bluuebunny/crossref_metadata_2025 huggingface dataset:
Pricing Powdery-mildew-resistant Dogwoods: Simulated Impacts on the Nursery-industry Supply Chain
Authors: Gardner Justin G. , Eastwood David B. , Hall Charles R. , Brooker John R.
Published: December 2018

The University of Tennessee developed a flowering dogwood tree (Cornus florida) that is resistant to powdery mildew (Microspaera pulchra). A simulated cooperative game was created to estimate a university fee and predict the behavior of nursery growers and nursery product retailers. The simulation suggests a university fee of $3.51, leading to an average retail price premium for the resistant tree of $10.41. At this price level the simulation predicts that 62 percent of all retail dogwood trees sold would be powdery mildew resistant. Based on 1998 sales of 1.475 million dogwood trees nationwide, 914,500 were predicted to be the powdery mildew resistant varieties, resulting in $3.2 million in revenue for the university. Given this level of sales and markup pricing, the cost of the trees will rise in subsequent stages of the distribution channel, and revenues will increase as well. The simulation suggests nursery revenue will increase by nearly $4 million and costs by $3.2 million, resulting in a net nursery gain of $0.8 million. Similar computations for the retail level are $9.5 million in revenue and a net increase of $5.5 million.
Reducing Insecticide Use in Home Gardens: Effects of Training and Volunteer Research on Adoption of Biological Control
Authors: Sadof Clifford S. , O'Neil Robert J. , Heraux Farah M. , Wiedenmann Robert N.
Published: December 2018

More than 500 Master Gardeners in Indiana and Illinois were taught alternatives to the use of insecticides in workshops that focused on biological control of insect pests in home gardens. Gardeners also learned to conduct experiments in their backyards and were encouraged to participate in a summer research program that tested specific control methods. Workshop participants were surveyed before the workshop, and in two successive growing seasons to measure changes in their pest management practices. Overall, a significant percentage of gardeners stopped applying insecticides for up to two consecutive growing seasons after attending workshops. In addition, the adoption of biological control by participants appeared to be linked to their insecticide use and willingness to participate in the research process. A significant increase in the adoption of biological control was noted among garden researchers who did not use insecticides before the workshop or had reduced insecticide use following the workshop. No such change was noted for gardeners that did not conduct research. The relative contributions of workshop participation and hands-on research experience in pesticide reduction and biological control adoption are discussed.
Assessment of Chlorophyll and Nitrate Meters as Field Tissue Nitrogen Tests for Cabbage, Onions, and Carrots
Authors: Westerveld Sean M. , McKeown Alan W. , McDonald Mary Ruth , Scott-Dupree Cynthia D.
Published: December 2018

Nutrient management legislation has prompted an evaluation of alternative nitrogen (N) management techniques. SPAD (Soil Plant Analysis Development) chlorophyll and Cardy nitrate (NO3-) meters were evaluated for their potential as tissue nitrogen tests in cabbage (Brassica oleracea var. capitata), onions (Allium cepa), and carrots (Daucus carota subsp. sativus). Cabbage, carrots, and onions were grown on both organic and mineral soils in Ontario, Canada in 2000 and 2001. Nitrogen was applied at five rates to cabbage and carrots and three rates to onions ranging from 0 to 200% of current provincial recommended N rates. In an additional treatment, 50% of the recommended rate was applied preplant and sidedress N applications of 40 kg·ha-1 (35.7 lb/acre) were applied when SPAD chlorophyll meter readings fell below 95 (2000) and 97% (2001) of the highest N rate treatment. Yields were generally unaffected by N rate, except in cabbage in 2000, suggesting adequate N was present in most treatments. SPAD chlorophyll meter readings were highly variable among soil types, cultivars, and years. Chlorophyll readings reached a plateau in adequately fertilized crops in many instances. Cardy readings were less variable among soil types, cultivars, and years. The relationship between N rate and sap NO3-N concentration was generally linear. The results suggest that the use of a well-fertilized reference plot is most appropriate for the SPAD meter on these vegetable crops, while the use of region-specific critical NO3-N concentrations was most appropriate for the Cardy NO3-meter. Both meters would be cost advantageous when over 500 samples are tested. The meters were generally easy to use, except for the SPAD meter on carrots. The meters have potential for N management of vegetable crops under Ontario growing conditions.
Evaluation of commercial inorganic and organic fertilizer effects on arbuscular mycorrhizae formed by Glomus intraradices
Authors: Linderman R.G. , Davis E.A.
Published: December 2018

