bluuebunny/crossref_metadata_2025 huggingface dataset:
Evaluation of Shrubs for Side Slope Greening and Protection in Urban Landscape
Authors: Amoroso Gabriele , Frangi Piero , Piatti Riccardo , Fini Alessio , Ferrini Francesco , Faoro Marco
Published: December 2018

Shrubs are often used for side slope greening and protection in the urban landscape. Only a few species are commonly used in the European city environment, bestowing upon cities a monotonous appearance. The aim of this 3-year trial, set up at Fondazione Minoprio (Vertemate con Minoprio; Como, Italy), was to evaluate the performance of 25 shrub species grown on a slope during three seasons (2007–09). Moreover, to evaluate the influence of weeds on plant growth and the weeding time, two mulches (biodegradable textile and polypropylene fabric) were used in comparison with bare soil (control). Shrubs were planted in late Spring 2007. To simulate urban conditions, no pruning or disease control were applied. Irrigation was carried out only in the driest periods of the first summer. Plant height and percent cover were measured every 2 months, whereas plant phenology and state of health were recorded weekly. Chlorophyll fluorescence and chlorophyll content were evaluated on two different drought-tolerant species during the third growing season. At the end of the trial shoot biomass was measured and root characteristics (root density and specific root length) were determined. Weeds were removed twice in the first and third years and three times in the second year. Time for weed removal was recorded for each experimental plot. Results show that the highest growth (height and biomass) was detected in mulched plots, probably because of both limited weed competition for water and nutrients and lower water loss by evaporation. Plants grown in bare soil showed higher root density and finer roots compared with mulched plants; this may be explained by the necessity of the plant root system to explore the soil to reach for water. Differences in growth, groundcovering, and root characteristics were observed among species. As a result of higher mulching cost and the poorer root characteristics of mulched plants, bare soil and fast growing shrubs should be used to limit weed competition and assure a satisfactory slope greening and consolidation.
Optimal Spray Application Rates for Ornamental Nursery Liner Production
Authors: Zhu Heping , Altland James , Derksen Richard C. , Krause Charles R.
Published: December 2018

Spray deposition and coverage at different application rates for nursery liners of different sizes were investigated to determine the optimal spray application rates. Experiments were conducted on 2- and 3-year-old ‘Autumn Spire’ red maple (Acer rubrum) liners. A traditional hydraulic sprayer with vertical booms between tree rows was used to apply the spray applications. Application rates were 10, 20, 30, and 40 gal/acre for the 2-year-old liners and were 20, 40, 60, and 80 gal/acre for the 3-year-old liners. Nylon screens were used to collect spray deposition of a fluorescent tracer dissolved in water, and water-sensitive papers were used to quantify spray coverage inside canopies. Spray deposition, coverage, and droplet density inside both 2- and 3-year-old liner canopies increased as the application rate increased. The minimum rates to spray 6.6-ft-tall, 2-year-old ‘Autumn Spire’ red maple liners and 8.7-ft-tall, 3-year-old liners were 20 and 40 gal/acre, respectively. An exponential equation was derived from these results to estimate the spray application rate required for different tree liner heights and to minimize excessive chemical use in rapidly growing tree liners.
Consumer Preferences and Willingness to Pay for Existing and New Apple Varieties: Evidence from Apple Tasting Choice Experiments
Authors: Yue Chengyan , Tong Cindy
Published: December 2018

We used choice experiments to investigate consumers’ preferences and willingness to pay (WTP) for various apple (Malus ×domestica) varieties. The experiments also asked consumers to evaluate a series of quality attributes by allowing them to taste apples. The choice experiments were conducted in real markets where consumers were making fruit purchases to eliminate any decontextualized biases. The objectives of this study were to determine how much consumers are willing to pay for 13 new and existing apple varieties and learn what quality attributes consumers’ like or dislike in new vs. older apple varieties. Results show that compared with other apple varieties, participants were willing to pay the highest prices for ‘SweeTango®’, followed by ‘Zestar!™’ and ‘Honeycrisp’. Frequent and infrequent buyers were willing to pay significantly different amounts for most of the studied varieties. In addition to WTP estimates, our study also shows what quality attributes consumers consider as improvements compared with existing varieties. Combined with objective measures of these quality attributes, our transdisciplinary study will help apple breeders make more targeted breeding decisions by better understanding what quality attributes consumers like or dislike about the studied varieties.
Postharvest Performance of Selected Colombian Cut Flowers after Three Transport Systems to the United States
Authors: Leonard Ria T. , Alexander Amy M. , Nell Terril A.
Published: December 2018

