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Paclobutrazol substrate drenches at 0, 1, 2, 3, or 4 ppm were compared to a 2,500 ppm daminozide foliar spray standard in two finishing seasons (fall 2015 and spring 2016) and at two application stages for plant size control and improved market quality of ‘Bright Red with Light Eye' Gerbera daisy (Gerbera jamesonii Hook. f. ‘Bright Red with Light Eye') in 12.7cm (5 in) pots. Stage 1 was when the majority of plants had roots to the bottom of the substrate, and stage 2 was 2 weeks later. A consumer preference survey assessed purchasing preference when plants had two or three open flowers. Plant size index, foliage height, peduncle length, flower diameter, and quality rating at first flower decreased linearly while days to first flower increased quadratically with increasing paclobutrazol concentration, regardless of stage or season. Paclobutrazol applications delayed flowering, and decreased flower diameter and flower and bud counts, but these differences were small and not considered of practical importance. Based on quality rating at first flower and survey results, a 1 or 2 ppm paclobutrazol drench produced the most marketable plants in fall, and 0, 1, 2, or 3 ppm produced the most marketable plants in spring.Index words: plant growth retardant, B-Nine, Bonzi, greenhouse productionChemicals used in this study: B-Nine (daminozide) [butanedioic acid mono (2,2- dimethylhydrazide)] and Bonzi (paclobutrazol) [(±)-(R*,R*)-β-[(4-Chlorophenyl)methyl]-α-(1,1- dimethylethyl)-lH-1,2,4-triazole-1-ethanol]Species used in this study: ‘Bright Red with Light Eye' Gerbera daisy (Gerbera jamesonii Hook. f. ‘Bright Red with Light Eye')

Phytophthora parasitica was transmitted within 6 weeks from vinca (Catharanthus roseus) plants growing in infested potting mix, on the drain end of ebb-and-flow benches, to plants in noninfested potting mix. Transmission of Phytophthora was very low when potting mix was not pasteurized. When potting mix was steam pasteurized, infection of plants, disease incidence, and severity increased with time and decreased with distance from plants in infested pots. The cultivar Pretty in Pink was more susceptible to infection by P. parasitica than cv. Peppermint Cooler, allowing more rapid and severe disease development as well as pathogen dissemination and transmission. Pot spacing did not significantly affect transmission of P. parasitica on an ebb-and-flow bench.

A study was conducted to determine the effects of pinching and the plant growth retardant, daminozide (B-Nine), on plant size and flowering of ‘Coronation Gold’ yarrow (Achillea × ‘Coronation Gold’). Greenhouse-grown plants were not pinched or were pinched by removing the apical bud from propagation offsets 3, 5 or 7 weeks after potting. One week after pinching, plants were provided night-interrupted lighting (NIL). Five weeks after pinching, a single application of daminozide was applied at 5,000 ppm to half the pinched and non-pinched plants. Pinching decreased inflorescence stem length by 6.4% and increased the number of flowering and total offsets by 33.3 and 9.1%, respectively. Daminozide application decreased inflorescence stem length and the number of flowering offsets by 7.9 and 40%, respectively, but increased the time to first open inflorescence and the number of non-flowering offsets by 6 days and 28.6%, respectively. Pinching at 7 weeks after potting resulted in the highest number of flowering, non-flowering, and total offsets, the fewest days to flower, and an intermediate flower stem length. In a second experiment, the effects of beginning NIL at different times after pinching the offset from propagation on offset production and flowering were evaluated. All plants were uniformly pinched and NIL was started 0, 1, 2, 3, or 4 weeks after pinching. Starting NIL at 4 weeks after pinching resulted in the fewest days to flower, the highest flowering offset number that was similar to starting NIL at 3 weeks, and a flower stem length about equal to all other NIL treatments.

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.

A study was conducted to determine how seedling development stage at transplanting from plug flats into small pots affected growth and flowering of two commonly grown bedding plants. Seeds of Showstar® medallion flower and ‘Las Vegas Pink’ globe amaranth were sown in 392-cell flats on five dates for each of two experimental runs before transplanting into 8.9 cm (3.5 in) cubic pots. At transplanting of both species, plant height, node count and shoot dry weight increased as days from sowing to transplanting increased and there was no visible cessation in shoot growth due to root restriction. Time to first flower from transplanting decreased linearly with both species in both runs, except with medallion flower in the second run, as time from sowing to transplanting increased. In contrast, time to flower of both species from sowing increased linearly as time from sowing to transplanting increased. However, the magnitude of the increase or decrease in time to flower differed between the two runs indicating that other factors, most likely light intensity and duration, besides node counts were affecting time to flower. Globe amaranth height and growth index and medallion flower growth index at first flower decreased as time from sowing to transplanting increased, whereas medallion flower height was not affected by time from sowing to transplanting.

A study was conducted to determine the effects of bulking duration and the plant growth retardant daminozide on plant growth and flowering of greenhouse-grown ‘Coronation Gold’ yarrow (Achillea בCoronation Gold’). Single-shoot liners of yarrow were transplanted on October 14 and December 2, 2010, into 15 cm (6 in) containers and bulked for 4, 6, 8, or 10 weeks prior to exposure to night-interrupted lighting (NIL). Increasing the bulking duration increased the number of shortened, thickened stems of rosette-like appearance, or offsets, that had developed from the base of the main stem by the end of bulking by 100 to 367% and reduced days to first and five open inflorescences, hereafter referred to as flowers, from the beginning of NIL by 13 to 16 days and 10 to 20 days for the October and December potting dates, respectively. Increasing the bulking duration increased flower and flower bud number by 67 and 25% in the October 14 and December 2 potting dates, respectively. Therefore, more flowers and flower buds formed on yarrow when potted early, compared to late potting. Lengths of the first five open flower stems were inconsistent and minimally affected by bulking duration. In a repeat of the experiment potted on December 2 using the same bulking treatments, 5,000 ppm of daminozide was applied as a foliar spray when half the plants in a bulking duration had begun to elongate and was reapplied 1 week later. Daminozide application decreased stem length at first open flower by 20 to 43%, but increased days to first flower and five open flowers by 6 and 8 days, respectively. As in the first experiment, increasing the bulking duration increased the number of offsets and flower and flower bud number and reduced days to first and five open flowers.

Production of non-timber forest products (NTFPs) offers a way for landowners to generate income without harvesting timber. In Alabama, pine straw is a NTFP with strong market potential, but the market is relatively undeveloped compared to markets in some other Southeastern states. A mail survey was conducted to assess the willingness of landowners to engage in alternative forestry enterprises, including pine straw harvesting. Those who owned a relatively large forest area (especially of planted pine), had used a consulting forester, and lived outside of the county where their forestland was located had higher levels of interest in harvesting pine straw for profit. Landowners who resided in the same county as their forestland expected higher prices for their pine straw than absentee owners. Primary concerns among landowners interested in harvesting pine straw were related to lack of technical information and lack of a product market.

A study was conducted under nursery production conditions to evaluate multiple concentrations of dikegulac sodium (dikegulac) (0, 800, and 1,600 ppm) applied either once or twice as a foliar spray to blackgum grown at two locations in Alabama and to southern sugar maple grown at a single location. Mid-season and end-of-season shoot counts increased linearly in response to increasing dikegulac concentrations in both species and at both locations. Shoot counts also were greater when dikegulac was applied twice compared to a single application, except when 800 ppm dikegulac was applied to blackgum at one location. Both southern sugar maple and blackgum were visibly more branched and compact following treatments with dikegulac than nontreated control plants, although the branching response was much greater in blackgum. Effects of dikegulac application on plant height and caliper varied with species, concentration, application number, and time after application. Southern sugar maple exhibited temporary reddening of immature foliage that dissipated over time, while immature foliage of blackgum yellowed at one location and cupped and developed necrotic lesions at the second location. No phytotoxicity was evident 6 weeks after dikegulac application.

