Volume 72

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Welcome to the Walter Sisulu National Botanical Gardens

Author: Andrew Hankey and Alice Aubrey

PP: 1-7

Walter Sisulu National Botanical Garden is a large botanical reserve with an Environ-mental Education Centre, numerous fea-ture gardens and plant collections. There are also areas for viewing native mammals, birds and reptiles.
Keywords: Black Eagle, Nature, Conservation, Biodiversity

Effects of Light Quality during Cultivation and Cutting on Rooting of Cuttings of Gynura bicolor DC.

Author: Chihiro Satoh, Arisa Noguchi, Hiroko Nakatsuka and Wakanori Amaki

PP: 8-12

Gynura bicolor DC. is a perennial plant belonging to the genus Gynuraof the Asteraceae family, said to be native to Southeast Asia. Usually, this plant is propagated by cuttings. We investigated the light quality effects for mother plant cultivation before cutting and during cutting on the rooting of the cuttings in Gynura bi-color. Cuttings prepared from plants grown under white fluorescent light were placed under different light quality conditions, and the production of adventitious roots was compared.

However, no statistically significant dif-ference was observed. On the other hand, the light quality during cultivation greatly affected the rooting of cuttings. Rooting of cuttings taken from plants grown under white mixed light emitting diode (LED) and blue LED monochromatic lights were delayed. Cuttings of plants grown under red LED monochromatic light rooted faster, and the average root weight was more than three times that under mixed white light and blue light.

Keywords: Asteraceae, supplemental light, LED, stock plant

Effect of Day Length and Tuber Storage Temperature and Duration on Sprouting, Enlargement and Flowering of Tubers in Pinellia ternata (Thunb.) Makino

Author: Masamichi Torii, Arisa Noguchi, Hiroko Nakatsuka and Wakanori Amaki

PP: 13-18

Pinellia ternata (Thunb.) Makino) is a perennial plant in the aroid family (Araceae), which grows naturally in various parts of East Asia. It can be propagated by dividing tubers. Large tubers that have been peeled and dried have long been used as a material in Kampo medicine called “Hange”. We investigated the effects of temperature and light on sprouting, growth, and flowering of tubers. Tubers sprouted 100% in 3.2 weeks under long-day conditions (L). On the other hand, un-der the short-day condition (S), no sprouting occurred even after 7 weeks. From these results, it was expected that the photoperiod was the main factor for sprouting. The tubers cultivated for 20 weeks after planting swelled about 5 times under the L-L condition and S-L conditions. Flowering was only observed where the storage temperature was 4℃ for 6 weeks. On the other hand, in the treatment plots stored at 16℃, the tuber enlargement rate tended to be higher in the 3-week storage than in the 6-week storage.

Keywords: Araceae, medicinal plant, aroid

Investigation of Seed Germination Inhibitory Factors by Allelopathy of Purple Nutsedge Essential Oil

Author: Arisa Noguchi, Misa Hatano and Hiroko Nakatsuka

PP: 19-25

The effect of allelopathic germination inhibitory effect of essential oil from tubers of purple nutsedge ( Cyperus rotundus L.) on seeds of weeds and crops was investigated. Test plants were 5 weeds and 5 cultivated crops (Weeds: Eleusine indica, Digitaria ciliaris, Bidens pilosa var. pilosa , Galinsoga quadriradiata (ciliata) (Raf.) Blake, Trifolium repens L., Crops: Zea mays L., Daucus carota L., Lactuca sativa var. crispa, Raphanus sativus var. sativus , Brassica rapa var. perviridis . Addition of 400 ppm concentration of purple nutsedge essential oil significantly reduced the germination percentage of weed seeds. In particular, the germination percentage was remarkably suppressed to 0% in Galinsoga . Among crop seeds, the germination rate decreased only in carrot. The germination rate tended to be lower for plants with smaller seed sizes. The seed germination rate of Galinsoga , which has the smallest seed size, decreased as the concentration of essential oil increased, even at concentrations of 40 ppm or less. On the other hand, the germination rate of komatsuna seeds did not decrease even at essential oil concentration of 600 ppm.

Keywords: weeds, crop seed, Cyperus rotundus

Tree Growth and Fruit Quality of Some Citrus Scion/Root- stock Combinations in Afghanistan

Author: Ziaurrahman Hejazi, Rohullah Niazi, Abdul Latif Barakzai, Bahader Khan Karimi, Fida Mohammad

PP: 26-35

Improvement of citrus production was focused on during the rehabilitation process of Afghanistan. The ex situ germplasm center of citrus was established and a field trial in the subtropical climate of Nangarhar province was launched by grafting the eight citrus scions (Washington navel, Moro, Tarocco, Tardivo, Marsh seedless, Femminello Siracusano, Minneola tangelo, and Ortanique tangor) onto seven different rootstocks (Volkamer lemon, Carrizo citrange, Troyer citrange, X639, Rough lemon, Trifoliate orange, and Sour orange). The objective of the present study was to measure the performance of these combinations in the local climate.

Keywords:Compatibility index, grafting, rootstock, seed number, sour orange

Morphological Characteristics of Tetraploid Rosa multiflora Obtained by Diploid Breeding

Author: AMasaki Ochiai, Daiki Maruyama, Hirokazu Fukui and Kunio Yamada

PP: 36-38

This paper reports the results of a survey of morphological traits from derived tetraploid compared to diploid R. multiflora plants. Leaf length did not change between diploid and tetraploid plants, but leaf width and petal size did show significant increases

Keywords: morphology, multiflora rose, hybrid, flower size

Technical Sessions of International Plant Propagators’ Society-Southern Region of North America Annual Meeting

Author: Bobby Green

PP: 39-41

The 46th Annual Meeting of the International Plant Propagators’ Society-Southern Region of North America (SRNA) convened at 8:00 am on 18 October 2022 at the University of Georgia Center for Continuing Education & Hotel, Athens, Georgia, with President Bobby Green presiding.

Keywords:Annual Meeting, Southern Region of North America (SRNA)

Pesticide Application Method and Timing Influences Contamination of Nectar in Salvia

Author: Vanesa Rostán, P. Christopher Wilson and Sandra B. Wilson

PP: 42-49

Exposure to pesticides is one potential factor contributing to the loss of pollinators and pollinator diversity observed over the recent past. This project evaluated the influence of pesticide application method (drench vs. spray) and timing (relative to flowering) on contamination of nectar of Salvia × ‘Indigo Spires’ (Salvia longispicata × S. farinacea). The systemic insecticide thiamethoxam (Flagship) was used as a model pesticide and applied at the lowest label-rate. The concentrations of thiamethoxam and its metabolite clothianidin in nectar were highest in drench applications, regardless of application timing, and exceeded published toxicity thresholds for native bees and/or honeybees in the case of thiamethoxam. In contrast, concentrations in nectar were below toxicity thresholds for both spray applications before and after flowering. Concentrations were lower for spray and drench applications made before flowering relative to applications made after flowers began opening.

