bluuebunny/crossref_metadata_2025 huggingface dataset:
Sensory and Storage Evaluation of Nectarine and White Peach Breeding Lines
Authors: Perkins-Veazie P. , Collins J.K. , Clark J.R.
Published: October 2019

Promising white peach and nectarine selections, many with nonmelting flesh, from the Univ. of Arkansas breeding program were evaluated for fruit quality and flavor. About 20 kg of fruit, consisting of mature ripe and ripe stages, were harvested from 4- to 7-year-old trees in Arkansas and transported to Lane, Okla. Fruit were divided into two boxes per selection. One box was held at 5 °C for 8 days, then transferred to 20 °C for 4 days to induce chilling injury and was evaluated for storage quality. The other box was held at 20 °C for 4 days and fruit used for taste panels. Of the 14 nectarine and 12 white peach selections evaluated, one nectarine and four white peach selections had slight chilling injury. Flesh firmness of selections after storage ranged from 6 to 50 N. Taste panelist scores indicated that sweetness was associated with peach flavor in both nectarines and white peaches and that overall acceptability was dependent on sweetness, peach flavor, and low tartness. Ten of the white peach selections were equal to or better in overall acceptability compared to `Summer Pearl' and `Carolina Belle' cultivars included in the study. Panelists did not consider firm texture to be detrimental to overall acceptability. Results indicate that many of the breeding lines used in this study had fruit equal to or better than currently available cultivars in storage life, firmness, and sweetness.
Photosynthetic Light Response of Six Clonal Selections of the Sweet Potato Cultivar `Beauregard'
Authors: Baker Jeffrey T. , Baker Marvin L. , Earhart D. Ron , Pike Leonard M. , Yoo Kil S. , Horns Roger
Published: October 2019

Eight individual potatoes, exhibiting a wide range of quality characteristics, were cloned at the Texas A&M Vegetable Improvement Center, College Station, Tex., in order to produce a large number of slips for field trials. Leaf photosynthetic light response for six of these clonal selections was determined during a greenhouse experiment conducted at the Texas A&M Univ. Agricultural Research and Extension Center at Overton, Tex. Photosynthesis data were fit to a rectangular hyperbola in order to estimate light saturated leaf photosynthetic rate (Amax), quantum efficiency (QE), and dark respiration rate (Rd). Significant differences (P ≥ 0.05) were detected in all three of these parameter estimates among the six clonal selections. Parameter estimates ranged from 23.4 to 28.8 μmol (CO2) m-2·s-1, 0.056 to 0.071 mol (CO2)/mol (photons), and –0.9 to –2.0 μmol (CO2) m-2·s-1 for Amax, QE, and Rd, respectively. However, these differences were not clearly related to quality characteristics determined for these clones in field trials.
Effect of GA3 and Pollination on Fruit Set and Development in Rabbiteye Blueberry
Authors: Cano-Medrano Raquel , Darnell Rebecca L.
Published: October 2019

To determine if multiple applications of GA3 would increase size of parthenocarpic fruit, and to assess the interaction between GA3 applications and pollination, `Beckyblue' rabbiteye blueberry (Vaccinium ashei Reade) flowers were treated with single or multiple applications of GA3 alone or in combination with full or partial pollination. Single or multiple applications of GA3 resulted in similar or increased fruit set compared with pollination, and increased fruit set compared with no pollination. GA3 applications decreased fruit mass and increased the fruit development period in comparison with pollination alone. Multiple, late applications of GA3 were ineffective in overcoming these effects. Partial (nonsaturating) pollination resulted in an average fruit set of 60%, while set following GA3 treatment in combination with full or partial pollination averaged 85%. Fruit mass was greater in the full pollination ±GA3 treatments than in all other treatments. The number of large seeds and seed mass per fruit were greatest in the full pollination treatment, and were significantly decreased by all treatments in which GA3 and/or partial pollination were used; however, there were no concomitant effects of GA3 in delaying the fruit development period. Our results indicate that under optimal pollination conditions, no detrimental effects of GA3 applications on fruit set, fruit size, or fruit development period in blueberry are to be expected, even though GA3 reduces seed number and seed mass. Furthermore, GA3 applications appear to be beneficial in increasing fruit set under suboptimal pollination conditions, although smaller fruit are to be expected under such conditions. Chemical name used: gibberellic acid (GA3).
Use of an Antitranspirant to Minimize Winter Injury on Nonflooded Cranberry Bogs
Authors: Sandler Hilary A.
Published: October 2019

The benefit of applying an antitranspirant for protection of cranberry (Vaccinium macrocarpon Ait.) vines exposed to desiccating conditions was evaluated at four different sites, two sites per year, for a period of 1 year each. Overall, plots receiving one fall application of an antitranspirant produced more berries and greater total fruit mass the following year than did nontreated plots. Overall dry leaf mass was not significantly affected. At one site, treated plots had more flowering uprights and more flowers per upright per unit of ground area than the nontreated plots. For cranberry growers who cannot maintain a winter flood, one fall application of pinolene (Vapor Gard) may offer some protection against winter injury. Further research is needed to document long-term yield effects as well as to clarify the role of the antitranspirant in protecting exposed vines and floral buds against adverse winter conditions. Chemical name used: di-1-p-menthene (pinolene).
Potato Yield and Quality Response to Deficit Irrigation
Authors: Shock C.C. , Feibert E.B.G. , Saunders L.D.
Published: October 2019

