A study was conducted to determine the role that plant developmental stage (DS) has on the efficacy of cyclanilide (CYC), a plant growth regulator (PGR) with cytokinin-like properties. In 2007, single foliar applications of 200 ppm CYC were applied to ‘Snow White’ Indian hawthorn (Rhaphiolepis indica (L.) Lindl. Ex Ker Gawl.) and ‘Sky Pencil’ holly (Ilex crenata Thunb.) at progressively later stages of lateral shoot development: bud break (DS 1), active shoot elongation (DS 2), or to recently matured shoots (DS 3). The experiment was repeated in 2008 and included an additional application to Sky Pencil holly before bud break (DS 0). In 2007 and 2008, Snow White Indian hawthorn treated with CYC at all DS formed more shoots than untreated plants, except in summer 2008 (DS 3 only) and fall 2008 (DS 1 only). New shoot counts of CYC-treated Indian hawthorn were 53 to 67% and 46 to 65% higher than those of untreated plants in summer and fall, respectively, in 2007 and 26 to 39% and 29 to 48% higher in summer and fall, respectively, in 2008. In the fall of 2008, the only effect of DS on shoot counts of Indian hawthorn was that plants treated at DS 3 formed 29% more new shoots than plants treated at DS 1; DS had no effect on shoot counts in 2007. Symptoms of foliar injury to Indian hawthorn included reddening, chlorosis, and cupping of new growth that appeared between 15 and 30 days after treatment (DAT) and, although not quantified in 2007, were generally less severe and more transitory as DS increased. In 2007, foliar injury lasted until about 90 to 120 DAT in DS 2 and DS 3 plants, but was more persistent in DS 1 plants. In 2008, foliar injury was also transient, regardless of DS, but was highest when CYC was applied at DS 1 or DS 2. CYC-treated Sky Pencil holly had formed more shoots than untreated plants by summer and fall of 2007. Although Sky Pencil holly treated at DS 2 in 2007 formed fewer shoots than DS 1 plants in fall, quality ratings were higher due to a larger canopy that was dense and compact. In the fall of 2008, shoot counts of CYC-treated Sky Pencil holly were greater than those of untreated plants, regardless of DS, and there were no effects of DS on shoot counts. Quality ratings of Sky Pencil holly treated at DS 2 or DS 3, but not at DS 0 and DS 1, were higher than those of untreated plants. In both years of the study, symptoms of foliar injury on Sky Pencil holly were minimal, suggesting a relatively high tolerance to foliar-applied CYC, and all plants were considered marketable.

Three experiments studying the effects of repeated over-the-top applications of Roundup Pro® to container-grown nursery crops were conducted. Plants in 3.8 liter (1 gal) containers were treated with either single or multiple applications of Roundup Pro® at 1.12 kg ai·ha−1 (1.0 lb ai·A−1) in July, August, September, or October, 2008 or 2009. Plants treated with multiple applications were treated in July and August (J+A); July, August, and September (J+A+S); July, August, September, and October (J+A+S+O); or July and September (J+S). Injury ratings were taken at multiple times after treatments. Growth indices (GI) [(height + width1 + width2) / 3] were taken in January and June 2009 and February and May 2010. Plants were rated for vigor and marketability in May 2009 or June 2010. Liriope muscari ‘Big Blue,’ Camellia sasanqua ‘Shishigashira,’ and Gardenia jasminoides ‘Radicans’ were evaluated in Experiment 1 (2008, Auburn). Liriope showed minor injury from two or more applications with reduced growth from 3 or 4 applications, but all plants were rated as marketable in June of the following season. ‘Shishigashira’ camellia exhibited no injury from any glyphosate application and all parameters were similar to non-treated controls (NTC). Gardenia showed fall chlorosis and stunting through early spring from multiple applications, but all plants were marketable. Even those treated 3 or 4 times were small but marketable. In Experiment 2 (2009, Auburn. AL), ‘Big Blue’ liriope, ‘Radicans’ gardenia, Camellia sasanqua ‘Martha Sims,’ and Juniperus conferta ‘Blue Pacific’ showed no injury from any treatment and GI in January and June were similar to NTC. Ilex cornuta ‘Dwarf Burfordi’ GI were similar to NTC with occasional chlorosis observed after July treatments. Ternstroemia gymnathera (cleyera) exhibited chlorosis, necrosis, and stunting of shoot tips for all treatments. Cleyera GI in January and June indicated that J+A+S, J+A+S+O, and J+S-treated plants were smaller than NTC, but regrowth was similar to NTC for all treatments the following spring. All plants were vigorous and marketable. In Experiment 3 (2009, Mobile, AL), ‘Big Blue’ liriope, ‘Radicans’ gardenia, ‘Blue Pacific’ juniper, ‘Martha Sims’ camellia, Ilex cornuta ‘Carissa,’ and cleyera GI were similar to NTC in February and late May. Slight injury occurred only on the new growth of cleyera and ‘Carissa’ holly with primary symptoms being chlorosis and/or slight stunting seen in mid-September and October from some single and double applications.

