AbstractProduction of quality greenhouse and nursery crops is dependent on high quality and quantities of water. At present, in some regions, insufficient water supply is a growing concern. This study was conducted to evaluate growth of New Guinea impatiens (Impatiens hawkerii 'Celebrate Salmon'), when watered with a polyoxyethylenesorbitan monolaurate (C58H114O26) solution commercially known as Tween 20, at differing irrigation levels compared with a conventional water regimen without the surfactant, and also to determine how Tween 20 would affect photosynthesis and transpiration. The treatment design was a 3 by 6 complete factorial design plus a control. The two factors were irrigation and Tween 20. Irrigation levels of 20%, 40%, or 60% of the full crop evapotranspiration (ET) requirements were used in combination with Tween 20 concentrations of either 0, 25, 50, 75, 100, or 125 mg·L−1 (0, 0.003338, 0.00668, 0.0100145, 0.01335, or 0.01669 oz per gallon). The control group was watered with tap water to container capacity with about 30% leachate. Evapotranspiration was determined as the difference of the applied water amount minus the leachate of the control. Plants irrigated with Tween 20 from 25 to 125 mg·L−1 (0.003338 to 0.01669 oz per gallon) at the 40% or 60% irrigation level had the same height and growth index as plants in the control after three months of growth. Plant fresh and dry weights were not different between the control and the treatments of Tween 20 from 50 to 125 mg·L−1 (0.00668 to 0.01669 oz per gallon) at the 60% irrigation level or the treatment of Tween 20 at 100 mg·L−1 (0.01335 oz per gallon) at the 40% irrigation level. Tween 20 had no effect on net photosynthetic rate. Tween 20 decreased the amount of transpired water of New Guinea impatiens 'Celebrate Salmon'. When the Tween 20 concentration increased from 0 to 100 mg·L−1 (0 to 0.01335 oz per gallon) at the 60% irrigation level, the transpiration rate and stomatal conductance decreased markedly by 43% and 47%, respectively, and water use efficiency was increased by 47%. Results from this study suggest that Tween 20 is able to increase plant water use efficiency through regulation of stomatal conductance or transpiration under deficit irrigation.Index words: irrigation management, chemigation, source-sink physiology, deficit irrigation, wetting agent, Tween 20, adjuvant.Species used in this study: New Guinea Impatiens (Impatiens hawkerii W. Bull. 'Celebrate Salmon').Chemicals used in this study: Tween 20 (polyoxyethylenesorbitan monolaurate). (aka: polysorbate 20, polyoxyethylene (20) sorbitan monolaurate)

Nursery and landscape professionals as well as homeowners throughout Alabama continue to experience deer damage to ornamental plants due to the increasing populations of white-tailed deer (Odocoileus virginianus Zimmerman). To understand the extent of damage, surveys were created for green industry professionals and homeowners. The industry survey was sent to members of the Alabama Nursery and Landscape Association (ALNLA) (N = 223). The homeowner survey was sent to nine Master Gardener associations and administered through one day of onsite surveys at Huntsville Botanic Garden (N = 668). Questions inquired if respondents encountered injury to plants from whitetail deer, what types of preventive methods they were using, plants typically browsed, and extent of plant loss annually as a result of deer activity. Fifty-five percent of green industry professionals and 37% of homeowners answered ‘yes’ to damage problems, and of those, more homeowners (61%) than industry (41%) employed preventive methods to reduce deer browse. High fencing, electric fencing, Liquid Fence® repellent, and motion irrigation were the most effective of eleven preventive measures listed. Indian hawthorn (Rhaphiolepis indica L.) and hosta (Hosta spp.) were the most commonly damaged plants according to industry and homeowners, respectively. The majority of homeowners experienced damage during the spring, while industry participants reported most damage during the winter and fall months.