Four potato (Solanum tuberosum L.) varieties were grown under four season-long sprinkler irrigation treatments in three successive years (1992-94) on silt loam soil in eastern Oregon. The check treatment was irrigated when soil water potential (SWP) at the 0.2-m depth reached -60 J·kg-1 and received at most the accumulated evapotranspiration (Etc) to avoid exceeding the water-holding capacity of the top 0.3 m of soil. The three deficit irrigation treatments were irrigated when SWP at the 0.2-m depth reached -80 J·kg-1 and had the following percent of the accumulated Etc applied at each irrigation: 1) 100%, 2) 70%, and 3) 70% during tuber bulking with 50% thereafter. Based on regression of applied water over 3 years, potatoes lost both total and U.S. No. 1 yields when irrigations were reduced. Based on regression on applied water, when irrigation was reduced gross revenues declined more than production costs, resulting in a reduction in profits. Leaching potential, as determined by the SWP treatments, was low for all treatments. The results of the study suggest that deficit irrigation of potatoes in the Treasure Valley of Oregon would not be a viable management tool, because the small financial benefits would not offset the high risks of reduced yields and profits from the reduced water applications.
Flowering of Herbaceous Perennials under Various Night Interruption and Cyclic Lighting Treatments
Authors: Runkle Erik S. , Heins Royal D. , Cameron Arthur C. , Carlson William H.
Published: October 2019

Six long-day species of herbaceous perennials were grown under six night-interruption (NI) photoperiod treatments to determine their relative effectiveness at inducing flowering. Photoperiods were 9-hour natural days with NI provided by incandescent lamps during the middle of the dark period for the following durations: 0.5, 1, 2, or 4 hours; 6 minutes on, 54 minutes off for 4 hours (10% or 6/54 cyclic lighting); or 6 minutes on, 24 minutes off for 4 hours (20% or 6/24 cyclic lighting). For five species, the experiment was repeated with more mature plants; for the sixth, Rudbeckia fulgida Ait. `Goldsturm', following a cold treatment of 8 weeks at 5 °C. The species generally showed a quantitative flowering response to the NI duration until a saturation duration was reached; as the length of the uninterrupted night break increased, flowering percentage, uniformity, and number and plant height increased and time to flower decreased. Minimum saturation durations of NI were 1 hour for Coreopsis grandiflora Hogg ex Sweet `Early Sunrise' and Hibiscus moscheutos L. `Disco Belle Mixed', 2 hours for Campanula carpatica Jacq. `Blue Clips' and Coreopsis verticillata L. `Moonbeam', and 4 hours for unchilled R. fulgida `Goldsturm'. Echinacea purpurea Moench `Bravado' flowered similarly across all lighting treatments. The 6/24 cyclic lighting regimen induced flowering comparable to that under a continual 4-hour NI for four of the six species and the cold-treated R. fulgida `Goldsturm'. Flowering under the 6/54 regimen was generally incomplete, nonuniform, and delayed compared to that under saturation duration treatments. Three of five species flowered earlier when more mature plants were placed under the NI treatments. Cold-treated R. fulgida `Goldsturm' flowered more rapidly than unchilled plants and the saturation duration of NI decreased to 1 hour.
Effects of Fertilizer Concentration and Minimum-leach Drip Irrigation on the Growth of New Guinea Impatiens
Authors: Lang Harvey J. , Pannkuk Timothy R.
Published: October 2019

New Guinea impatiens `Barbados' (Impatiens ×hawkeri) were fertilized with solutions containing N at 6, 12, or 18 mmol·L-1 delivered from a drip irrigation system with either minimum leaching or standard leaching (0.3 to 0.4 leaching fraction). Irrigation was monitored and controlled by computers using microtensiometers placed in representative pots of each treatment. In two separate experiments, growth index, fresh mass, and dry mass were dependent upon both fertilizer concentration and irrigation treatment. Maximum growth overall was achieved at 12 mmol·L-1 N regardless of irrigation treatment; however, standard-leached plants receiving N at both 6 and 18 mmol·L-1 produced larger plants than did similarly fertilized minimum-leached plants. Leaf scorch, spotting, or marginal necrosis did not occur in any of the treatments. Leaf N, P, and K concentrations were highest in plants treated with N at 18 mmol·L-1, but Ca, Mg, and several micronutrients were highest in plants at 6 mmol·L-1 N. At the end of the cropping period for both experiments, growing medium electrical conductivity (EC) in the uppermost one-third layer of the pot was two to four times as high as that in the bottom two-thirds (root zone) layer. Root-zone EC ranged from 0.6 to 4.0 dS·m-1 and increased as fertilizer concentration increased. Standard leaching had little effect in reducing root-zone EC except in plants fertilized with N at 18 mmol·L-1. All plants continued to perform well and flower after 4 weeks in a simulated interior environment. Minimum-leach drip irrigation used ≈35% less solution than did standard irrigation with leaching, and eliminated N runoff.
Late-season Applications of Various Nitrogen Sources Affect Color and Carbohydrate Content of `Tiflawn' and Arizona Common Bermudagrass
Authors: Goatley J.M. , Maddox V.L. , Hensler K.L.
Published: October 2019

