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Benedict C. Posadas, Christine H. Coker, Patricia R. Knight, and Glenn Fain

The objective of this survey was to determine the levels of liking and willingness to pay for selected garden chrysanthemum (Dendranthema ×grandiflorum) cultivars, and to measure relative infl uence of socioeconomic characteristics on consumer preferences and valuations. The survey was conducted during the 2003 Fall Flower and Garden Fest at the Truck Crops Experiment Station in Crystal Springs, Miss. Nine garden chrysanthemum cultivars were presented to 579 survey participants in three pot sizes. Respondents preferred `Mithra Maroon', `Venus Purple', `Amory Yellow White', `Adonis Purple', and `Road Runner Bronze' more than `Night Hawk Lemon', `Freya Salmon', `Amata Purple', and `Starlet Ivory'. Of the five preferred cultivars, however, respondents were willing to pay more for `Mithra Maroon', `Road Runner Bronze', and `Amory Yellow White'. Consumers of White or Caucasian origin liked the cultivars less and were willing to pay less for them as compared to other respondents who reported other racial origins, primarily Native Americans and African Americans. The levels of liking for the cultivars were similar for participants of different gender classification, but female respondents were willing to pay more for the cultivars. Respondents who previously bought chrysanthemums reported higher level of liking for the cultivars but were not willing to pay more for them. Participants who were interviewed on Saturday liked the cultivars more but were willing to pay less than those who were interviewed on Friday. Larger-sized households tended to like the cultivars less and were not willing to pay more for the cultivars. Respondents did not like the cultivars in larger-sized pots and were not willing to pay more for plants in larger-sized pots included in the survey.

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Benedict C. Posadas, Patricia R. Knight, Christine E.H. Coker, Randal Y. Coker, and Scott A. Langlois

This work describes workers’ socioeconomic characteristics and evaluates the determinants of workers hiring decisions among 215 randomly selected wholesale nurseries and greenhouses located in eight selected southern states in the United States. The participating nurseries and greenhouses employed on average 5.40 permanent workers per horticulture operation or 2.27 permanent workers per acre under cultivation. Participating nurseries and greenhouses hired an average 2.38 part-time workers per horticulture operation or 0.80 part-time workers per acre placed under production. Empirical models were estimated to determine the significant factors affecting hiring decisions by this industry. Hiring decision models covered age groups, racial backgrounds, formal education levels, and gender. Analysis of the decision-making process involving the employment of hired workers among the participating wholesale nurseries and greenhouses provided insights into the hiring decisions in the industry. The hiring decisions by demographic characteristics serve as benchmarks for assessing impacts of regulations affecting the industry in the near future. About 1.9% of all the establishments employed more than 50 permanent and part-time workers and 1.4% employed more than 50 permanent workers.

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Patricia R. Knight, D. Joseph Eakes, Kenneth M. Tilt, and Charles H. Gilliam

Stem cuttings of Ilex cornuta `Burfordii Nana' and Ilex × `Nellie R. Stevens', were direct stuck into cell pack, rose pot, quart pot, and trade gallon containers on March 4, 1991. Ten weeks and again at twenty weeks after sticking, rooted liners from cell pack, rose pot, and quart pot containers were transplanted into trade gallon containers. Thirty weeks after sticking, Nellie R. Stevens holly had a greater total root dry weight compared to Dwarf Burford holly. There were no differences in total root dry weight for any transplant treatment, but root distribution was influenced. Cell pack and rose pot liners transplanted twenty weeks after sticking showed a reduction in root growth in the root sector between the radius of a quart pot and a trade gallon pot. Shoot growth was also reduced for cell pack and rose pot liners that were transplanted into trade gallon containers twenty weeks after sticking.

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Patricia R. Knight, D. Joseph Eakes, Charles H. Gilliam, and Harry G. Ponder

Seed geraniums (Pelargonium × hortorum Bailey `Scarlet Elite') were grown in 10-cm pots in a 1 pine bark : 3 peat moss : 1 perlite medium from 18 March until 5 May 1993. Plants received Osmocote 14N-6.1P-12.5K and either conventional overhead (CO), drip (DI), or subirrigation (SI). Subirrigation produced greater shoot and root dry weights than CO or DI. Plants grown using DI produced fewer branches than plants grown using CO or SI. Plants receiving SI reached anthesis before plants receiving CO or DI. Method of irrigation had no influence on total root, soil, or leachate N, but SI did increase total shoot N.