In the southeast United States, Subsurface Drip Irrigation (SDI) is an available agricultural irrigation practice. Research performed at the Tennessee Valley Research and Extension Center (TVREC), Belle Mina, Alabama indicated poor irrigation uniformity in an active experimental plot equipped with pressure-compensated SDI. The need therefore existed to quantify the performance of the SDI without disrupting ongoing crop research. A study was conducted to develop and validate an in-situ testing technique to assess the application uniformity of SDI, and to evaluate if variable operating pressure or slope was a significant response variable. Laboratory investigations indicated that new pressure-compensated SDI dripline of the type used at TVREC had an emitter discharge of 1.04 L h(-1) (0.275 gal h(-1)) at 5% coefficient of variation (CV) above the manufacturer's specification of 0.98 L h(-1) (0.26 gal h(-1)) at 2.5% CV. A trailer mounted field testing apparatus was fabricated to interface with the in-situ SDI dripline in order to deliver water over a range of operating pressures while measuring sample discharge from a predetermined number of emitters. This apparatus was tested under laboratory conditions to compare emitter discharge equivalent values with per-emitter discharge; measurements from the apparatus agreed to within a half percent of per-emitter discharge values. Field evaluations indicated that the lowest discharge occurred for the irrigated SDI dripline operating at 48-kPa (7-psi) pressure. Discharges from non-irrigated and irrigated driplines operating at 83 and 117 kPa (12 and 17 psi) were not significantly different (alpha = 0.05). Emitter discharge estimates were within +/- 5% of the baseline discharge rate determined from laboratory evaluations (1.04 L h(-1); 0.275 gal h(-1)) regardless of operating pressure or system activity, except for irrigated driplines operating at 48 kpa (7 psi) (-7%). Three sample driplines exhibited flows exceeding +/- 5% of the baseline discharge; flows that may prompt a system manager to investigate this discharge anomaly more closely. Spatial yield estimates indicated that cotton lint yield may have been adversely affected by poor SDI uniformity Techniques and equipment developed in this study provide SDI researchers and users a field method to evaluate in-situ SDI application uniformity and emitter discharge performance.

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.

Abstract With environmental concerns increasing, non-chemical weed control in container plant production is increasing in the United States. Pine bark mini-nuggets were evaluated as a non-chemical weed control technique for two weed species; Chamaesyce maculata (L.) Small (spotted spurge) and Eclipta alba (L.) Hassk.(eclipta). On June 19, 2006, seed (25 per container) were directly placed on the potting substrate surface of #3 containers before mulching with pine bark mini-nuggets to a depth of either 0, 1.27 or 2.54 cm (0, 0.5 or 1.0 in). Additional treatments consisted of applying the mini-nugget mulch at either 1.27 or 2.54 cm (0.5 or 1.0 in) on the potting substrate then overseeding with either spotted spurge or eclipta. Eclipta number per container were 87% less 60 days after seeding (DAS) with the 1.0 in mulch depth compared to non-mulched. Furthermore, spotted spurge fresh weight (FW) was reduced by 45 and 87% (0.5 and 1.0 in, respectively) compared to the non-mulched treatment. The experiment was repeated on August 30 and spurge number per container was 90% less 60 DAS in the 1.0 inch mulch treatment compared to the non-treated containers. A third and fourth experiment also demonstrated that pine bark mini-nuggets have potential to provide non-chemical weed control in nursery crops grown in #3 containers. Results, suggest that with proper application pine bark mini-nuggets can enhance weed control in container nurseries.

In this Workshop, experts will summarize the status of specialty tree nut crop industries in North America-including both Old World and native New World nut tree species.They will discuss historical challenges and successes of these industries and the potential for each to survive, and even thrive, in the future.

Abstract In 2000 and 2004, cultivars of Hemerocallis were treated with foliar applications of 2500 or 5000 ppm benzyladenine (BA) for 1, 2, 3, 4 or 5 consecutive weeks. In both years, BA increased ramet production of all cultivars although treatment response was cultivar dependent. In 2000, an increasing number of BA applications resulted in ‘Lavinia Love’ and ‘Beguine’ forming 1.6 to 3.2 and 0.7 to 1.1 more ramets, respectively, than control plants at 9 weeks after initial treatment (WAT), regardless of concentration. Increasing BA concentration increased ramet formation by up to one ramet in ‘Beguine’ and up to 3 ramets in ‘Lavinia Love’ at 9 WAT, regardless of the number of applications. At 9 WAT in 2004, increasing weekly applications of BA increased ramet formation in ‘Dainty Deb’ from a mean of 1.3 ramets with one application to a mean of 3.0 ramets with five applications, and in ‘Sarah Sikes hybrid’ from 0.5 ramets with one application to 2.1 ramets with five applications, regardless of concentration. Compared to control plants, ‘Dainty Deb’ increased ramet production by 1.9 ramets and 2.3 ramets at 9 WAT in 2004 when treated with 2500 ppm and 5000 ppm BA, respectively, regardless of the number of applications. Compared to untreated controls, ‘Sarah Sikes hybrid’ formed 1.1 and 1.3 more ramets when treated with 2500 ppm and 5000 ppm BA, respectively.