Bermudagrass turfs in the southern United States often receive late growing season applications of nitrogen (N) in order to sustain turfgrass color prior to dormancy, even though such applications might increase winterkill potential. Yearly research trials were initiated in the last week of Sept. 1989 to 1991 at Mississippi State Univ. to evaluate fall and spring color responses and rhizome levels of total nonstructural carbohydrates (TNC) of `Tiflawn' and Arizona (AZ) Common bermudagrass [Cynodon dactylon L. (Pers.)] treated with various N sources delivering N at 98 kg·ha-1 in a single application. The fertilizers were ammonium nitrate (AN), sulfur-coated urea (SCU), a natural organic (`Milorganite', NO), isobutylidene diurea (IBDU), ureaformaldehyde (UF), and methylene urea (MU). Color responses from N fertilization were most prominent in the fall except when there was an early frost event in Oct. 1990. The most rapid greening response and highest color ratings were consistently observed for the water-soluble AN. Of the slow-release sources, SCU, MU, and IBDU provided color responses as long as temperatures remained warm enough to promote bermudagrass growth. The NO source provided an unexpected, significant greening response in Oct. 1989 and 1991 on `Tiflawn', but not on AZ Common. The UF consistently provided the lowest color ratings. There were virtually no differences in TNC levels between N treatments for either grass. At no time was there any indication that N fertilization increased bermudagrass winterkill potential; to the contrary, the predominant responses were better fall and spring color than the nontreated control.
Use of a Resistant Pepper as a Rotational Crop to Manage Southern Root-knot Nematode
Authors: Thies J.A. , Mueller J.D. , Fery R.L.
Published: October 2019

A 3-year field study was conducted at Blackville, S.C., to evaluate the potential of using resistant pepper (Capsicum annuum L.) cultivars as a rotation crop for managing the southern root-knot nematode [Meloidogyne incognita (Kofoid and White) Chitwood]. The experiment was a split-plot with main plots arranged in a randomized complete-block design. In 1993, the entire experimental site was infested with M. incognita by inoculating a planting of susceptible PA-136 cayenne pepper with eggs of M. incognita race 3. In 1994, the main plots were planted to either highly resistant `Carolina Cayenne' or its susceptible sibling line PA-136. In 1995, `Carolina Cayenne' and the susceptible bell cultivars California Wonder and Keystone Resistant Giant were grown as subplots in each of the original main plots. `Carolina Cayenne' plants were unaffected by the previous crop. Previous cropping history, however, had a significant impact on the performance of the bell cultivars; the mean galling response was less (P < 0.01) and the yield was 2.8 times greater (P < 0.01) in the main plots previously cropped with `Carolina Cayenne' than in those previously cropped with PA-136. These results suggest that resistant pepper cultivars have considerable merit as a rotation crop for managing M. incognita infestations in soils used for growing high-value vegetables.
Comparison of Devices for Measuring Cherry Fruit Firmness
Authors: Mitcham E.J. , Clayton M. , Biasi W.V.
Published: October 2019

The performance of three relatively new nondestructive cherry firmness devices and a penetrometer were evaluated and compared with the firmness testing performance of an Instron Universal Testing Machine. The inherent variability of the nondestructive devices was estimated by repeated measurement of a uniform, symmetrical, and resilient rubber ball. Analysis of residuals from correlations between each device and the Instron from firmness testing on common samples of sweet cherries (Prunus avium L.) confirmed the relative variability of the nondestructive devices, and estimated measurement reliability of the penetrometer. Subjective firmness sensing by compression of cherries between the fingers of human evaluators proved to be less reliable than the devices tested. Sweet cherry firmness correlated reasonably well with skin color, with the strength of the correlations from each device agreeing with device ranking in terms of firmness measurement reliability. Firmness correlated poorly with soluble solids, titratable acidity, and specific gravity; soluble solids correlated well with specific gravity; and skin color correlated reasonably well with both soluble solids and specific gravity. Fruit surface pit volume, induced by a specific impact force from a ball bearing, correlated relatively well with fruit firmness measured by the penetrometer, but poorly or inconsistently with measurements from the remaining firmness devices.
Time of Harvest and Method of Storage Affect Granulation in Grapefruit
Authors: Burns Jacqueline K. , Albrigo L. Gene
Published: October 2019

