Surface disinfested nodal and shoot-tip sections of chinkapin oak (Quercus muehlenbergii Engelm.), obtained from adult or juvenile source, when cultured on WFM supplemented with BA or kinetin (1.0 -5.0 mg l-1) produced greater number of axillary shoots per explant and shoot lengths than MS medium. Nodal and shoot-tip explants cultured in WPM containing cytokinins, BA or kinetin (0.1 - 5.0 mg l“) resulted in greater number of axillary shoots than media containing auxins, 2,4-D or NAA (1.0 - 5.0 mg l-1). In vitro grown shoot explants cultured in WFM shoot multiplication medium containing thidiazuron did not produce axillary shoots. Microshoots when cultured in WFM plus NAA or IBA (0.1 -2.0 mg l-1), or subjected to IBA (0.5 mg l-1) pulse treatment (0, 5, 10 or 15 min.) did not root.
Sudeep Vyapari and Houchang Khatamian
Houchang Khatamjan and Sudeep Vyapari
One-year-old liners of Firebird crape myrtle (Lagerstroemia indica L. 'Firebird') and Vicary golden privet (Ligustrum X vicaryi) were planted in 7.6 liter containers. The growing media consisted of 3 pinebark: 1 Canadian peat moss: 1 sand and 3 sawdust: 1 Canadian peat moss: 1 sand (v/v/v). Both media were amended with NH4NO3 and dolomite. Several controlled release fertilizers at varying rates were incorporated into each medium prior to planting. Thirty, 60 and 90 days after planting, leachate samples were collected and tested for E.C. and pH. Fertilizer Sierra (17-6-10) and Osmocote (18-7-13) resulted in maximum shoot dry weight with both species and media types followed by Osmocote (24-4-8) and Escote (20-4-11). Plants grew equally well in pinebark and sawdust medium. After 30 and 60 days leachate from Sierra (17-6-10) had highest E.C. levels. Osmocote (18-7-13 and 24-4-8) recorded highest E.C. at 90 day sampling date. The sawdust medium had higher pH values than the pinebark.
Sudeep Vyapari and Houchang Khatamian
Somatic embryogenesis was successfully achieved in chinkapin oak (Quercus muehlenbergii Engelm.) and pin oak (Quercus palustris Muenchh.) when surface disinfested zygotic embryo explants were cultured on MS or WPM containing BA or kinetin (1.0 or 2.0 mg 1-1) plus IBA (1.0 mg 1-1). Immature embryos resulted in greater callus induction than the mature ones. Two weeks of dark, proved to be superior to 4 weeks or no dark in callus induction. Somatic embryos of pin oak distinctly showed globular, heart and cotyledonary stages.
Maturation and germination of pin oak somatic embryos was done in growth regulator free WPM by increasing levels of agar (7 - 15 g 1-1). Somatic embryos cultured at various levels of agar were then maintained in incubator under standard conditions, desiccated by air-drying or subjected to chilling temperature for 4 weeks to enhance germination of somatic embryos. Root or shoot formation was observed in some cultures, and medium with 9 g 1-1 agar induced plantlet production in 7% of the cultures.
Sudeep Vyapari, Robert Graves and Edmund Thralls
Use of growth regulators in ornamental plant production is a common nursery practice. Research conducted in determining landscape establishment of herbaceous plants treated with various concentrations of growth regulators is limited. The first phase of this study was conducted to evaluate response of three herbaceous ornamental species to application of ethephon. Containerized plants of irish moss, scotch moss, and salvia were treated once with FLOREL® (ethephon) at 0, 250, 500, or 750 ppm 2 weeks after transplanting into #1 size containers. During the course of the 6-week production period, standard nursery practices of fertigation, pest control, and weed management were followed. Data were collected on growth indices and marketable quality ratings (scale of 1–5) every 2 weeks. Mean initial and final shoot and root dry weights were calculated at the start and end of this phase of the experiment. The experimental design was completely randomized and data analyses were made using the analysis of variance with SAS general linear model procedure. Growth indices (cm) were significantly affected by increasing concentrations of FLOREL®. At 750 ppm concentration the mean growth indices were low (2516 cm) whereas, control (0 ppm) produced the highest mean growth indices (4317 cm). Significant differences in marketable quality ratings were also observed among the treatments where control (0 ppm) plants had the best mean rating (4.3) as compared with 500 ppm (3.6) or 750 ppm (3.5) concentrations. Salvia produced mean growth indices and mean width of 9106 and 513 cm, respectively. However, irish moss had asignificantly higher mean quality rating (4.4) when compared with either salvia (3.7) or scotch moss (3.3).
Sudeep Vyapari*, S.M. Scheiber and Richard C. Beeson Jr.
During Fall 2003, a study was conducted to determine the effect of soil amendments on growth and response of Pentas lanceolata `New Look Red' in the landscape. Pentas were grown in 250L drainage lysimeters in an open-sided clear polyethylene covered shelter filled with local top soil (Apopka fine sand). The treatments used were non-amended top soil (control) and soil amended with either compost (5% by volume) or clay (5% by volume) in the top 15 cm. Best Management Practices were followed. Irrigation frequency and rate were regulated using a tensiometer-controlled automatic irrigation system. When plant available water in each soil type had declined to 70% or less, the plants were irrigated back to field capacity. Data were recorded on initial and final growth indices, shoot dry weight, and root dry weight. Final growth indices between control and soil amended with compost were not different; however, growth in the clay-based soil was significantly less than the compost-based soil type. The mean shoot dry weight (77.2 g) produced from plants in compost amended soil type was significantly higher than either control (57.45 g) or clay amended (54.92 g) soil types. No significant differences were found for either initial growth indices or root dry weight among the three treatments.