Formation and function of arbuscular mycorrhizae (AM) are affected by levels of fertility in soil or fertilizers applied to soilless container mixes. For AM fungi, phosphorus (P) is the main element influencing colonization of host plant roots. The question addressed in this study was whether inorganic or organic fertilizers were more compatible with the formation and function of AM. Several controlled-release inorganic (CRI) fertilizers were compared with several organic (OR) fertilizers at different rates (½× to 4× the recommended rate) to determine (1) threshold levels of tolerance by the AM fungus Glomus intraradices in relation to root colonization, and (2) growth responses of `Guardsman' bunching onion (Allium cepa) and `Orange Cupido' miniature rose (Rosa spp.) plants grown in a soilless potting mix or sandy loam soil. AM colonization in soil was greatly decreased or totally inhibited by CRI fertilizers with high P content at the 2× rate or greater, whereas colonization was decreased but never eliminated by low-P OR fertilizers at the 3× rate or greater. Shoot growth of onions was similar with or without AM inoculation when fertilized with CRI, but in general was only enhanced by OR fertilizers if inoculated with AM fungi, compared to the noninoculated controls. Shoot and root growth of onions were significantly increased by AM inoculation when OR fertilizers were used at the 1× rate. In contrast, root growth was not increased by the combination of CRI fertilizers and AM fungal inoculation. Inoculation of miniature roses grown in sandy loam amended with 25% peat and perlite and fertilized with all the CRI or OR fertilizers resulted in high AM colonization, but without much AM-induced growth increase except where OR fertilizers or CRI fertilizers with low P were used. In a soilless potting mix, growth of miniature roses was less with OR fertilizers at the rates used than CRI fertilizers, but mycorrhiza formation was greater in the former unless P was low in the latter. These results indicate that release of nutrients from organic fertilizers, as a result of microbial activity, favors AM establishment and function more than most inorganic fertilizers unless P levels of the latter are low.
EcoLyst Application Timing and Juice Corrected Soluble Solids (Brix) of Processing Oranges and Grapefruit in Florida
Authors: Davies Frederick S. , Zalman Glenn R. , Stover Ed , Ciliento Scott
Published: December 2018

EcoLyst, a formulation of N-N-diethyl-2-(4-methylbenzyloxy) ethylamine hydrochloride containing 1 g/floz [4.5 oz/gal (33.8 g·L-1)] a.i., is a plant growth regulator that has been reported to increase soluble solids concentration (SSC) in juice oranges by 0.6% to 1.2%. Our objectives were to determine the effectiveness of EcoLyst application for increasing SSC in Florida oranges (Citrus sinensis) and grapefruit (C. paradisi), and to identify the optimum rate and time of application. Experiments were conducted for three seasons using `Hamlin,' `Pineapple,' and `Valencia' sweet oranges; and for two seasons using `Flame,' `Marsh,' and `Ray Ruby' grapefruit, all in commercial groves. EcoLyst was applied at 6 and 12 floz/acre (0.44 and 0.88 L·ha-1) for oranges and 16 and 32 ppm (mg·L-1) [effectively 9 and 18 floz/acre (0.66 and 1.32 L·ha-1) in most sprays] for grapefruit, and included Silwet L-77 adjuvant at 0.05%. Applications were made at several stages of development from prebloom to initial fruit set. In all cases, SSC was determined as juice corrected SSC, by adjusting refractometer readings based on titratable acidity. In 13 trials with sweet orange only five displayed significant increases in SSC (P ≤ 0.05) resulting from EcoLyst application. Two additional trials produced SSC increases significant at P < 0.10. Even where significant increases in SSC occurred they were typically observed in only one harvest and at one time of application and were always relatively low in magnitude (highest increase over controls was 0.38%). No rate or timing of EcoLyst application was consistently associated with best response, although eight of nine SSC increases observed in orange occurred with applications ranging from prebloom to 25% open flowers. Only one significant increase in SSC was observed in five trials with grapefruit. In these studies, increases in SSC resulting from EcoLyst application were neither sufficiently consistent nor large enough to justify a recommendation for commercial use in Florida citrus.
Effects of Preservatives and Cold Storage on Postharvest Performance of Deciduous Holly Branches
Authors: Jones Michelle L. , Cochran Kenneth K. , Anderson Gary A. , Ferree David C.
Published: December 2018

Deciduous holly branches were visually rated over a period of 5 weeks to evaluate differences in display life between various cultivars of winterberry (Ilex verticillata) and japanese winterberry (I. serrata) x winterberry. Holly branches were naturally defoliated and the postharvest performance of the cut branches was therefore based on the quality and longevity of the fruit. Chemical treatments including floral preservative, floral preservative plus silver, and anti-transpirant were also evaluated. `Bonfire' and `Sunset' had the highest ratings for marketability based on the longevity and quality of their fruit. `Bonfire' and `Winter Red' had the highest fruit density per stem. Treatment with floral preservatives significantly increased the display life of holly branches. Preservative plus silver delayed deterioration later in the study, presumably by delaying the senescence of the fruit. Anti-transpirant treatment did not decrease solution uptake by the holly stems. Cold storage of dry branches at 0.00 ± 1.11 °C (32.0 ± 2.0 °F) did not significantly reduce branch display life if held for 23 days or less. Cut branches of all cultivars had a longer display life when stuck in sand and left outdoors in a lath house than when rated in vase solutions indoors. This study indicates that deciduous holly branches provide an attractive alternative cut branch for both interior and outdoor holiday displays.
A New Technology That Determines Low-oxygen Thresholds in Controlled-atmosphere-stored Apples
Authors: DeLong John M. , Prange Robert K. , Leyte Jerry C. , Harrison Peter A.
Published: December 2018