Keywords:thiamethoxam, clothianidin, pollinators, Salvia × ‘Indigo Spires’, best management practices (BMPs)

Effects of Auxin and Taxa on Rooting Performance of Vegetatively Propagated Wild Coffee (Psychotria spp.)

Author: Teagan Young, Sandra B. Wilson and Mack Thetford

PP: 50-57

Wild coffee (Psychotria nervosa), softleaf wild coffee (Psychotria tenuifolia), and Bahama wild coffee (Psychotria ligustrifolia) are evergreen shrubs with attractive foliage, fragrant white flowers, and colorful fruit. A cutting propagation study was conducted to evaluate the effects of auxin concentration on rooting of these three species, and a dwarf form, P. nervosa ‘Little Psycho’. Percentage of rooting, root system quality, root length, and root number were determined for semi-hardwood cuttings treated with one of three indole-3-butyric acid (IBA) talc treatments: 0, 8000 or 16000 mg/kg (ppm) - placed under mist for 8 wk. Among all four taxa, at least one of these measures of rooting performance was improved with a talc formulation containing 8000 mg/kg IBA. The percentage of cuttings with roots was greatest for cuttings treated with auxin (88±4% and 88±2% for 8000 and 16000 mg/kg auxin, respectively) compared to cuttings not treated with auxin (control) (71±10%). Results of this study reveal that all four Psychotria taxa evaluated can be easily rooted with or without auxin in a relatively short production cycle and show promise for widened commercial production and use in Florida. For improved root quality, application of auxin is recommended for more efficient liner propagation systems.

Keywords: Bahama coffee, dwarf wild coffee, soft leaf wild coffee, Rubiaceae, propagation

Effect of Cutting Time and Auxin Application Method on Propagation of Magnolia grandiflora ‘Southern Charm’

Author: Anthony T. Bowdena, Patricia R. Knight, Jenny B. Ryals, Christine E.H. Coker, Scott A. Langlois, and Eugene K. Blythe

PP: 58-66

Use of foliar auxin applications are increasing in the nursery and greenhouse industry. However, previous research has shown that insufficient auxin is being absorbed or translocated to the site of action. Research was conducted to determine whether cutting time, addition of surfactant to the auxin solution, or auxin application method had an impact on the propagation of Magnolia grandiflora ‘Southern Charm’. Terminal cuttings of ‘Southern Charm’ magnolia (M. grandiflora ‘Southern Charm’) were taken at two times of the year: spring and fall and sprayed to the drip point using a solution of Hortus IBA Water Soluble Salts™ at concentrations of 0, 500, 1,000 or 1,500 ppm or dipped for 3-sec in a solution of 2,500 ppm IBA. For many of our tested parameters, fall cuttings were better than spring cuttings. Fall cuttings treated with 1,500 ppm foliar IBA solution plus 0.85 ppm Regulaid® had greater root numbers than spring cuttings treated with less than 1,500 ppm IBA with or without Regulaid®, or fall cuttings treated with a 2,500 ppm basal quick dip, a foliar application of 1,000 ppm or less without Regulaid®, or fall cuttings receiving a foliar application of 0.85 ppm Regulaid®.

Keywords:Adventitious rooting, indole-3-butyric acid (IBA), surfactant, season

High-efficiency plant regeneration via callus-induced organogenesis from leaf explants of Queen's crapemyrtle (Lagerstroemia speciosa)

Author: Bin Wu, Benjamin Dixon, Ivan Sierra, Natalia Mesa, Qiansheng Li, Nicholas Zhang, Mengmeng Gu, Hongmin Qin

PP: 67-78

Crapemyrtle (Lagerstroemia sp.) is the best-selling flowering tree and provides excellent pollen sources for pollinators in the U.S. However, the market’s most commercially available crapemyrtle cultivars are easily infested by a recently invasive insect, crapemyrtle bark scale (CMBS; Acanthococcus lagerstroemiae), which jeopardizes the production and esthetic value of crapemyrtles anticipated by the Green Industry. Therefore, breeding CMBS-resistant cultivars is in great need on the market. Our previous study revealed that Queen’s crapemyrtle (L. speciosa) was resistant to CMBS among all available crapemyrtle species. Establishing a highly efficient regeneration system for Queen’s crapemyrtle is essential to molecular plant breeding for resistance improvement. Here, our study found that 97.9 ± 1.0% of leaf explants were induced callus when cultured on Lloyd & McCown woody plant medium (WPM) supplemented with 0.20 mg/L 2,4-D and 1.00 mg/L 6-BA. After transferring to the WMP medium supplemented with 10.00 mg/L 6-BA with 0.50 mg/L NAA, 32.4 ± 3.2% of callus successfully differentiated as the largest number of adventitious buds (23.4 ± 3.4) at the highest differentiation ratio (3.9 ± 0.1). The WPM medium supplemented with 1.00 mg/L 6-BA and 0.02 mg/L NAA induced 94.6 ± 4.0% of nodal segments of the regenerated shoots to produce 80.40 ± 15.16 new shoots (4.1 ± 0.9 cm in length) at the proliferation ratio of 4.5 ± 0.3. Half-strength WPM supplemented with 0.20 mg/L IBA induced 100.0 ± 0.0% of the regenerated shoots to produce 10.4 ± 1.1 roots (3.6 ± 0.7 cm in length) per shoot, and 98.3 ± 1.7% of the rooted plantlets survived after transplanting into the pots containing Jolly Gardener ® Pro-Line C/GP soil and 30% perlite for acclimatization. The successful establishment of the highly efficient callus-induced regeneration system lays a critical foundation for the genetic engineering of crapemyrtle to improve plant resistance or other desired traits, which meet priority needs of the nursery production or Green Industry.

