The effect of five irrigation scheduling treatments on shoot growth [growth index (GI)] and stem water potential (SWP) of Itea virginica L. ‘Henry's Garnet’ (‘Henry's Garnet’ sweetspire) and Rhododendron austrinum Rehd. (Florida flame azalea) were studied. Plants were transplanted on 13 Mar. 2008 at soil grade level under shade structures in field plots of sandy loam soil on the Auburn University campus in Auburn, AL. Matric potential was continuously measured 7.6 cm from the stem in the root ball and 20.3 cm from the stem in the soil backfill for three plants per treatment per taxa. Irrigation scheduling treatments included (in order of decreasing irrigation frequency): root ball and surrounding soil matric potential maintained at or above –25 kPa [well-watered (WW)]; root ball and surrounding soil rewatered when root ball matric potential dropped to either –50 kPa (50RB) or –75 kPa (75RB); and root ball and surrounding soil rewatered when surrounding soil matric potential dropped to either –25 kPa (25S) or –50 kPa (50S). In both taxa, GI increased linearly over time in all five irrigation treatments. For I. virginica ‘Henry's Garnet’, GI increased most in WW and 25S treatments followed by 50S, 50RB, and 75RB. Shoot growth of R. austrinum was similar among treatments. Both I. virginica ‘Henry's Garnet’ and R. austrinum had a larger increase in GI during the first growing season (2008). For I. virginica ‘Henry's Garnet’, SWP was higher in 50S and 75RB treatments than in 50RB, WW, and 25S. For R. austrinum, SWP was not different among treatments. Results indicate that although plant growth might be diminished slightly, irrigation frequency can be reduced without compromising plant visual quality or survival if root ball and soil matric potential is monitored. Additionally, until roots grow into the backfill soil, monitoring both backfill soil and root ball matric potential is important for scheduling and reducing post-transplant irrigation applications.
Abby B. Griffin, Amy N. Wright, Kenneth M. Tilt, and D. Joseph Eakes
Mary B. Musgrove, J. David Williams, Bridget K. Behe, and Kenneth M. Tilt
Before analyzing the responses of Alabama garden center employees about the training they had received, we determined how satisfied 100 Alabama Master Gardeners were with the employee-s who helped them in the store from which they most often purchased plants for their homes, landscapes, or gardens. We mailed the primary survey to 472 employees of 130 retail garden center businesses in Alabama to determine the percentage of employees who received job training and the amount, frequency, and methods of training they received while working for their current employers (37% responded). Employees were categorized as managers (28%) or subordinate employees (72%) and full-time (72%) or part-time (28%). Forty-four percent of the employees had received some training at the time they were hired. Training continued for 68% of the respondents. Only 39% of the employees had a written description of their job responsibilities discussed with them. Most (85%) believed the training they received had prepared them to do their jobs well, but 82% said more training would increase their confidence in their work performance. Most employees were trained by one-on-one instruction (60%) and small-group sessions (5 or fewer persons) (65%). Few employees received training from videotapes (5%) or educational seminars (26%), and most that did were managers and full-time employees.
Julie Guckenberger Price, Amy N. Wright, Robert S. Boyd, and Kenneth M. Tilt
Planting shrubs above-grade with organic matter has shown potential for improving landscape establishment. To further investigate this technique, wax myrtle [Morella cerifera (syn. Myrica cerifera)] (3 gal) and mountain laurel (Kalmia latifolia ‘Olympic Wedding’) (5 gal) were planted on 30 Oct. 2006 (fall planting) and 12 Apr. 2007 (spring planting) in the ground in a shade house in Auburn, AL. At each planting date, plants of each species were assigned one of four treatments. Three of four treatments used a modified above-grade planting technique in which shrubs were planted such that the top 3 inches of the root ball remained above soil grade. Organic matter, either pine bark (PB), peat (PT), or cotton gin compost (CGC), was applied around the above-grade portion of the root ball, tapering down from the top of the root ball to the ground. In the fourth treatment, plants were planted at-grade with no organic matter (NOM). In general, both species had higher shoot dry weight (SDW) and root spread (RS) when planted in the fall than when planted in spring. Among all treatments, plants also typically had larger RS when planted above-grade with PB or PT. For easy-to-transplant species (such as wax myrtle) and especially for difficult-to-transplant species like mountain laurel, fall planting using this modified above-grade planting technique with PB or PT may improve post-transplant root growth and speed establishment in the first growing season.
Katie L. Dylewski, Amy N. Wright, Kenneth M. Tilt, and Charlene LeBleu
The effect of short interval cyclic flooding on root and shoot growth of ‘Shamrock’ inkberry holly (Ilex glabra), ‘Henry's Garnet’ sweetspire (Itea virginica), and ‘Winterthur’ possumhaw (Viburnum nudum) was studied in a greenhouse in Auburn, AL. Liners (4.4 inches long) of each species were planted into trade 1-gal pots in 1 pine bark:1 peat by volume (PB:P) or fine textured calcined clay (CC). ‘Shamrock’ inkberry holly and ‘Henry's Garnet’ sweetspire were planted 18 Apr. 2008; the experiment was repeated with the addition of ‘Winterthur’ possumhaw on 16 June 2008. Plants were flooded to substrate level for 0 (non-flooded), 3, or 7 days. Flooding cycles were repeated at least five times with 7 days of draining between each flood cycle. During draining, plants received no irrigation. Non-flooded plants were watered as needed. Flooded plants for all species except ‘Winterthur’ possumhaw showed decreased root dry weight, shoot dry weight, and final growth index when compared with non-flooded plants. Survival was higher in CC than PB:P for both experiments. All plants maintained good visual quality and shoot growth. As a result, overall, these plants seemed tolerant of flooding despite differences in growth.