Temporal studies were conducted from mid- to late-harvest season of `Ruby Red' grapefruit (Citrus paradisi Macf.) to evaluate the effect of on- and off-tree storage, fruit size, and juice vesicle position on the development of granulation. Juice vesicle fresh and dry masses were highest at the stem and stylar positions of the fruit section and were not affected significantly by time of harvest or by storage. Juice vesicles isolated from each position were subjectively evaluated for the presence of granulation. Granulation was highest in stylar juice vesicles obtained from large fruit (≈600 g) that were harvested late in the season (March and May) and stored in air at 21 °C for 60 days. Large fruit harvested in March and May and examined immediately, and fruit harvested in January and stored for 60 days had low granulation scores. Thus, fruit remaining on the tree until May are less susceptible to the disorder than those harvested in March and held in storage until May. Levels of alcohol-insoluble solids (AIS), largely composed of pectins and other cell wall materials, were significantly higher in juice vesicles that were granulated. The results suggest that storage itself was not responsible for the marked accumulation of AIS in granulated juice vesicles. Rather, some interaction of fruit size with maturation, as well as other factors such as tree age and rootstock, likely contributed to the development of granulation.
Interactions of Flower Stage, Cultivar, and Shipping Temperature and Duration Affect Pot Rose Performance
Authors: Cushman Lisa Chen , Pemberton H. Brent , Miller J. Creighton , Kelly John W.
Published: October 2019

Simulated shipping (storage) experiments were conducted to determine the effects of shipping temperature and duration on flower longevity and leaf abscission of pot rose Rosa L. `Meijikatar' (= Orange Sunblaze) and `Meirutral' (= Red Sunblaze). In addition, three flower stages (1 = tight bud, calyx not reflexing; 2 = showing color, calyx reflexing, no petals reflexed; 3 = full color, petals beginning to reflex, traditional bud stage) were selected immediately prior to storing plants at 4, 16, or 28 °C for 2, 4, or 6 days. The experiment was conducted during the summer and repeated during the winter. Evaluations were made in an interior environment at 21 °C for both experiments. `Meirutral' exhibited longer poststorage longevity and less leaf abscission than `Meijikatar' in both experiments. Flowers of both cultivars advanced by about one stage during storage at temperatures greater than 4 °C in summer, but developed more slowly in winter. Results from both experiments showed that plants stored at 4 °C had the longest poststorage floral longevity, the best flower quality, and the least leaf abscission, regardless of cultivar, storage duration, or flower stage at the beginning of storage. For plants stored at 16 °C, floral longevity decreased and leaf abscission increased when the duration was longer than 4 days. At 28 °C, flower longevity decreased and leaf abscission increased, especially at durations longer than 2 days. In the winter experiment, there was no leaf abscission on plants placed in the dark at 21 °C and watered during storage treatments lasting up to 6 days. In the summer experiment, the younger the flower, the more it was negatively affected by high storage temperature. Overall, poststorage floral longevity was longer in the summer than the winter experiment.
Life Cycle Assessment: A Tool for Determining the Environmental Impact of Horticultural Crop Production
Authors: Ingram Dewayne L. , Fernandez R. Thomas
Published: October 2019

System-level research has resulted in significant advancements in horticultural crop production. Contributions of individual components to production efficiency, cost, and environmental impact have been a focus of such research. Public awareness of the environmental impact of products and services is increasing. Life cycle assessment (LCA) is a tool to study horticultural crop production systems and horticultural services and their individual components on environmental impacts such as the carbon footprint, stated as global warming potential. This manuscript introduces LCA and describes how this tool can be used to generate information important to the industry and consuming public.
Microclimate Modification Using Eco-friendly Nets for High-quality Tomato Transplant Production by Small-scale Farmers in East Africa
Authors: Gogo Elisha O. , Saidi Mwanarusi , Itulya Francis M. , Martin Thibaud , Ngouajio Mathieu
Published: October 2019

Unfavorable environmental conditions, pests, and viral diseases are among the major factors that contribute to poor growth and quality of tomato (Solanum lycopersicum) seedlings in tropical areas. Improving crop microclimate and excluding insects that transmit viruses may improve transplant quality and yield in production fields. This study was carried out in two seasons at the Horticulture Research and Teaching Field of Egerton University in Njoro, Kenya, to investigate the effects of agricultural nets herein called eco-friendly nets (EFNs) on germination and performance of tomato seedlings. Tomato seeds were either raised in the open or under a permanent fine mesh net (0.4-mm pore diameter). Eco-friendly net covers modified the microclimate resulting in significantly higher day temperatures and relative humidity, compared with the open treatment. Nets increased temperature and relative humidity by 14.8% and 10.4%, respectively. Starting seeds under a net advanced seedling emergence by 2 days and resulted in higher emergence percentage, thicker stem diameter, more leaves, and faster growth leading to early maturity of seedlings and readiness for transplanting. Netting improved root development by increasing root quantity and length. Stomatal conductance (gS) and estimates of chlorophyll content were higher in seedlings under net covering compared with those in the noncovered control treatment. Insect pests and diseases were also reduced under net covering. The use of the net in the production of tomato transplants presented a 36.5% reduction in the cost of seeds, through improved emergence and reduced pest damage. All other factors held constant, healthy and quality transplants obtained under a net covering also translate into better field performance; hence, increasing economic returns for commercial transplants growers, as well as for tomato farmers. Results of this study suggest that EFNs can be customized not only for their effective improvement on growth and quality of tomato transplants but also for their pest and disease management in the nursery alone or as a component of integrated pest and disease management.
Effect of Host Resistance and Fungicide Application on Clubroot Pathotype 6 in Green Cabbage and Napa Cabbage
Authors: Saude Catarina , McKeown Alan , Gossen Bruce D. , McDonald Mary Ruth
Published: October 2019

