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- Author or Editor: James C. Sellmer x
Mature specimens of the norway maple (Acer platanoides) and cultivars Columnare, Crimson King, Emerald Queen, Faasen's Black, Globosum, and Rubrum were evaluated over a 3-year period to determine flower and seed production and to understand their invasive potential using seed yields. Flower and seed yield data were collected each year and were used to estimate whether differences existed among cultivars and if variation in these traits occurred from year to year. For this study, it was observed that norway maple cultivars differed in annual flower and seed yield and that production varied from year to year. ‘Columnare’, ‘Emerald Queen’, and the species produced many seeds, which suggest that these plants may be problematic in landscapes that adjoin natural areas. In contrast, ‘Crimson King’, ‘Globosum’, ‘Faasen's Black’, and ‘Rubrum’ were relatively low in seed yield, which make them suitable alternatives for landscape use where invasiveness is a concern to surrounding communities.
Norway maple (Acer platanoides), 15 cultivars, and two hybrids were assessed for 3 years to evaluate seed germination (e.g., growth chamber, open landscape, and forest) and viability in an initial attempt to understand their invasive potential. Differences in germination were observed among the cultivars over the study. Low to moderate germination was found in growth chambers (0%–35%). Lower germination was found at open landscape (0%–23%) and forest floor sites (0%–18%). Inconsistent viability was observed among cultivars across the seed lots. Viability testing with tetrazolium chloride under two protocols revealed that seed viability was higher than germination and that viability alone was not a good estimate of germination potential. Differences in the accuracy of viability testing procedures were also observed. Short-term germination and viability studies provide only limited information to characterize the possible invasiveness of cultivars.
A mail survey was conducted in 2000 to determine awareness and use of integrated pest management (IPM) practices by nurseries in Pennsylvania. Survey participants were randomly selected from the Pennsylvania Dept. of Agriculture, Bureau of Plant Industry, list of certified nurseries. Participants answered questions pertaining to awareness of common practices, frequency that IPM practices were employed, and specifics on monitoring and pest management decision-making processes. Responses were analyzed by Cluster Analysis (SPSS Inc., Chicago), which resulted in the formation of three distinct segments. The segments were labeled “IPM Savvy” (nursery managers who were more likely to employ IPM practices); “Part-time IPMers” (nursery managers who employed some IPM strategies and were interested in future adoption of IPM practices); and “Reluctant IPMers” (nursery managers who were least likely to employ IPM strategies). The “Part-time IPMers” and “Reluctant IPMers” segments represent a substantial part of the industry (51%), who continues to have concerns about the cost, efficacy, and implementation of IPM practices into their businesses. Overall, Pennsylvania growers are aware of IPM practices; however, maintaining permanent records of pests identified and pest management strategies employed remain low. Continued education is warranted to enhance pest monitoring skills and recordkeeping along with demonstrable evidence to the cost effectiveness and marketing benefits that the implementation of IPM practices offer the nursery operators.
Needle retention, xylem pressure potential and overall quality of canaan fir (Abies balsamea var. phanerolepis (L.) Mill.) and fraser fir (Abies fraseri (Pursh) Poir.) Christmas trees were evaluated over a 40-day display period. Cut trees were stored outdoors for 24, 48, or 96 hours, and half the trees had a 2.5-cm section trimmed from the basal portion of the stem, before placement in water at an indoor display room. Controls were placed in water immediately after harvest. Xylem pressure potentials and overall quality were similar for both species except for trees stored 96 hours. Untrimmed canaan fir dried to -2.4 MPa and was rated below average by the end of the display period compared to -1.3 MPa and a good quality rating for fraser fir. Needle retention and color characteristics were excellent across all treatments for fraser fir during the entire display period. Needle loss for canaan fir began relatively soon during display, generally increased across all treatments, and was highly variable. In addition, quality of some canaan fir trees decreased as needles turned brown, but did not shed during the display period. Tree water status alone did not completely account for loss of needles and quality in canaan fir; the need exists to identify seed sources with better postharvest characteristics.
An Internet survey was conducted from 28 May to 8 June 2008 to investigate consumer awareness and interest in attending programming offered at The Scott Arboretum of Swarthmore College (Swarthmore, PA). The study was designed to investigate what traditional and non-traditional programs might attract community members to the arboretum and to identify potential barriers, perceived or real, that might discourage community members from visiting the arboretum. Among demographic groups, more females were interested in “hands-on workshops” (42.5%) and “fact sheets, instructional bulletins, and how-to guides” (37.4%) than males (26.8% and 26.3%, respectively). In examining events and activities, significant differences were found for “wine tasting and tours” and “outdoor concerts and live performances” based on household income; however, no significant differences were found among age groups and other demographics tested. Differences in interest in other activities were apparent based on number of adults and number of children in the household. Public gardens and arboreta can use this information as the foundation for modifying programs and services offered, though input from the community and trialing of alternative programs should be considered before completely changing programs and services offered.