Three herbicides were evaluated during propagation of Loropetalum chinense ‘Ruby’ to determine the effects on rooting and subsequent plant growth. Herbicides evaluated were: Gallery (isoxaben), Ronstar 2G (oxadiazon), and Regal O-O (oxyfluorfen + oxadiazon). Herbicides were applied at three separate times during the propagation process: before sticking, lightly rooted, or fully rooted. Before sticking treatments were applied to flats filled with standard medium prior to the cuttings being stuck. About 1 month later when roots had just begun to emerge [3 to 5 cm (1 to 2 inches) long], a separate group of cuttings (lightly rooted) were treated. Finally, the third application occurred to a separate group of cuttings (not previously treated) once the cuttings were fully rooted. Data was collected at 65, 248, and 342 days after sticking (DAS). One year after sticking, growth indices of ‘Ruby’ loropetalum were similar regardless of when Gallery was applied. At that time there was no effect on root coverage except when Gallery was applied before sticking, which had 58% root coverage compared to 69% for nontreated plants. With Ronstar and Regal O-O shoot growth was similar about 1 year later; however, root coverage was suppressed with Ronstar applied before sticking and at lightly rooted, while Regal O-O suppressed root coverage on all dates of application.

Clematis socialis Kral, commonly known as the Alabama Leatherflower, is an endangered species with only six known populations in northeast Alabama and northwest Georgia. Cutting propagation of the species will aid in establishing additional self-sustaining populations and provide genetic material for future hybridization and genetic preservation. Such research would also benefit growers, especially native nurseries, who wish to produce this species commercially for its ornamental value. Several experiments were performed to determine the effects of four non-amended substrates on root initiation, root growth, and survival of C. socialis stem cuttings. The four substrates tested included sand, perlite, vermiculite, and a 1 peat (P): 1 pine bark (PB): 1 sand (S) mix (by volume). Some of the best results in the preliminary experiments in 2000 were observed when 2 to 3 node cuttings kept under shade and treated with higher IBA/NAA concentrations were used. In 2004, there was a correlation between root growth and cutting survival and particle size of the substrates. Cuttings rooted in the finer-particle substrates sand and vermiculite had higher cutting survival, root growth, root number, and root quality than those rooted in perlite and the 1 P: 1 PB: 1 S mix. Sand, perlite and vermiculite consistently outperformed the 1 P: 1 PB: 1 S mix which had some of the lowest growth data means. Sand was among the highest performing substrates in all years and it is the most inexpensive and readily available making it the most logical substrate for rooting C. socialis stem cuttings.

Abstract In landscape studies conducted in 2002 and 2003, Buddleja davidii (Franch.) ‘White Profusion’, ‘Pink Delight’, and ‘Honeycomb’ were visited by native butterflies to a greater extent than to the remaining four Buddleja examined. In general, the lowest visitation was experienced by B. crispa (Benth.) and B. lindleyana (Fortune) ‘Miss Vicie’. Overall, B. davidii ‘Pink Delight’ was visited by the greatest number of species, while B. crispa and B. lindleyana ‘Miss Vicie’ were visited by the least. Total visit duration by one randomly selected butterfly was greater for B. davidii ‘White Profusion’, ‘Honeycomb’, ‘Pink Delight’, and ‘Royal Red’ in 2003, while no differences among cultivars were found in 2002. Differences in duration per visit were observed in 2003 with B. davidii ‘White Profusion’, ‘Pink Delight’, and ‘Royal Red’ having the greatest and B. crispa the least. Plant characteristics including inflorescence number, growth index, flower morphology, and flower color characteristics differed among cultivars. Through correlation analysis plant characteristics that contributed in part to cultivar differences in visitation were determined. Cultivar differences that consistently correlated with visitation preferences were inflorescence number and growth index. Based on correlation analysis, the cultivar characteristics that did not contribute to visitation differences included flower morphology and flower color characteristics.

