THE USE OF FIBER AND PITH OF THE COCONUT IN HORTICULTURE, FLORICULTURE, AND PROFESSIONAL PLANT NURSERY.
Introduced in the sector of specialized agriculture by the Dutch in the cultivation of roses in the mid-80s, it was immediately clear that coconut was an ideal substrate that stimulated an excellent development of the root and aerial apparatus of young plants. Unfortunately, this could not be repeated with all crops due to the non-guaranteed quality of the material and insufficient knowledge of the methods of application and cultivation on this substrate. In order to objectively judge the full potential of this cultivation substrate, there were various phases of direct experimentation in crops. After years of tests and analysis of the excellent results obtained, from the end of the 90s it was introduced into the specialized agriculture sector in the Netherlands. Since its introduction to date, by virtue of the dissemination of the excellent agronomic characteristics of this substrate, the share of demand on the market has continued to increase with applications in professional floriculture, professional horticulture, and professional ornamental plant nursery worldwide.
ECO-RENEWABLE AND ECO-COMPATIBLE
It truly represents a renewable and always available resource, not subject to exhaustion as in the case of a peat deposit, which is subject to increasing restrictions as regards its extraction (destruction of wetlands with their flora and fauna).
Currently, around 12 million hectares of coconut palm are cultivated in the world, giving rise to about 64 billion of coconuts, the equivalent of about 45 million tons, which correspond to 670 million cubic meters of the product derived from the processing of the coconut husk (fiber and pith).
DEVELOPMENT AND ROOTING OF PLANTS
The pith obtained from the coconut husk, from a technical agronomic point of view, features some peculiar physical characteristics:
- A bulk density comparable to a peat of medium decomposition.
- High porosity, which is mainly occupied by air in the coarse fractions and by water in the finely ground fractions. The available and reserve water content for root absorption increases as the particle size decreases and reaches high values in the fractions between 0 and 6 mm.
- Water retention (intended as the ability of a substrate to store the water added in shots from above) higher than that of a milled peat of similar humidity.
This physical characteristic, according to Magnani (et al., 2005), determines a decrease in irrigation consumption. Indicated as an ideal substrate for crops grown with the ebb and flow irrigation system.
- The shrinkage is comparable, if not even lower, to a medium-low decomposition peat with similar grain size (Cattivello 2009). Mixtures with coconut do not induce hydrophobicity, typical of many peats that have undergone drastic dehydration.
The fiber obtained from the processing of coconut husk has some peculiar characteristics:
- Extremely low bulk density.
- High porosity (as regards its microtubule structure), mainly occupied by air (oxygen tank). The water retained is minimal (the excellent draining action prevents water stagnation).
- High elasticity, particularly low shrinkage.
- High capacity of phreatic rise and imbibition speed, much higher than that of the pith and of milled peat.
By virtue of these peculiar characteristics, the fiber is not used as it is but enters a mixture with the pith, according to defined percentages.
- The optimal and harmonious development of the root system, which results from the use of fiber and pith of the coconut husk as a cultivation substrate, as well as depending on its structural physical characteristics, according to recent studies is also related to the natural presence of substances having rhizogenic action (salicylic acid).
- The use of coconut fiber substrates, compared to peat, results in early germination of seeds and greater size and uniformity of the seedlings (Cresswell 1992).
SOCIAL AND ECONOMIC ASPECTS
The use of this resource also has a socially useful purpose, since the areas of cultivation and production are in economically disadvantaged areas, so its use contributes to improving the economic opportunities of developing countries