HarvestWatch is a new chlorophyll fluorescence (F)-based technology that identifies the low-oxygen threshold for apple (Malus × domestica) fruit in dynamic low-O controlled atmosphere (DLOCA) storage environments [e.g., <1% oxygen (O2)]. Immediately following harvest, `Cortland', `Delicious', `Golden Delicious', `Honeycrisp', `Jonagold' and `McIntosh' fruit were cooled and loaded into 0.34 m3 (12.0 ft3) storage cabinets. A static controlled atmosphere (CA) regime of 1.5% O2, 1.5% carbon dioxide (CO2) and 3 °C (37.4 °F) [0 °C (32.0 °F) for `Delicious' and `Golden Delicious'] was established for the control fruit, while the low-O2 threshold was identified by a spike in the fluorescence parameter, Fα, as the O2 levels in the DLOCA cabinets were lowered below 1%. The DLOCA storages were then maintained at O2 levels of 0.1% to 0.2% above the threshold value for each cultivar, which returned Fα to prethreshold signatures. Quality measurements following 5 to 9 months of storage and a 7-day shelf life of 20 °C (68.0 °F), showed that the HarvestWatch fruit were generally firmer, had no incidence of superficial scald in `Cortland' and `Delicious' apples, and did not accumulate fermentative volatile compounds. The HarvestWatch system permits rapid, real-time measurements of the status of stored apple fruit in ultra low-O2 environments without the inconvenience of breaking the room's atmosphere. Our results indicate that HarvestWatch facilitates what may be the highest possible level of fruit quality retention in long-term, low-O2 apple storage without the use of scald-controlling or other chemicals before storage.
Consumer Survey Identifies Plant Management Awareness and Added Value of Dogwood Powdery Mildew Resistance
Authors: Klingeman William E. , Eastwood David B. , Brooker John R. , Hall Charles R. , Behe Bridget K. , Knight Patricia R.
Published: December 2018

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.
Economics of Fruit Thinning: A Review Focusing on Apple and Citrus
Authors: Davis Kathy , Stover Ed , Wirth Ferdinand
Published: December 2018

Hundreds of fruit thinning experiments have been reported for various fruits including apple (Malus × domestica) and citrus (Citrus spp.). Unfortunately, very few of these reports attempt to evaluate the economic implications of thinning. Researchers routinely report significant cropload reduction accompanied by an increase in fruit size. Although these are crucial responses to thinning, they are not always associated with an increase in crop value, which is the commercial justification for thinning. The few economic studies summarized in this review illustrate that the economic effects of fruit thinning vary widely, and successful thinning often reduces returns to the grower, at least in the year of treatment. It is important to quantify the economic benefits of thinning and identify croploads that balance the trade-off between yield and fruit size to provide optimal crop value. Future thinning research should report total yields and fruit size distributions to permit economic assessments and comparisons of treatments.
Performance of Fresh-market Cabbage Hybrids during the Cool Season in a Subtropical Region
Authors: Morales-Payan J. Pablo , Stall William M.
Published: December 2018

A field study was conducted in the Constanza Valley [1234 m (4048.6 ft) above sea level, loam soil, average temperature 14.7 to 25.0 °C (58.46 to 77.00 °F), photoperiod 11.2 to 12.6 hours] in the Dominican Republic, to compare the head characteristics, damage caused by diamondback moth larvae (Plutella xylostella), yield, and earliness of cabbage (Brassica oleracea Group Capitata) hybrids `Bravo', `Blue Vantage', `Express', `Genesis', `Green Cup', `Head Start', SW 2007, `Hildur' (SW 2008), `Gretania' (SW 2010), `Hampus' (SW 2011), and XPH 847, to the industry standard `Izalco'. `Genesis' had the highest yield among all the hybrids tested, including `Izalco'. The yield of `Izalco' did not significantly differ from the yield of `Blue Vantage', `Green Cup', `Express', XPH 847, SW 2007, and `Bravo'. However, `Bravo' and `Express' were more damaged by diamondback moth larvae. `Head Start', XPH 847, SW 2007, `Gretania', `Hildur', and `Hampus' were either significantly less productive or more susceptible to damage by the diamondback moth larvae than `Izalco'. In terms of yield, earliness, head shape, and losses due to the diamondback moth larvae, `Green Cup', `Blue Vantage' and `Genesis' were comparable or superior to `Izalco'.
Effect of Rootstock on Stem-end Rind Breakdown and Decay of Fresh Citrus
Authors: Ritenour Mark A. , Stover Ed , Boman Brian J. , Dou Huating , Bowman Kim D. , Castle William S.
Published: December 2018

