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Student learning from producing crops in recirculating culture for a 6-week module in the Fall 2013 course HORT 570 Greenhouse Operations Management at Kansas State University was assessed. The module design followed Kolb’s experiential learning model, with teams of students responsible for production of lettuce (Lactuca sativa ‘Green Oak Leaf’) or basil (Ocimum basilicum ‘Italian Large Leaf’) and chives (Allium schoenoprasum ‘Purly’) crops in either a nutrient film technique (NFT) or in-pot recirculating culture system. Goals were to discern if this class experience would 1) improve student confidence and understanding of not only recirculating solution culture systems, but also general crop nutrient management; and 2) improve higher-order learning (HOL) skills of applying, analyzing, and evaluating information. Student learning was evaluated by administering the same survey, which included questions to evaluate student perception, lower-order learning (LOL), and HOL, at four separate times during the semester: 1) before mentioning plant nutrition, hydroponics, or recirculating solution culture; 2) after plant nutrition lectures but before the experiential module; 3) immediately upon completion of the experiential module; and 4) at the end of the semester. An increase in student confidence related to managing crop production in recirculating solution culture and nutrient management was perceived by students upon completion of the module. A significant increase in LOL occurred after the material was presented during the course lectures with an increase also occurring upon completion of the experiential module. In contrast, HOL did not significantly increase after the lecture material was presented, but significantly increased upon completion of the module. Both LOL and HOL was retained at the end of the semester. This evidence supports the role of experiential learning in improving student understanding and fostering HOL.

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This decision case presents the issues a grower would face when deciding where to place and how to orient a high tunnel structure on a specific farm site. It provides a tool to teach site planning concepts on a small scale that are easily transferable to issues addressed when planning for construction of all sizes and types of protected-environment structures. In this case, the owner of Full Moon Farm must decide the placement of her high tunnels on a given farm site. Factors to consider include wind, snow, and ice loads as well as structural integrity, labor efficiency, and optimizing light levels. Ultimately, no one solution meets all recommended criteria, so the grower must prioritize the importance of various factors to come to a decision. This case study is intended for use in upper-level undergraduate horticulture courses, and although the principles are broadly applicable to site planning across geographic regions, it is most appropriate for climates above lat. 35°N. In particular, it may prove useful in courses such as greenhouse management and production courses for vegetables, cut flowers, and small fruits, where students assume the role of grower/farmer in the site planning process. This case study is supported by a website version with digital images, digital video, and maps that can be used both inside and outside of the classroom; all are downloadable from the website http://www.hightunnels.org/planningcasestudy.htm. The teaching notes present an unorthodox solution to the Full Moon Farm site planning dilemma.

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Chat rooms and their use in everyday life are becoming increasingly common, and the technology may be a useful tool to link students with experts of a given subject material and each other. In our shared course Plant Nutrition and Nutrient Management, we experimented with using a chat room to link students with experts in the field of plant nutrition. Our main goal was to enhance the learning experience of the students by providing them with access to national and international plant nutrition researchers. Web CT was used to create and conduct the chat rooms and a chat etiquette evolved to prevent crosstalk and control the flow of the discussions. Positive outcomes of the chat room use included exposure of students to the technology and beneficial interaction between students and experts. Negative aspects of chat room use included the time involved to coordinate the overall effort and train experts to use the technology; the slow pace of some chats; effective grading; and the superficial coverage of some topics. We are developing modifications for future sessions to allow subjects to be explored in more depth and to improve networking between students and experts.

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In commercial interior green walls, plant trimming and replacement necessitated by stem elongation under low interior light levels is labor intensive and costly. Antigibberellin plant growth regulators (PGRs) may slow stem elongation and thus reduce maintenance costs in this environment. In Expt. 1, two PGRs were applied as foliar spray or drench to three spiderwort selections [two of zebra plant (Tradescantia zebrina) and one of inch plant (Tradescantia fluminensis)] immediately before installation in a green wall, each at three rates: ancymidol (ANC) foliar spray at 25, 100, and 200 mg·L−1; paclobutrazol (PBZ) foliar spray at 20, 80, and 160 mg·L−1; and PBZ drench at 1, 4, and 8 mg·L−1, along with an untreated control. In Expt. 2, 80 mg·L−1 PBZ foliar spray, 1 mg·L−1 PBZ applied via subirrigation four times, and the combination of these two treatments, was evaluated on ‘Burgundy’ zebra plant. In both experiments, plants were placed in a vertical modular tray interior green wall. Change in total stem and specific internode length were measured every 14 days after installation for 3 months to calculate growth per month. Antigibberellin application slowed internode elongation of spiderwort selections during the first month after installation. Antigibberellins were more effective in zebra plant at reducing overall stem growth rate and less so on inch plant. Across the three spiderwort selections, 25 mg·L−1 foliar spray of ANC resulted in no difference in growth rate when compared with the control, although 100 to 200 mg·L−1 foliar spray was effective. Based on the results of both experiments, moderate and high rates of PBZ, applied both as a foliar spray and drench, resulted in similar reduction in stem elongation. PBZ applied as 20 to 80 mg·L−1 foliar spray, 4 mg·L−1 drench before installation in the wall, or a combination of an 80 mg·L−1 PBZ pre-installation foliar spray and recurring 1 mg·L−1 via subirrigation (four times) were effective at growth suppression of spiderworts for at least 3 months. Even rates of PBZ of 160 mg·L−1 foliar spray or 8 mg·L−1 drench did not show phytotoxicity in treated plants and could be considered for use. We recommend a pre-installation application of 80 mg·L−1 foliar spray or 4 mg·L−1 drench for controlling stem growth across spiderwort selections. Application of antigibberellin PGRs to plants before installation in green walls slows stem growth and can contribute to reduced maintenance costs.

