Lawn Care and Landscape Maintenance Professional Acceptance of Insect- and Disease-resistant Ornamental Plants

Although lawn care and landscape maintenance professionals appear increasingly willing to use Integrated Pest Management (IPM) strategies and adopt nonchemical pest management alternatives into management practices, the opinions of landscape management professionals have not been assessed regarding anticipated influences of increased use of insectand disease-resistant ornamental plants on grounds management activities, client satisfaction, or business profitability. Lawn care and landscape professionals are well positioned to implement many IPM practices into landscape use and to educate their consumer clients about ecologically sustainable landscape designs and beneficial management techniques. Conversely, if some of these professionals are unwilling to advocate installation of ornamental host plants that are resistant to certain pests or diseases, market success of such plants can be limited. To better understand perceptions of green industry professionals related to these issues, we surveyed lawn care and landscape business owners and employees to categorize their perceptions about insector disease-resistant ornamental plants and qualified their beliefs in relation to both personal and firm demographics. A total of 391 completed surveys were received from Tennessee, Florida, and Georgia participants. Data analyses revealed that lawn care and landscape maintenance professionals largely believe that insectand diseaseresistant plants will benefit their businesses and should result in increased client satisfaction. Only ’4% of respondents stated concern that business would incur at least some negative effect if pest-resistant plants were made more available or used in greater numbers in client landscapes. Among all respondents, there was an average expectation that 60% or more of plants within a given client’s landscape would have to be resistant to insect pests or plant diseases to result in a decrease in company profits. If insectand disease-resistant ornamental plants were used more widely in client landscapes, respondents expected that the required number of site visits to client landscapes would remain unchanged and that moderate reductions in insecticide and fungicide use would result. In past surveys, lawn care and landscape maintenance professionals have reported their willingness to adopt Integrated Pest Management (IPM) strategies and use nonchemical pest management alternatives (Braman et al., 1998a; Garber and Bondari, 1996; Hubbell et al., 1997). Garden and landscape enthusiasts are also willing to seek pestand disease-resistant ornamental plants for residential landscape use despite initial public skepticism about IPM (Ball, 1986; Garber and Bondari, 1992, 1996; Holmes and Davidson, 1984; Klingeman et al., 2004, 2006; Koehler, 1989; Stewart et al., 2002). Numerous ornamental plant species and cultivars have been exposed to pests and plant diseases in university trials and then evaluated for subsequent injury. Results of some of these studies have been compiled into published plant lists highlighting plants that demonstrate tolerance and resistance to specific pests and diseases (Smith-Fiola, 1995). Ornamental host plant resistance (HPR) to pests and diseases is an integral component of successful landscape IPM. Increased use of pestand disease-resistant ornamental plants would offer advantages to grounds maintenance professionals by reducing the time needed to monitor key plants in client landscapes (Stewart et al., 2002) and would address stated needs for a ‘‘total system approach’’ to IPM by affecting a shift in management behavior with benefits that persist for longer durations within the environment (Lewis et al., 1997). Although end-users of ornamental plants are interested in pest resistance (Braman et al., 1998a, 1998b; Garber and Bondari, 1992, 1996), opinions of landscape management professionals have not been assessed, particularly with regard to how ornamental HPR may be perceived to affect company profitability. If insectand disease-resistant plants are widely adopted by the gardening public, it is possible that landscape maintenance firms would have real or perceived loss of income resulting from reduced need for pesticide applications or fewer onsite visits to client landscapes. We consider landscape management professionals to include grounds managers, landscape designers, landscape architects, pesticide spray technicians, and others. The extent to which this peer group is unwilling to adopt or advocate use of resistant ornamental host plants (e.g., because of concerns about profit decline or client unwillingness to accept plant substitutes) will place constraints on the market success of these plants as new cultivars are introduced to commercial trade. Therefore, objectives of this study were to question landscape management professionals and categorize their perceptions about the potential for insector disease-resistant ornamental plants to affect company or personal profitability as well as client satisfaction and to qualify these beliefs as related both to personal and firm demographics. Materials and Methods A four-page questionnaire was developed and pretested with participants of the Jan. 2006 Grounds Maintenance Short Course in Knoxville, TN, to assess perceptions of lawn care and landscape maintenance professionals about insectand disease-resistant ornamental plants. The final survey was then mailed in April by the UGA Survey Center to more than 1500 landscape management professionals and firms registered in Tennessee and Georgia. Anticipating a response rate from the direct mail survey of 10% (Reed, 1999), mailed surveys were also supplemented with direct delivery to landscape management professionals attending servicelearning workshops (from June 2006 through Oct. 2007) at the Tennessee Nursery and Landscape Association winter workshop in Pigeon Forge, TN; Middle Tennessee Nursery Association Trade Show in McMinnville, TN; Spring Express Landscape Seminar in Chattanooga, TN; Tri-Cities Landscape Seminar Received for publication 10 June 2009. Accepted for publication 31 July 2009. We are grateful to Dr. Mark Fly and Becky Stephens (Director and research associate with the University of Tennessee Human Dimensions Research Lab) for their assistance with the design of our survey instrument, Dr. Jim Bason (Director of the University of Georgia Survey Research Center) who coordinated the mail survey and data collection, and Ann Reed (University of Tennessee Statistical Consulting Services) who helped with our statistical analyses as well as to reviewers of earlier drafts of the manuscript. To whom reprint requests should be addressed; e-mail [email protected]. 