Field trials were conducted to evaluate resistance to clubroot (Plasmodiophora brassicae, pathotype 6) in green cabbage (Brassica oleracea var. capitata) and napa cabbage (Brassica rapa ssp. pekinensis) at sites in southern Ontario in 2009 and 2010. The reaction of green cabbage cultivars Kilaton, Tekila, Kilaxy, and Kilaherb and the commercial standard cultivars, Bronco or Atlantis, were evaluated on organic (two site-years) and mineral soils (two site-years) that were naturally infested with the clubroot pathogen. In addition, fluazinam fungicide was drench applied to one treatment of the commercial standard cultivar immediately after transplanting. The napa cabbage cultivars Yuki, Deneko, Bilko, and Mirako (in 2009) and Emiko, Mirako, Yuki, and China Gold (in 2010) were evaluated only on organic soils (two site-years). At harvest, the roots of each plant were assessed for clubroot incidence and severity. Also, plant and head characteristics of the resistant green cabbage cultivars were evaluated at one site in 2010. The green cabbage cultivars Kilaton, Tekila, Kilaxy, and Kilaherb were resistant to pathotype 6 (0% to 3.8% incidence), but ‘Bronco’ was susceptible (64% to 100% incidence). Application of fluazinam reduced clubroot severity on ‘Bronco’ by 6% at one of three sites. Resistance was more effective in reducing clubroot than application of fluazinam. Plant and head characteristics of the resistant cultivars were similar to those of ‘Bronco’ treated with fluazinam. Napa cabbage cultivars Yuki, Deneko, Bilko, Emiko, and China Gold were resistant to clubroot (0% to 13% incidence), and ‘Mirako’ was highly susceptible (87% to 92% incidence). We conclude that the clubroot resistance available in several cultivars of green and napa cabbage was effective against P. brassicae pathotype 6.
Horticultural Therapy Program for the Improvement of Attention and Sociality in Children with Intellectual Disabilities
Authors: Kim Bo-Young , Park Sin-Ae , Song Jong-Eun , Son Ki-Cheol
Published: October 2019

This study was conducted to determine the effects of a horticultural therapy (HT) program, based on B.F. Skinner’s behavior modification theory and special education science curriculum for Korean children with intellectual disabilities for the improvement of attention and sociality. Twenty-four participants (10 males, 14 females, in grades 1 to 3) with intellectual disabilities were recruited from a special education class at an elementary school in Seoul, South Korea. Twelve children participated in the HT program after-school for 6 months (Mar. to Aug. 2009, once per week, ≈40 min per session); the control group consisted of the remaining 12 children. Before and after the HT program, Conners’ teacher rating scales—revised and the social skills rating system assessments were conducted by parents/caregivers or teachers for each of the children. Analysis of covariance (ANCOVA) and chi square tests were used to compare differences between the two groups. Difference in attention was not significant between groups. Children in the HT group had statistically significant higher sociality scores than those in the control group (P < 0.001). In conclusion, the HT program improved the sociality of children with intellectual disabilities. To maximize the therapeutic effects of the HT program for attention, the program should be revised and supplemented based on the results in this study. A larger sample size and factoring in the level of disability and year in school of the participants would increase the precision in assessing therapeutic effects.
Effect of Time of Planting and Plant Size on the Productivity of ‘Festival’ and ‘Florida Fortuna’ Strawberry Plants in a Subtropical Environment
Authors: Menzel Christopher M. , Smith Lindsay
Published: October 2019

The effect of time of planting and plant size on the performance of ‘Festival’ and ‘Florida Fortuna’ strawberry (Fragaria ×ananassa) plants was studied at Nambour in southeastern Queensland, Australia, over 2 years. The main objective of the work was to determine whether small plants yielded proportionally less than large plants as planting was delayed. First, bare-rooted transplants of ‘Festival’ were divided into small (crown diameters ranging from 6 to 10 mm) or large plants (10 to 17 mm) and planted in late March, mid-April, or late April. Second, transplants of ‘Florida Fortuna’ were divided into small (5 to 8 mm) or large plants (8 to 17 mm) and planted in early April, mid-April, or early May. The early planting for each cultivar corresponded with the time that the transplants are first available from commercial strawberry nurseries. Yields were generally greater in plants planted in late March/early April compared with plants planted later. Differences in yield between the small and large plants were consistent across the different times of planting, with the small plants always having lower yields. Small transplants are an issue for the productivity of strawberry fields in this environment whether they are planted early or late. Producers should consider paying a premium for large transplants delivered early in the season.
Survival and Yields of Fall-planted Winter Sprouting Broccoli Grown in High Tunnels for Spring Harvest in the Northeastern United States
Authors: Martin Clifton A. , Sideman Rebecca Grube
Published: October 2019