A study was conducted to evaluate dikegulac sodium (dikegulac) and benzyladenine (BA) as branching agents on landscape trees during production. Common among the six species in this two-year study was an increase in new shoot development following the application of dikegulac. Relative to shoot counts of nontreated plants, trees treated with a single foliar application of 800 to 3200 ppm of dikegulac had an increase in shoot numbers of 29 to 107% in Japanese maple, 75 to 158% in red maple, 67% in redbud, 50 to 65% in bald cypress, and 56 to 103% in black gum. Nontreated plants of green ash formed only one or two lateral shoots in 2011, whereas dikegulac-treated green ash had 10 to 12 new shoots. In 2012, green ash treated with 200 to 800 ppm of dikegulac developed 100 to 150% more new shoots than nontreated green ash. Foliage of all species, except Japanese maple, was injured to varying degrees by dikegulac, but the injury dissipated over the growing season. BA promoted increased shoot development only in bald cypress, and canopies of that species were visually fuller and more compact than those of bald cypress treated with dikegulac.

Staggered starting dates for night-interrupted lighting (NIL) were evaluated for accelerated sequential flowering of herbaceous perennials with different photoperiod requirements outdoors in a southern nursery setting. Plants evaluated were black-eyed Susan (Rudbeckia fulgida ‘Goldsturm’), an obligate long-day (LD) plant; obedient plant (Physostegia virginiana ‘Miss Manners’), a facultative LD plant; and Stokes' aster (Stokesia laevis ‘Peachie's Pick’), a facultative intermediate-day plant. With all species, the dates of first flower and maximum flower number occurred sooner under LDs from incandescent (INC) and fluorescent (FLU) lamps than under natural photoperiod (NP). Mean and maximum flower numbers were greater under NIL than under NP for black-eyed Susan and Stokes' aster but not for obedient plant. Time in flower increased in Stokes' aster, but either decreased or was not affected by NIL for black-eyed Susan and obedient plant. Flowering periods of black-eyed Susan and obedient plant exposed to different NIL timings overlapped extensively while leaving a gap in flowering between plants exposed to NIL and those under NP. This gap in flowering suggests that the intervals between NIL start dates could be longer to lessen the flowering overlap of plants under NIL, and that the interval between the start of the last NIL treatment and the onset of an inductive photoperiod be reduced to maintain sequential peak flowering until the natural flowering period. With Stokes' aster, flowering overlapped for plants in the different NIL timings and under NP, resulting in continuous sequential blooms from first flowering of plants under NIL until the plants' natural flowering period under NP in late May. Flowering periods of Stokes' aster exposed to NIL beginning on different dates overlapped extensively, suggesting that at least one NIL start date could be omitted and the intervals between the start of NIL increased without sacrificing continuous sequential peak flowering. NIL from INC and FLU lamps promoted growth in plant height compared to that of plants under NP, although the increase in plant height was less under FLU lamps.

The effects of bulking duration on growth and flowering of ‘Goldsturm’ black-eyed Susan (Rudbeckia fulgida Ait. ‘Goldsturm’) and ‘Moonbeam’ coreopsis (Coreopsis verticillata L. ‘Moonbeam’) forced into flower under nursery conditions were evaluated as part of a system for the accelerated production of herbaceous perennials requiring long days to flower. Bulking duration treatments were established by a factorialization of potting date (September 24, October 13, December 2, and December 14, 2009) and night-interrupted lighting (NIL) start date (February 1, February 22, and March 15, 2010). Leaf counts of black-eyed Susan at the beginning of NIL increased linearly with progressively longer bulking durations based on potting date and NIL start date, although the effect was more pronounced when compared across potting dates. Based on leaf counts, black-eyed Susan potted in December were still in the juvenile phase when NIL was begun on February 1, 2010. Stem counts of black-eyed Susan at first flower followed a similar pattern as leaf counts. Black-eyed Susan given NIL flowered 40 to 59 days before plants under natural photoperiod (NP). Flower plus flower bud counts of black-eyed Susan at first flower increased linearly with increasing bulking duration based on potting date: by 325, 268, and 243% when NIL was begun on February 1, February 22, and March 15, respectively. Flower counts also increased linearly approximately 46% with increasing bulking duration based on NIL start dates, but only when plants were potted in December. At first flower, plant height of black-eyed Susan given NIL increased linearly as bulking duration increased based on potting date, but did not differ when trended across the NIL start dates. Days to flower of coreopsis decreased with increasing bulking duration, while stem counts increased with bulking duration, and the number of marketable plants was greater when plants were repotted on the three earliest dates compared to those bulked the shortest duration. Effects of bulking duration on flower plus flower bud counts and height of coreopsis were inconsistent.

A study was conducted in 2004 and 2005 to determine how ‘Early Sunrise’ coreopsis (Coreopsis grandiflora Hogg ex Sweet. ‘Early Sunrise’), ‘Moonbeam’ coreopsis (Coreopsis verticillata L. ‘Moonbeam’) and ‘Goldsturm’ rudbeckia (Rudbeckia fulgida Aiton ‘Goldsturm’) responded to two plant growth retardants applied at three stages of plant development (SOD) when plants were exposed to night-interrupted lighting (NIL) while grown outdoors under nursery conditions in the southern United States. With few exceptions, height of all species was suppressed by 2 weeks after first treatment (WAT) compared to NIL only, regardless of whether 5000 ppm B-Nine or 20 ppm Sumagic was applied at the beginning of a period of rapid shoot elongation (SOD 2) or 2 weeks prior to (SOD 1) or following this stage (SOD 3), and continued throughout the plants’ vegetative phase, although the level of suppression varied with SOD and PGR. Applying either PGR at SOD 2, when rapid shoot elongation first began, was most effective in suppressing vegetative height of ‘Early Sunrise’ coreopsis and ‘Goldsturm’ rudbeckia, whereas vegetative height suppression of ‘Moonbeam’ coreopsis was not affected by SOD when Sumagic was applied, but suppression was greatest when B-Nine was applied at SOD 1, two weeks before rapid shoot elongation began. ‘Early Sunrise’ coreopsis and ‘Goldsturm’ rudbeckia were shortest at first flower when PGRs were applied at SOD 2 and SOD 3, respectively, but plant height of ‘Moonbeam’ coreopsis at first flower was not affected by SOD. Where differences in height suppression occurred at first flower, B-Nine was more effective than Sumagic. Plant SOD when PGRs were applied had no effect on flowering or plant quality of ‘Moonbeam’ coreopsis and minimal effect on ‘Early Sunrise’ coreopsis or ‘Goldsturm’ rudbeckia.

A study was conducted in 2004 to determine if end-of-day lighting (EOD) alone or in combination with night-interrupted lighting (NIL) could be used to suppress stem elongation of ‘Goldsturm’ coneflower (Rudbeckia fulgida Aiton ‘Goldsturm’), ‘Moonbeam’ coreopsis (Coreopsis verticillata L. ‘Moonbeam’) and ‘Early Sunrise’ coreopsis (Coreopsis grandiflora Hogg ex Sweet. ‘Early Sunrise’) when grown outdoors under nursery conditions in the southern U.S. without negating the benefits of earlier flowering from NIL. End-of-day lighting, NIL, and the combination of the two treatments accelerated time to flowering of all three cultivars compared to that of plants under a natural photoperiod (NP); however, rudbeckia flowered quicker when exposed to NIL or NIL + EOD than when grown under EOD only. Height of rudbeckia grown under EOD or NIL was greater than that of plants grown under NP, whereas ‘Moonbeam’ coreopsis exposed to EOD, NIL or EOD + NIL were similar in height and taller than plants grown under NP. Height of ‘Early Sunrise’ coreopsis was minimally affected by treatments, except that plants under EOD were shorter than those under EOD + NIL. Growth index, flower number, shoot length and quality rating were similar in almost all cases for plants of the three cultivars when grown under EOD lighting, NIL, or EOD + NIL. These results indicate EOD was ineffective in suppressing height growth and provided no benefit, either alone or in combination with NIL, over NIL alone in the accelerated production of these cultivars outdoors under nursery conditions.

The Auburn University campus in Auburn, Alabama, USA, was the location for a case study to compare carbon storage, carbon sequestration, and air pollution (CO, O3, NO2, PM10, SO2) removal estimates between protected and maintained urban forests. Results were from a complete tree inventory and i-Tree Eco analysis of the 237 ha maintained and 5.5 ha protected areas of the campus. Trees in the maintained landscapes had an average diameter at breast height of 16.4 cm and basal area of 2.24 m2/ha when compared with 24.4 cm and 12.04 m2/ha for the protected area. The maintained landscapes were estimated to store 6652 kg of carbon per ha and sequester 291 kg/year/ha of carbon. The protected area was estimated to store 41,975 kg of carbon per ha and sequester 1758 kg/year/ha of carbon. Trees in the maintained areas removed 2970 kg/year of air pollution (12.5 kg/year/ha) compared with 560 kg/year for the protected area (102 kg/year/ha), which was 8 times the amount on a unit area basis compared with the maintained...