1608 HORTSCIENCE VOL. 44(6) OCTOBER 2009 in Jonesboro, TN; Southern Nursery Association Tech Shop in Atlanta, GA; Southeastern Greenhouse Conference in Greeneville, SC; and three separate Georgia/Florida Green Industry Update Conferences in Jacksonville, FL, and Quincy, FL. Respondents at outreach sessions who indicated they had already completed the survey were either excused from participation in the subsequent assessment or their notated second survey was excluded from data analyses. Respondents were able to anonymously complete the questionnaire to encourage them to provide personal demographic information. They also described personal experiences within the green industry, professional interactions with clients, and their personal participation in practices related to grounds and landscape maintenance (Tables 1 and 2). Modified Likert scales, in which 1 was ‘‘not important’’ and 7 was ‘‘extremely important’’ to respondents, were used to assess perceptions about management characteristics that professionals considered ideal for a customer’s landscape. Similarly, modified Likert scales were used to assess willingness to recommend insectand disease-resistant ornamental plants for use or replacement in client landscapes, relative willingness to pay for resistant ornamental plants, and to compare insect and disease resistance between introduced and U.S. native ornamental plants. A series of questions was posed to assess expectations about business profitability and action outcomes to firms if the respondent were to plant insectand disease-resistant ornamental plants in client landscapes. Participants were also asked to indicate on a sliding scale marked at 10% intervals and labeled with 0% = no insectand disease-resistant plants in the client landscape, 50% and 100% = the entire ornamental plant assemblage comprised of insectand disease-resistant plants, the point beyond which additional insectand diseaseresistant ornamental plants were expected to decrease company profits if planted in a clients’ landscape. Respondents were offered the choice to state they ‘‘[Did] not think insect or disease resistant plants would yield profit’’ (Table 3). To obtain a metric that gauged respondent familiarity with insectand disease-resistant ornamental plants, respondents were asked to choose which plant was more resistant to a specific insect pest or plant disease from a pair of ornamental plants selected as complimentary in aesthetic form and landscape function and for which resistance levels have been reported. Participants were encouraged to acknowledge if their selection was merely a best guess. To generate a ‘‘knowledge’’ variable, all blank, incorrect, and guess responses were excluded and correct responses were subjected to Cronbach’s reliability analysis (Table 4). Because responses to these questions yielded a coefficient alpha of 0.83 when each question was omitted, the reliability (range = 0.79 to 0.83) remained above the acceptable threshold of 0.70 (Nunnally, 1978); correct scores for all 10 susceptibility/ resistance choices were summed to generate a valid host plant resistance ‘‘knowledge’’ value. When significant, differences in means were assessed in multiple comparisons using Tukey’s honestly significant difference test (SPSS, 2003). Unequal sample sizes resulted from excluding answers that were missing or marked as ‘‘don’t know’’ by respondents. Valid responses were tested for equal variance and normality and then assessed using c comparisons, Student’s t test, and Pearson’s correlation coefficient test. Two-factor multivariate analysis of variance tested the relationship of respondent expectations about how increased availability of insectand disease-resistant ornamental plants would influence landscape business performance with self-stated expectations of how increased insectand disease-resistant ornamental plant use in client landscapes would affect key landscape company performance parameters. If the overall c was significant, adjusted residual values (a nonparametric equivalent of z-scores) for cell percentage in each subgroup were examined. Adjusted residual scores greater than 2.0 and less than –2.0 for a given subgroup percentage indicated that the subgroup differed significantly (P # 0.05) from the overall group percentage (Haberman, 1978). Response pools that violated assumptions of equal variance and normality by Shapiro-Wilk and Levene tests (P $ 0.05 and P # 0.05, respectively) were analyzed using Kruskal-Wallis’ nonparametric test (SPSS, 2003). Results and Discussion By Nov. 2007, 391 completed surveys were received from respondents contacted either by mail (n = 160) or by direct delivery in conjunction with outreach activities (n = 231). Of the landscape management professionals who returned surveys, 52% worked in Tennessee, 28% were located in Georgia, 16% were from Florida, and 4% were from all other states. Respondent job responsibilities were as sole employees or owners of the business (56%), landscape crew forepersons (12%), and crewmembers (9%). Approximately 49% had achieved at least a Bachelor’s degree and 21% of respondents had some level of postgraduate education. Nearly half of respondents were 45 years old or younger, were most likely to be male (82%), Table 1. Demographic characteristics that describe the lawn care and landscape maintenance professionals who returned a completed four-page questionnaire. Number of respondents 392 Characteristic Percentage of respondents Professional occupation Owner/general manager 56 Landscape crew member 9 Office/sales/company support 4 Landscape crew foreman 12 Did not work in landscape maintenance 7 Other 9 Did not respond 3 Number of clients served (range) Fewer than 20 11 21 to 50 14 51 to 100 16 101 to 200 11 201 to 500 9 More than 500 4 Did not respond 35 Gender Male 79 Female 17 Did not respond 4 Age 15 to 24 2 25 to 34 16 35 to 44 25 45 to 54 35 55 to 64 15 Older than 65 3 Did not respond <3 Highest level of education completed High school 19 Some college 27 Associate’s degree 10 Bachelor’s degree 27 Some graduate school 5 Master’s degree 7 Doctorate <1 Did not respond 4 Number of years earning income as a landscape management professional Mean ± SEM (n = 322) 16 (±0.56) HORTSCIENCE VOL. 44(6) OCTOBER 2009 1609 MARKETING AND ECONOMICS