh water. High salinity or rather high concentrations of sodium and chloride caused chlorosis or necrosis of leaves of plants cultivated in some mixtures as soon as two weeks after potting. Four weeks later the edges of the older leaves of the primary cuttings suffered interveinal chlorosis. Leaves of plants in 100% washed coir dust were strongly affected. Tissue samples indicate an excess of boron (128 mg B/kg DM). At the end of the experiment marketable plants had been cultivated in all tested mixtures. However using 100% raw coir dust resulted in the plants being very inhomogeneous, being much smaller than in the peat substrate. It also resulted in a 25% loss of plants. The higher the amount of coir dust in growing media, the more important is the quality of the material. Depending on the sensibility of the cultivated plant species, not only is the salinity important, but also the content of sodium, chloride and boron, and reducing these elements may correspondingly reduce the risks of damages during plant cultivation.
Emmel, M. (2014). THE INFLUENCE OF THE PROCESSING STAGE ON THE SUITABLE AMOUNT OF COIR DUST IN GROWING MEDIA. Acta Hortic. 1034, 335-339
DOI: 10.17660/ActaHortic.2014.1034.41
https://doi.org/10.17660/ActaHortic.2014.1034.41
substrate, peat alternative, coco pith, boron, sodium, chloride
English

Acta Horticulturae