Nine species of container-grown plants were treated over-the-top with Roundup Pro® (41% glyshosate) at four rates: 0.28, 0.56, 1.12, and 2.24 kg ai·ha−1 (0.25, 0.5, 1.0 and 2.0 lb ai·A−1) either in June 2007, September 2007, or February 2008. A fourth group was treated on all three dates (June + September + February) (JSF). The experiment was repeated on eight species in 2008–2009. Growth indices (GI) were taken before the spring growth flush in March and after the first growth flush in June. In Exp. 1, dwarf mondo grass (Ophiopogon japonicus ‘Nana’), mondo grass (O. japonicus), liriope (Liriope muscari ‘Cleopatra’), variegated liriope (L. muscari ‘Variegata’), and ‘Blue Pacific’ juniper (Juniperus rigida subsp. conferta ‘Blue Pacific’) were not affected by glyphosate rates up to 1.12 kg ai·ha−1 (1.0 lb ai·A−1) applied singly or JSF, except for temporary injury on ‘Blue Pacific’ from February applications. The remainder of the species had reduced growth as Roundup Pro® rates increased. ‘Blue Rug’ juniper (J. horizontalis ‘Wiltonii’) was tolerant in February but injured at ≥ 1.12 kg ai·ha−1 (1.0 lb ai·A−1) in June and September (JS). Asiatic jasmine (Trachelospermum asiaticum) was tolerant of single applications at rates ≤ 1.12 kg ai·ha−1 (1.0 lb ai·A−1) in JS, but showed stunting of new foliage from all February applications. Dwarf yaupon (Ilex vomitoria ‘Stoke's Dwarf’) showed injury at 74 days after treatment (DAT) after June applications, no injury at rates ≤ 1.12 kg ai·ha−1 (1.0 lb ai·A−1) in September, and stunting and delay of new foliage from all February applications and rates ≥ 0.56 kg ai·ha−1 (0.5 lb ai·A−1) in June. ‘Pink Gumpo’ azalea (Rhododendron eriocarpum ‘Gumpo Pink’) was injured by rates ≥ 1.12 kg ai·ha−1 (1.0 lb ai·A−1) applied in June, February, and JSF, however no injury occurred with any September treatment. In Exp. 2, dwarf mondo and mondo tolerated all single application rates up to 1.12 kg ai·ha−1 (1.0 lb ai·A−1). Asiatic jasmine was injured by all February treatments and growth was reduced and stunted by ≥ 1.12 kg ai·ha−1 (1.0 lb ai·A−1) in February and JSF. Dwarf yaupon GI were reduced by rates ≥ 1.12 kg ai·ha−1 (1.0 lb ai·A−1) in February, 2.24 kg ai·ha−1 (2.0 lb ai·A−1) in June, and by all treatments in JSF. February treatments ≥ 0.28 kg ai·ha−1 (0.25 lb ai·A−1) delayed shoot growth of dwarf yaupon for at least 6 weeks. ‘Hardy Daisy’ gardenia (Gardenia jasminoides ‘Hardy Daisy’) showed slight injury from February rates ≥ 1.12 kg ai·ha−1 (1.0 lb ai·A−1), but growth was reduced at 2.24 kg ai·ha−1 (2.0 lb ai·A−1) for June and JSF. Sky pencil holly (Ilex crenata ‘Sky Pencil’) showed stunting from all February applications, but was tolerant up to 2.24 kg ai·ha−1 (2.0 lb ai·A−1) in June and September; GI were similar for all treatments. Purpleleaf wintercreeper euonymus (Euonymus fortunei ‘Coloratus’) was injured by rates ≥ 1.12 kg ai·ha−1 (1.0 lb ai·A−1) applied in June and JS, all February treatments, and stunted by two or three applications of 2.24 kg ai·ha−1 (2.0 lb ai·A−1), but all other treatments had similar GI. Wintergreen boxwood (Buxus sempervirens ‘Wintergreen’) was injured at 2.24 kg ai·ha−1 (2.0 lb ai·A−1) in June, ≥ 1.12 kg ai·ha−1 (1.0 lb ai·A−1) in JS, and all February applications. Growth was reduced by rates of 2.24 kg ai·ha−1 (2.0 lb ai·A−1) in February and ≥ 1.12 kg ai·ha−1 (1.0 lb ai·A−1) in JSF.