Keywords:Queen’s crapemyrtle, callus-induced regeneration, leaf-derived organogenesis, micropropagation, plantlet rooting

Container Grown Plants are Gassy

Author: Forrest J. Brown, James S. Owen Jr. and Alex X. Niemiera

PP: 79-86

Rising mineral nutrient and polymer costs are placing a direct economic burden on nursery crop producers utilizing controlled-release fertilizer. Nitrogen (N) inputs in the containerized crop production have potential inefficiencies under a broad scope of cultural practices. While N gas emissions have been investigated in other forms of crop production, emission research on container-grown nursery production has been limited due to analytical methodology and the complexity of gaseous fate. The objective was to compare two control-release fertilizers (CRFs), ammonium nitrate (AN) vs urea ammonium nitrate (UAN), to determine the gaseous emissions between fertilizer treatment based on time of day using fourier transform infrared spectroscopy (FTIR). These data were then used to estimate seasonal flux loss over a 51-day period. Results showed there was a higher degree of variability of gaseous flux [nitrous oxide (N2O), nitric oxide (NO), and nitrogen dioxide (NO2)] in the beginning of the season when CRFs began releasing, more consistent fluxes were exhibited during the mid to late production season. Gaseous fluxes of N species were similar regardless of CRF and time treatments for all N species; only summation of N species (∑N) showed statistical differences. The study of gaseous emissions in nursery production is still in its infancy and more research is necessary to gain a better understanding of gaseous flux and factors influencing flux for container-grown crops.

Keywords: Nitrogen, containerized crops, soilless substrates, nursery production, control-release fertilizer, Fourier Transform Infrared Spectroscopy (FTIR)

Effect of X-ray Irradiation on Populations of Pseudomonas amygdali pv. loropetali pv. nov.

Author: Jenny B. Ryals, Patricia R. Knight, Rebecca A. Melanson, Warren E. Copes, Anthony T. Bowden, Christine E. H. Coker, Scott A. Langlois, Haley N. Williams, Jim M. DelPrince, Benny Park, Sam Chang, Kassie Conner, Jeremy M. Pickens, Ronald C. Stephenson, and

PP: 87-93

Loropetalum, Loropetalum chinense (R. Br.) Oliv., is a popular landscape plant, but it can be infected by the gram-negative bacteria Pseudomonas amygdali pv loropetali pv. nov. Bacterial diseases are difficult to control, and this particular bacterium usually leads to disposal of the plant, resulting in economic losses for the nursery. These bacteria are causing galls on loropetalum which can cause stem girdling leading to reduced growth and possibly death of the plant. The bacteria will infect the plant if it can permeate through a cut or wound in the bark. This creates a major avenue for disease transmission when propagating from cuttings if cuttings are taken from infected plants. It is important that nurseries use proper sanitation steps to reduce the number of infested plants. One of the best ways to begin those sanitation steps is to start with clean cutting material. With growing public concerns on chemical pesticides and their residues, irradiation is becoming a viable alternative and an effective nonchemical treatment for the control of several pathogens. Studies have shown successful results when gamma irradiation was applied to Pseudomonas spp., therefore we hypothesize that radiation could eliminate P. amygdali pv loropetali pv. nov. on loropetalum stock plants. Bacteria were subjected to six levels of x-ray irradiation 0, 0.5, 1, 1.5, 2, 2.5 kGy (0, 500, 1000, 1500, 2000, 2500 Gy). Initial results showed that x-ray treatment to pure bacteria strains resulted in significant bacterial reduction at all levels, with complete inactivity being observed in the 1.5, 2, and 2.5 kGy (1500, 2000, and 2500 Gy) treatments. With these preliminary findings, further studies are being conducted to determine the application of radiation’s ability to clean up infected loropetalum plant material.

Keywords: irradiation, x-ray, loropetalum gall, Loropetalum chinense

Physiological Response of Wax Begonia to Heat and Light Stress

Author: Julian Ginori, Heqiang Huo, Sandra Wilson

PP: 94-101

Wax begonia (Begonia ×semperflorens-cultorum) is a common ornamental plant used in flower beds for its diverse flower coverage to beautify public spaces. The intense Florida summers can increase its greenhouse production costs and hinder its year-round landscape potential, especially in full sun conditions. The physiological response of wax begonia to stress associated with heat, drought and light is not well understood but necessary for plant selection and improvement. Experiments were conducted to compare physiological plant responses (i.e., photosynthesis, fluorescence, and ion leakage) of four different wax begonia genotypes (FB08-059, OPGC 5104, ‘Sprint White’ and ‘Cocktail Vodka’) grown under light 35/22.5 °C or shade (30/22.5°C) conditions for 41 d. Results showed that when stressed (nonshaded and hot) FB08-059 (a noncommercial red genotype) had greater stomatal conductance (0.23 compared to 0.12-0.16 mol m⁻² s⁻¹), greater chlorophyll fluorescence (0.7-0.75 compared to 0.45-0.64), and less ion leakage (11.91% compared to 20.34%-33.72%) than the other three genotypes. Results of this study combined with subsequent morphological data are foundational for breeding enhanced abiotic stress tolerance in wax begonia. Additional studies are in place to measure physiological stress and severe drought tolerance of these same genotypes.

Keywords: Stomatal conductance, carbon assimilation, transpiration, ion leakage, fluorescence

Quantifying the Influence of Moisture Content on Bark Screening for Improved Particle Separation

Author: Kristopher S. Criscione, Jeb S. Fields, Amanda Mizell

PP: 102-110

Historically, tree bark was regarded as a waste product of the timber industry for decades. After lumber harvesting and debarking, bark is often hammer-milled and screened to decrease its particle size for further use. This bark processing is impacted by many variables such as moisture content, which can influence the manufacturing and alter the final product. However, little work has been conducted to quantify moisture contents effect on bark screening. Thus, this study consisted of bark screened at five different moisture contents (50, 55, 60, 65, and 70%) and its yield were quantified and analysed. In general, as moisture content increased, bark that was processed through the screen (unders) had a decrease in yield on a volume and mass basis, whereas bark that did not process through the screen (overs), increased in volume and mass. More fine particles attached to the overs bark; however, this did not largely influence container capacity or air-filled porosity values. Hence, the drier the bark prior to screening resulted in more balanced particle separation.

Keywords: Greenhouse growing, growing media, material processing, nursery crops, pine bark, screening, soilless substrates

Seed Germination and Cryopreservation of Wild Lime (Zanthoxylum fagara)

Author: Lindsay Mikell, Sandra B. Wilson, S. Christopher Marble, Wagner Vendrame and Edzard van Santen 

PP: 111-118

Wild lime Zanthoxylum fagara (L.) Sarg., is a small tree having attractive evergreen foliage and fragrant, yellow flowers. Native to Florida and Texas, this drought tolerant species is sought after for use in butterfly gardens in warm climates or conservatories. Yet, its nursery availability and ornamental use remain limited, as propagation protocols are largely unknown. To determine if seed propagation is a reliable and efficient means of producing wild lime, a series of studies were conducted in incubators to evaluate the effects of seed origin, temperature, dormancy, and cryopreservation on germination. Initial x-ray analysis and seed viability tetrazolium (TZ) tests determined the majority of seeds were filled (90-98%) and moderately viable (86-87%), regardless of the location they were collected from. However, seeds collected from northcentral Florida (Gainesville) and south Florida (Miami) responded differently to temperature treatments deployed to mimic spring (29/19 °C), summer (33/24 °C), fall (27/15 °C) and winter (22/11 °C) conditions. After 8 weeks, northcentral FL seeds had 10.7-41.1% germination, with seeds in the coolest temperature (winter) having the lowest germination, whereas south FL seed germination ranged from 30.2-71.2% across temperatures with the lowest germination occurring in the warmest temperature (summer). Additionally, seeds were found to imbibe regularly (do not require scarification) and tolerate cryopreservation procedures for long-term storage but possess physiological dormancy that must be overcome prior to germination.