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Patricia R. Knight*, Christine E. Coker, Benedict Posadas, and John M. Anderson

The IR-4 program works to identify potential minor-use horticultural chemicals and evaluate them for phytotoxicity and efficacy. The objective of this experiment was to evaluate phytotoxicity and weed control of three unlabeled herbicides on field production of Hemerocallis spp. `Ming Toy'. Ten-cm pots of `Ming Toy' were planted into the field 16 July 2001. Each plot consisted of 3 plants per treatment with 6 replications in a completely random design. Each herbicide was analyzed as a separate experiment. Herbicide treatments consisted of clopyralid (0.14, 0.28, 0.56, or 1.1 kg·ha-1 a.i.), clethodim (125, 250, or 500 mL·L-1 a.i.), or bentazon (1.1, 2.2, or 4.4 kg·ha-1 a.i.). Data collected included weed number, percentage of weed coverage (% weed coverage), and phytotoxicity and foliar color ratings for `Ming Toy'. Clopyralid reduced total weed number 90 DAT although % weed coverage was similar or worse compared to the control treatment. Phytotoxicity 90 DAT was not significant for plants treated with clopyralid, but foliar color ratings were reduced. Application of clethodim to `Ming Toy' plots, regardless of rate, resulted in similar weed numbers compared to the control 49 DAT. Clethodim application, regardless of rate, reduced % weed coverage compared to the control treatment. Phytotoxicity 90 DAT was not significant, regardless of herbicide treatment, but foliar color ratings were lower for herbicide treated plants compared to the control. Bentazon, regardless of rate, reduced weed number and % weed coverage 49 DAT compared to the control. Phytotoxicity was similar to the control for plants treated with 1.1 kg·ha-1 a.i.

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Jenny B. Ryals, Patricia R. Knight, and Eric T. Stafne

Production of passion fruit (Passiflora sp.) via cuttings is a way to eliminate genetic variation in the crop and also results in a faster establishment time. This could aid producers in increasing production efficiency while maintaining genetic lines. The objective of this research was to evaluate ease of rooting and determine the optimal auxin source for seven species of passion fruit. Semihardwood two-node cuttings were taken from the middle of the parent vine, and auxin treatments were applied to the basal end of the cutting. The cuttings were then stuck to a depth of 1 inch on 20 Aug. 2019. Treatments included three auxin sources and seven passion fruit species. Treatments were set up as a randomized complete block design blocking on species, with 10 single-plant replications per treatment. Data were collected 30 d after sticking cuttings and included percent rooted, total root number, average root length (of the three longest roots, measured in centimeters), root quality (0–5 scale, with 0 = dead and 5 = healthy, vigorous root system), root dry weight (measured in grams), and percent callus. Results showed that passion fruit cuttings receiving a hormone treatment had significantly positive effects on rooting responses, such as increased number, length, quality, and dry weight of roots. Blue passionflower (P. caerulea) was the only species in which hormone treatment did not increase rooting compared with the control. The use of hormone to aid in cutting propagation of passion fruit is recommended, depending on the species being propagated.

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William E. Klingeman, David B. Eastwood, John R. Brooker, Charles R. Hall, Bridget K. Behe, and Patricia R. Knight

A survey was administered to assess plant characteristics that consumers consider important when selecting landscape plants for purchase. Visitors to home and garden shows in Knoxville and Nashville, Tenn.; Detroit, Mich.; and Jackson, Miss., completed 610 questionnaires. Respondents also indicated their familiarity with integrated pest management (IPM) concepts, pest control philosophy, recognition of flowering dogwood (Cornus florida) pests and diseases, including dogwood powdery mildew (Microsphaera pulchra), and willingness-to-pay a price differential for a powdery-mildew-resistant flowering dogwood. Fewer than half of the respondents in any city indicated familiarity with IPM, although they were familiar with organic farming and pest scouting components of an IPM program. Willingness-to-pay was relatively consistent across all four locations. The uniformity of average tree premiums, which ranged from $11.87 in Jackson to $16.38 in Detroit, supports the proposition that customers are willing to pay a substantially higher price for a landscape tree that will maintain a healthier appearance without the use of chemical sprays. Factors affecting consumer demand for landscape nursery products and services can be paired with consumer awareness of IPM terminology and practices to create an effective market strategy for newly developed powdery-mildew-resistant dogwood cultivars.