Rootstock significantly affected the development of stem-end rind breakdown (SERB) on `Valencia' and navel oranges (Citrus sinensis), but not `Ray Ruby' grapefruit (C. paradisi) or `Oroblanco' (C. grandis × C. paradisi), and affected postharvest decay on navel orange, `Ray Ruby' grapefruit, `Oroblanco' and one of two seasons (2002) on `Valencia' orange. In `Valencia' and navel oranges, fruit from trees grown on Gou Tou (unidentified Citrus hybrid) consistently developed low SERB. `Valencia' oranges on US-952 [(C. paradisi × C. reticulata) × Poncirus trifoliata] developed high levels of SERB in both years tested. Relative SERB of fruit from other rootstocks was more variable. Navel oranges, `Ray Ruby' grapefruit, and `Oroblanco' fruit from trees on Cleopatra mandarin (C. reticulata) rootstock consistently developed relatively low levels of decay, and in navel this level was significantly lower than observed from trees on all other rootstocks. In three of five trials we observed significant differences between widely used commercial rootstocks in their effects on postharvest SERB and/or decay. Given the expanding importance of sales to distant markets, it is suggested that evaluations of quality retention during storage be included when developing citrus rootstocks and scion varieties for the fresh market.
Plant Population Affects Pumpkin Yield Components
Authors: Cushman Kent E. , Horgan Thomas E. , Nagel David H. , Gerard Patrick D.
Published: December 2018

Pumpkins (Cucurbita pepo, C. moshata) were grown in northern Mississippi during 2000 and 2001 for the purpose of more narrowly defining plant population recommendations for commercial production in the humid southeastern United States. Four plant populations were examined for `Aspen': 908, 1361, 2045, and 3068 plants/acre (2244, 3363, 5053, and 7581 plants/ha, respectively) and for `Howden Biggie': 605, 908, 1361, and 2045 plants/acre (1495, 2244, 3363, 5053 plants/ha, respectively). Plant populations were adjusted by varying in-row spacing while holding between-row spacing constant at 8 ft (2.4 m). Plant population significantly affected yield of `Aspen' and `Howden Biggie'. Linear and quadratic terms were significant for `Aspen', with maximum yield (ton/acre and fruit/acre) for the quadratic relationship occurring at about 2045 plants/acre. In contrast, yield of `Howden Biggie' decreased significantly (ton/acre) and nonsignificantly (fruit/acre) in a linear relationship as plant population increased from 605 to 2045 plants/acre. Plant population significantly affected fruit weight and size. As plant population increased, weight and size decreased slightly but significantly in a linear relationship for `Aspen' (lb/fruit and inch3/fruit) and `Howden Biggie' (lb/fruit). The quadratic relationship for `Howden Biggie' (inch3/fruit) was significant and the minimum value occurred at about 1361 plants/acre. Plant population significantly affected pumpkin yield components associated with plant productivity. As plant population increased, number and weight of fruit per plant decreased sharply in a quadratic relationship for `Aspen' (lb/ plant and fruit/plant) and `Howden Biggie' (lb/plant). The linear relationship for `Howden Biggie' (fruit/ plant) also decreased significantly. At the highest plant populations for `Howden Biggie', 40% of the plants did not produce marketable pumpkins. In conclusion, recommendations of optimum plant populations for a semi-vining cultivar such as `Aspen' should be centered on about 2045 plants/acre. Published recommendations from Kentucky appear sound, advocating plant populations within the range of 1360 to 2720 plants/acre (3361 to 6721 plants/ha). For a vining cultivar such as `Howden Biggie', recommendations can be as low as 605 plants/acre. Published recommendations from Kentucky and Georgia, along with those published in the Vegetable Crop Guidelines for the Southeastern U.S., advocate plant populations for vining cultivars of approximately 725 to 1465 plants/acre (1790–3620 plants/ha). Our results with `Howden Biggie', a cultivar that produces larger pumpkins than most other vining cultivars grown for the wholesale market, indicate that producers of vining cultivars should use plant populations from the lowest values of these recommendations or use even lower values. Our results also indicate that growers can control size and weight of pumpkins by varying plant population, with increasing populations resulting in a slight decrease of size and weight.
Quality of Modified Atmosphere Packaged `Hedelfingen' and `Lapins' Sweet Cherries
Authors: Padilla-Zakour O.I. , Tandon K.S. , Wargo J.M.
Published: December 2018

`Hedelfingen' and `Lapins' sweet cherries (Prunus avium) were stored in air or in two types of modified atmosphere (MA) bags (LifeSpan 204 and 208) at 3 °C (37.4 °F) and 90% relative humidity for 4 weeks. Various analytical and quality measurements were conducted weekly on `Hedelfingen' cherries, whereas on `Lapins' these were done initially and at the end of 4 weeks. For `Hedelfingen' cherries, there were differences in carbon dioxide (CO2) and oxygen (O2) composition within the MA bags, depending on the bag used. This resulted in slightly better cherry quality for the bag with lower O2 permeability (L204), which equilibrated at 4% to 5% O2 and 7% to 8% CO2. For `Lapins', the two MA bags showed concentrations of 9% to 10% O2 and 8% to 9% CO2 and similar final fruit quality. There was a significant weight loss for the control treatments over time (6% to 13%), whereas the MA treatments showed minimal losses. A higher incidence of cracking and decay was observed in MA treatments of `Hedelfingen' but not in `Lapins'. Control cherries had significant shriveling and browning of stems; MA-stored cherries had green and healthy stems after 4 weeks. No significant differences were observed in pH, acidity, soluble solids, firmness, and hue angle among the storage treatments. MA packaged cherries seemed to maintain better color than control cherries over time. Similarly, MA cherries had better appearance and eating quality after 4 weeks when compared to control cherries.
Evaluation of Winter-killed Cover Crops Preceding Snap Pea
Authors: Grimmer Orion P. , Masiunas John B.
Published: December 2018