S.M. Scheiber, Richard C. Beeson Jr and Sudeep Vyapari
Pentas lanceolata Schum. ‘New Look Red’ plants were grown in compost-amended, mined field clay-amended, or unamended sand soils in drainage lysimeters to evaluate growth, aesthetic quality, and irrigation requirements. Treatments were evaluated with irrigation controlled by tensiometers set to irrigate back to near field capacity when plant-available water in each soil declined to 50%. Compost-amended soils had greater (P < 0.05) mean shoot dry weight, total biomass, shoot-to-root ratios, growth indices, and landscape quality than other amendment treatments. Unamended soils and clay-amended treatments were comparable for all plant parameters. Total irrigation volumes applied were similar among treatments. Compost-amended soils yielded larger canopies, improved quality, and tended toward less cumulative irrigation. Clay amendment was not beneficial.
Sloane M. Scheiber, Jennifer Hitchcock, Sudeep Vyapari and Lance Osborne
A series of video clips and narrated PowerPoints were developed to aid in the presentation of common horticultural techniques. To determine the most effective format for delivery of horticultural subject matter, video clips and PowerPoints were developed for three topic areas and presented to two target audience groups. Target audiences consisted of Master Gardeners (Orange and Osceola County, Fla.) and future horticulture professionals (UF Environmental Horticulture students enrolled in Landscape Plant Establishment). Upon completion of viewing both media formats, participants were asked to complete a survey. Eighty-six percent of participants completed and returned surveys. Data were sorted and analyzed for calculation of mean percent for each response sought. Results of the survey indicated that, depending upon the topic, a higher proportion (66% to 93%) of Master Gardeners preferred narrated PowerPoints in comparison to video clips. However, 60% to 70% of students preferred video clips to narrated PowerPoints. In reference to the informative nature of both videos and PowerPoints, >67% of all respondents rated both media formats between good and excellent; however, most respondents indicated new information gained was less than 40%. Factoring the costs associated with production (about $1000 per video vs. essentially no cost for narrated PowerPoints) and participant responses, narrated PowerPoints appear the best option for conveying common horticultural practices.
Sudeep Vyapari, S.M. Scheiber and E.L. Thralls
Three root ball conditions—nonroot-bound (NRB), root-bound (RB), and root-bound sliced (RBS)—were evaluated for their effect on plant growth of plumbago (Plumbago auriculata) during establishment and postestablishment in the landscape. At transplant, NRB plants were smaller than other treatments. Canopy size, shoot dry weight, root dry weight, and total biomass growth rates were faster for NRB plants compared with RB or RBS. By 6 and 8 weeks after transplanting, respectively, biomass and canopy size were similar among treatments. Rootbound and RBS plants were similar indicating root ball slicing does not affect growth in the landscape.
Sloane M. Scheiber, Richard C. Beeson Jr. and Sudeep Vyapari
Root ball slicing is often recommended for root-bound woody ornamentals to promote new root development during establishment in the landscape. It is a common practice among gardeners, but not necessarily landscapers, to disrupt root-bound annuals during transplant. However, little if any evidence exists for such practices. Therefore, this study evaluated the effect of root ball condition of annual bedding plants on landscape establishment and growth. Begoniasemperflorens were transplanted from 0.72-L (#1) containers into field plots in an open-sided clear polyethylene covered shelter and managed with Best Management Practices. Three root ball conditions were evaluated: non root-bound (6-week-old plants), root-bound (10-week-old plants), and root-bound with the bottom 1 cm of the root ball removed. Shoot and root dry masses and growth indices were collected weekly for 12 weeks and evaluated relative to root ball condition by linear regression analysis. Nonroot-bound plants had significantly greater biomass, growth indices, height, and root dry weights than the other treatments tested. No significant differences were found between root-bound and manipulated root-bound plants for any parameter examined. The data indicate that the practice of disrupting root-bound plants has no benefit on establishment or growth of annual bedding plants in the landscape.
Sudeep Vyapari, Edmund L. Thralls and Michele S. Scheiber
A study was conducted to evaluate establishment of root-bound vs. nonroot-bound container-grown Plumbago auriculata Lam. in a landscape. A total of 144 plants were transplanted from #1 containers in a rain-out shelter at Mid-Florida Research and Education Center, Apopka, Fla., in June 2004. The field soil type was amended with composted yard waste. The three treatment types used for the study were: 1) root-bound plants; 2) root-bound plants with a vertical slice made through the root ball at a 90° angle; and 3) nonroot-bound plants. To evaluate the effect of these three treatments during the course of establishment period, harvesting was done once every 2 weeks. Data on growth indices (height × width × width), shoot dry weight, root dry weight, and length of the longest root were recorded. The experimental design was a completely randomized design consisting of three treatments, 12 harvest dates (days after planting), and four replicates per harvest date. Plants were maintained according to the best management practices recommended by the UF/IFAS, and were irrigated once a day using microirrigation. Experimental data were analyzed for significance of correlation among variables using SAS version 9.1. Results of the correlation and regression analysis indicated that the increase in the shoot dry weights (g), root dry weights (g), growth indices (m3), and root: shoot ratio had significant relationship with the harvest dates. Correlation among harvest dates and shoot dry weight, root dry weight, or growth indices was found to be positive. However, results of the study indicated that as the number of days after planting increased, the root to shoot ratio decreased.