Pine straw is a popular landscape mulch material used by landowners and homeowners throughout the southeastern United States. Pine straw is collected, transported, and sold through an informal network of landowners, harvesters, forest labor contractors, and dealers. Quality varies widely, depending on factors such as species of pines, land management practices, and harvesting techniques. A mail survey of landscapers, retailers, and lawn maintenance specialists was used to assess market demand and characteristic preferences of those buying and selling pine straw in Alabama. Purchase volumes varied widely among buyers, both annually and for single-time purchases. Buyers placed high importance on straw free from weeds and foreign material. There were differences in species of pine straw purchased among respondents, some of which appear attributable to location of the buyer. While there was a strong preference for longleaf pine straw, those who reported purchasing loblolly and slash were more likely to prefer those species. Responses from buyers who know their pine straw's origin reveal differences in the distance from which they purchase pine straw, with many buying straw from more than 150 miles away. Results also show that many do not know where their pine straw comes from or what species it is.

Models that predict ecosystem services in urban areas are useful tools to urban forest managers. Predictive open-grown crown width equations were developed for three oak species common in urban forests in the southern United States. Tree crown form is an important component of these equations; however, there are few predictive equations available for urban, open-grown trees. The species used were Quercus lyrata Walt. (overcup oak), Quercus nuttallii Palmer (Nuttall oak), and Quercus phellos L. (willow oak). The study authors believe that these are the first predictive open-grown crown width equations developed for these species in the southern U.S. Diameter at breast height (DBH) (independent variable), DBH2 (independent variable), and average crown width (dependent variable) data were used to create the predictive crown width equations and yielded R2 values of 0.96, 0.94, and 0.91 for overcup, Nuttall, and willow oaks, respectively. These equations can aid urban landscape and utility planners by providing a means to predict crown dimensions at varying trunk diameters. Field time could also be minimized by reducing the need to measure crown width and with time, these equations could be used to validate species specific equations (e.g., leaf biomass) for these and other southern urban-planted tree species.

Herbaceous perennials were screened for increased branching and flowering in response to foliar sprays of cyclanilide (CYC), a plant growth regulator with cytokinin-like activity. Coreopsis verticillata ‘Creme Brulee’ (‘Creme Brulee’ coreopsis) and Rudbeckia fulgida ‘Goldsturm’ (‘Goldsturm’ coneflower), the only two species that responded positively to CYC, were used in subsequent experiments evaluating CYC concentration, method of application, and stage of plant development at application. Foliar sprays of 25 to 100 ppm CYC promoted increased shoot development, flowering, and plant width of coreopsis and coneflower, although flowering was delayed. Applying foliar sprays to both species when they were vegetative resulted in similar or more new shoots and flowers than an application when plants exhibited early signs of approaching flowering or at both stages. Increases in shoot counts from the application of substrate drenches of CYC to coreopsis and coneflower generally were less than from foliar sprays, while flower counts either decreased with increasing CYC concentration (coreopsis) or were unaffected (coneflower). Species used in this study: Coreopsis verticillata L. ‘Creme Brulee’ (‘Creme Brulee’ coreopsis), Lantana ×hybrida hort. ‘New Gold’ (‘New Gold’ lantana), Pennisetum setaceum (Forssk.) Chiov. ‘Rubrum’ (purple fountain grass), Perovskia atriplicifolia Benth. (Russian sage), and Rudbeckia fulgida Aiton ‘Goldsturm’ (‘Goldsturm’ coneflower).

A study was conducted to determine if there were synergistic effects from applying two plant growth regulators (PGRs), cyclanilide (CYC) and benzyladenine (BA), with cytokinin properties on Rhaphiolepis sp. (L.) Lindl. ‘Conor’ and ‘Snow White’ (Indian hawthorn), Rhododendron L. ‘North Lake Beauty’ (azalea), and Ilex crenata Thunb. ‘Sky Pencil’ (Japanese holly) during nursery production. Foliar applications of 100 or 200 ppm CYC promoted new shoot development in all species, whereas 2500 ppm BA either had no effect or suppressed shoot development, except in one of two experiments when shoot development was promoted in holly. With no species was there a synergistic effect on shoot development from combining the two PGRs, even when both PGRs individually promoted new shoot development in holly. Indian hawthorn and holly developed transient symptoms of toxicity in response to CYC, BA, and CYC + BA combinations that had dissipated by the end of the growing season and had no lasting effects on plant quality.

A study was conducted in 2002 and 2003 to determine if growth retardants could be used to suppress stem elongation of ‘Moonbeam’ coreopsis (Coreopsis verticillata L. ‘Moonbeam’) and ‘Goldsturm’ coneflower (Rudbeckia fulgida Aiton ‘Goldsturm’) when grown outdoors under nursery conditions in the southern United States without negating the benefits of earlier flowering from night-interrupted lighting (NIL). Night-interrupted lighting accelerated flowering of both cultivars without adversely affecting flower and flower bud counts or plant quality. However, plants grown under NIL generally were taller than plants grown under natural photoperiod (NP). When several PGRs [Cutless, B-Nine, B-Nine/Cycocel, Bonzi (2002 only), and Sumagic (2003 only)] were applied to plants under NIL, results varied with PGR type and concentration and year. Height of ‘Moonbeam’ coreopsis was effectively suppressed by 5000 or 7500 ppm B-Nine + 1500 ppm Cycocel in both years of the study and with 40 or 60 ppm Sumagic in the one year it was tested. Higher concentrations of Cutless and B-Nine suppressed height growth in 1 of 2 years, while Bonzi was ineffective. None of the PGR types or concentrations suppressed height growth of ‘Goldsturm’ coneflower to the level of the NP control in 2002. However, in 2003 when an additional application of Cutless and B-Nine were made, and Bonzi was replaced with Sumagic, applications of Cutless, B-Nine, B-Nine/Cycocel, and Sumagic all resulted in heights similar to or less than that of plants under NP with minimal effects on time to flower or flower and flower bud counts.

Cyclanilide (CYC) is a bioregulator that promotes the development of lateral shoots in ornamental and fruit tree crops, potentially reducing the need for mechanical pruning during nursery production. In 2006, three foliar applications of 200 ppm CYC applied at a 1, 2, or 3 week application interval increased shoot counts of ‘Diana’ sasanqua camellia, ‘Sky Pencil’ holly, and ‘Snow White’ Indian hawthorn when compared to pruned and unpruned controls. However, application interval had no effect on shoots counts in holly or camellia and minimal effect in Indian hawthorn. Foliar injury to Indian hawthorn was severe, regardless of application interval. In 2007, three applications of 50 or 100 ppm CYC were applied at a 1, 3, or 6 week interval to ‘Sky Pencil’ holly and ‘Snow White’ Indian hawthorn. At 120 to 150 days after initial treatment (DAIT), shoot counts in both species increased with application interval, and all CYC-treated plants formed more new shoots than controls. Transitory injury to new growth of Indian hawthorn, although not quantified, appeared to increase as application interval decreased. At 120 DAIT foliar injury was no longer evident in Indian hawthorn. At 180 DAIT quality rating of both cultivars increased with CYC application interval and was greater than that of controls, and CYC-treated plants were visibly more dense and compact.