Abstract WholeTree (WT) and clean chip residual (CCR) are potential new nursery substrates that are by-products of the forestry industry containing high wood content. Initial immobilization of nitrogen is one concern when using these new substrates; however the addition of composted poultry litter (CPL) to substrates containing high wood content could balance initial nitrogen immobilization and provide an inexpensive fertilizer source for growers. This study evaluated five woody nursery species being grown in WT, CCR, and pinebark (PB) with the addition of CPL or peat as a substrate amendment. Results indicate that these species can be grown successfully in WT and CCR substrates 6: 1 (by vol) with CPL. Use of CPL in WT and CCR substrates may provide an alternative to traditional PB plus peat based combinations in container plant production while providing poultry producers an environmentally sound means of waste disposal.

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.

Abstract In an effort to compare yield and time required to remove substrate from roots of liners, Ophiopogon japonicus and Ophiopogon japonicus ‘Nana’ (lilyturf) bare root bibs were potted into 100% aged pine bark, 8: 2 (v: v) pine bark: peat moss, 100% perlite, 100% fine grade Profile™ porous ceramic (Profile™ products LLC, Buffalo Grove, IL), or 100% course grade Profile™ porous ceramic. In a second study Ophiopogon japonicus was potted into 100% aged pine bark, 100% 3/16-inch HydRocks® (Big River Industries Alpharetta, GA), fine grade 100% Profile™, 100% perlite, 100% sand, 8: 2 (v: v) pine bark: peat moss, and 3: 1 (v: v) 3/16 HydRocks®: sand. In the second study, fine grade Profile™ produced the highest number of total bibs per container and bib production was similar to 8: 2 pine bark: peat moss. HydRocks® was similar to pine bark in total bibs per container but was more efficiently removed from roots. Removal of the HydRocks® substrate from plant roots required 50% less time than removal of pine bark: peat moss substrate and 51% less time than removal of pine bark substrate. HydRocks® took 23% less time to remove from roots than fine grade Profile™. Results indicate that clay materials such as HydRocks® and Profile™, when compared to conventional substrates can provide suitable yields while also decreasing labor cost by decreasing time to bare-root.

Abstract Three experiments were conducted to evaluate the effect of fertilizer placement on prostrate spurge growth (Chamaesyce prostrata) in container production. In experiment one, Polyon 17N–2.TP–9.2K (17–5–11) was topdressed or dibbled at 45 g (1.6 oz) or 90 g (3.2 oz) per 11.3 liter (#3) container and either 90 g (3.2 oz) or 180 g (6.3 oz) per 26.3 liter (#7) container. In experiments two and three, 180 g (6.3 oz) of Polyon 17N–2.1P–9.2K (17–5–11) was topdressed or dibbled per 26.3 liter (#7) container. In all experiments 20 prostrate spurge seed were applied to the container surface 30 days after potting. In all experiments, weed count and weight were less in dibbled containers compared to topdressed. Across all experiments, weed shoot weights at or beyond 90 days after potting were from 31 to 888% greater in topdressed containers, compared to dibbled containers. Overall, dibbling fertilizer greatly reduced weed growth while producing no visible difference in ornamental plant growth.