Keywords: Rutaceae, native plants, plant propagation

The Effects of Microalgae as a Biostimulant on Seed Germination

Author: Runshi Xie, Kevin Dang, Sonya Kan, Jakob Sauve, Riley Johnson, Meredith Clay, Russell Jessup, Hongmin Qin

PP: 119-126

Microalgae have been considered the safe and sustainable new source of biostimulant or soil amendment in organic plant production. As an emerging concept, further research on the effect of different microalgae strains on the production of different crops is needed to develop successful algal biostimulant products. In this study, the effects of microalgae (under different culturing conditions) on seed germination were investigated by treating different plant seeds with microalgae extractions or deionized water. This study included two horticultural crops, basil and tomato, for their fast-growing cycle and evaluation of their nutritional values. Industrial hemp was also included in this study. Seed germination parameters, including daily germination rate, germination index, and seedling growths (root length and shoot length), were evaluated. The results show that the microalgae treatments positively affected the initial seed radicle emergence and final germination percentage of hemp and tomato, respectively. All microalgae treatments had increased the seedling vigor of basil by positively influencing root growth. The results suggest that microalgae have the potential to be used as biostimulants in different crop productions, and further research is required.

Keywords: Organic farming, basil, tomato, hemp, soil amendment, biofertilizer

Germination of Viola odorata, a Genetic Resource for Fragrance in Viola Breeding

Author: Shea A. Keene and Thomas A. Colquhoun

PP: 127-132

The highly scented Viola odorata is a potential genetic resource for fragrance-focused Viola breeding; however, the species is thought to exhibit seed dormancy and germination of the seeds is difficult. The objective of this study was to investigate two methods to break dormancy and promote germination in V. odorata, including different concentrations of gibberellic acid in the culture media, and different durations of cold stratification. Ultimately, the highest germination percentage was achieved via cold stratification at 4 °C for 8 and 12 weeks.

Keywords: Seed germination, non-deep physiological dormancy, cold stratification

Groundcover Type and Irrigation Delivery Affect Soil Moisture Dynamics in the Landscape

Author: Max McKeown, Jeb S. Fields, Jeff Kuehny, and Heather Kirk Ballard

PP: 133-141

There is little research published on the effect ornamentals groundcovers have on soil health. Soil properties can be manipulated by groundcover growth habit and irrigation type. This research was designed to evaluate the effects groundcover form and habit have on soil moisture and temperature under different irrigation regimes. A bunching (Liriope muscari ‘Big Blue’) and matting groundcover (Sphagneticola trilobata) were planted in individual plots that were irrigated by either overhead or micro-irrigation. Soil volumetric water content (VWC) and temperature were monitored by soil sensors buried 15cm deep in each plot. Overhead and micro spray irrigation, along with groundcover growth habit, affected soil temperature and soil VWC. Plots with Wedelia had the largest increase in VWC during irrigation events, regardless of irrigation type. Soil VWC was found to be lower in planted treatments than fallow treatments. At each irrigation event, micro spray showed a greater increase in VWC when compared to overhead irrigation across all treatments. However micro spray irrigation soil VWC decreased at the same rate for the overhead irrigation. Soil temperatures fluctuations were reduced under both groundcover species, when compared to fallow plots. Irrigation delivery method was also found to influence soil temperatures. Micro spray irrigation caused a slight increase in temperature at each irrigation event, while there was no temperature increase with overhead irrigation events. Ornamental groundcovers can lower soil VWC and temperature through increased transpiration and shielding solar radiation. Furthermore, groundcovers mitigate the rapid fluctuations in temperature creating a more normalized soil dynamic.

Keywords: Liriope, mulch, Sphagneticola trilobata, wedelia, soil temperature, volumetric water

Comparison of Auxin Formulations and Concentrations on Rooting Woody Softwood Cuttings

Author: Jerry H. Yu, Andra W. Nus, and Thomas G. Ranney

PP: 142-150

This study evaluated a range of auxin formulations and concentrations for their effects on root initiation on difficult-to-root, softwood cuttings including Acer palmatum, Cornus [(Cornus florida x kousa) x florida], Metasequoia glyptostroboides ‘Ogon’, and Zelkova serrata 'Goshiki'. Auxin formulations included gels, powders, and liquid quick-dips. Auxin concentrations ranged from 0 to 16,000 ppm as either IBA or a mixture of KIBA and KNAA. Results varied by taxa. The highest rooting percentages for Cornus (75.3 – 92.9%) were achieved with rooting gels containing 3,100-5,500 ppm IBA, a powder containing 16,000 ppm IBA, and liquid quick-dips containing 5,000 – 10,000 ppm auxin (mixture of 2/3 KIBA and 1/3 KNAA). For Metasequoia glyptostroboides ‘Ogon’, the treatments with the highest rooting percentages (19.1 – 37.2%) included two gels, powders ranging from 1,000 to 16,000 ppm IBA, and liquid quick-dip containing 5,000-10,000 ppm auxin (mixture of 2/3 KIBA and 1/3 KNAA), plus the control. Rooting percentages for Acer palmatum and Zelkova serrata ‘Goshiki’ ranged from 2.4 to 23.5% and 0 to 9.5%, respectively, with no significant treatment effects. These results identify numerous treatments that were effective for rooting selected cultivars of Cornus and Metasequoia; the effectiveness of rooting treatments varied considerably among taxa and environment.

Keywords: Asexual propagation, stem cuttings, Acer palmatum, Cornus [(Cornus florida x kousa) x florida], Metasequoia glyptostroboides ‘Ogon’, Zelkova serrata 'Goshiki'.

Teaching in an Arboretum: Spartanburg Community College Horticulture, the First 50 years

Author: Kevin Parris

PP: 151-172

The green industry is experiencing a shortage of skilled labor, yet the number of institutions offering horticulture degree and certificate programs has been on the decline. In this paper the 50-year history of the Horticulture department at Spartanburg Community College (SCC) is presented as an example of a traditional horticulture program that has been able to adapt, survive, and thrive.