Cyclanilide (CYC), a plant growth regulator with cytokinin-like properties, was applied as a substrate drench to containerized woody ornamentals to determine its effects on plant growth. At 70 days after treatment (DAT) in 2005, drench applications of 50 to 1,000 ppm CYC had increased shoot development 7 to 74% for ‘Alabama Beauty’ sasanqua camellia (Camellia sasanqua ‘Alabama Beauty’), 63 to 205% for small anisetree (Illicium parviflorum), 21 to 74% for ‘Snow White’ Indian hawthorn (Rhaphiolepis indica ‘Snow White’), and 266 to 626% for ‘Sky Pencil’ holly (Ilex crenata ‘Sky Pencil’), when compared to control plants. Shoot counts the following spring, 270 DAT, increased from 16 to 101% for sasanqua camellia, 42 to 158% for small anisetree, 121 to 241% for Indian hawthorn, and 33 to 167% for ‘Firepower’ nandina, when compared to control plants. At 30 DAT foliar injury to sasanqua camellia, Indian hawthorn, and small anisetree increased with CYC concentration, and application of 500 or 1,000 ppm CYC resulted in severe injury or death of small anisetree and ‘Snow White’ Indian hawthorn. At 75 DAT in 2006, drench application of 25 to 100 ppm CYC had increased shoot counts of Eleanor Taber™ Indian hawthorn from 100 to 218%, when compared to controls, and quality ratings were highest at 130 DAT in plants drenched with 50 ppm CYC, although foliar injury ratings increased with CYC concentration at 75 and 130 DAT. At 60 DAT in 2007, application of 10 to 40 ppm CYC had increased shoot counts for ‘Snow White’ Indian hawthorn and ‘Sky Pencil’ holly 100 to 182% and 22 to 78%, respectively, and 96 to 171% and 30 to 63%, respectively at 90 to 110 DAT. In both species, quality ratings at 160 DAT increased with increasing CYC concentration. Single CYC drench applications were more persistent than previously reported single spray applications, effective at lower concentrations, and promoted shoot production in a species not responsive to single or multiple spray applications (Nandina domestica).

A study was conducted to determine if limited inductive photoperiod (LIP) initiated in late winter could be used to control stem elongation in ‘Goldsturm’ coneflower (Rudbeckia fulgida ‘Goldsturm’), ‘Moonbeam’ coreopsis (Coreopsis verticillata ‘Moonbeam’), or ‘Early Sunrise’ coreopsis (Coreopsis grandiflora ‘Early Sunrise’), grown outdoors under nursery conditions in the southern United States, without negating the benefits of earlier flowering from night-interrupted lighting (NIL). Treatments were NIL beginning on February 1 and ending on February 15, March 1, March 15, or April 1,2002, plus a natural photoperiod (NP) treatment. The experiment was repeated in 2003 with the inclusion of an additional NIL treatment ending on April 15. LIPs of at least 15 to 30 days, 30 to 45 days, and 30 to 45 days promoted earlier flowering of ‘Early Sunrise’ coreopsis, ‘Moonbeam’ coreopsis, and ‘Goldsturm’ coneflower, respectively. Flower counts and quality ratings of the three cultivars that received LIPs were similar to or higher than those of plants under a NP, except for a reduction in flowering and quality ratings of ‘Goldsturm’ coneflower exposed to LIPs ending on March 1 and March 15, 2002, and on March 1, 2003, and later. LIP effects on plant height were mixed, although there was at least one duration of LIP that resulted in earlier flowering of the three cultivars and plants similar to or shorter than plants under a NP.

A study was conducted to determine the effects of pruning on plant response to cyclanilide (CYC), a bioregulator that promotes lateral branching of fruit trees and selected woody nursery crops. In April 2004, non-pruned ‘Elizabeth Ann’ Japanese camellia (Camellia japonica L.) and small anisetree (Illicium parviflorum Michx. ex Vent.) received a single foliar application of 0, 25, 50, 100 or 200 ppm CYC, while the same species received a foliar spray of 0, 50 or 100 ppm CYC following uniform pruning. In June 2006, a single foliar application of 0, 100 or 200 ppm CYC was made to plants of ternstroemia (Ternstroemia gymnanthera Thunb.), ‘Sky Pencil’ holly (Ilex crenata Thunb.) and ‘Jennifer’ azalea (Rhododendron L.) that were either not pruned or uniformly pruned before CYC treatment. At 30 and 60 days after treatment (DAT), non-pruned, CYC-treated plants formed more shoots than pruned CYC-treated plants, however quality ratings at 120 DAT were generally higher in plants pruned prior to CYC treatment. In a third experiment, the effects of 200 ppm CYC on branching of ternstroemia, ‘Sky Pencil’ holly, ‘Jennifer’ azalea and ‘Snow White’ Indian hawthorn were ascertained when applied at three stages of lateral shoot development following pruning: immediately after pruning [developmental stage 1 (DS 1)], when new shoots were 1.3 to 2.6 cm (0.5 to 1 in) in length (DS 2), or when new shoots were 2.6 to 5.1 cm (1.0 to 2.0 in) in length (DS 3). At 60 days after pruning (DAP), shoot counts in ternstroemia and ‘Sky Pencil’ holly treated at DS 3 and ‘Snow White’ Indian hawthorn treated at DS 2 were greater than those of pruned controls. Shoot counts in ‘Jennifer’ azalea were not affected by plant developmental stage at the time of CYC application. Relatively minor injury was evident at 60 and 120 DAP in all species except ‘Jennifer’ azalea, and was most pronounced in ternstroemia and ‘Sky Pencil’ holly treated at DS 3 and in ‘Snow White’ Indian hawthorn treated at DS 2. Quality ratings were similarly high for plants of all species and treatments, except in ‘Sky Pencil’ holly in which quality ratings of plants treated with CYC at DS 1 or DS 3 were higher than those of pruned controls.

Foliar sprays of 10, 15, or 20 ppm paclobutrazol followed by a second application of 50 ppm were applied to ‘Bravo Lavender’ and ‘Celebrity Blue’ petunias and ‘Salvador Red’ and ‘Vista Red’ salvia during production to determine their effects on plant growth, flowering and market quality during production, simulated shipping, and while in a simulated retail environment. Paclobutrazol effectively suppressed shoot growth and enhanced market quality of all cultivars during production, while minimally or not affecting time to first flower. Growth suppression and enhanced market quality continued through simulated shipping and the period plants were in the retail environment. While in the simulated retail environment, plants were exposed to six or seven wilt/hydration cycles. The % wilted plants of all four cultivars previously treated with paclobutrazol during production was much less than that of the controls: ‘Bravo Lavender’ petunia, 21 vs. 67%; ‘Celebrity Blue’ petunia, 10 vs. 88%; ‘Salvador Red’ salvia, 15 vs. 69%; and ‘Vista Red’ salvia; 13 vs. 74%.

An experiment was conducted to determine the effects of several widely used plant growth retardants on plant size and flowering of Achillea × ‘Coronation Gold’. Plants in 10 cm (4 in) pots were grown in a greenhouse and treated with B-Nine at 0, 2550, 5100, or 7650 ppm; Cycocel at 0, 767, 1534, or 2301 ppm; B-Nine/Cycocel at 0, 1275/1534, 2550/1534, or 3825/1534 ppm; Sumagic at 0, 11, 22, 33, 44, or 55 ppm; Bonzi at 0, 32, 64, 96, 128, or 160 ppm; or Cutless at 0, 40, 80, or 120 ppm as a spray 1 week after vernalization. B-Nine, Cycocel, B-Nine/Cycocel, Sumagic, Bonzi, and Cutless reduced shoot height and growth index by 36 and 26%, 39 and 27%, 61 and 41%, 75 and 52%, 52 and 36%, and 75 and 51%, respectively, with the highest rate of each. B-Nine, Cycocel, B-Nine/Cycocel, and Sumagic, but not Bonzi or Cutless, increased the number of days to open inflorescence by 3-5 days with increasing rate. Sumagic, Bonzi, and Cutless reduced inflorescence diameter by up to 15, 18, and 14%, respectively but not B-Nine, Cycocel, or B-Nine/Cycocel. The highest quality ratings of 2.8 to 3.0 were found with B-Nine/Cycocel at 3825/1534 ppm, Sumagic at 22 and 33 ppm, and Bonzi at 64 ppm. Differences between the results in this study and earlier studies implicate the possible impact of differences in experimental environments, container size, or stage of development when the plant growth retardant treatments were applied.