Winter sprouting broccoli [WSB (Brassica oleracea var. italica)] is a biennial crop that is typically planted in the fall and harvested in the spring in the United Kingdom. To evaluate their suitability as an early spring crop in the northeastern United States, 10 cultivars of WSB were grown in replicated experiments inside an unheated high tunnel over 2 years in Durham, NH. Results showed that the use of a secondary low tunnel covered with heavy rowcover (1.25 oz/yard2) significantly increased winter survival, yields, and earliness of all WSB cultivars. Cultivars differed in terms of days to maturity, yields, and shoot quality. For September planting dates, broccoli shoots were harvested from March to early May. Across cultivars, days to harvest range from 190 to 216 days in 2008–09, and from 209 to 238 days in 2009–10. Season-long yields ranged from 150 to 238 g/plant. The cultivars, Santee, Red Spear, White Sprouting Early, and Late White Star, were among the highest yielding cultivars that produced attractive and tender shoots, spanning the entire harvest season. Our experiments established that fall plantings of WSB may be overwintered in an unheated high tunnel for a spring harvest in USDA Hardiness Zone 5 sites.
Effect of High Electrical Conductivity of Hydroponic Nutrient Solution on Vaccine Protein Content in Transgenic Tomato
Authors: Matsuda Ryo , Kubota Chieri , Alvarez M. Lucrecia , Cardineau Guy A.
Published: October 2019

Using greenhouse tomato (Solanum lycopersicum) as a model system to produce pharmaceutical proteins, electrical conductivity (EC) of hydroponic nutrient solution was examined as a possible factor that affects the protein concentration in fruit. Transgenic tomato plants, expressing F1-V protein, a plant-made candidate subunit vaccine against plague (Yersinia pestis), were grown hydroponically at high (5.4 dS·m−1) or conventional EC [2.7 dS·m−1 (control)] with a high-wire system in a temperature-controlled greenhouse. There was no significant difference in plant growth and development including final shoot dry weight (DW), leaf area, stem elongation rate, or leaf development rate between high EC and control. Net photosynthetic rate, transpiration rate, and stomatal conductance (gS) of leaves were also not significantly different between EC treatments. For both EC treatments, immature green fruit accumulated DW at a similar rate, but dynamics observed in fruit total soluble protein (TSP) and F1-V during the fruit growth were different between the two ECs. Fruit TSP concentration per unit DW decreased while TSP content per whole fruit increased as fruit grew, regardless of EC. However, TSPs were significantly lower in high EC than in control. Fruit F1-V concentration per unit DW and F1-V content per whole fruit were also lower in high EC than in control. Our results found that increasing EC of nutrient solution decreased TSP including the vaccine protein in fruit, suggesting that adjusting nutrient solution EC at an appropriate level is necessary to avoid salinity stress in this transgenic tomato.
Description of Clean Chip Residual Forest Harvest and Its Availability for Horticultural Uses in the Southeastern United States
Authors: Boyer Cheryl R. , Gallagher Thomas V. , Gilliam Charles H. , Fain Glenn B. , Torbert H. Allen , Sibley Jeff L.
Published: October 2019

Residual chipping material, also called clean chip residual (CCR), has potential use as a growth substrate in the nursery and greenhouse horticultural industries. A survey was conducted in the southeastern United States among companies conducting harvesting operations on pine (Pinus sp.) plantations for the production of pulpwood in the forest industry. Fourteen operators in four states (Alabama, Mississippi, Georgia, Florida) were visited to evaluate the on-site status of residual material. Sample analysis of CCR revealed that it was composed of ≈37.7% wood (range, 14.2% to 50.5%), 36.6% bark (range, 16.1% to 68.5%), 8.8% needles (range, 0.1% to 19.2%), and 16.9% indistinguishable (fine) particles (range, 7.5% to 31%). pH ranged from 4.3 to 5.5 for all locations and electrical conductivity (EC) averaged 0.24 mmho/cm. Most nutrients were in acceptable ranges for plant growth with the exception of three sites above recommended levels for iron and four sites for manganese. Survey participants estimated that ≈27.5% of the harvest site biomass was composed of CCR. Some harvesters were able to sell CCR as fuelwood to pulp mills, while others did not recover the residual material and left it on the forest floor (44.3% total site biomass). Operations in this survey included typical pine plantation chipping and grinding operations (harvesters), woodyards (lumber, fuelwood, etc.), and operations processing mixed material (salvage from trees damaged in hurricanes or mixed tree species cleared from a site that was not under management as a plantation). Residual material varied depending on the plantation age, species composition, site quality, and natural actions such as fire. Average tree age was 11.5 years (range, 8 to 15 years), while average tree stand height was 37.0 ft (range, 25 to 50 ft) and average diameter at breast height (DBH) was 5.9 inches (range, 4 to 7 inches). Residual material on site was either sold immediately (28.6%), left on site for 1 to 3 months (28.6%), left on site for up to 2 years (7.1%), or not collected/sold (35.7%). Several loggers were interested in making CCR available to horticultural industries. Adequate resources are available to horticultural industries, rendering the use of CCR in ornamental plant production a viable option.
Economic Impacts of Mechanization or Automation on Horticulture Production Firms Sales, Employment, and Workers’ Earnings, Safety, and Retention
Authors: Posadas Benedict
Published: October 2019

