Container plants, especially those in 1-gal or smaller containers, are a perishable commodity when on display in the retail nursery. From the time of delivery by the wholesaler until purchased by customers, plants need to be maintained in good condition and require regular watering. Frequent turnover of product results in most businesses using limited automated overhead irrigation and relying primarily on hand watering to keep plants moist. Hand watering is the least efficient and most costly means of irrigation but efforts to automate irrigation have been greatly hindered by the necessary multiple irrigations per day during periods of high evaporative demand, product turnover, customer traffic, and mixing of plants of different sizes and water requirements in displays.
Capillary mats have been used for producing floriculture (Bjerre, 1983; Morvant et al., 1998) and foliage (Neal and Henley, 1992) crops in the greenhouse, and their use has been advocated for maintaining plants in garden centers (Baldwin and Stanley, 1982). Capillary mats consist of absorbent fabric lined on the bottom with polyethylene film and covered on top with perforated polyethylene or similar material that minimizes water loss to evaporation. Water moves vertically into pots through the drainage holes once plants are placed on the mat and capillary action is established. One advantage of capillary mats is that plants of different size and water requirement can be placed on the same mat to meet different water needs. Empty areas of the mat are subject to minimal evaporative loss and can be restocked when practical. Uniform water application, always a problem with hand watering, and generation of large amounts of runoff water will not be an issue with capillary mats as long as the mat is on a level surface. Capillary mats can provide automated irrigation to different size plants, help with water conservation, and free retail nursery personnel from hand watering. Disadvantages of capillary mats include the higher initial installation costs, the need for a very flat surface to avoid puddling or dry spots on the mat, the need for a soil mix with porosity that allows the capillary rise of water, and cleaning and maintenance of the mats (Hodges and Haydu, 2001). According to a market analysis of this technology for wholesale nurseries in the southeastern United States, ≈25% of nurseries surveyed, especially larger firms with annual sales greater than $2.5 million, were interested in the technology for wholesale production (Hodges and Haydu, 2001). Comparing the economic feasibility of capillary mats versus overhead irrigation for wholesale production, subirrigation tray, and microirrigation showed that using projected costs and profits over a 6-year period, capillary mats had the highest net return of the systems (Haydu et al., 2004).
The objective of this study was to compare water application and plant performance during the maintenance of plants in a simulated retail nursery environment using capillary mats or overhead spray irrigation. Partial budgets including initial investment and maintenance costs using capillary mats, overhead spray irrigation, or hand watering with a hose were compared during two seasons.
Haydu, J.J., Beeson, R.C. & Caron, J. 2004 Economics of five irrigation technologies for container-grown Viburnum odoratissimum Acta Hort. 664 309 315
Hodges, A.W. & Haydu, J.J. 2001 Market analysis of the capillary mat irrigation technology for wholesale nurseries in the southeastern United States Proc. South. Nursery Assn. Res. Conf 46 570 573
Morvant, J.K., Dole, J.M. & Cole, J.C. 1998 Irrigation frequency and system affect poinsettia growth, water use, and runoff HortScience 33 42 46
Neal, C.A. & Henley, R.W. 1992 Water use and runoff comparisons of greenhouse irrigation systems Proc. Florida State Hort. Soc 105 191 194
Scoggins, H.L. & van Iersel, M.W. 2006 In situ probes for measurement of electrical conductivity of soilless substrates: Effects of temperature and substrate moisture content HortScience 41 210 214
U.S. Department of Agriculture 2006 Arizona agricultural statistics 8 Nov. 2007 <http://www.nass.usda.gov/Statistics_by_State/Arizona/Publications/Annual_Statistical_Bulletin/05bul/pdf/pg00E_TOC.pdf>.