In landscape studies conducted in 2002 and 2003, Lantana camara (L.) ‘New Gold’ and ‘Radiation’ were visited by native butterflies to a greater extent than the remaining eight lantana in the studies. Other lantana visited preferentially but not as consistently included L. camara ‘White Doves’, ‘Firewagon’, ‘Confetti’, and Lantana montevidensis (Spreng.) ‘Weeping Lavender’. In general, the lowest visitation was experienced by L. camara ‘Cherry’ and ‘Carlos’. Total visit duration by one randomly selected butterfly was greater for ‘New Gold’, ‘Radiation’, ‘Firewagon’, and ‘White Doves’ than the remaining lantana. Plant characteristics including inflorescence number, number of flowers per inflorescence, percentage of yellow flowers per inflorescence, growth index, flower morphology, and flower color characteristics differed among cultivars. Cultivar differences that consistently correlated with visitation preferences were inflorescence number in 2002 and 2003, flower number per inflorescence in 2003, percentage of yellow flowers per inflorescence in 2002 and 2003, and growth index in 2003. Flower lightness and flower chroma correlated sporadically with visitation in late September and October 2002 and 2003. Percentage light reflectance of flowers for the wavelengths of green, yellow, orange, and red correlated with visitation in 2003. Based on correlation analysis, the cultivar characteristics that did not contribute to visitation differences included inflorescence width, corolla width, and corolla tube length. In a separate study conducted in 2003 using the same lantana as in the visitation study, nectar volume, carbohydrate composition, and sucrose and fructose concentrations differed among inflorescences. Of ten Lantana evaluated, ‘Carlos’ and ‘Confetti had the largest inflorescence nectar volumes combined from nine flowers while ‘New Gold’, ‘White Doves’, and ‘Weeping Lavender’ had the smallest. The ratio of sucrose to hexose (fructose and glucose) in nectar from ‘Weeping Lavender’, ‘White Doves’, and ‘New Gold’ was greater than that of the remaining Lantana. The lowest ratios of sucrose to hexose were found for ‘Irene’, ‘Hot Country’, and ‘Carlos’, while similar to ‘Cherry’ and ‘Radiation’. The sucrose to hexose ratio for recently opened inner flowers was double that of middle and outer flowers. Sucrose and total sugar concentrations were greatest in recently opened inner flowers compared to middle and outer flowers. While direct comparison to the 2002 and 2003 studies of butterfly visitation preferences was not possible due to experimental design, data trends suggest a possible relationship between sugar composition, inflorescence nectar production and visitation from native butterfly species.

This investigation was conducted to determine the plant growth retardant type, application method, and rate required to produce a marketable greenhouse pot plant of Coreopsis verticillata L. ‘Moonbeam’. Pruned plants in 10 cm (4 in) pots received growth retardant treatments in two experiments consisting of one application of ancymidol or paclobutrazol medium drenches at 0, 2, 4, or 6 ppm; daminozide spray at 0, 2550, 5100, or 7650 ppm; paclobutrazol spray at 0, 12, 24, 36, 48, or 60 ppm; flurprimidol spray at 0, 25, 50, 75, 100, 150, or 200 ppm; or maleic hydrazide at 0, 360, 720, 1080, 1440, or 1800 ppm in the first experiment and sprays of daminozide at 0, 2550, 5100, or 7650 ppm; paclobutrazol at 0, 60, or 120 ppm; daminozide/paclobutrazol combinations at 0, 2550/16, 2550/32, 2550/48, or 2550/64 ppm, chloromequat at 0, 767, 1534, or 2301 ppm; or daminozide/chloromequat combinations at 0, 1275/1534, 2550/1534, 3825/1534, or 5100/1534 ppm in the second experiment. In the first experiment, there was a linear decrease in shoot height, growth index, and lateral shoot length with increasing rates of ancymidol and paclobutrazol drenches and flurprimidol sprays while daminozide decreased growth quadratically. There was a linear increase in shoot height and lateral shoot length with increasing rates of maleic hydrazide but no effect on growth index. Only daminozide and maleic hydrazide increased the number of days from treatment to flower with increasing rates. Quality ratings increased with increasing rates of ancymidol, daminozide, and flurprimidol with the highest ratings found at the two highest rates of daminozide and flurprimidol. Paclobutrazol spray did not affect the parameters measured. In the second experiment, chloromequat spray did not affect the parameters measured but when combined with increasing rates of daminozide, linearly decreased shoot height, growth index, and lateral shoot length while increasing the number of days to flower. Daminozide alone resulted in a quadratic change in growth index and lateral shoot length while linearly increasing the number of days to flower but with no effect on quality rating. The higher rates of paclobutrazol than were used in the first experiment decreased shoot height and lateral shoot length with no effect on growth index, the number of days to flower, or quality rating. Overall, the best quality ratings and the most compact plants resulted from spray applications of daminozide at 5100 ppm or 7650 ppm and flurprimidol at 150 ppm or 200 ppm, however flurprimidol is not currently registered for application to greenhouse crops but a newer product, Topflor, has the same active ingredient and greenhouse crop labeling.

Inconsistencies have been reported in the role of vernalization and photoperiod on growth and flowering of Leucanthemum x superbum Bergmans ex J. Ingram cultivars. Five cultivars were used to determine the effects of vernalization and photoperiod on days to flower, shoot height, growth index, flower shoot number, and quality rating. Plants received 0, 3, 6, 9, or 12 weeks of vernalization time (VER) at 4.4C (40F) and afterward were placed under either natural short days (SD) or night-interrupted lighting (NIL) in a greenhouse. ‘Becky’ showed an obligate requirement for NIL to flower with 100% of plants flowering under NIL and 0% of plants flowering under SD regardless of VER. Vernalization for 6 weeks before NIL increased shoot height, growth index, flower shoot number, and quality rating but the fewest days to flower occurred after 12 weeks of VER. ‘Silver Princess’, ‘Snow Cap’, ‘Snow Lady’, and ‘Summer Snowball’ showed a facultative requirement for NIL to flower. Plants under NIL flowered earlier, were larger, had more flower shoots, and had a higher overall quality rating than plants under SD. Shoot height and growth index were highest under NIL after 3 and 6 weeks of VER, flower shoot number was highest after 3 to 9 weeks of VER, but days to flower was least after 12 weeks of VER. Therefore, NIL after 3 or 6 weeks of VER would maximize plant size and quality for practical application in the cultivars studied but result in more DTF when compared to 12 weeks of VER.

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.

The effects of geographic location and production light level on vegetative growth and flowering were evaluated as a means of accelerating the development of tree-form crapemyrtles. By the end of the first year of the experiment, Dynamite™, ‘Muskogee’, ‘Natchez’, and ‘Tuscarora’ grown in Oregon were as much as 42, 51, 43, and 92% taller, respectively, than plants in Alabama, while plants generally had less trunk diameter in Oregon. ‘Muskogee’ and ‘Natchez’ in both locations and ‘Tuscarora’ in Alabama were generally taller when grown under 50% shade than plants in full sun, while height of Dynamite™ was not affected by production light level. Trunk diameter of ‘Natchez’ in both locations and of Dynamite™ in Alabama was less when plants were grown under shade, while trunk diameter of ‘Muskogee’ and ‘Tuscarora’ was not affected by production light level. Flowering of plants grown under shade in Alabama was delayed, while no plants in Oregon flowered the first year. In the second year of the experiment when all plants were grown in full sun, all cultivars continued to be taller in Oregon, while trunk diameter remained greater in Alabama. The height advantage gained from growing plants under shade the previous year was not evident in any cultivar by the end of the second year, while trunk diameter was similar for all cultivars previously grown in full sun and under 50% shade. There was no difference in flowering of plants in Alabama previously grown under 50% shade and in full sun, while 50 to 100% of the four cultivars in Oregon flowered with no obvious difference due to prior production light level.

The effects of production light level on growth of crapemyrtle were evaluated as a means of accelerating the development of tree-form crapemyrtles (Lagerstroemia spp.). By the end of the first growing season, plant height and shoot length of ‘Fantasy’ and ‘Tuscarora’ were greater when grown under 50 or 80% shade than when grown in full sun. By the end of the second growing season, height and shoot length of all three cultivars grown under one or both shade levels were greater than those of plants grown in full sun. In a second experiment, ‘Carolina Beauty’ and ‘Tuscarora’, but not Dynamite™, were taller at the end of the first growing season when grown under 50 or 80% shade than when grown in full sun. Flowering of all cultivars grown under shade was suppressed or delayed. Caliper of Dynamite™ and ‘Tuscarora’ at the end of the first growing season was greatest when grown in full sun, while production light level had no effect on caliper of ‘Carolina Beauty’. At the end of the second season, during which all plants were grown in full sun, there were no height, caliper, or flowering differences of any cultivar due to previous production light level, except for less caliper growth of ‘Tuscarora’ previously under 80% shade compared to plants grown in full sun.