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Hydrogen peroxide (H2O2) is a well-known oxidizing agent often used as a remedy by consumers to treat algae and root decay from presumed root disease on interior plants, as well as to encourage root growth and health. To characterize the phytotoxic effects and define the safe concentration threshold for H2O2 use on ‘Vivaldi’ hybrid phalaenopsis orchid (hybrid Phalaenopsis), root systems were dipped for 3 minutes in 0%, 3%, 6%, or 12% H2O2 one time and observed in greenhouse conditions for the following 27 days. Root systems of each plant were assessed over time for percent visible root damage; ratings of root health on a scale of 1 to 5 points, with 5 points indicating “very healthy”; and final fresh and dry weights. To determine when symptoms manifested above the root zone, foliage and flower damage was evaluated over time by assessing percent visible foliage damage, ratings of foliage health, percent foliar wilt, flower/bud count, and final foliage and flower fresh and dry weights. Over the evaluation period, the root health rating of the ‘Vivaldi’ hybrid phalaenopsis orchids treated with 12% H2O2 decreased from 5 to 1.13, whereas those treated with 3% H2O2 only decreased from 5 to 4.13. H2O2 concentrations of 6% and 12% damaged root health permanently, whereas the 3% H2O2 concentration only caused minor damage to overall root health. However, algae were not killed at the 3% rate. Neither foliage nor flowers were seriously affected during the 3 weeks after application, but foliage wilt did result in the 6% and 12% treatments by week 4. As H2O2 concentration increased, fresh weights decreased in roots and leaves. Although a single 3% H2O2 root dip did not result in severe symptoms of phytotoxicity, the treatment’s long-term plant health effects are unknown. Because the 3% H2O2 root dip caused minor plant health setbacks and failed to subdue algae populations in the root zone, consumers should be wary of using H2O2 to improve orchid (Orchidaceae) root health and should instead focus on altering care and watering practices.

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This research examines whether knowledge about floral preservatives increases consumers’ perception of quality, purchase intention, and price of a floral arrangement. A survey was administered to 222 participants at two locations in Manhattan, KS. Seventy-three percent of respondents fell within Generation Y (18 to 30 years old). The survey instrument presented four levels of presentation of a floral arrangement that were associated with increasing knowledge about the use of floral preservatives on consumers’ perceptions about the quality and price of that arrangement, as follows: Level 1 showed a photo of a floral arrangement without preservatives; Level 2 showed the same photo of a floral arrangement with a small, unlabeled packet of preservatives; Level 3 showed the same photo of a floral arrangement with a large, clearly labeled packet of preservatives; and Level 4 showed the same photos as Level 3 but was presented after a 191-word message describing the three functions of floral preservatives. Participants of the survey rated the quality of a floral arrangement higher from Level 2 (presence of floral preservatives not explicit) to Level 3 (presence of floral preservatives explicit) and from Level 3 to Level 4 (after reading a message about floral preservatives’ function and effectiveness). Their intent to purchase the floral arrangement generally increased with each level of presentation. Females indicated intention to purchase flowers more frequently than males. Participants increased the price that they were willing to pay for the floral arrangement at each level of presentation, starting at $25.46 at Level 1 (no floral preservatives use indicated) to $29.19 at Level 4. Participants were more knowledgeable about the benefits of floral preservatives and believed that floral preservatives increased the value of floral arrangements after reading a message describing their function and effectiveness more so than before reading a message. The younger the respondent, the more willing they were to pay more for floral arrangements with floral preservatives. As consumers become more aware of the use of floral preservatives and more knowledgeable about how and why they are effective, they attribute higher quality to floral arrangements with preservatives, they are willing to pay more for arrangements with preservatives, and their purchase intention frequency increases. Florists should always use preservatives in their processing and construction of fresh floral arrangements, consider providing a message about the function and effectiveness of floral preservatives to their customers, and then market their use of these materials.