Abstract Four experiments were conducted to evaluate herbicides for postemergence prostrate spurge (Chamaesyce prostrata (syn. Euphorbia prostrata)) control and tolerance of container-grown liriope (Liriope muscari). In Experiment 1, Manage, Image, Trimec Southern, and Roundup were applied at three rates each to single bib liners of ‘Big Blue’ liriope in 10.2 cm (4 in) pots. Pots were infested with prostrate spurge that were 1 to 2 cm (0.4 to 0.8 in) wide with no flower or seed structures. Only Roundup at 0.45 kg ai/ha (0.4 lb ai/A) provided effective postemergence spurge control (96%) and caused no short-term or long-term injury to ‘Big Blue’. In Experiment 2, Finale and Roundup were applied at three rates each to established ‘Big Blue’ in 3.8 liter (1 gal) containers. By 21 DAT, Finale at rates of 0.28 kg ai/ha (0.25 lb ai/A) or greater caused slight though significant injury to ‘Big Blue’ while Roundup caused no injury. No injury was observed on any plant at 60 DAT and the following spring, growth was similar among all treatments indicating no long-term effects. In Experiment 3, Finale and Roundup applications were made to recently divided liners of ‘Variegata’ liriope infested with mature spurge 17.0 to 20.1 cm (6.7 to 7.9 in) wide, which were flowering and seeding. Finale at 1.12 kg ai/ha (1.0 lb ai/A) and Roundup at 1.8 kg ai/ha (1.6 lb ai/A) provided effective spurge control (100 and 92.8%, respectively) and caused no short-term or long-term injury to ‘Variegata’. Lower rates were not effective in controlling mature spurge. In Experiment 4, Finale and Roundup were applied to recently divided liners of ‘Big Blue’ infested with mature spurge 23 to 31 cm (9.1 to 12.2 in) wide, which were flowering and seeding. At 21 DAT, Finale at 1.12 kg ai/ha (1 lb ai/A) and Roundup at 1.8 kg ai/ha (1.6 lb ai/A) provided 100% control, while lower rates of both herbicides provided poor control (14 to 85%). Both herbicides caused slight initial injury to ‘Big Blue’, however, injury was outgrown by 60 DAT and by the following spring all plants were similar in size and number of new bibs produced compared to non-treated controls.

Abstract A study was conducted to determine the effects of root mass and benzyladenine (BA) on offset formation in hosta. Stock plants of two cultivars, ‘Francee’ and ‘Frances Williams’, were divided, and offsets were placed in either small, medium, or large root mass groups. Offsets were potted and, when surface root development was evident, half of the plants in each root mass group received a foliar spray application of 3000 ppm BA, while half served as BA controls. Offset formation was positively correlated with increasing root mass, regardless of BA application. BA stimulated the outgrowth of axillary and rhizomic buds in both cultivars. Offsets on plants treated with BA were at a more advanced stage of development (SOD) than offsets on BA controls, but root mass did not affect SOD. Root mass, but not BA, affected whole plant growth index, which increased with increases in root mass.

Abstract Twenty-four nurseries producing container-grown plants were surveyed along the coastal zone of south Alabama to determine Best Management Practices (BMPs) implemented since 1988. All nurseries utilized multiple BMPs. Seventy-five percent of all nurseries surveyed have the capability to capture runoff water; however, larger nurseries (medium 4.5–16.6 ha (11–40 A); large 16.6+ ha (40+A)) were more likely to capture runoff than smaller nurseries 0.4–4.1 ha (1–10 A). Since 1988, 78% of all collection ponds have been built with 44% of those being built in the past 5 years. Other BMPs widely used included installation of grass filter/erosion strips, having specific personnel devoted to water management, use of control release fertilizers, scouting for pests, use of horticultural oils, and staggered herbicide applications.

Abstract Three experiments were conducted to evaluate the effectiveness of postemergence applied herbicides for hairy bittercress (Cardamine hirsuta L.) control in container-grown crops. Manage (halosulfuron), Image (imazaquin), Action (fluthiacet-methyl), Resource (flumiclorac pentyl), Trimec Southern (Mecoprop + 2,4-D + dicamba), and Gallery (isoxaben) were applied to emerged bittercress in ‘Variegata’ and ‘Big Blue’ liriope. ‘China Girl’ holly and ‘Midnight Flare’ azalea were also treated with Manage, Image, Trimec Southern, and Gallery to evaluate injury. Among all experiments, Gallery provided 90 to 100% bittercress control at the labeled rate of 1.12 kg ai/ha (1.0 lb ai/A) with no injury to liriope, holly, or azalea. Among non-flowering bittercress, Manage applied at 0.035 kg ai/ha (0.031 lb ai/A) provided 90 to 100% bittercress control, with slight to moderate injury to ‘Variegata’ liriope; Image applied at 0.070 kg ai/ha (0.062 lb ai/A) provided 73 to 99.5% bittercress control and caused severe injury to azalea; and Trimec Southern applied at 0.31 kg ai/ha (0.28 lb ai/A) provided 50 to 100% bittercress control and caused severe injury to liriope and azalea. However, using the same rates applied to flowering bittercress Manage, Image, and Trimec Southern provided only 55, 6, and 50% bittercress control, respectively. Action and Resource did not control bittercress.