Tree shelters were evaluated as a means of accelerating height growth of tree-form crapemyrtles. In two experiments, Dynamite™ grown in shelters were 124 and 48% taller at the end of the growing season, while shelter-grown ‘Potomac’ were 61 and 50% taller. Height of ‘Tuscarora’ was not affected by tree shelters. In the first experiment calipers of sheltered and non-sheltered ‘Tuscarora’ and Dynamite™ were similar at the end of the season, while caliper of ‘Potomac’ was 35% less when grown in shelters. In the second experiment there were no caliper differences between sheltered and unsheltered Dynamite™ or ‘Potomac’ at the end of the growing season. All plants grown in tree shelters flowered later than unsheltered plants and had visibly straighter, more upright trunks with minimal lateral shoot development.

The effects of production light level on coppicing and coppice timing were evaluated as means of accelerating the development of tree-form crapemyrtles. By the end of the growing season, ‘Fantasy’ and ‘Tuscarora’ coppiced in March and grown under 80% shade were 23 and 18% taller, respectively, than coppiced plants in full sun, but similar in height to plants under 50% shade. Coppiced Dynamite™ under 80% shade and coppiced ‘Carolina Beauty’ under 50% shade were 11 and 26% taller than coppiced plants in full sun, respectively, by the end of the growing season. Height of ‘Fantasy’ and ‘Tuscarora’, but not ‘Natchez’, at the end of the growing season decreased as coppicing was delayed from January to June. ‘Natchez’ coppiced in March were taller than plants coppiced in January or February and 68% taller than plants coppiced in June by the end of the growing season. Cross-sectional stem area of coppiced Dynamite™ and ‘Fantasy’ grown in full sun was greater than that of plants under 50 or 80% shade. Stem area of coppiced ‘Tuscarora’ under 50% shade was greater than that under 80% shade, but similar to that of coppiced plants in full sun. Stem area of coppiced ‘Carolina Beauty’ was greatest when grown in full sun, followed by growth under 50% shade, and least in plants grown under 80% shade. Stem area of ‘Fantasy’, ‘Natchez’, and ‘Tuscarora’ at the end of the growing season decreased linearly as coppicing was delayed from January to June. Visually, coppiced plants had straighter shoots, more uniform shoot diameters, and less branching off the main trunks than non-coppiced plants.

Night-interrupted lighting (NIL) outdoors in a southern nursery setting was evaluated as a system for accelerated production of herbaceous perennials requiring long days to flower. Treatments were NIL beginning February 1, February 15, March 1, or March 15, and a natural photoperiod control. Compared to plants under the natural photoperiod and depending upon initiation of NIL treatment and year, NIL accelerated and increased flowering of ‘Moonbeam’ coreopsis (Coreopsis verticillata L. ‘Moonbeam’) 7 to 36 days and 20 to 244%, ‘Early Sunrise’ coreopsis (Coreopsis grandiflora Hogg ex Sweet. ‘Early Sunrise’) 3 to 20 days and 26 to 64%, ‘Sunray’ coreopsis (Coreopsis grandiflora Hogg ex Sweet. ‘Sunray’) 6 to 13 days and 21 to 44%, ‘Autumn Joy’ stonecrop (Sedum x ‘Autumn Joy’) 26 to 57 days and 200 to 300%, and ‘Blue Queen’ salvia (Salvia x superba Stapf ‘Blue Queen’) 7 to 12 days and 56 to 83%. Flowering of ‘Red Beauty’ obedient plant (Physostegia virginiana (L.) Benth. ‘Red Beauty) was accelerated 20 to 54 days; however, inflorescence counts decreased 38 to 46% in one year and was not affected by treatments in the second year. Plants of all cultivars, except ‘Autumn Joy’ sedum and ‘Red Beauty’ obedient plant, were taller when exposed to NIL than when grown under the natural photoperiod, however plant quality rating of all cultivars was as high or higher under NIL.

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.

Hardy ferns are widely grown for use in the landscape. The 1998 National Agricultural Statistics Services census of horticulture reported production of hardy/garden ferns at 3,107,000 containers from over 1200 nurseries. There is little research on herbicide use in hardy ferns, and herbicides that are labeled for container production are not labeled for use on hardy ferns. Studies were conducted to evaluate the tolerance of variegated east indian holly fern (Arachniodes simplicior `Variegata'), tassel fern (Polystichum polyblepharum), autumn fern (Dryopteris erythrosora), rochford's japanese holly fern (Cyrtomium falcatum `Rochfordianum'), and southern wood fern (Dryopteris ludoviciana), to applications of selected preemergence applied herbicides. Herbicides evaluated included selected granular or liquid applied preemergence herbicides. Spray-applied herbicides were pendimethalin at 3.0 or 6.0 lb/acre, prodiamine at 1.0 or 2.0 lb/acre, isoxaben at 1.0 or 2.0 lb/acre, and prodiamine + isoxaben at 1.0 + 1.0 lb/acre. Granular-applied herbicides were pendimethalin at 3.0 or 6.0 lb/acre, prodiamine at 1.0 or 2.0 lb/acre, oxadiazon + prodiamine at 1.0 + 0.2 or 2.0 + 0.4 lb/acre, oxyfluorfen + oryzalin at 2.0 + 1.0 or 4.0 + 2.0 lb/acre, trifluralin + isoxaben at 2.0 + 0.5 or 4.0 + 1.0 lb/acre, oxadiazon at 4.0 or 8.0 lb/acre, and oxadiazon + pendimethalin at 2.0 + 1.25 or 4.0 + 2.5 lb/acre. The greatest reduction in growth of autumn fern was observed with the high rates of oxadiazon, oxadiazon + pendimethalin, and oxadiazon + prodiamine. Reductions in rochford's japanese holly fern growth were most severe when plants were treated with the high rate of trifluralin + isoxaben resulting in a 66% and 72% decrease in frond length and frond number, respectively. There were also reductions in frond length and number of fronds when treated with the high rate of oxadiazon + pendimethalin. There were no reductions in frond numbers on tassel fern with any herbicides tested. However, there were reductions in frond length from four of the 10 herbicides evaluated. The most sensitive fern to herbicides evaluated in 2004 was variegated east indian holly fern with reductions in frond length and number of fronds with four of the 10 herbicides tested. Southern wood fern appeared to be quite tolerant of the herbicides tested with the exception of the high rate of oxadiazon. Granular prodiamine proved to be a safe herbicide for all species tested in both 2004 and 2005. In 2005 all plants from all treatments were considered marketable by the end of the study. The durations of both studies were over 120 days giving adequate time for any visual injury to be masked by new growth. However, there was significant visual injury observed on the rochford's japanese holly fern treated with isoxaben at 60 and 90 days after treatment, which might reduce their early marketability.

Vegetative bud growth was controlled on dormant peach rootstock of budded Prunus persica (L.) Batsch. ‘Bon Fire’ with naphthaleneacetic acid (NAA) applied as a trunk paint. Vegetative bud growth was suppressed with all test concentrations (2,875 to 11,500 ppm) throu gh 210 days after treatment (DAT), although scion b ud mortality of ‘Bon Fire’ was greater with concentrat ions above 8,625 ppm. Naphthaleneacetic acid applied at 5,750 ppm provided excellent vegetative bud control, vigorous scion bud growth, and minimal scion bud mortality. Index words: auxin, growth regulator, NAA, nursery production. Growth regulators used in this study: K-Salt™ FruitFix™ (NAA), 1-naphthaleneacetic acid, potassium salt; Tre-hold ® RTU (NAA), 1-naphthaleneacetic acid. Species used in this study: Prunus persica (L.) Batsch . ‘Bon Fire’.

A study was conducted to determine the effects of developmental stage (DS) on plant response to benzyladenine (BA), a synthetic cytokinin that promotes lateral shoot development. Beginning in March, April, or June 2003, three applications of 1750 or 3500 ppm BA were applied at 7-day intervals to ‘Conor’ (Eleanor Taber™) Indian hawthorn (Rhaphiolepis Lindl.) at three stages of increased shoot development (DS 1–3). At 30 and 60 days after last treatment (DALT), new shoot counts were highest on DS 2 plants, and new shoot counts increased with increasing BA rate. Plants treated at DS 1 and DS 2 incurred foliar injury, but not those treated at DS 3. A second experiment with ‘Nigra’ inkberry holly (Ilex glabra L.), ‘Harbour Dwarf’ nandina (Nandina domestica Thunb.), and ‘Conia’ (Olivia™) Indian hawthorn determined how plant DS affected severity of injury following BA application. Extensive foliar injury to ‘Nigra’ inkberry holly occurred when BA was applied to actively growing, immature foliage, but not when applied to mature foliage. Olivia™ Indian hawthorn showed moderate injury following BA treatment of plants with the most immature foliage, but not when plants were treated at more advanced stages of development. ‘Harbour Dwarf’ nandina foliage was unaffected by BA treatment regardless of DS.

