Getting the most out of coco substrates.


The first use of coco peat as a substrate for growing plants already dates back more than 100 years. It’s however in the last decade that coco peat really gained momentum as substrate for growing plants. The demands of today’s horticulturist is different from yesterdays growers. For this reason, properly treated and certified coco substrates with a constant high quality are required to satisfy the needs of even the most demanding crop.

What is required to obtain a high quality coco material for use as substrate? Growers require a physical stable coco substrate, with no excessive content of salt, free of weed seeds and of soil borne nematodes. Coco products which fulfil these requirements are available under the (Dutch) RHP quality certification mark. To ensure a physically stable substrate, coco peat which is sold under the RHP quality mark requires a composting process of at least six months. During this composting process the heap is physically separated from the soil to ensure that soil-borne nematodes, which may be harmful to a crop, cannot penetrate the heap. Windscreens positioned around the composting heap prevent weed seeds from being blown into the substrate.

Today’s coco peat in standard form is often sold as ‘washed’, a treatment used to get rid of excess sodium or potassium. For a high quality RHP certified substrate this is not enough. Because coco peat has a negatively charged complex, the positively charged potassium and sodium ions are drawn onto it like iron to a magnet. Problems may start when the grower starts using fertilizers containing calcium or magnesium which have a higher affinity towards the complex than sodium or potassium. As a consequence, sodium and potassium are liberated into the soil’s moisture and may give rise to a too high a level of these ions taken up by the plant root, with detrimental results to the plant. For this reason, RHP certified coco peat has already been processed to reduce the level of potassium and sodium. Typical values of potassium and sodium in RHP coco peat delivered by Bucotec are 0.5 and 1.5 mmol?ltr-1 for potassium and sodium respectively (1:1.5BaCl2 extraction method).

Active support of Cocopeat-producers - Shirdas Menon talks with Otfried Myny during IPM 2006

Excellent pepper horticulture
in South-Hungary