The 2012 ASHS Annual Conference

Thirty juvenile, trunkless plants each of Canary Island date palms (Phoenix canariensis Chabaud) and queen palms (Syagrus romanzoffiana (Cham.) Glassman) growing in 68-liter (15-gallon), standard nursery containers were subjected to five leaf removal and tie up treatments ranging from no leaf removal/no tie up (control) to complete leaf removal. The container opening, from the lip to the palm base, was covered with aluminum foil to reduce evaporative water loss from the potting medium. Containers were initially irrigated to container capacity, allowed to drain overnight, then weighed the following morning and again at one-, two-, or three-day intervals. Other than the initial weighing, the amount of water lost after each weighing was immediately replaced. The differences in weights between the intervals would indicate the approximate the amount of water lost via leaf transpiration during each interval. Any combination of leaf removal and tie up reduced leaf transpirational water loss for both species. Complete leaf removal resulted in the least amount of water loss while no leaf removal and no tie up resulted in the greatest water loss. Crop coefficients ranged from 0.8 to 5.0 for Canary Island date palms and 2.1 to 4.0 for queen palms, which are comparable in magnitude to those developed for several woody shrubs. This information provides guidelines for leaf removal and tie up when transplanting palms and is another tool to help nursery and irrigation managers schedule irrigations more accurately.