In this issue...
PLANT BREEDING - 'Red Hot' Anthurium
PHYSIOLOGY - Factors Affecting the Efficiency of Overhead Irrigation Uniformity
ECONOMICS - Business Analysis Opportunity
Crop Notes, Research Reports and More!
Check it out on the World Wide Web
http://www.ifas.ufl.edu/~apkweb/
Factors Affecting the Efficiency of Overhead Irrigation Uniformity
R.C. Beeson, Ph.D., Horticulturist
This article is the fourth in the series of discussions (spacing, March 1995; canopy effects, May 1995; droplet momentum, January 1996) of the factors that reduce overhead irrigation efficiency to the 10 to 30% typical of most commercial nurseries.
Irrigation uniformity refers to how evenly water is distributed by an irrigation system. For overhead irrigation, uniformity depends on the spacing of overhead risers, the type and condition of sprinklers, and the operating pressure. These factors should be incorporated into the final design and installation. Frequently however, changes occur to the original system. Pumps age or deposits accumulate in pipes causing pressure drops, or pumps are replaced with more powerful pumps and the pressure increases. Sprinklers will eventually wear, resulting in larger orifices, which decreases pressure and increases flow. Screws and deflectors used to adjust the breakup of the water stream become out of adjustment and/or do not meet design specifications. Frequently, one type of sprinkler head is replaced with another type or different model, changing the irrigation pattern and therefore distribution. In expanding operations, the irrigated area may be increased without increasing the capacity of the existing system causing sprinkler patterns to change; this may not be noticed through casual observations. Any or all of these changes will alter the water distribution uniformity of an irrigation system.
Because the market demands uniformity in plant size, irrigation systems are operated to meet the requirements of those plants receiving the least amount of water. Since canopy size is tightly linked to the degree of water stress, the only way to maintain a uniform crop is to completely meet the needs of the least irrigated plants, resulting in over-irrigation of the rest of the plants in that zone. Any water in excess of that required to re-saturate the container substrate is wasted and lowers the efficiency of irrigation system. The more uniform the irrigation application, the less difference there is between the least and most irrigated plants; therefore, there is less excess watering and more efficient use of the water applied. Most overhead irrigation systems are designed for 80% uniformity with near 90% being the best obtainable. However, any of the factors that change irrigation uniformity can change it dramatically. Low irrigation uniformity magnifies the problems associated with container spacing since it requires that even more water be applied to areas where roots are not growing.
'Red Hot' Anthurium
R.J. Henny, Ph.D., Plant Geneticist
Anthuriums are grown as a flowering pot plant by many growers because of their attractive foliage and colorful flowers. They can be grown under similar environmental conditions as foliage plants and do not require costly greenhouse modifications. Cultivars of Anthurium andraeanum, traditionally grown for production of cut flowers because of their large and showy spathes, occur in shades of red, orange, pink or white. However, their long petioles and large leaves are not in proper proportion for to be desirable as a pot plant.
New anthurium hybrids, developed in the past few years, are smaller in stature, better proportioned for pot plant production, and very floriferous. Anthurium X 'Red Hot' is one such hybrid. It flowers profusely producing blooms with showy red spathes and has a compact, freely branching growth habit.
Anthurium X 'Red Hot' has a diverse pedigree that includes A. andraeanum, A. amnicola, and A. 'Lady Jane'. A mature 'Red Hot' in a 6-inch (15.2 cm) pot has dark green lanceolate leaves that average 19 to 20 cm (7.5 to 7.9 in.) in length and 11 to 12 cm (4.3 to 4.7 in.) in width at the widest point. Spathes average 7 cm (2.8 in.) long by 5 cm (2 in.) wide and are a medium red (Royal Horticulture Society [RHS] Color Chart 47B) at anthesis. The spadix is approximately 3 to 4 cm (1.2 to 1.6 in.) long, 5 to 6 mm (0.2 to 0.23 in.) wide and is orange-red (RHS 34A) at the tip, blending to red (RHS 53B) at the base. The spadix gradually changes to a lighter red (RHS 48B) prior to senescence.
Growth characteristics of 'Red Hot' were determined in a greenhouse trial conducted with tissue cultured liners rooted in 25 mm (1 in.) cell trays and potted in 6 in. (15.2 cm) plastic pots containing a medium of 6:4 peat:perlite (v/v) under 80% shade. Plants were grown at each of three fertilizer levels (525, 700 or 875 kg N/100m2/year) from November 1993 to October 1994. Under these conditions, 'Red Hot' reached marketable size in 11 months. Its flowers are very similar in size and shape to 'Southern Blush' but its leaves are smaller with a maximum length of 20 cm (7.9 in.) compared to 25 cm (9.8 in.) Both plants have lanceolate leaves that are twice as long a wide. Fertilizer level did not affect plant canopy, leaf size or number of flowers. Plants were well-branched, producing an average of 6 basal shoots each. Plant quality averaged between good and excellent at each fertilizer level. 'Red Hot' is suitable for commercial producers growing finished plants in 6- or 8-inch (15.2 or 20.3 cm) containers. Good growth and flowering can be expected when plants are grown with a minimum light intensity of at least 1200 foot candles (225 µmol•m2•s2).
Anthurium ‘Red Hot' is being patented. Patent rights have been assigned to the Florida Foundation Seed Producers and plants have been released to Florida tissue culture labs for propagation and distribution. Inquiries regarding participating labs may be obtained by writing the Florida Foundation Seed Producers, Inc., P.O. Box 309, Greenwood, FL 32443.
Business Analysis Opportunity
J.J. Haydu, Ph.D., Economist
As part of the Financial Management Strategies discussed in April's Ornamental Research News, John Haydu, Alan Hodges, and P.J. van Blokland are reinstating the Nursery Business Analysis program, which presents information on sales, costs, returns and production efficiency for comparable groups of nurseries (foliage, woody ornamentals, flowering, etc.). All participants receive a comprehensive financial statement of their individual operation.
This program serves two purposes. First, it provides invaluable information to participating nurseries who can use data from the report to improve their operational efficiency, and second, it establishes baseline information for Florida's nursery industry. Following Hurricane Andrew, results from this program were used by numerous nurseries to receive financial compensation. Therefore, participating not only helps you, but your industry as well! If you are willing to contribute fiscal year 1995 information, please call Liz Felter, Orange Co. Ext. Agent (407) 836-7570, or Loretta Satterthwaite, statistician at Apopka (407) 884-2034, for information. All information provided is held in the strictest confidence.