164 THE POTENTIAL OF COIR (COCONUT MESOCARP PITH) AS A PEAT SUBSTITUTE IN CONTAINER MEDIA.

Abstract

Coir is the name given to the fibrous material that constitutes the thick mesocarp of the coconut fruit (Cocos nucifera L.). The long fibers of coir are extracted from the coconut husk and utilized in the manufacture of various products. The short fibers and dust (“pith”) left behind have accumulated as a waste product. Coir pith is light to dark brown in color and consists primarily of particles in the size range 0.2-2.0 mm (75-90%). In composition, it is 65-70% lignin and 20-30% cellulose. To date, few replicated tests have assessed the performance of coir pith as a plant growth medium. From April, 1993 to April, 1994, four ornamental crops (pentas, ixora, anthurium and majesty palm) were grown in container media that differed only in the peat fraction (40%), either sphagnum, Florida (sedge) peat, or coir pith. On the basis of plant growth parameters, coir pith was superior to sedge peat as a medium component (though only marginally for the anthurium) and at least equal to sphagnum peat. In addition to physical qualities equal to or better than sphagnum peat, coir decomposes more slowly than either sedge or sphagnum peat, withstands compression better and is easier to wet than peat. There are also no ecological drawbacks to the use of coir -- a waste product -- relative to the harvest of peat from wetland ecosystems.