Winter-killed cover crops may protect the soil surface from erosion and reduce herbicide use in an early planted crop such as pea (Pisum sativum). Our objective was to determine the potential of winter-killed cover crops in a snap pea production system. White mustard (Brassica hirta) produced the most residue in the fall but retained only 37% of that residue into the spring. Barley (Hordeum vulgare) and oats (Avena sativa) produced less fall residue but had more residue and ground cover in the spring. Greater ground cover in the spring facilitated higher soil moisture, contributing to higher weed numbers and weight and lower pea yields for oat and barley compared with a bare ground treatment. White mustard had weed populations and pea yields similar to the bare ground treatment. Within the weed-free subplot, no differences in pea yields existed among cover crop treatments, indicating no direct interference with pea growth by the residues. In greenhouse experiments, field-grown oat and barley residue suppressed greater than 50% of the germination of common lambsquarters (Chenopodium album) and shepherd's-purse (Capsella bursapastoris), while in the field none of the cover crop provided better weed control than the fallow.
Evaluation of Winegrapes in British Columbia: New Cultivars and Selections from Germany and Hungary
Authors: Reynolds Andrew G. , Cliff Margaret , Wardle Douglas A. , King Marjorie
Published: December 2018

Eighty-five cultivars, selections and clones of winegrapes (Vitis) from European breeding and selection programs were evaluated between 1993–95 in a randomized completeblock experiment. These included selections from Alzey, Freiburg, Geilweilerhof, Geisenheim, Weinsberg, and Würzburg (Germany); Hungary; and the former USSR. Vines were grown under an organic management regime that included sodium silicate sprays for powdery mildew (Uncinula necator) control and oil + detergent for insect control but with little to no nitrogen or other nutritional inputs. The Weinsberg cultivars Heroldrebe and Helfensteiner showed promise viticulturally and sensorially as alternatives to `Pinot noir'. Cultivars from Geisenheim (`Gm 7117-10' and `Gm 7117-26') and Würzburg (`Cantaro' and `Fontanara') appeared promising as `Riesling' alternatives; many displayed similar sensory characteristics to `Riesling', along with reasonable viticultural performance. Cultivars selected at Alzey (`Faberrebe'), Freiburg (`Nobling'), and Weinsberg (`Holder') displayed sensory characteristics superior to the standard cultivar Müller-Thurgau, with very intense muscat, pear, fig, and spicy aromas and flavors. Several muscat-flavored Hungarian white wine cultivars appeared to be superior viticulturally and sensorially to the standard `Csabagyongye'; these included `Kozma Palne Muscotaly', `Zefir', and `Zengo'. Miscellaneous red wine cultivars that showed promise included Geilweilerhof cultivar Regent, and Hungarian selections Kozma 55 and Kozma 525. Vine yields decreased substantially in the 3-year evaluation period, primarily due to lack of nitrogen. Many of these cultivars appeared to be highly adaptable to viticultural regions where cold winters and low heat units during fruit maturation presently restrict cultivar choices.
Full Moon Farm Builds High Tunnels: A Case Study in Site Planning for Crop Production Structures
Authors: Spaw Marci , Williams Kimberly A.
Published: December 2018

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.
Pesticide Spraying in Indian River Grapefruit: III. Opportunities for Improving Efficacy and Efficiency while Reducing Off-target Deposition
Authors: Stover Ed , Wilson Chris , Scotto Dominick , Salyani Masoud
Published: December 2018

Parts I and II of this series revealed substantial opportunities for improving spraying of Indian River citrus (Citrus spp.). In this segment of our work we develop guidelines for growers to select the spray parameters providing an optimal balance between efficiency and efficacy while minimizing environmental contamination.

It is proposed that these guidelines could be codified in a simple expert system to make them easier to use. We propose that understanding limiting conditions may be the key to choosing spray options. Wind is a major factor influencing spray deposition and offtarget drift. Based on weather records, wind speeds below 5 mph (8.0 km·h-1) are only routinely observed from 2000 HR until 0800 HR, making night spraying a good choice for low-volume applications. The importance of adjusting sprayer set-up for individual groves is demonstrated, with economic estimates of the cost of failing to make these adjustments. Routine use of careful sprayer adjustments is also likely to reduce off-target drift. Improvements in equipment and spray chemicals are also discussed. Use of non-orchard buffer areas and/or windbreaks appear to offer considerable opportunity for reducing off-site spray movement.
Long-term Field Performance of Primocane Fruiting Raspberry Cultivars in New York
Authors: Weber C.A. , Maloney K.E. , Sanford J.C.
Published: December 2018