Using a socioeconomic database collected by face-to-face interviews of nurseries and greenhouses, empirical models were estimated to measure the economic impacts of mechanization or automation on annual gross sales, annual employment, and workers’ earnings, safety and retention. The survey was conducted among 215 randomly selected wholesale nurseries and greenhouses located in eight southern states from Dec. 2003 to Nov. 2009. The level of mechanization or automation (LOAM) observed among the participating wholesale nurseries and greenhouses averaged 20% of the major tasks performed by workers. Nurseries and greenhouses that reported greater annual gross sales demonstrated higher levels of mechanization, implying economies of scale associated with technology adoption by these wholesale horticulture production firms. The increase in total workers’ earnings associated with improved mechanization indicated that nurseries and greenhouses were able to pay their workers higher wages and salaries. The increased levels of mechanization produced neutral effects on employment and raised the value of the marginal productivity (VMP) of labor, implying that technology adoption by wholesale nurseries and greenhouses did not displace any worker but instead improved total workers’ earnings. Growers that reported higher levels of mechanization hired fewer new workers with basic horticultural skills, especially among horticultural firms which operated both nursery and greenhouse enterprises. The length of training period for basic horticultural skills was not influenced by the level of mechanization, but was significantly extended when nurseries or greenhouses hired more new workers without basic horticultural skills. The number of work-related injuries increased as a result of improvements in mechanization, which primarily consisted of back strains, cut fingers, shoulder and ankle strains, and eye injury. The workers’ retention impact (WRI) of the level of mechanization turned out to be neutral or indeterminate since almost all of their workers were with them during the past 2 years before conducting the interviews. Overall, advances in mechanization or automation generated enhancing effects on the annual gross sales of horticultural production firms, enabled them to retain and pay better wages for their workers, hired fewer new skilled workers, and reported more work-related injuries.
FloraGator: A Novel, Interactive, and Online Multiple-entry Key for Identifying Plant Families
Authors: Wilson Sandra B. , Flory Luke
Published: October 2019

An interactive plant key was developed as an online tool with the specific goal of improving student learning of botanical vocabulary, plant morphology, and plant families. The online tool provides two options for using the multiple-entry key: identification of plant families based on historic botanical illustrations or live plant samples. The database consists of 196 angiosperm families, each with up to 220 botanical characters, and includes all of the plant families found in Florida. The tool uses a ternary system to record the diversity within each plant family such that upon entering identification information, families are eliminated that do not contain specific characters, which narrows the list of possible correct families. The remaining families are ranked according to total score, so families in which the features are common will appear first. This versatile online tool can be used nationwide to supplement in-person laboratory courses or distance education classes in horticulture, botany, systematics, and biology. To date, the newly launched site has been accessed by 1148 unique visitors from 15 countries.
Annual Under-vine Cover Crops Did Not Impact Vine Growth or Fruit Composition of Mature Cool-climate ‘Riesling’ Grapevines
Authors: Jordan Lindsay M. , Björkman Thomas , Vanden Heuvel Justine E.
Published: October 2019

In the cool and humid climate of the northeastern United States, vegetation is typically maintained between the rows of wine grape (Vitis vinifera) vineyards, but the area directly beneath vines is conventionally kept bare using herbicides or cultivation, to reduce competition for water and nutrients. Yet with rising concerns of herbicide resistance, environmental contamination, and soil erosion, alternatives to maintaining bare ground in vineyards should be considered. In warmer and more arid climates, using cover crops as an alternative to bare soil has sometimes resulted in reduced vine growth and yields. In more cool and humid climates, like in the northeastern United States, where conditions can promote excessive vine growth, replacing bare soil with under-vine cover crops was hypothesized to improve vine growth characteristics and fruit quality from reducing excessive vigor. This study compared three annual under-vine cover crops of resident vegetation (RES), buckwheat (BW) (Fagopyrum esculentum), and annual ryegrass (ARG) (Lolium multiflorum), planted in the 1-m-wide strip directly under vines at the start of each growing season, against the conventional weed-free under-vine row maintained with glyphosate. The experiment was established in 2011 and repeated in 2012 and 2013 in a 20-year-old block of ‘Riesling’ wine grapes (clone 198 on S04 rootstock) in a commercial vineyard in the Finger Lakes region of New York State. Harvested grapes were fermented in duplicate using standard white wine procedures. Among the four under-vine treatments, no significant differences were found in measures of vegetative growth, yield, petiole nutrient concentrations at veraison, or predawn and midday stem water potentials. Under-vine treatments were not found to significantly affect soil organic matter, aggregate stability, and nutrient concentrations. Juice characteristics were also not significantly different among treatments. In this study, the mature vines in this rain-fed ‘Riesling’ vineyard likely had a well-developed and extensive rooting system that was able to overcome any competition effects for water or nutrients from the comparatively shallow root systems of the annually established cover crops. Without any induced competition in the conditions of this study, under-vine cover crops had no effects on vine growth, yield, or juice characteristics when compared with conventional herbicide use in the under-vine row. When multidimensional scaling (MDS) analysis was used to determine differences in aroma among wine treatment replicates, treatments were found to significantly impact the perceived aromatic properties of the wines, even though no measures of growth or juice characteristics were affected. Using under-vine vegetation may be a viable alternative to conventional herbicide use for vineyard floor management in mature wine grape vineyards in cool and humid climates.
Comparative Consumer Perspectives on Eco-friendly and Insect Management Practices on Floriculture Crops
Authors: Getter Kristin L. , Behe Bridget K. , Wollaeger Heidi Marie
Published: October 2019