Keywords: college enrollment, horticulture, arboretum, sustainable agriculture, hands-on experience, inspiration, persistence, Spartanburg Community College (SCC)

A New Way to Serve

Author: Samantha Manning

PP: 173-178

Agriculture, the green industry and horticulture can help returning veterans integrate back into civilian life with productive careers. Likewise, the human talent and skill-sets that veterans offer can be a great employee resource for the green industry. After being first introduced to The Veteran’s Farm of North Carolina (VFNC) in 2016, I became a founding board member and was inspired to pursue a career in agriculture. The Veteran’s Farm of NC, Inc. (VFNC), a 501(c)(3) non-profit organization dedicated to assisting veterans and military personnel/unit commands with consultation, training and education, equipment usage, and land acquisition. Through a grant from USDA/NIFA and thanks to partnership with other industry leaders, VFNC now offers three on farm training programs: 1) Veterans Agricultural Training and Education Program (VATEP), 2) Farm Military Assistance Program (FARM MAP), and 3) Skillbridge Internships. The flagship program for VFNC is VATEP, a six month on farm training program for veterans. FARM MAP is a more concise program of on farm training lasting two to four months for transitioning service members.

Skillbridge internships offer transitioning service members on farm or on the job training in the agricultural industry https://skillbridge.osd.mil/. In addition to these on farm training programs, VFNC continues to offer mentorship, networking, and an extensive equipment loan program.

Keywords: Career Skills Program (CSP), Farm Military Assistance Program (FARM MAP), Tran-sition Assistance Program (TAPS), Skillbridge, leadership, nursery industry profes-sion, superior problem-solving skills, work ethic, Veteran’s Farm of North Carolina, Inc. (VFNC), Veterans Agricultural Training and Education Program (VATEP)

Alternatives to Loose-fill Media for Improved Plug Handling

Author: Ben Sanders

PP: 179-190

We specialize in the propagation of woody ornamentals, and our primary focus is rooting cuttings quickly and uniformly. However, many factors contribute to uneven rooting and finishing, and liners always need to be graded prior to shipping. In general, rooted crops finish unevenly over the course of weeks, and it may be necessary to go through a crop several times to fill orders. Grading can also damage the plants. In many instances, extracting a plant prematurely will destroy the root system or harm it to the point that it will never be salable. This paper reports alternatives to loose-fill media in plug trays that could improve the handling process and shorten the production cycle. There were twelve plant species that were rooted as liners using five different media systems: LF: Loose-fill media, GC: Loose-fill + Growcoon, EP: Ellepot, PF: Preforma plugs, and GB: Bark fill + Growcoon. Our best liner production system was the GC: Loose-fill (30% Peat, 55% composted fines, 10% perlite, 5% vermiculite, amendments) + Growcoon liner holder.

Keywords: rooting, plug, liner, handling, extraction, shipping, Ellepot, Preforma, Grow Coon

Softwood Cutting Propagation of Clonal Oak Trees

Author: Dwayne Moon

PP: 191-195

Selected species of oak can be clonally propagated from cuttings. Clonal rooting practices at Moons Tree Farm, Inc., Washington, Georgia, for three oak species are described. Optimal rooting of Quercus phellos (Willow Oak) occurred with softwood cuttings propagated between May to August, quick-dipped in a solution of 3000 ppm indole butyric acid with potassium salt (K-IBA). For Quercus nutallii ‘QNMTF’, Tytlest® (Nuttall Oak), optimal rooting occurred with softwood cuttings propagated between May to June, quick-dipped with 4000 ppm K-IBA. Optimal rooting of Quercus lyrata (Overcup Oak) occurred between May and August with softwood cuttings quick-dipped at 2500 ppm K-IBA. The first spring flush is the best time to harvest softwood cuttings. Timing of softwood cutting collection season, and water-management of the mist irrigation system are critical and discussed in greater detail.

Keywords: Indole butyric acid with potassium salt (K-IBA), Quercus phellos, Quercus nutallii, Quercus lyrata

Propagation Research and Teaching for Ecologically-Friendly Landscapes and Gardens in Florida

Author: Sandra B. Wilson

PP: 196-202

For nearly two decades plant propagation has been central to the authors research and educational programs. Recently, a course in plant propagation was used to evaluate perceived student knowledge gains of 17 core subject areas before and after using a mobile application called PropG (htpps://propg.ifas.ufl.edu). Results revealed PropG to be a valuable tool in learning propagation concepts and terms, with an average knowledge gain of 52%. In addition to launching tools to facilitate plant propagation education, a series of propagation and production research studies have been conducted over the years to: 1) evaluate the fertility and landscape performance of cultivars and/or hybrids of ornamental invasives and 2) develop reliable propagation systems of novel or underutilized natives having ornamental and ecological value. Attractive, fruitless selections of hugely popular species such as butterfly bush (Buddleja sp.), heavenly bamboo (Nandina domestica), Mexican petunia (Ruellia simplex), lantana (Lantana strigocamara), trailing lantana (Lantana montevidensis), privet (Ligustrum sp.), maiden silvergrass (Miscanthus sp.) and fountain grass (Pennisetum sp.) have been identified as suitable non-native alternatives to the invasive or potentially invasive resident taxa. Also, as alternatives to ornamental invaders, over a dozen native species have been studied to determine their optimal propagation by seeds, cuttings, and/or micropropagation, as well as their performance in statewide landscape trials. Promising results are hoped to facilitate their increased availability and wider use in landscapes and gardens of Florida and other warm climates.

Keywords: invasive plants, mobile application, native plants

Zoo Horticulture: Growing Plants with Wild Appeal

Author: Eric Shealy

PP: 203-206

This is a general overview of zoo horticulture and the challenges that horticulturists and plant production workers face dealing with this side of public horticulture. Riverbanks Zoo and Garden provides a unique confluence of public horticulture having both the botanical garden and a zoo, both of which are heavily planted. Challenges arise in each area of design and production to account for plant toxicity, aesthetic use, functional use, and conservation. Plant toxicity is chief among the concerns with the zoo and aesthetics, of course, are the main concerns for the botanical garden. We have a database that keeps all information about plant placement and installation, as well as other helpful cultural and conservation information. Animal interactions with plants can be complex and exhibit design needs to be able to meet these challenges while providing the animal with a wonderful habitat and the visitor with a great guest experience. Plants that we particularly find helpful in these endeavors will be discussed, as well as our conservation efforts towards two native perennials.

