GORSE COMPOST AS A PEAT-SUBSTITUTE IN GROWING MEDIA FOR THE PRODUCTION OF THUJA PLICATA 'ZEBRINA'
The use of composted forest gorse as a peat substitute, alone or as a growing medium component was investigated. Rooted cuttings of Thuja plicata 'Zebrina' were transplanted into 300 ml pots filled with different growing media based on composted gorse (100%, 50% or 25%) or Sphagnum light peat (100% or 25%). A controlled release fertilizer was applied. A treatment of 100% composted gorse without fertilizer was also evaluated. Physical and chemical properties determined in pure composted gorse were bulk density, electrical conductivity, pH, Carbon/Nitrogen ratio (C/N) and organic matter content. A randomized block design with five replications per treatment and five rooted cuttings per replication was used. Plant height, dry weight of canopy, shoots and roots were measured during growth. Furthermore, shoots were analysed for mineral elements contents (P, N, S, Ca, Mg, Na, K, Fe, Cu, Mn, Zn and Pb). Statistical analysis was performed using analysis of variance following by the Duncan test (P<0.05). No significant differences were detected between treatments for all parameters of growth assayed. With respect to foliar mineral contents, the plants growing in 100% composted gorse without fertilizer showed the highest values of N and Mg and the lowest in K. Differences between treatments were also detected for some micronutrients. The results showed that gorse compost is a good peat substitute for the production of Thuja plicata 'Zebrina'. The physical-chemical properties of pure composted gorse type, bulk density, electrical conductivity, pH, Carbon/Nitrogen ratio (C/N) and organic matter content were suitable for use in growing medium. It could be used alone or in a mixture for nursery stock production.
Iglesias, M.I., Rodil, C., Bessa, P. and Lamosa, S. (2008). GORSE COMPOST AS A PEAT-SUBSTITUTE IN GROWING MEDIA FOR THE PRODUCTION OF THUJA PLICATA 'ZEBRINA'. Acta Hortic. 779, 615-622
Thuja plicata 'Zebrina', organic substrates, peat substitute, mineral nutrition, growing media