LONG-TERM NUTRIENT LAND WATER UTILIZATION DURING MICROPROPAGATION OF CATTLEYA ON A LIQUID MEMBRANE SYSTEM/

Growth of two Cattle?ra clones (Sophrolaeliocattleya Jewel Box 'Schehe rezade' and Brassolaeliocattleya Rugley's Mill 'Mendenhall') over 6 or 8 months on microporous polypropylene membrane rafts was compared for several inorganic nutrient formulations: Murashige and Skoog at full, half and quarter strength; Hoagland's hydroponic medium; and three me dia formulated specifically for orchid culture (Knudson, Lindemann, an d Vacin and Went). Greatest fresh weight and number of plants per vess el were obtained on Murashige and Skoog medium and dilutions thereof. Shoot growth was greater than root growth only on full strength MS med ia. Media uptake by tissue and evaporation from the vessels required a dditional water to maintain contact between membrane and liquid. Most rapid growth occurred in periods following addition of water. In more dilute media formulations, shifting growth from shoots to roots was a possible outcome of low concentrations of ammonium.