The performance of 11 primocane fruiting raspberry (Rubus idaeus) cultivars was evaluated based on yield and fruit weight from the first three seasons compared to the eighth and ninth seasons, respectively. Plot vigor and cane density was evaluated in the eighth season. `Prelude', `Caroline', and `Heritage' did not show a decline in yield in the eighth season compared to the first three seasons. `Kiwigold', `Graton Gold' (sold as `Goldie'), `Watson' (sold as `Ruby'), `Autumn Bliss', `Anne, and `Amity' had substantial yield decreases from early production seasons ranging from -30% to -82%. `Kiwigold' had the highest yield of 4015 kg·ha-1 (3582.2 lb/acre) in the eighth season followed by `Caroline' at 3649 kg·ha-1 (3255.6 lb/acre), `Heritage' at 3614 kg·ha-1 (3224.4 lb/acre), and `Prelude' at 3591 kg·ha-1 (3203.9 lb/acre). Fruit weight did not vary significantly among years, but there were differences among cultivars. In the ninth season, `Ruby' had the largest fruit at 3.1 g (0.11 oz), followed by `Autumn Bliss' at 2.9 g (0.10 oz), and `Caroline' and `Prelude' at 2.8 g (0.10 oz). `Summit', `Goldie', and `Rossana' had the smallest fruit at 1.5 g (0.05 oz). `Goldie' was the most vigorous cultivar and `Anne' the least in the eighth season based on vigor ratings. `Rossana' had the highest cane density at 41.6 canes/m2 (3.86 canes/ft2). Seven of 11 cultivars had cane density of 32 canes/m2 (3.0 canes/ft2) or higher, which is sufficient to produce acceptable yields in cultivars suited to the region. Overall, `Prelude', `Caroline' and `Heritage' and its sports, `Kiwigold' and `Goldie', show the most potential for long production cycles in climates similar to western New York state.
Graduate Student Professional Development: A Case Study
Authors: Pérez Hector Eduardo , Kobayashi Kent D.
Published: December 2018

Graduate students within the Tropical Plant and Soil Sciences Department at the University of Hawaii at Manoa developed a program that addressed their concerns regarding career enhancement and planned a Professional Development Seminar Series. Students identified topics related to enhancing their overall graduate experience and professional development, such as ethics in research, leadership in graduate school and beyond, interviewing skills, and writing critically for publications. Experts from the University of Hawaii and business communities presented 35- to 40-minute seminars on the various topics. Expectations of the students included participation in discussion sessions and completion of a critical thinking exercise after each presentation. Course evaluations revealed that the new seminar series was considered to be as effective as established courses within the department. On a scale from 1 = strongly disagree to 5 = strongly agree, students learned to value new viewpoints [4.2 ± 0.8 (mean ± SD)], related what they learned in class to their own experiences (4.5 ± 0.8), and felt the course was a valuable contribution to their education (4.4 ± 0.9). Students suggested offering the course during fall semesters to incoming students, reinforcing of the critical thinking exercise, and making the course mandatory for first-year graduate students.
Total Quercetin Content in Onion: Survey of Cultivars Grown at Various Locations
Authors: Lombard Kevin A. , Geoffriau Emmanuel , Peffley Ellen B.
Published: December 2018

Because of potential benefits on human health, the content of quercetin, the major flavonol found in onion (Allium cepa), could become a selection trait in breeding programs. Total flavonol concentration in onion was examined by spectrophotometric analysis at 374 nm in three long-day hybrid cultivars grown at three locations (Parma, Idaho; Grand Rapids, Mich; Elba, N.Y.), and in three shortday hybrid cultivars grown at one location in Georgia in three different fields. Mean total flavonol concentrations for long-day hybrids ranged from 176 to 232 mg·kg-1 (ppm) fresh weight and 110 to 173 mg·kg-1 fresh weight among short-day cultivars. No significant effect of location (state or field) was detected (P > 0.05). A significant (P > 0.05) cultivar by field interaction was detected in the short-day experiment, with the hybrid `Sweet Vidalia' showing significant differences among fields. Overall, our results suggest that quercetin content in onion, as expressed by the total flavonol content, does not vary depending on the growing origin, and therefore could be evaluated effectively in breeding or commercial material.
Improving Irrigation Water Use in Container Nurseries
Authors: Mathers Hannah M. , Case Luke T. , Yeager Thomas H.
Published: December 2018

As limitations on water used by container nurseries become commonplace, nurseries will have to improve irrigation management. Several ways to conserve water and improve on the management of irrigation water applied to container plants are discussed in this review. They include 1) uniform application, 2) proper scheduling of irrigation water, 3) substrate amendments that retain water, 4) reducing heat load or evaporative loss from containers, and 5) recycling runoff water.
Involvement of Nursery Operators and Educators in Development of Fertilization and Irrigation Regulation
Authors: Yeager Thomas H.
Published: December 2018

Nursery operators had the opportunity to participate in a process to develop a voluntary incentive-based regulation that consummated the consensus of nursery and regulatory personnel regarding the best fertilization and irrigation cultural practice information available for producing plants in containers. Florida Department of Agriculture and Consumer Services (FDACS), which has statutory authority to develop and adopt practices by administrative rule, administered the process, and they relied on university extension personnel to provide education so nursery operators would be prepared to implement practices consistent with the regulation. Nursery operators who voluntarily implemented these practices received a waiver of liability from the recovery costs associated with the cleanup of groundwater contaminated with nitrate nitrogen if each of the following activities had taken place: 1) a notice of intent was filed with FDACS to implement accepted practices; 2) practices based on consensus of the industry were used and guidelines followed; and 3) fertilization and irrigation records were maintained. Participation in an industry-driven regulatory program where nursery operators agreed to use the best cultural practices available prior to the identification of a specific groundwater issue was a significant proactive step for the industry.
More Plant per Gallon: Getting More Out of Your Water
Authors: Warren Stuart L. , Bilderback Ted E.
Published: December 2018