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Chrysanthemum [Dendranthema ×grandiflorum (Ramat.) Kitamura] growth and nutrient leaching of three clinoptilolite-based root media—NZ, EZ1, and EZ2—were compared to the performance of control plants grown in Sunshine Mix #2 [3 peat : 1 perlite (v/v)]. The control received 210 mg·L−1 N from an 18N-4P-15K soluble fertilizer at each irrigation. NZ contained untreated zeolite and received the same soluble fertilizer as the control but leached lower concentrations of NH4-N, K, and PO4-P during most of the production cycle compared to the control. EZ1 was formulated to provide N, P, and K as fertilizer nutrients and produced plants similar to the control based on ratings, height, width, and dry mass, but not fresh mass, at harvest when the fertilizer rate was half of that applied to the control—105 mg·L-1N. EZ2 did not receive P or K from soluble fertilizer and produced plants similar to the control based on rating, height, and dry mass, but not width or fresh mass, with soluble fertilizer input reduced to N alone. Tissue N, P, and K concentrations of plants grown in EZ1 and EZ2 were lower than those of control plants. With further refinements, these zeolitebased products show promise for decreasing nutrient leaching during crop production and allowing for application of lower rates of soluble fertilizers.

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In recent years, many horticulture departments around the United States have been concerned with recruiting and retaining an adequate number of students. One potential recruitment opportunity is the horticulture Future Farmers of America (FFA) Career Development Events (CDEs). For the time period of 1999 to 2012 (14 years), 1462 students participated in the annual state-level horticulture contests, comprising floriculture and nursery/landscape CDEs, held at Kansas State University (KSU). Using the rosters from these two CDEs, we referenced the university’s student information database to determine whether the high school students who participated as FFA horticulture CDE contestants ultimately matriculated to KSU. Fifty-two percent of former FFA horticulture CDE participants were accepted to KSU and 32% matriculated. Of these, 58% enrolled in the College of Agriculture and 19% majored in horticulture. Therefore, 3.5% of total horticulture CDE participants majored in horticulture at KSU. Students who participated in more than one horticulture CDE over time were more likely to major in horticulture at KSU compared with students who competed only once. Thirty-nine percent of students who participated in both horticulture CDEs pursued a baccalaureate program in horticulture. These two student characteristics could be used as indicator data points to target recruitment of future horticulture students. Data about the high school programs that generated contest participants were also summarized. Exceling in the CDE contests was not an indicator CDE participants would pursue a baccalaureate degree in horticulture. These analyses suggest FFA CDEs have some potential to optimize student recruitment efforts.

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Biological and chemical control strategies for the twospotted spider mite (TSM; Tetranychus urticae) were evaluated in a greenhouse experiment replicated over time in mixed production of ivy geranium (Pelgargonium peltatum ‘Amethyst 96’) and two impatiens cultivars (Impatiens wallerana ‘Impulse Orange’ and ‘Cajun Carmine’). Chemical control using the miticide bifenazate was compared with two release strategies for biological control using the predatory mite, Phytoseiulus persimilis. Specific treatments included 1) a single application of bifenazate at 0.3 g·L−1 formulation (22.6% a.i.); 2) a single release of predatory mites at a 1:4 predator to pest ratio based on sampled pest density; 3) a weekly release of predatory mites at numbers based on the area covered by the crop; and 4) an untreated control. TSM populations were monitored for 4 weeks. After another 4 weeks, when plants were ready for market, plant quality ratings were recorded. The number of TSM per leaf dropped for all treatments on all genotypes but increased in the untreated plants. On ivy geranium, the fact that there were significantly more TSM on untreated plants was not reflected in average plant quality, but it did reduce the proportion of containers rated as salable at full price compared with both chemical and biological control. On impatiens, both treatment and cultivar had significant effects on the mean plant quality rating and on the proportion of containers rated as salable at full price. The use of a sampling plan to determine the appropriate number of predators to release was as effective as the currently recommended management treatments for TSM in bedding plants.

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Plants in the interiorscape have many documented benefits, but their potential for use in conjunction with mechanical heating, ventilation, and air conditioning (HVAC) systems to humidify dry indoor environments requires more study. In this research, evaporation and evapotranspiration rates for a root medium control, variegated spider plants (Chlorophytum comosum), and green jade plants (Crassula argentea) were measured over 24 hours at 25% and 60% relative humidity (RH) and 20 °C to generate data for calculation of the leaf surface area and number of plants necessary to influence indoor humidity levels. Evaporation and evapotranspiration rates were higher for all cases at 25% RH compared with 60% RH. At 25% RH during lighted periods, evapotranspiration rates were ≈15 g·h−1 for spider plants and 8 g·h−1 for jade plants. Spider plants transpired during lighted periods due to their C3 photosynthetic pathway, whereas jade plants had greater evapotranspiration rates during dark periods—about 11 g·h−1—due to their crassulacean acid metabolism (CAM) photosynthetic pathway. A combination of plants with different photosynthetic pathways (i.e., C3 and CAM combination) could contribute to greater consistency between evapotranspiration rates from day to night for humidification of interior spaces. Using the measured data, calculations indicated that 32,300 cm2 total spider plant leaf surface area, which is 25 spider plants in 4-inch-diameter pots or fewer, larger plants, could increase the humidity of an interior bedroom from 20% RH to a more comfortable 30% RH under bright interior light conditions.

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