Coconut fiber: a peat-like substrate for acidophilic plant cultivation

A remarkable topic related to pot cultivation is the increasing need for suitable peat alternatives. Recent studies emphasized the interest in using environment-friendly substrates with good quality, low cost, and high availability, with a view to sustainable floriculture. Peat is widely used for container plant production. Due to its high ability to preserve acidic pH through cultivation phases, high water holding capacity and porosity, and generally inertness, peat quite meets acidophilic plants needs. Physicochemical analyses performed on several peat substitute candidates elected coconut fiber as the most peat-like material. Hence, a first experimentation was conducted replacing 30% peat with coconut fiber in Camellia japonica L. cultivation. Positive results on growth and ornamental values led to a second greenhouse experiment on camellia where coconut fiber was raised up to 50%. Results on growth and flowering were in line with those of the standard substrate, with the exception of chlorophyll content in leaves which resulted lower, but still in the acceptable range. A further experiment addressed to the use of 50% coconut fiber on Rhododendron (evergreen azalea), Pieris and Leucothoe, so as to evaluate transferability among different acidophilic species. Suitability of coconut fiber was confirmed as generally growth values did not differ statistically in Pieris and Leucothoe, while in azalea vigor and health status were even improved. It can be concluded that peat can be partially substituted by coconut fibers up to 50% without adverse effects on plant health and appearance. Considering both technical and economic factors, large-scale use of coconut fiber as peat alternative could lead to a more environment-friendly and sustainable acidophilic plants production.