Keywords: Animal/plant interactions, conservation, plant toxicity, aesthetic use, functional use, plant database, Hymenocallis coronaria

Windows of Opportunity for Rooting Woody Stem Cuttings

Author: Yiping Zou, Donglin Zhang, and Zach Hutzell

PP: 207-214

To share newly developed woody ornamental plants with the public, it is absolutely essential to be able to regenerate them. In the past 10 years, we have propagated more than 60,000 plants in our woody ornamental plant breeding programs. Our successes and failures indicated that our first consideration should be optimal seasonal timing in taking stem cuttings. Timing and types of woody stem cuttings significantly impacted the rooting ability of different species. Depending on the taxa, the higher rooting percentages were largely from semi-hardwood cuttings, collected during late spring and summer. In addition to timing, stock plant source, hormone application, plant materials, hormone cofactors, and other environmental factors should also be considered.

Keywords: Phytohormones, ornamental plants, plant exploration, propagation, regeneration, seasonal timing

New Introductions from the Mountain Crop Improvement Lab

Author: Irene Palmer

PP: 215-229

The North Carolina State University Mountain Crop Improvement Laboratory (MCIL) is an integrated research and development driven program where faculty, staff, students, and interns work together to develop a greater understanding of plant breeding and genetics in a wide array of nursery, bioenergy and emerging crops. In this paper, new plant introductions are discussed including native hydrangeas, new non-invasive introductions in Spiraea japonica, Berberis sp., and Miscanthus, tough evergreen rhododendrons, new cold-tolerant evergreen azaleas, and deer-resistant Illicium.

Keywords: Phytohormones, ornamental plants, plant exploration, propagation, regeneration, seasonal timing

Translating the European Approach to Domestic Plant Production

Author: Laura Kline

PP: 230-234

This paper details how European practices can be applied to plant production in North America. After multiple trips to the Netherlands and investigating how plants are produced overseas, only the most fitting automation and production ideas were brought to our greenhouse and implemented. From our state-of-the-art greenhouse to our choice of environmental controls, we strive for top quality plants and ease-of-work and greater efficiency of our team. Our team is vital in our success, and if our automation and equipment can make their life easier and our plant quality better - we have succeeded.

Keywords: Automation, mechanization, European production, environmental controls, beneficial insects

How to Help Your Plants Hold Their “P” in Container-Based Nursery Production

Author: Jacob H. Shreckhise and James E. Altland

PP: 235-248

Pine bark substrate used for container-based nursery crop production poorly retains phosphorus (P), resulting in much of the applied P leaching from containers. Research was conducted to evaluate the effect of FeSO4·7H2O (ferrous sulfate heptahydrate)-amended pine bark in nursery containers, added as a bottom layer (50% volume) or sole substrate, on P leaching and plant growth of economically important nursery crops. Freeman maple (Acer ×freemanii ‘Jeffersred’ Autumn Blaze®), panicle hydrangea (Hydrangea paniculata ‘SMNHPRZEP’ Zinfin Doll®), shrub rose (Rosa ×'HORCOGJIL' At Last®), nandina (Nandina domestica), and arborvitae (Thuja ×'Green Giant') were grown for 13 weeks in 6.1-L (#2) containers with surface-applied controlled-release fertilizer [(CRF); 16N−2.6P−9.1K + micronutrients] and received daily overhead irrigation that was periodically adjusted to achieve a 0.35 leaching fraction. Plants were grown in one of four substrate treatments comprised of dolomite-amended pine bark with: 1) no FeSO4·7H2O (control); 2) 1.5 kg/m3 (2.5 lbs/yd3) FeSO4·7H2O (FS-1.5); 3) 3 kg/m3 (5 lbs/yd3) FeSO4·7H2O (FS-3); or 4) stratified substrate (FS-3St) in which containers had a 2.5-L layer of FS-3 in the bottom and a 2.5-L layer of the control substrate on top. All leachate from Freeman maple was collected from each container weekly and analyzed for P. Relative to the control, the FS-1.5, FS-3, and FS-3St treatments reduced P leaching by 32%, 57%, and 54%, respectively. Shoot and root dry weight of panicle hydrangea, nandina, shrub rose, and arborvitae were unaffected by substrate treatments. Freeman maple had highest dry weight when grown in the control, but there were no differences in visual quality among treatments. Pine bark amended with 3 kg/m3 FeSO4·7H2O either layered in the bottoms of nursery containers or used as the sole substrate can substantially reduce P leaching without affecting growth of four economically important shrub taxa; however, additional fast-growing taxa with high nutrient requirements (like Freeman maple) should be evaluated.

Keywords: phosphorus (P), ferrous sulfate, leaching, soilless substrate, cationization, best man-agement practices (BMPs), controlled release fertilizer (CRF)

Getting Started with the H2A Visa Program

Author: Dan Bremer

PP: 249-253

The Immigration Reform and Control Act (IRCA) enables agricultural producers to employ foreign, agricultural workers – which is becoming an increasing important source of employees for the Green/Nursery industries. It is important to develop a plan that includes: housing, transportation, workers compensation, record keeping, appropriate supervisors, the application process, recruitment of workers, and expenses of participating in the program. A specialized attorney or consultant can be helpful in planning and staying in compliance of regulations.

Keywords: Foreign - seasonal agricultural workers, Immigration Reform and Control Act of 1986 (IRCA), form I-9, Federal Employer Identification Number (FEIN), three-quarter work guarantee, farm labor contractor

From Curios to Champions: Delayed Value in Plant Collections

Author: Richard T. Olsen

PP: 254-259

Modern plant breeding relies not only on new technologies and new germplasm, but new thoughts on existing, overlooked, or underappreciated plants. Often, these passé plants are the domain of arboreta, who collect, catalog, and curate these plant genetic resources for use by enterprising nursery professionals, public and private breeders, and academics. A given plant’s perceived value fluctuates over its cultivated lifetime, whether the initial introduction was an immediate success or not. A vast majority of introductions and selections are relegated to the historical record, persisting as curios for collectors, but in many cases, their traits are awaiting a new trend, threat, or technology to rerelease their importance to American landscapes.

Keywords: germplasm, plant genetic resources, plant breeding, Frank Meyer, Metasequoia glyptostroboides, Acer truncatum, Viburnum macrocephalum, Ilex cornuta, Loropetalum chinense, Syringa oblata, Syringa meyeri, Hydrangea arborescens

New, Exciting and Superior Flowering Trees and Shrubs for the Forward-Thinking Horticulturist

Author: Vincent A. Simeone

PP: 260-262

This presentation puts into focus some of the newer and most promising selections of trees and shrubs available on the market as well as some old favorites that offer exceptional garden merit.

Keywords: Historic park, newer promising plants, old standby plants, underutilized and excep-tional mainstays.