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Diana R. Cochran, Richard L. Harkess, Patricia R. Knight, Maria Tomaso-Peterson, Eugene K. Blythe, and Charles H. Gilliam

Regalia®, a commercial extract of giant knotweed [Fallopia sachalinensis F. Schmidt (synonyms: Reynoutria sachalinensis (F. Schmidt) Nakai, Polygonum sachalinense F. Schmidt, Tiniaria sachalinesis (F. Schmidt) Janch.)], was evaluated for its potential to enhance drought tolerance of container-grown impatiens (Impatiens walleriana Hook. f. ‘Super Elfin XP White’). In two separate experiments, Regalia® was foliar-applied once a week for 4 weeks at four different rates (0, 5, 10, or 15 mL·L−1). In Expt. 1, Regalia® was applied to impatiens grown under three target substrate volumetric water contents (TVWCs): 85%, 55%, or 25%. In Expt. 2, Regalia® was applied to impatiens watered with 1, 3, or 6 days between waterings (DBW). In Expt. 1, root dry weight (RDW) of impatiens receiving applications of Regalia® at the 0.5× rate was greater compared with the 0.0× rate across all TVWCs. Additionally, soluble protein content was greater after Regalia® application at the 0.5×, 1.0×, or 1.5× rates compared with the 0.0× rate for plants grown at 55% TVWC. In Expt. 2, leaf greenness (SPAD) and leaf net photosynthetic rate (Pn) were greater with Regalia® applied at the 0.5× and 1.0× rates compared with the 0.0× rate, respectively. Soluble protein content was greater in impatiens treated with Regalia® at the 1.5× rate and 1 DBW and the 0.5× rate with 3 DBW compared with the 0.0× rate with 1 or 3 DBW. However, there was no indication that impatiens grown under different moisture levels had increased drought tolerance after application of Regalia®.

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Benedict C. Posadas, Patricia R. Knight, Randal Y. Coker, Christine H. Coker, Scott A. Langlois, and Glenn Fain

Using results of a socioeconomic survey of nurseries and greenhouses, Tobit regression analysis was used to estimate empirical models to measure the socioeconomic impact of automation or mechanization on annual gross sales, annual employment, and workers' earnings, safety, and retention. The survey was conducted among 87 randomly selected nurseries and greenhouses located in Mississippi, Louisiana, and Alabama, from Dec. 2003 to Mar. 2005. About 20% of all the identified major tasks were performed by workers in nurseries and greenhouses with some form of mechanization or automation. Regression results showed that nurseries and greenhouses that experienced higher levels of sales also demonstrated higher levels of automation or mechanization. The employment impact of automation or mechanization was neutral, indicating that any improvement in automation or mechanization did not necessarily lead to a reduction, but instead to a more efficient use of labor by nurseries and greenhouses. Improvements in automation or mechanization resulted in higher total workers' earnings reported by participating nurseries and greenhouses. Further Tobit regression results showed that automation or mechanization had neutral effects on the length of training period, workers' safety, and retention rates and enabled nurseries and greenhouses to hire less-skilled workers.

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S. Christopher Marble, Stephen A. Prior, G. Brett Runion, H. Allen Torbert, Charles H. Gilliam, Glenn B. Fain, Jeff L. Sibley, and Patricia R. Knight

Increased trace gas emissions of carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O) are widely believed to be a primary cause of global warming. Agriculture is a large contributor to these emissions; however, its role in climate change is unique in that it can act as a source of trace gas emissions or it can act as a major sink. Furthermore, agriculture can significantly reduce emissions through changes in production management practices. Much of the research on agriculture’s role in mitigation of greenhouse gas (GHG) emissions has been conducted in row crops and pastures as well as forestry and animal production systems with little focus on contributions from specialty crop industries such as horticulture. Our objective was to determine efflux patterns of CO2, CH4, and N2O associated with three different fertilization methods (dibble, incorporated, and topdressed) commonly used in nursery container production. Weekly measurements indicated that CO2 fluxes were slightly lower when fertilizer was dibbled compared with the other two methods. Nitrous oxide fluxes were consistently highest when fertilizer was incorporated. Methane flux was generally low with few differences among treatments. Results from this study begin to provide data that can be used to implement mitigation strategies in container plant production, which will help growers adapt to possible emission regulations and benefit from future GHG mitigation or offset programs.