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.

Benzyladenine (BA) is a synthetic cytokinin that promotes lateral shoot development in herbaceous and woody ornamentals and may be a viable alternative to mechanical pruning in nursery production. A study was conducted to determine the effects of BA application number, interval and concentration on two Indian hawthorn [Rhaphiolepis Lindl. Cor. Poir. indica (L.) Lindl. (Crataegus indica L.)] cultivars. In spring 2002, actively growing ‘Olivia’ and ‘Eleanor Taber’ received three applications of 2500 or 5000 ppm BA at a one-, two-, or three-week interval. Data collected four weeks after initial treatment (WAT) reflected the effects of one, two, or three BA applications at each concentration. At this time new shoot counts in both cultivars and foliar injury in ‘Olivia’, but not in ‘Eleanor Taber’, increased with increasing number of applications and BA concentration. Data collected 12 WAT reflected the effects of BA application interval and concentration. At this time new shoot counts increased with decreasing application interval in ‘Olivia’, while ‘Eleanor Taber’ formed the most new shoots when BA was applied at a two-week interval. All treated plants sustained minimal to moderate injury to immature foliage. The experiment was repeated in 2003 using 1750 ppm and 3500 ppm BA on ‘Olivia’ Indian hawthorn. Applications were halted at the first sign of foliar injury resulting in plants treated at one, two, and three-week intervals receiving three, two, and two applications, respectively. New shoot counts on ‘Olivia’ treated at the three application intervals were similar, but greater than those on untreated plants. Control plants had a foliar injury rating similar to that of plants treated at a two or three-week interval, but less than that of plants treated at a one-week interval. Growth index was not affected by treatment in either year.

New offset formation in hosta in response to benzyladenine (BA) drenches applied at division and establishment was examined. Hosta Tratt. ‘Frances Williams’ and H. ‘Francee’ were separated into uniform single-bud divisions and drenched with 50 ml of 0, 100, 500, 1000, 2000 or 3000 ppm (mg/liter) BA just prior to potting (division) or two weeks later when substrate-container interface root development was evident (establishment). A 3000 ppm (mg/liter) foliar spray applied to established plants served as a standard. Offsets were counted in plants treated at division 14 days later at which time BA was applied to established plants. Offsets were counted on all plants 30 and 60 days after BA was applied to established plants and in spring of the following year. Offset counts increased rapidly in both cultivars following drench applications of increasing BA concentrations, whether applied at division or establishment. This positive response to increasing BA drench concentrations was evident 60 days after treatment (DAT) and the following spring, except in H. ‘Frances Williams’ drenched at division. However, benefits of either BA method or time of application were less pronounced in spring, following a period of dormancy.

A study was conducted to determine effects of multiple weekly applications of different concentrations of a synthetic cytokinin, benzyladenine (BA), on two Indian hawthorn [Rhaphiolepis Lindl. Cor. Poir. indica (L.) Lindl. (Crataegus indica L.)] cultivars, ‘Olivia’ and ‘Eleanor Taber’. In a greenhouse in winter 2000-2001, ‘Olivia’ Indian hawthorn received four weekly applications of 2500 ppm or 5000 ppm BA. At 45 days after last treatment (DALT) untreated plants had formed no new shoots, while plants treated with 2500 and 5000 ppm BA produced 6.8 and 5.4 new shoots, respectively. New leaves of plants treated with 5000 ppm BA were abnormally mottled, twisted, and cupped. In an outdoor nursery in summer 2001, ‘Olivia’ in 3.8 liter (#1) and 26.5 liter (#7) containers received three and two applications, respectively, at concentrations from 0 to 5000 ppm. Untreated plants in 26.5 liter (#7) containers formed 4.7 new shoots at 30 days after initial treatment (DAIT), and new shoots increased from 83 with 1250 ppm BA to 126 with 5000 ppm BA. Plants in 26.5 liter (#7) containers were retreated in September, at which time shoots were inactive. At 30 DAIT controls averaged less than one new shoot per plant, while plants averaged 18 new shoots when treated with 1250 ppm BA and 105 new shoots when treated with 5000 ppm BA. In spring 2002, plants in 3.8 liter (#1) containers were retreated following the same protocol as in 2001, in conjunction with a new set of ‘Olivia’ and the Indian hawthorn cultivar, ‘Eleanor Taber’. At 30 DALT new shoot formation increased three fold in ‘Olivia’ and five fold in ‘Eleanor Taber’ after three applications of up to 5000 ppm BA. Injury increased with increasing BA rates in ‘Olivia’ at 30 DALT, with leaf cupping and discoloration apparent on plants treated with concentrations above 1250 ppm. No injury was observed in ‘Eleanor Taber’. By 90 DALT new shoots had matured normally and exhibited minimal phytotoxic symptoms.

Hosta plantaginea and 11 selections with H. plantaginea parentage were chilled at 4C (39F) for 0, 1, 2, 3, or 4 weeks to determine the effect of chilling duration on subsequent plant growth. At 6 and 12 weeks after chilling treatment (WAT), response to chilling duration was selection dependent with three trends evident. At 6 WAT, eight of the 12 selections showed a decrease in new leaf formation with one or two weeks of chilling, but an increase in new leaf formation with additional chilling. In three of the 12 selections, new leaf formation increased linearly with increased chilling. New leaf formation of H. plantaginea ‘Grandiflora’ was not affected by chilling duration at 6 or 12 WAT. At 12 WAT, growth response of four of the 12 selections changed quadratically with increased chilling, similar to the response at 6 WAT, while leaf formation in seven of the 12 selections increased linearly with increasing chilling duration. At 18 WAT, leaf counts increased linearly in all H. plantaginea selections with increasing chilling duration, demonstrating increased vigor. All selections showed increases in new leaf formation over the 18-week period following chilling, demonstrating that chilling, though beneficial, was not required, and in the short-term, the response to chilling was selection dependent.

A study was conducted over a two-year period to determine how time of pruning affects cold hardiness of butterfly bush (Buddleia davidii (Franchet) ‘Royal Red’). Plants were pruned in November, January, or March, and pruned and non-pruned plants were exposed to six freezing temperatures two weeks after pruning treatments were applied. In addition, plants pruned in previous seasons were included in subsequent freezing treatments. Plants were rated for injury 2 or 3 weeks after treatment (WAT), and for mortality at 6 WAT. In fall 2001, at −6C (21.2F), injury ratings were higher in pruned than non-pruned plants. At all other treatment temperatures, injury to pruned and non-pruned plants was similar. In fall 2001, mortality increased with decreasing temperatures and was higher in pruned plants than in non-pruned controls, regardless of treatment temperature. In winter and spring 2002, injury and mortality increased with decreasing temperatures, but were not affected by pruning treatments. In fall 2002, temperature decreased as injury rating and mortality increased, regardless of pruning treatment and pruned plants had a higher injury rating and mortality than non-pruned across all temperatures. In winter 2003, injury rating and mortality increased with decreasing temperatures and pruning did not affect either. Spring 2003 plants, which had deacclimated prior to freeze treatment, were not affected by pruning or freezing treatments.