Recycled paper pellets in the bottom of containers were evaluated for retention of N from container leachate. `Formosa' azalea were transplanted on 15 Apr. in 2.8-L containers in a pine bark/peat substrate (3:1; v/v). Treatments included paper (0 or 2.5 cm depth) in the bottom of containers and two rates of Osmocote 18–6–12 (0.68 kg or 1.36 kg N/yd 3 ). Immediately after transplanting, plants were topdressed with 3.2 g of 12–4–6 fertilizer. Data collected included leachate samples every 2 weeks for NO 3 -N and NH 4 -N levels and destructive sampling every 4 weeks for shoot dry weight, foliar N, and total paper N. Nitrate-N and NH 4 -N leachate concentrations were reduced with the 0.68 kg N/yd 3 fertilizer rate and with paper. For example, 28 days after planting (DAP) NO 3 -N leachate concentrations were reduced 36% with the 0.68 kg N/yd 3 fertilizer rate and 46% with paper in the bottom of containers. NH 4 -N in the leachates was reduced 53% with the 0.68 kg N/yd 3 fertilizer rate and 59% with paper. Azalea shoot dry weight was not affected by paper or fertilizer rate up to 112 DAP; however, as the study progressed, plants with paper in the bottom of containers grew larger than plants in no paper treatments (29% at 168 DAP, 31% at 196 DAP). Total N absorbed by paper was not affected by fertilizer rate, and peaked at 168 DAP [980 (0.68 kg N/yd 3 ) to 1066 (1.36 kg N/yd 3 ) mg per container, or 41% – 28% of applied N], after which it began to decline. This decline in paper N was associated with greater growth of azalea with paper.

Abstract Three experiments were conducted to evaluate the effects of preemergence-applied herbicides on growth of liriope [Liriope muscari (Decne.) L.H. Bailey ‘Big Blue’ and ‘Variegata’] when applied immediately after division. Overall, most herbicides caused no injury or suppression of root or shoot development. Surflan (oryzalin) and a Surflan + Gallery (isoxaben) combination inhibited root and shoot growth. Predict (norflurazon) caused foliar injury characterized by bleached bands or spots on both old and new foliage.

Abstract Primo (cimectacarb) was applied to four herbaceous and six woody landscape plants at rates and in volumes recommended for turfgrass application. Phytotoxic symptoms, including bleaching or bronzing of foliage or bleaching of flowers, occurred in coleus, petunia, butterfly bush and azalea (Southern Indica cultivar). In general, symptoms were more severe with increasing Primo rate, while application volume had less effect. Effects on shoot growth were minimal and not considered of practical significance in a landscape setting.

Abstract Primo (cimectacarb), applied as a foliar spray, suppressed shoot growth of four of six bedding plants and all four woody landscape species tested. However, phytotoxic symptoms occurred on the foliage of all bedding plants and two woody species and to flowers of three bedding plants and one woody species. Foliage and flowers of affected plants exhibited a loss of pigmentation that increased at higher rates of Primo, resulting in a bleached appearance.

Abstract ‘Prize’ forcing azalea was treated with 15 or 30 ppm Sumagic at one of 4 stages of shoot apex development (stage 0 = vegetative; 1 = apex broadened; 2−3 = sepals and petals initiated; 4 = stamen initiated) in 2 experiments. Plants were taller and broader as the application was delayed; these parameters decreased with increasing Sumagic rate. Bypass shoot count decreased quadratically with increasing rate, and was not affected by stage of development (SOD) in one experiment but decreased when plants were treated at a later SOD in a second experiment. Time to flower increased and flower count decreased when plants were treated at a later SOD. Plants treated at SOD 0 flowered earlier with more blooms or at a similar time with a similar flower count to control plants.

Pecan [Carya illinoinensis (Wangenh.) C. Koch 'Melrose'] and pear (Pyrus calleryana Decne. 'Bradford') trees in the nursery grew more in containers designed to hold water in the lower portion. The water-holding reservoir was obtained either by placing 76-liter containers in a frame holding water to a depth of 6 cm or by using containers with drainage holes 6 cm from the bottom. Continuous waterlogging at the bottom of containers resulted in root pruning and root death in the lower portion of the containers, but roots grew well above the constantly wet zone. Fresh weight of plant tops and trunk diameters were greater after two growing seasons in the containers with water reservoirs compared to those grown in similar containers with no water reservoirs. Total root dry weight was unaffected.