Irrigation of container-grown ornamental crops can be very inefficient, using large quantities of water. Much research was conducted in the 1990s to increase water efficiency. This article examined water management, focusing on three areas: water application efficiency (WAE), irrigation scheduling, and substrate amendment. Increases in WAE can be made by focusing on time-averaged application rate and pre-irrigation substrate moisture deficit. Irrigation scheduling is defined as the process of determining how much to apply (irrigation volume) and timing (when to apply). Irrigation volume should be based on the amount of water lost since the last irrigation. Irrigation volume is often expressed in terms of leaching fraction (LF = water leached ÷ water applied). A zero leaching fraction may be possible when using recommended rates of controlled-release fertilizers. With container-grown plant material, irrigation timing refers to what time of day the water is applied, because most container-grown plants require daily irrigation once the root system exploits the substrate volume. Irrigating during the afternoon, in contrast to a predawn application, may increase growth by reducing heat load and minimizing water stress in the later part of the day. Data suggest that both irrigation volume and time of application should be considered when developing a water management plan for container-grown plants. Amending soilless substrates to increase water buffering and reduce irrigation volume has often been discussed. Recent evidence suggests that amending pine bark substrates with clay may reduce irrigation volume required for plant production. Continued research focus on production efficiency needs to be maintained in the 21st century.
Leaf Spectral Reflectance for Nondestructive Measurement of Plant Nutrient Status
Authors: Davenport J.R. , Stevens R.G. , Perry E.M. , Lang N.S.
Published: December 2018

The ability to monitor plant nutrient status of high value horticultural crops and to adjust seasonal nutrient supply via fertilizer application has economic and environmental benefits. Recent technological advances may enable growers and field consultants to conduct this type of monitoring nondestructively in the future. Using the perennial crop apple (Malus domestica) and the annual crop potato (Solanum tuberosum), a hand-held leaf reflectance meter was used to evaluate leaf nitrogen (N) status throughout the growing season. In potato, this meter showed good correlation with leaf blade N content. Both time of day and time of season influenced leaf meter measurement, but leaf position did not. In apple, three different leaf meters were compared: the leaf spectral reflectance meter and two leaf greenness meters. Correlation with both N rate and leaf N content were strongest for the leaf reflectance meter early in the season but nonsignificant late in the season, whereas the leaf greenness meters gave weak but significant correlations throughout the growing season. The tapering off of leaf reflectance values found with the hand-held meter is consistent with normalized difference vegetation index (NDVI) values calculated from satellite images from the same plots. Overall, the use of leaf spectral reflectance shows promise as a tool for nondestructive monitoring of plant leaf status and would enable multiple georeferenced measurements throughout a field for differential N management.
Controlled-release Fertilizers for Vegetable Production in the Era of Best Management Practices: Teaching New Tricks to an Old Dog
Authors: Simonne Eric H. , Hutchinson Chad M.
Published: December 2018

Best management practices (BMPs) for vegetable crops are under development nationwide and in Florida. One goal of the Florida BMP program is to minimize the possible movement of nitrate-nitrogen from potato (Solanum tuberosum) production to surface water in the St. Johns River watershed without negatively impacting potato yields or quality. Current fertilizer BMPs developed for the area focus on fertilizer rate. Controlled-release fertilizers (CRF) have long been a part of nutrient management in greenhouse and nursery crops. However, CRFs have been seldom used in field-vegetable production because of their cost and release characteristics. Nutrient release curves for CRFs are not available for the soil moisture and temperature conditions prevailing in the seepage-irrigated soils of northern Florida. Controlled-leaching studies (pot-in-pot) in 2000 and 2001 have shown that plant-available nitrogen (N) was significantly higher early in the season from ammonium nitrate, calcium nitrate and urea compared to selected CRFs. However, N release from off-the-shelf and experimental CRFs was too slow, resulting in N recoveries ranging from 13% to 51%. Cost increase due to the use of CRFs for potato production ranged from $71.66 to $158.14/ha ($29 to $64 per acre) based on cost of material and N application rate. This higher cost may be offset by reduced application cost and cost-share pro-grams. Adoption of CRF programs by the potato (and vegetable) industry in Florida will depend on the accuracy and predictability of N release, state agencies' commitment to cost-share programs, and CRFs manufacturers' marketing strategies. All interested parties would benefit in the development of BMPs for CRFs.
Transplanting Specimen Palms: A Review of Common Practices and Research-based Information
Authors: Pittenger Dennis R. , Hodel Donald R. , Downer A. James
Published: December 2018