A study conducted from 2000 to 2002 determined the effects of multiple applications of benzyladenine (BA) applied at different concentrations on shoot formation, whole plant size, and phytotoxicity in Nandina domestica Thunb. In 2000, shoot counts increased in ‘Harbour Dwarf’ by up to 107% and 480% as the number of weekly BA applications at 2500 and 5000 ppm, respectively, increased to five. Likewise, the number of shoots per plant increased as BA rate increased. In response to five weekly foliar BA applications in 2001 and 2002, the number of new shoots on ‘Harbour Dwarf’ increased linearly 10-fold over the control as BA rate increased to 5000 ppm in 1250 ppm increments. In 2002, shoot formation increased linearly by up to six additional shoots per plant with increasing BA rate in ‘Harbour Dwarf’ and quadratically by up to two additional shoots per plant in ‘Firepower’ by 90 days after initial treatment (DAT) with five applications of up to 5000 ppm BA. Shoot formation in the tall, upright cultivars ‘Royal Princess’ and ‘Moyer's Red’ also increased linearly with increasing BA rate, by two and

Eight hosta species or cultivars, Hosta plantaginea, H. ventricosa ‘Aureo Marginata’, H. ‘Tokudama’, H. ‘Francee’, H. ‘Sum and Substance’, H. ‘Fragrant Bouquet’, H. ‘Frances Williams’, and H. sieboldiana ‘Elegans’, were chilled in a walk-in cooler in two-week increments from 2 to 10 weeks at 4C (39F), prior to forcing in a heated greenhouse. More than 80% of all cultivars in all treatments emerged, except for H. ‘Tokudama’. For all cultivars tested, days to shoot emergence and days to first leaf unfurled decreased quadratically as chilling duration increased. Most rapid decreases occurred between 0 and 6 weeks of chilling. In the absence of chilling, H. plantaginea was the first cultivar to emerge, between 34 and 79 days before other cultivars. H. plantaginea was followed by H. ventricosa ‘Aureo Marginata’, H. ‘Sum and Substance’, and H. ‘Fragrant Bouquet’, all of which emerged before H. ‘Frances Williams’. Leaf area index, an indicator of plant vigor, increased linearly as chilling duration increased. Shoot dry weight increased in H. ‘Fragrant Bouquet’, H. ‘ Frances Williams’ and H. ‘Francee’, decreased slightly in H. plantaginea, and did not change in H. ventricosa ‘Aureo Marginata’, H. ‘Tokudama’, H. ‘Sum and Substance’, or H. sieboldiana ‘Elegans’ as chilling duration increased. This study indicates that there is no absolute chilling requirement for shoot emergence or subsequent growth of hosta tested. All cultivars benefited from chilling with quicker shoot emergence and fewer days to first leaf unfurled, with the greatest benefits occurring between 0 and 6 weeks. However, the benefits of chilling, as exemplified by growth and vigor, varied widely among species and cultivars.

Profuse flowering, followed by heavy fruit set and cessation of vegetative growth, extends the production cycle of many crapemyrtle cultivars, particularly ‘Tuscarora’. A study was conducted in 2002 to determine the effect of multiple applications of 1000 ppm Pistill (ethephon) on flower abortion and subsequent axillary shoot growth in Lagerstroemia indica xfauriei ‘Tuscarora’ when applied to open flowers in July and August before fruit set. In one experiment, Pistill was applied 0, 1, 2, 3, 4, or 5 times during the two flowering periods, and at 7-, 14-, and 21-day intervals (DI) during each period in a second experiment. In the first experiment, two applications made during the July flush led to 48% flower abortion, whereas by the fifth application, made during the August flush, the abortion rate had increased to 58%. Axillary shoot formation occurred predominantly following the July flush, with 34 and 60 new shoots developing on plants receiving one and two applications, respectively. Pistill applications every 7, 14, or 21 days to open flowers during the first floral flush prompted flower abortion of 81, 51, and 18%, respectively, compared to no abortion in untreated trees. The same Pistill treatments applied during the August flush resulted in 96, 96, 54, and 0% abortion, respectively. Trees receiving Pistill at 7 DI, 14 DI, and 21 DI, respectively, formed 96, 108, and two new shoots following the July flower flush and 13, 27, and two new shoots following the August flush.

Two experiments were conducted with pansy (Viola ×wittrockiana Gams `Bingo Yello') to determine the relationship between foliar nitrogen (% of dry weight) (FN) and either sap nitrate concentration (SN) in petioles or SPAD readings of foliage. FN was highly correlated to SN throughout both experiments (r = 0.80 to 0.91). FN was poorly correlated to SPAD readings early in both experiments (r = 0.54 to 0.65), but more highly correlated later when visual symptoms of N deficiency were apparent (r = 0.84 to 0.90). SN determined with the Cardy sap nitrate meter was a reliable predictor of FN in pansy, while SPAD readings were only reliable after symptoms of N deficiency were visually evident. FN can be predicted with SN using the following equation: log(SN) = 0.47*FN + 1.6 [r2 = 0.80, n = 132]. Growers and landscape professionals can use SN readings to predict FN levels in pansy, and thus rapidly and accurately diagnose the N status of their crop.

Two experiments were conducted to evaluate fertilizer formulations, methods of application, and frequency of application on growth of winter-grown landscape bedding plants and N leaching. In Expt. 1, ‘Majestic Giants White’ pansy (Viola xwittrockiana Gams.) and ‘Telstar Purple’ dianthus (Dianthus chinensis L.) were planted in raised beds. Four inorganic fertilizer formulations were applied at 4.9 g/m2 N (1 lb N/1000 ft2) either incorporated pre-plant or topdressed post-plant. Additional treatments included an industry practice (IP) of incorporating a granular water soluble (GWS) fertilizer pre-plant and topdressing a controlled release fertilizer (CRF) post-plant, and a pre-plant incorporation of an organically-based fertilizer (OBF) composed of recycled newspaper amended with chicken manure. In Expt. 2, similar treatments were applied to the following species: ‘Bingo Blue with Blotch’ pansy, ‘Telstar Crimson Picotee’ dianthus, and ‘Tall Red’ snapdragon (Antirrhinum majus L.). Across both studies, CRFs generally improved foliar color and plant size compared to GWS fertilizers, while reducing total-N in soil-water in some instances. The IP treatment provided superior foliar color and larger plants compared to other inorganically fertilized plants, while causing no more or less total-N in soil-water leaching below plant roots. Response to the OBF differed among the two experiments. The OBF resulted in adequate foliar color and plant size and reduced total-N recovered from soil-water in Expt. 1. However, it generally provided superior foliar color and size compared to all other treatments in Expt. 2, but also caused elevated levels of total-N in soil-water.

Two experiments were conducted to evaluate fertilizer formulation, method of application, and frequency of application on growth of landscape bedding plants and nitrogen (N) leaching. In the first experiment, ‘Peppermint Cooler’ vinca (Catharanthus roseus (L.) G. Don ‘Peppermint Cooler’), ‘Bonanza Yellow’ marigold (Tagetes patula L. ‘Bonanza Yellow’), and ‘Hawaii Blue’ ageratum (Ageratum houstonianum Mill. ‘Hawaii Blue’) were planted in raised beds. Four inorganic fertilizer formulations used included 13N–5.6P–10.9K (13–13–13) and 15N–0P–12.6K (15–0–15) granular water soluble (GWS) fertilizers, Osmocote 14N–6.0P–11.6K (14–14–14) (3 to 4 month release) controlled-release fertilizer (CRF), and Osmocote 17N–3.0P–10.1K (17–7–12) (12 to 14 month release) CRF. Each fertilizer was applied at a rate of 4.9 g N/m2 (1 lb N/1000 ft2) either incorporated into the top 10.2 cm (4 in) pre-plant or topdressed postplant. Additional treatments included an industry practice of incorporating 13N–5.6P–10.9K (13–13–13) pre-plant and topdressing 17N–3.0P–10.1K (17–7–12) post-plant; and a pre-plant incorporation of an organically-based fertilizer composed of recycled newspaper amended with chicken manure (caged layer manure). In Expt. 2, a similar experimental setup was used with ‘Peppermint Cooler’ vinca, ‘Red Vista’ salvia (Salvia splendens F. Sellow ex Roem. & Schult. ‘Red Vista’), and ‘Strata’ salvia (Salvia farinacea Benth. ‘Strata’). Inorganic fertilizers were applied in either single or multiple applications. Inorganic fertilizers included 15N–0P–12.6K (15–0–15) GWS fertilizer, Osmocote 14N–6.0P–11.6K (14–14–14) CRF, and Osmocote 17N–3.0P–10.1K (17–7–12) CRF. Three organically-based fertilizers were applied pre-plant and were composed of recycled newspaper amended with either chicken, beef cattle, or dairy cow animal manures. Summarizing across both experiments, plants treated with GWS fertilizers appeared to benefit with improved foliar color from immediate release of nutrients, while those treated with CRFs required at least 4 weeks to achieve dark foliar color. Nutrient leaching below plant roots was greater for GWS compared to CRFs. The industry practice treatment provided some improved plant growth in both experiments; however, it also caused initially high levels of soil-water-N (SWN) in Expt. 1. The organically-based fertilizer resulted in larger, more attractive (higher foliar color ratings) plants than inorganic fertilizers, though it also resulted in the highest levels of SWN compared to all other treatments.