Cornus (Dogwood) Breeding at Rutgers University

Author: Thomas J. Molnar

PP: 263-274

The Rutgers Woody Ornamental Breeding program began in 1960 and continues to this day. The breeding of big-bracted dogwoods has been a focal point of the program since Dr. Elwin Orton, the original breeder, pioneered the crossing of Cornus florida with the Asian C. kousa, which led to the successful Stellar® series of hybrid dogwoods. In 2006, the dogwood program transitioned over to new leadership and breeding efforts were expanded, building from a large collection of unique trees developed by Dr. Orton. In a fortunate turn of events, trees with vivid pink floral bracts were recovered in the new kousa and hybrid dogwood breeding populations leading to the 2015 release of C. kousa ‘Rutpink’ Scarlet Fire® dogwood. This manuscript describes some of the history of the dogwood program, followed by the lessons learned growing and selecting dogwoods at Rutgers for 15 years and what comes next after Scarlet Fire® dogwood.

Keywords: woody ornamental breeding, clonal propagation, budding, seedlings, novel cultivars

Hazelnut (Corylus) Breeding at Rutgers University

Author: Thomas J. Molnar

PP: 275-285

The Rutgers University hazelnut (Corylus spp.) breeding program was started in 1996 by turfgrass breeder Dr. C. Reed Funk as one component of a project focused on temperate nut trees. In 2006, hazelnuts emerged as the target group of species due to a number of attributes that includes their small tree size, ease of making controlled crosses, relatively short generation time, and increasing demand for their kernels. In collaboration with Oregon State University, wide germplasm collection and evaluation efforts were undertaken to help identify trees with resistance to eastern filbert blight, the primary limiting factor of cultivation in the eastern U.S.A. This manuscript provides an overview of the Rutgers hazelnut breeding program starting from its inception and spanning over twenty years to the release of the first cultivars in 2020. It also describes collaborative efforts to develop “hybrid” hazelnuts adapted to colder regions.

Keywords: eastern filbert blight, disease resistance, filbert, clonal propagation, seedlings, novel cultivars

Production in the Absence of Automation

Author: Alisha Conde

PP: 286-290

The path of growth at Carolina Native Nursery is discussed. Carolina Native Nursery produces over 200 different native shrubs, perennials, ferns, and grasses. Procedures becoming more efficient through the years are discussed.

Keywords: production, without automation, native plants, efficiency

Control of Broad Mite on English Ivy Cuttings with Dip Treatments

Author: Daniel Gilrein, Kevin Dicht, and Lucille Siracusano

PP: 291-294

Research into the control of broad mite [Polyphagotarsonemus latus] infesting English ivy (Hedera helix) is discussed. In general, mist in propagation as used here appears to be an effective control for broad mite, but in the absence of mist a cutting dip in horticultural oil provides significantly better control of the egg stage and to some extent adults as well compared with other treatments.

Keywords: Broad mite (Polyphagotarsonemus latus) control, English ivy (Hedera helix), dip treatments, horticultural oil treatments

Tissue Culture Panel Write-up for Microplant Nurseries

Author: Jonathan Jasinski

PP: 295-297

The history of the development of Microplant Nurseries, Inc., is discussed from the beginning with two employees to the present day with 60 employees. Microplant Nurseries, Inc., goals are discussed. Their focus is growing great, healthy plants and learning together how to do things better. The timing of plant material induction to production as well as hormone concentrations and their effect on plant growth are discussed.

Keywords: Tissue culture, Microplant Nurseries, Inc., production timing, hormone concentrations

New Research Determines Successful and Secure Disposal Method for Greenhouse Waste Infected with ToBRFV

Author: Keith Osborne

PP: 298-302

This research evaluated the efficacy of Walker’s static aerated composting process in deactivating the tomato brown rugose fruit virus (ToBRFV) in spent stone wool substrates and infected vines in order to create a circular economy for greenhouse waste. It was concluded that Walker’s standard 6-week GORE composting process is 100% effective at deactivating ToBRFV when the cell maintains an internal temperature of over 75C for 47% of the composting life cycle duration.

Keywords: Aerated composting, tomato brown rugose fruit virus, ToBRFV, greenhouse waste, stone wool substrates, compost, recycling

The IPPS Website: A How To

Author: William Barnes

PP: 303-314

The IPPS website use is explained in detail. Significant changes to the website are explained. The paper explores the IPPS website and members will understand how to use this new technology so that they, the members, can use it to their best advantage.

Keywords: using the website, International Plant Propagation Society, proceedings

Breeding for Non-Invasive Nursery Crops: Status of Cultivars and Regulation

Author: Ryan N. Contreras

PP: 315-319

Breeding for noninvasive plants is discussed. The author proposes that the nursery industry should not wait for the attention generated by invasive plants to turn to regulation, but to be proactive and take ownership of the issue. The goal of regulation on this issue should be to prevent the further spread of invasive species but to allow production and sale of plants that have been proven to present little or no ecological risk. Methods for reducing fertility, testing for fertility, and current regulations and the future are discussed.

Keywords: Breeding, noninvasive plants, invasive plants, ecological risks, native plants, cultivars and regulations

The Cutting Cooler Journey

Author: Rose Daly

PP: 320-325

I will be covering our process on how we improved our cutting storage. I will talk about our old cooler, its challenges and what inspired us to change. Then I will segway into our new and improved humidified cooler and the benefits we have gained from the switch. Lastly, we will go into detail about how we built our humidifier and touch on some of the mistakes we learned along the way.

Keywords: Cutting storage cooler, humified cooler, quality liners, cooler construction

Steps to Success with Bareroot Liner Herbaceous Perennials

Author: Laura Robles

PP: 326-329

Walters Gardens founded in 1946 is a major producer of field-grown herbaceous perennial liners and has an extensive breeding program. The field production program is discussed.

Keywords: field production, breeding, bareroot liners

Are We Propagating Plant Diseases?

Author: Margery Daughtrey

PP: 330-329

In this presentation the author discusses examples of a few of the currently notable diseases caused by each of the major groups of pathogens (fungi, oomycetes, bacteria, viruses and nematodes). In the process, the author touches on boxwood blight, downy mildews, rose rosette and other diseases caused by emaraviruses, phytoplasmas, beech leaf disease, and the new vascular streak dieback disease.

Keywords: pathogens, fungi, oomycetes, bacteria, viruses, nematodes, boxwood blight, downy mildews, rose rosette, phytoplasmas

Impact of Foliar Applied Paclobutrazol in Combination with Auxin on Rooting and Subsequent Shoot Growth in Angelonia Cuttings

Author: Anna G. Baloh, W. Garrett Owen, Robert L. Geneve

PP: 340-344

Angelonia cuttings were treated with a combination of Bonzi and K-IBA as a quick dip and foliar spray. The foliar auxin spray was not as effective as a basal dip at the concentrations used in this study. A foliar spray using Bonzi increased rooting with or without auxin. Bonzi did not have a significant impact on plant height post-rooting. This study provides initial evidence that a tank-mix of auxin and a gibberellin inhibitor used as a spray application could be an efficient and effective means for application in commercial cuttings.