`Formosa' azalea ( Rhododendron indicum ) was grown for 4 months in 7.6-L (2 gal) containers in four substrate blends: 100% pine bark (PB) (by volume), 1 PB: 1 cotton gin compost (CGC), 3 PB: 1 CGC, and 3 PB: 1 peat (PT) at three irrigation levels [600, 1200, and 1800 mL·d -1 (20.3, 40.6, and 60.9 floz/d)] in a polyethylene-covered greenhouse. Plants were evaluated for growth on a biweekly basis using a growth index. Roots were evaluated visually at the end of the study using a 0 (no root growth) to 5 (root bound) scale. Initial physical properties were determined and leachates were collected every 30 days. There was no difference in percent increase in growth across irrigation and substrate treatments. Visual root rating was greatest (4.5) for azaleas grown in 3 PB: 1 PT and least (3.5) in 1 PB: 1 CGC. The two PB/CGC blends improved water-holding capacity (WHC) in comparison to 100% PB, with 1 PB: 1 CGC exhibiting the greatest WHC among all four substrates. Bulk density was greatest with the CGC-amended substrates. Leachate pH tended to increase and electrical conductivity (EC) tended to decrease with increasing irrigation volume. Leachates from the CGC-amended substrates were less acidic and EC tended to be similar or greater than leachates from the 100% PB and 3 PB: 1 PT substrates.

Abstract Coreopsis verticillata ‘Moonbeam’ and Rudbeckia fulgida ‘Goldsturm’ were sprayed with tank mixes of B-Nine and Cycocel in all combinations of 0, 2500, 5000 or 7500 ppm B-Nine and 0, 1000, 1500 or 2000 ppm Cycocel. B-Nine was more effective in controlling height of both cultivars than Cycocel or B-Nine/Cycocel tank mixes. B-Nine alone suppressed height of coreopsis 26-52% (over all concentrations and all data collection dates), in contrast to a 17–41% height suppression when B-Nine was combined with Cycocel. Cycocel alone suppressed height of coreopsis 6–16% over all concentrations and data collection dates. B-Nine suppressed height of rudbeckia 20–40% over all data collection dates, while Cycocel suppressed height of rudbeckia only in the last two weeks of data collection (10 and 12% at weeks 8 and 9, respectively). Tank mixes applied to rudbeckia were not as effective as B-Nine alone for height suppression. Flowering of coreopsis was delayed 6 days by B-Nine and 12–14 days by tank mixes of B-Nine and Cycocel; Cycocel accelerated flowering up to 5 days when used alone. Flowering of rudbeckia was delayed up to 9 days with increasing B-Nine concentrations but was unaffected by Cycocel alone or tank mixes of B-Nine/Cycocel. No phytotoxicity was observed at the concentrations used.

Clematis socialis Kral, also known as the Alabama Leatherflower, is an endangered species with only six known populations in northeast Alabama and northwest Georgia. Cutting propagation of the species would be beneficial for establishing additional self-sustaining populations and providing genetic material for future hybridization. A study conducted in 2000 and 2004 determined the effects of four nonamended substrates on root initiation and growth, as well as survival of C. socialis stem cuttings. Of the four substrates tested, including sand, perlite, vermiculite, and 1:1:1 (by volume) peat (P): pine bark (PB): sand (S), cutting survival was highest in sand in both 2000 and 2004. In 2000, sand also produced the longest roots and highest root quality. Vermiculite produced the longest and most roots and highest root quality in the 2004 study. In 2004, cuttings rooted in fine-particled substrates, such as sand and vermiculite, had higher cutting survival, root growth, root number, and root quality than those rooted in perlite and 1:1:1 (by volume) P:PB:S. The 1:1:1 P:PB:S substrate produced the lowest averages for all data collected in both the 2000 and 2004 studies. Sand was among the two highest performing media in both years, regardless of differences in IBA concentration, misting times, and environmental conditions, making it the overall best substrate for rooting C. socialis stem cuttings. Increasing the concentration of IBA in the rooting solution, providing a cooler environment, and decreasing the number and duration of misting cycles the cuttings received increased cutting survival, root length, root number, and root quality for all four substrates from 2000 to 2004.