Patricia R. Knight, D. Joseph Eakes, Kenneth M. Tilt, and Charles H. Gilliam
Stem cuttings of Ilex cornuta `Burfordii Nana' and Ilex × `Nellie R. Stevens', were direct stuck into cell pack, rose pot, quart pot, and trade gallon containers on March 4, 1991. Ten weeks and again at twenty weeks after sticking, rooted liners from cell pack, rose pot, and quart pot containers were transplanted into trade gallon containers. Thirty weeks after sticking, Nellie R. Stevens holly had a greater total root dry weight compared to Dwarf Burford holly. There were no differences in total root dry weight for any transplant treatment, but root distribution was influenced. Cell pack and rose pot liners transplanted twenty weeks after sticking showed a reduction in root growth in the root sector between the radius of a quart pot and a trade gallon pot. Shoot growth was also reduced for cell pack and rose pot liners that were transplanted into trade gallon containers twenty weeks after sticking.
D. Thayne Montague, D. Joseph Eakes, Charles H. Gilliam, Kenneth M. Tilt, and Harry G. Ponder
This study was conducted to determine the influence of production methods on the growth of container grown flowering dogwood (Cornus florida). The production practices were: full sun, 40% white shade cloth, 40% black shade cloth, and pot-in-pot. The cultivars studied were: cv. `Welch's Junior Miss', cv. `Barton's White', cv. `Weaver's White', and cv. `Welch's Bay Beauty'. The one variety used was pink. Height and caliper data was collected. Plants grown under white shade cloth had the highest overall height and caliper growth, followed by black shade cloth, full sun, and the pot-in-pot production method. The cultivar `Weaver's White' had the highest overall height and caliper growth and the variety pink had the least, regardless of treatment. The remaining cultivars had similar growth regardless of treatment.
Julie Guckenberger Price, Amy N. Wright, Kenneth M. Tilt, and Robert L. Boyd
The need for reliable planting techniques that encourage posttransplant root growth in adverse conditions has prompted research into planting above soil grade (above-grade). Container-grown Morella cerifera (L.) Small (syn. Myrica cerifera L.) (wax myrtle), Illicium floridanum Ellis (Florida anise tree), and Kalmia latifolia L. (mountain laurel) plants were planted in Horhizotrons (root observation chambers) in a greenhouse in Auburn, AL, on 1 Mar. 2006, 6 June 2006, and 3 Jan. 2007, respectively. The experiment was repeated with all three species being planted 18 June 2007. Horhizotrons contained four glass quadrants extending away from the root ball providing a nondestructive method for measuring root growth of the same plant into different rhizosphere conditions. Each quadrant was filled with a native sandy loam soil in the lower 10 cm. The upper 10 cm of the quadrants were filled randomly with: 1) milled pine bark (PB); 2) peat (P); 3) cotton gin compost (CGC); or 4) more native soil with no organic matter (NOM). Horizontal root lengths (HRL, length measured parallel to the ground from the root ball to the root tip) of the five longest roots visible along each side of a quadrant were measured weekly for M. cerifera and I. floridanum and biweekly for K. latifolia. These measurements represented lateral growth and penetration of roots into surrounding substrates on transplanting. When roots of a species neared the end of the quadrant, the experiment was ended for that species. M. cerifera had the fastest rate of lateral root growth followed by I. floridanum and then by K. latifolia. In most cases, roots grew initially into the organic matter rather than the soil when organic matter was present. In general, HRL and root dry weight (RDW) of I. floridanum and K. latifolia were greatest in PB and P, whereas for M. cerifera, these were greatest in P. Differences in root growth among substrates were not as pronounced for M. cerifera as for the other species, perhaps as a result of its rapid increase in HRL. Increased root growth in PB and P may be attributed to the ideal physical and chemical properties of these substrates. Results suggest that planting above soil grade with organic matter may increase posttransplant root growth compared with planting at grade with no organic matter.
Togo M. Traore, Deacue Fields, Floyd M. Woods, Amy N. Wright, Kenneth M. Tilt, Weidong Ke, and Yiman Liu
Lotus (Nelumbo nucifera Gaertn.) is an underused edible aquatic perennial vegetable currently evaluated as a potential functional food source and promoted in the southeastern United States as a rich source of phytonutrients. There is a paucity of information concerning consumer acceptance and willingness to purchase edible, value-added lotus products in the southeastern United States. The purpose of this exploratory study was to evaluate the potential demand and consumer preference for fresh lotus rhizomes and value-added products namely lotus salad, baked lotus chips, and lotus stir-fry. Results of two taste panels indicated that lotus stir-fry was the most preferred value-added product with 77% of participants strongly liking stir-fry, whereas 92% of the participants were willing to recommend this preparation. Results suggest socioeconomic characteristics such as gender (P = 0.014), age (P = 0.005), income (P = 0.043), education (P = 0.003), shopping habits (P = 0.013), and type of meal purchased (P = 0.004) are the factors affecting consumer choice and willingness to recommend lotus stir-fry. Results provide information on consumer acceptance of fresh lotus rhizomes and value-added products. Findings of this case study will assist in analyzing consumer behavior and development of sustainable niche markets for locally cultivated fresh edible lotus rhizomes.