Keywords: propagation, gibberellin, bedding plant, K-IBA

Evaluation of Auxin (K-IBA) Concentrations on Rooting Success of maple (Acer) Stem Cuttings

Author: Sharika Elahi and Kim Shearer

PP: 345-353

Initial experiments were conducted to evaluate auxin (K-IBA) concentrations on the rooting of selected Acer species. the results indicate that water-soluble K-IBA concentrations used in this study do not have a significant effect on rooting success in these seven maple selections after 6 to 7 weeks. Further rooting in all seven maple selections was observed 90 days after initiation, suggesting that greater rooting success could potentially be achieved with extended time in the propagation flats before transplanting.

Keywords: Auxin, adventitious rooting, Acer, vegetative propagation, cutting propagation

Asexual Propagation of Forestiera neomexicana (A. Gray) Using Semi-Hardwood Stem Cuttings

Author: Alyssa M. Headley, Benjamin P. Desrosier, Taylor R. Mathison, and Brandon M. Miller

PP: 354-356

Forestiera neomexicana (desert olive) a native plant found throughout arid regions in the southwestern United States. This species could be utilized more broadly within ornamental landscapes in urban settings. Little is known regarding asexual propagation techniques for producing this plant and experiments were undertaken to study this. Results show a numerical trend suggesting that increasing IBA concentration leads to bolstered root length and number of roots. Additional studies are needed.

Keywords: Desert olive, IBA (Indole-3-butyric acid), adventitious roots

New Plant Forum 2022 – Eastern Region IPPS

Author: Kim Shearer

PP: 357-370

New plants for 2022 are highlighted and described. This year six IPPS-ER breeders presented herbaceous and woody perennial plants.

Keywords: New plants

Berry Big business: Commercialisation/bulk production of Berry Species

Author: James Burnett

PP: 371-374

We spend a lot of time talking about the art of plant breeding, and if you haven’t already picked up Plant breeders are a passionate group of artists at that. Without these plant breeders we are likely to be a much smaller industry today.

So, as I am sure you can observe from my robust physique, I am a strong fan of Edible plants and their fruits. Coincidentally but completely unrelated, this has ended up being a factor in propelling my career choices and so I find myself in the wonderful world of berries.

Keywords: Strawberry, blueberry, raspberry, blackberry

Looking Back Looking Forward: Learning from the Past in Preparing for the Future

Author: John Bunker

PP: 375-383

This presentation was an overview of the history of the International Plant Propagator’s Society in Australia as well as an historical perspective on the Australian nursery industry and how those activities influence our horticultural professions today.

Keywords: history, plant production, Australia, IPPS.

Accelerated In Vitro Breeding Creates Improved Designer Papaya

Author: Puthiyaparambil Josekutty, Mark MacLaughlin, Pui Lam Jay Ma, Teresita Steele, Bongani Ndawana, Candy MacLaughlin, Paul Fagg, Marion MacLaughlin, Ian Mac Laughlin

PP: 384-388

Papaya (Carica papaya L) has very limited genetic variability that hampers conventional breeding. Therefore, we developed, novel, high yielding, more flavoursome designer Skybury papaya lines with high Brix through accelerated in vitro breeding. Skybury farm changed to clonal papaya cultivation, which allowed us to achieve continuous improvement through somaclonal selection from the 300,000 plus papaya grown annually. We developed a high throughput somatic embryogenesis system for Skybury papaya. Induced genetic variability among the embryogenic cell lines, regenerated variant papaya through non-GM method, conducted large scale field trials and recovered unique variants with better agronomic and fruit qualities. We also generated several mutant lines free of dreaded Papaya Sticky Diseases (PSD) caused by the Papaya Meleira Virus (PMeV). We developed a rapid and reliable molecular diagnostic test to screen for PSD and verified the PSD free status of several of the mutant lines using this kit. We field trialled PSD free lines on a large scale to select PSD free lines with improved characteristics in a brief 5 year period compared to other breeding options. Our results confirm that accelerated in vitro breeding approach is the best way for rapid papaya crop improvement in the non-GM agriculture system of Australia. Gene editing technology like CRISPR technology can be handy for further rapid crop improvement (disease resistant e. g. phytophthora resistant) papaya in future.

Keywords: Carica, tissue culture, somatic embryogenesis, somaclonal variation

Organic Fertilizers for Container Plants

Author: Heinrich Beltz

PP: 389-390

Container plants of hardy nursery stock are usually being fertilized with coated mineral fertilizers (controlled release fertilizers) at a rate of 3.0 – 6.0 g per litre substrate. The coating material of all commonly used controlled release fertilizers (Osmocote, Multicote, Nutricote etc.) are made of synthetic polymers. They are usually smaller than 5 mm, so they are microplastic. It is estimated that in the EU 30,000 – 90,000 tonnes of controlled release fertilizer (= 3,000 – 9,000 tonnes coating material) are being consumed.

Keywords: Controlled release fertilizer, biodegradable, plant nutrients

CO2 Balance of Hardy Nursery Stock

Author: Heinrich Beltz

PP: 391-392

Discussions about the carbon footprints of the products we consume are popular, so the nurseries are interested in the effects of their plants on climate. It is fundamental to understand that the carbon footprint, the assessment of impacts on the climate, is measured by a life cycle assessment. And such a life cycle assessment is being done following certain rules like ISO 14040.

Keywords: carbon footprint, life cycle assessment

Biodegradable Tying Materials

Author: Louise Heissel

PP: 393-394

In a comparative test, seven different bio-degradable tube tying materials and four degradable binding materials for the MAX-pliers were compared.

Keywords: nursery, MAX-pliers, cotton, jute, staking

Alternatives for glyphosate in nursery production

Author: Britta Zielke

PP: 395-396

Glyphosate is widely used in nursery practice. The advantage to Glyphosate is that it is translocated in plants and therefore effective against root weeds, large weeds and overwintering rosettes. In addition, it works in unfavourable weather. In Germany, the most commonly used products (e.g., Durano TF, GlyfosTF Classic) contain 360 g/l glyphosate and TF formulation. There is lots of experience regarding tolerance.

Keywords: herbicide, weeds, seeds

Mechanical Weed Control – Including Robots

Author: Heinrich Lösing

PP: 397

In times of less availability and restriction on herbicides, especially like Glyphosate, growers are again focusing more on alternatives for example mechanical weed control. Modern machinery is looking totally different than before. The main goal is still the reduction of competition for light, water and nutrients for our plants.

Keywords: herbicide, Glyphosate, autonomous weeding