Declining bee populations has garnered media attention, which has pressured plant retailers to ask or demand the reduction or elimination of neonicotinoid insecticide use in greenhouse production. This study investigated consumer perspectives on eco-friendly ornamental plant production practices in combination with a variety of insect management practices. Data from an online study were collected from 1555 Americans in May 2015. Over half (55%), nearly half (48.2%), and more than 30% of the participants felt that “bees are not harmed,” “better for the environment,” or “plants that attract bees,” respectively, was a characteristic of bee-friendly insect management practices. The latter group erroneously confused bee-friendly insect management practices with plants that are a potential food source for bees. When asked to rate various insect management plant production practices on a five-point Likert scale, consumer mean scores were positive (defined here as 3.5 to 5.0) for “plants grown using bee-friendly insect management practices,” “plants grown using insect management strategies that are safe for pollinators,” “plants grown using best insect management practices to protect pollinators,” and “plants grown using insect management practices that leaves no insecticide residue on the plant.” Plant species accounted for 31.6% of the decision to purchase the plant, followed by price (25.1%), insect management strategy (23.3%), and eco-friendly practices (20.1%) that was similar to prior published findings. Analyses showed that plants labeled as “grown using bee-friendly insect management practices” were worth $0.26, $0.26, $0.89, and $1.15 more than plants labeled as “grown in a sustainably produced potting soil/mix,” “grown using recycled/recaptured water,” “grown using protective neonicotinoid insecticides,” and “grown using traditional insect management practices,” respectively. In addition, plants labeled as “grown using best insect management practices to protect pollinators” were worth $0.10, $0.10, $0.73, and $0.99 more than plants labeled as “grown in a sustainably produced potting soil/mix,” “grown using recycled/recaptured water,” “grown using protective neonicotinoid insecticides,” and “grown using traditional insect management practices,” respectively. Thus, selected insect management strategies were valued more, on average, than eco-friendly production practices.
Effects of Mowing and Trinexapac-Ethyl on St. Augustinegrass Sod Establishment during a Simulated Water Variance Period
Authors: Hargey Daniel , Wherley Benjamin , Malis Andrew , Thomas James , Chandra Ambika
Published: October 2019

During water conservation periods, municipal water purveyors often limit irrigation for established lawns to once every 7 to 14 days, although a 4- to 6-week variance to these restrictions is often permitted for turfgrass establishment. Therefore, establishment practices promoting rapid development of a deep and expansive root system during this time may support long-term success of the turf once irrigation is scaled back. Sod producers and turf managers could benefit from information on the influence of mowing practices and plant growth regulator (PGR) applications on turf root development during this initial establishment period. The objectives of this greenhouse study were to 1) evaluate the effects of mowing and trinexapac-ethyl (TE) application on final turf quality and root development characteristics (weight, total length, and extension rate) of st. augustinegrass (Stenotaphrum secundatum) sod during a 35-day establishment period, and 2) compare the quality and rooting potential of ‘TamStar’, a newly released, embryo-rescue-derived cultivar possessing good drought resistance, with ‘Floratam’, the current industry standard for drought resistance. Weekly mowing reduced both total (2.5 to 90 cm) and deep (45 to 90 cm) root weight and root length in both cultivars. TE had no effect on visual quality of ‘TamStar’, but decreased turf quality in ‘Floratam’. TE reduced clipping yields of both cultivars but did not improve root development for either cultivar. Depth of maximal root extension during establishment was unaffected by cultivar, mowing, or TE treatment. At the conclusion of the 35-day establishment period, ‘TamStar’ exhibited superior turf quality and root weight relative to ‘Floratam’, but also produced higher rates of shoot growth. Results emphasize the importance of withholding mowing during st. augustinegrass establishment, particularly for improving total root length and deep root production, and also show that TE does not improve root development of st. augustinegrass during establishment.
Education Programs in Public Children’s Gardens in the United States
Authors: Kwon Min Hyeong , Kim Jongyun , Seo Changwan , Lee Chiwon W. , Jang Eu Jean , Lee Woo-Kyun
Published: October 2019

This study examines the current status, implementation, and foci of children’s education programs as a subset of general audience-targeted public education programs offered by public children’s gardens in the United States. Children were a major target audience of the examined public gardens, followed by adults, families, and youth. Public children’s gardens tended to offer more programs overall compared with public gardens without children’s gardens. In addition, there was a greater diversity of children’s education programs offered (classified into 10 topics and 11 activities) in public children’s gardens. The most frequently offered topics were plants (39.1%), animals (22.0%), and art (11.3%). Observation was the most frequently offered activity (17.1%), followed by visual art (14.4%). However, the proportions of offered programs significantly differed across individual public children’s gardens. The subjects (i.e., topics and activities) offered by children’s education programs were more often directed toward younger children. Education coordinators and horticulture directors were asked about desired improvements to children’s education programs. A large number of respondents (50) indicated a need to develop programs with greater topical variety, revealing a desire to diversify programs. In conclusion, the results of this study indicate that it is important to diversify the natural environmental experiences of education programs for children through developing children’s gardens and age-specific education at public children’s gardens in the United States.