Abstract
A comparison was made of Canadian sphagnum peat (SP) and Philippine coconut (Cocos nucifera L.) coir dust (CD) as growing media components for greenhouse production of Dracaena marginata Bak. and Spathiphyllum Schott ‘Petite’. Three soilless foliage plant growing mixes (Cornell, Hybrid, University of Florida #2 [UF-2]) were prepared using either SP or CD and pine bark (PB), vermiculite (V), and/or perlite (P) in the following ratios (% by vol): Cornell = 50 CD or SP:25 V:25 P, Hybrid = 40 CD or SP:30 V:30 PB, UF-2 = 50 CD or SP: 50 PB. Dracaena root growth was not affected by treatments but there were significant mix × media component interactions that affected plant top growth parameters. In general, the growth and quality of D. marginata were reduced by using CD in Cornell, had no effect in Hybrid, and increased in UF-2. S. ‘Petite’ grew equally well in all growing mixes regardless of whether CD or SP was used; however, plants grew more in Cornell and Hybrid than in UF-2. S. ‘Petite’ roots, which were infested with Cylindrocladium spathiphylli, had higher grades when grown in CD than when the media contained SP.