Evaluation of a cocopeat-based substrate system for rose production in Naivasha, Kenya

The current production system of roses in Kenya involves mostly the use of soil and open drip irrigation, which is inefficient as water and nutrients are lost through drainage. A recycling system can improve efficiency, as drainage water containing nutrients is re-used. A study was carried out from January to June 2013, at van den Berg Roses (a commercial rose farm) in Naivasha, Kenya, to evaluate a cocopeat-based system for rose production in comparison with a conventional soil-based production system. Net water use, stem production, stem length and economic benefits were assessed. Net water use in the cocopeat system and soil systems were 411 and 1098 L m-2, respectively. The difference of 687 L m-2 equals 65% water saving as a result of using the cocopeat system. The cumulative number of harvested stems m-2 in the cocopeat system was 24% higher than in the soil system. Rose stems harvested from the cocopeat system were on average longer, with 64% of the stems falling in the 60 and 70 cm categories, while this was 46% for the stems harvested from the soil system. Average stem weights were 39.2 and 33.6 g in the cocopeat and soil system, respectively. The results show that a cocopeat system with re-use of drain water in a soil system results in water saving, higher yield and better rose flower quality. A total of 764 L m-2 containing 1482 g m-2 fertilizer was collected from cocopeat and used in soil system over the period. The fertilizer in the drain solution was valued at € 0.93 m-2. Overall turnover from cocopeat was greater than soil system by € 3.15 m-2. The higher amount of marketable weight can be attributed to the greater number of stems that were obtained from the cocopeat compared to the soil.