Two studies were conducted to better understand arboreta and community members' attitudes toward programming and benefits offered at arboreta and public gardens. The first study, a mail survey sent to arboreta members, included questions regarding what encourage them to become members and the services they value pertaining to their paid membership. The second study, an Internet survey of consumers residing within a 30-mile radius of the arboreta, also focused on interest in leisure activities and interest in traditional, gardening-related programs offered at the arboreta in an effort to understand what might increase membership. Over half of the members (62.5%) responded that they were “completely satisfied,” with only 3.4% selecting “neither dissatisfied nor satisfied” or some level of “dissatisfied.” The top three reasons that motivated members to join the arboretum's association included “benefits offered” (28.2%), followed by providing the “arboretum with financial support” (22.9%), and “to attend horticultural educational programs at a discounted rate” (22.6%). Interest level in gardening appeared to be greater among arboreta members compared with community members, on the basis of the percentage of both groups who self-identified with phrases such as “skilled and knowledgeable” and “enjoys spending time gardening.” Arboreta member interest in garden programming activities differed from those of local community respondents in all categories except “outdoor concerts and live performances,” “wine tasting and tours,” and “painting and drawing.” The one program/activity that appeared to be more of interest to community members than arboreta members was “cooking and entertaining,” with community members returning an average mean rating of 4.77 (1 = “very disinterested,” 7 = “very interested”) and arboreta members returning an average mean rating of 4.29. On the basis of the results of the survey and the strong interest expressed by both survey groups in program activities offered, arboreta staff should consider offering programming that appeals to both current members and community members at large and in an effort to assure a sustainable membership level.
Plant growth retardant (PGR) substrate drenches (in mg a.i per pot.) of ancymidol at 0.25, 0.5, 1, 2, or 4; paclobutrazol at 1, 2, 4, 8, or 16; and uniconazole at 0.25, 0.5, 1, 2, or 4 (28,350 mg = 1.0 oz) were applied to pampas grass (Cortaderia selloana). Control of height growth during greenhouse forcing and the residual effects on plant growth in the landscape were evaluated. During greenhouse forcing, plant height exhibited a quadratic dose response to paclobutrazol and uniconazole, while ancymidol treated plants exhibited a linear response to increasing dose. All rates of uniconazole resulted in plant heights which were 56% to 75% shorter than the nontreated control, whereas paclobutrazol and ancymidol treatments resulted in 6% to 64% and 5% to 29% shorter plants, respectively. Severe height retardation was evident with {XgtequalX}2 mg uniconazole. When the plants were transplanted and grown in the landscape (24 weeks after the PGR application), all plants treated with ancymidol, paclobutrazol, and {XltequalX}0.5 mg uniconazole exhibited heights similar to the nontreated control, suggesting no residual effects of the PGR for these treatments. Only plants treated with uniconazole at {XgtequalX}1 mg remained shorter than the nontreated control in the landscape. These results demonstrate that plant growth regulators can be effectively and economically applied in the greenhouse production of pampas grass.
Attendees at the 2001 Philadelphia Flower Show participated in an interactive-quiz-formatted survey on touch-screen computers to determine their knowledge and use of plant health care (PHC) and integrated pest management (IPM) practices. Participants answered 15 questions in three categories: 1) PHC practices (criteria for proper plant selection, correct planting practices, and reasons for mulching and pruning); 2) IPM practices (insect identification, plant and pest monitoring, and maintenance of records on pests found and treatments applied to their landscape plants); and 3) demographic and sociographic questions to aid in characterizing the survey population. Over half of the participants (58%) were interested in gardening and a majority (77%) were interested in protecting the environment. Most participants (66%) were between 36 and 60 years of age with a mean age of 47 years, 76% lived in and owned a single-family home, and greater than half (56%) had never purchased professional landscape services. Most recognized PHC criteria for proper site selection, although not all environmental site characteristics were recognized as being equally important. Nearly half (49%) identified the correct planting practice among the choices offered; while an equal number of participants chose among the several improper practices listed. Although reasons for mulching were properly identified by the respondents, excess mulching around trees was considered a proper planting practice by over 39% of the participants. When questioned about IPM practices, a majority reported that they identify pests prior to treating them (71%) and that they scouted their landscapes (82%). However, only 21% kept records of the pests that they had found and the treatments that they applied for those pests. Participants' responses were further examined using cluster analysis in order to characterize the participants and identify meaningful consumer knowledge segments for targeting future extension programming. Three distinct segments were identified: 1) horticulturally savvy (69% of the participants), 2) part-time gardener (25% of the participants), and 3) horticulturally challenged (6%). At least 47% of the horticulturally savvy and part-time gardeners correctly answered plant health care questions (44% of the total survey participants). These two segments included more individuals who were interested in gardening and protecting the environment and are potential targets for future PHC and IPM extension education programs. In contrast the horticulturally challenged recorded no interest in or opinion on gardening or protecting the environment. It is apparent that a majority of consumers are learning and employing PHC and IPM concepts. Proper site selection, planting practices, and mulching along with record keep- ing and pest identification proficiency remain key educational areas to be developed. Although not all gardeners are well versed in all subject matter, a basic knowledge of PHC and IPM is being demonstrated.