Successful reestablishment of transplanted palms [members of the Arecaceae (Palmae)] depends on rapid regeneration of roots, avoiding injury and desiccation of the trees during transit and handling, and maintaining sufficient soil moisture around the root balls after transplanting. Since landscape contractors and nurserymen spend considerable resources and labor transplanting specimen palms, understanding the seasonality of palm root growth, how palm roots respond when trees are dug, and the effects of canopy manipulation during transplanting will enable them to adopt effective and rational transplanting practices. This manuscript provides a review of research findings that can be applied to maximize reestablishment of transplanted specimen palms.
Using Intercept and Telephone Survey Methods to Assess Consumer Awareness and Purchasing of Pennsylvania Gardener Selects
Authors: Wehry Rebecca H. , Kelley Kathleen M. , Berghage Robert D. , Sellmer James C.
Published: December 2018

A consumer-research study was conducted in two locations in Pennsylvania utilizing two survey methods: intercept and telephone. This study was designed to assess: 1) what national brand name plant material participants purchased in the past; 2) the consumer's awareness of the Pennsylvania Gardener Selects (PGS) program; and 3) the gardening habits and demographics of Pennsylvania gardeners. The first survey was an intercept survey of 390 self-selected participants who attended Ag Progress Days (APD), a 3-day outdoor educational event and farm implement show from 20-22 Aug. 2002. The second survey was a telephone survey of 500 randomly selected households in the metro-Philadelphia area and was conducted from 20 Aug. through 17 Sept. 2002. Only responses from Pennsylvania gardeners were used in the analysis of the results. A comparison of survey results indicated that metro-Philadelphia-area participants spent more on plant material annually than APD participants, who primarily resided in rural locations. The results showed that metro-Philadelphia-area gardeners tend to live in single-adult households and have one or more children, whereas APD gardeners tend to live in a household with two or more adults and have no children. Eighty-one percent of APD participants and 62% of metro-Philadelphia participants reported that they would be willing to purchase plant material that has been evaluated and chosen as being outstanding for use in all areas of Pennsylvania, a premise for the PGS program.
Influence of Soil and Nutrient Management on Growth and Quality of Collards
Authors: Mylavarapu R.S. , Smith J.P. , Munoz F.
Published: December 2018

High temperature and humidity during summer months in the southeastern U.S., in addition to crop nutritional status, are suggested to be the primary reasons for tipburn incidence in collards (Brassica oleracea Acephala Group) adversely affecting their marketability. A 2-year study was conducted to evaluate the efficiency of grower's standard practice (GSP), GSP + gypsum, and a programmed-release fertilizer (PRF) under conventional and deep tillage on collard yield and tipburn incidence. Subsoiling significantly increased yield over conventional tillage. Nutrient supply through PRF did not increase the yields; however, it resulted in either similar or higher levels of macro- and micronutrient levels both in soils and collard tissue compared to GSP and GSP + gypsum treatments. The occurrence of tipburn in collards is dependent on several factors, including nutritional, physiological, and environmental stresses. Regression analyses of tipburn ratings at harvest time and the soil and tissue nutrient content suggested that 47% of the variation could be attributed to soil and tissue levels of sulfur (S), zinc (Zn), and phosphorus (P). It is important, therefore, to ensure an optimum supply of nutrients to the plants to maintain the quality of the yields. The advantage of PRF in sandy soils, and identification of other factors affecting the tipburn in collards should be further investigated.
Bur Seeding Rate Effects on Turf-type Buffalograss Establishment
Authors: Shearman R.C. , Budak H. , Severmutlu S. , Gaussoin R.E.
Published: December 2018

Little or no research information exists in the literature regarding recommended seeding rates of improved turf-type buffalograss (Buchloë dactyloides) cultivars, like `Bowie'. This research was conducted to determine the effect of bur seeding rate on turfgrass establishment of `Bowie' buffalograss. Two experiments were initiated on 21 July 2002 on diverse sites at the John Seaton Anderson Turfgrass Research Facility located near Mead, Nebr. Bur seeding rate effects on turfgrass quality, shoot density and cover, and seedling density were evaluated during the 2002 and 2003 growing seasons. Burs were seeded at 2.5, 5, 10, 20, and 40 g·m–2 (0.51, 1.0, 2.0, 4.1, and 8.2 lb/1000 ft2) of pure live seed (PLS). Turfgrass quality ratings increased linearly with bur seeding rate during the first growing season. However, by early in the second growing season, the response was quadratic with little or no difference in quality between 10 and 40 g·m–2. Turfgrass cover ratings responded in a similar manner to the quality ratings. Buffalograss is reported to establish slowly, taking more than one growing season to establish an acceptable level. In this study, `Bowie', a turf-type cultivar, had acceptable turfgrass quality (≥5.0) and cover (≥75%) ratings by 3 months at bur seeding rates of 5 to 40 g·m–2 of PLS, and acceptable quality and cover ratings were obtained at slightly over 1 month at rates of 20 to 40 g·m–2. These results indicate that bur seeding rates of 20 to 40 g·m–2 are advisable where rapid establishment of turf-type buffalograss is desired, and rates as low as 5 g·m–2 can be used when establishment within two growing seasons is deemed reasonable.