This study examined three transport systems used to transport fresh, non-stored cut flowers from Bogotá, Colombia, to the United States on a monthly basis for 1 year. Five cultivars of cut rose (Rosa hybrida), alstroemeria (Alstroemeria peruviana), carnation (Dianthus caryophyllus), and gerbera (Gerbera jamesonii) were commercially transported using a 7-day conventional distribution system with temperature controls and two rapid transport systems (3-day or 24-hour) with little or no temperature controls, respectively. Temperatures during the 24-hour transport system increased steadily and temperatures were at or above 10 °C for ≈18 h, with half of that time above 15 °C for all shipments. The 3- and 7-day systems had temperature fluctuations ranging from 3 to 24 °C and 3 to 19 °C, respectively. Flowers transported using the rapid transport systems had a significantly longer vase life compared with the 7-day transport in 83% of the shipments of alstroemeria and roses, in 58% of the shipments of carnations, and in 50% of the shipments of gerberas. Vase life increased 5.6% to 17.1% (0.7 to 2.1 days) for roses, 3.2% to 16.7% (0.5 to 2.7 days) for alstroemerias, 12.8% to 34.6% (1.1 to 6.2 days) for gerberas, and 4.6% to 8.8% (1.1 to 2.3 days) for carnations when using the rapid transport systems compared with the 7-day transport system. Some cultivars were more tolerant of the longer transport. The results show that when using fresh, non-stored flowers, the rapid transport systems had equal or longer vase life than the 7-day transport system in the majority of shipments for each flower species. Results also demonstrate that better temperature management during transport is a critical issue in the floral industry that needs to be improved upon.
Ornamental Grasses Show Minimal Response to Cultural Inputs
Authors: Thetford Mack , Knox Gary W. , Duke Edwin R.
Published: December 2018

Full sun trial gardens were established at two sites in northern Florida. Six U.S. native and three non-native warm season grass species were evaluated in a split-plot design. Only eastern gamagrass (Tripsacum dactyloides), elliott's lovegrass (Eragrostis elliottii), gulf hairawn muhly (Muhlenbergia capillaris), little bluestem (Schizachyrium scoparium), and ‘Central Park' maiden grass (Miscanthus sinensis) showed a significant response to supplemental irrigation or fertilization. Supplemental irrigation did not influence foliage height for any of the grasses, whereas supplemental fertilization influenced foliage height only for chinese fountain grass (Pennisetum alopecuroides). The response differences between locations were attributed in part to soil types. This study observed minimal or no response of shoot growth to supplemental irrigation or fertilization for the grass species tested, thereby affirming the broad adaptability and minimal need for inputs for these ornamental landscape plants.
Cultivar-specific Weed Management Programs for ‘Russet Burbank’ and ‘Bannock Russet’ Potato Production in Wisconsin
Authors: Solan Renata L. , Colquhoun Jed B. , Rittmeyer Richard A. , Heider Daniel J.
Published: December 2018

Field trials were conducted at Hancock, WI, in 2008 and 2009 to determine reduced-herbicide weed management programs for ‘Russet Burbank’ and ‘Bannock Russet’ potato (Solanum tuberosum) based on cultivars’ developmental characteristics. Six treatments applied to each cultivar included: preemergence (PRE) broadcast s-metolachlor and metribuzin (the industry standard); PRE in-row banded s-metolachlor and metribuzin with cultivation at 15% canopy development; postemergence (POST) broadcast rimsulfuron and metribuzin; POST between-row banded glyphosate; POST in-row banded rimsulfuron and metribuzin with cultivation at 15% canopy development; and cultivation alone at 15% canopy development. In 2008 and 2009, for both cultivars, visual assessments indicated weed suppression was reduced when glyphosate was POST between-row banded, compared with other treatments, and weed suppression was consistently high when rimsulfuron and metribuzin were POST broadcast. As expected, in-row weed control was consistently poor when glyphosate was between-row POST banded, providing no in-row weed control. Regardless of cultivar or year, in-row weed control was comparable to or better than the industry standard when herbicides were broadcast or in-row banded with cultivation at 15% canopy development. Potato yield was poor when glyphosate was POST between-row banded and when cultivation was used without herbicide application. Yield was consistently high when herbicides were POST broadcast, which provided no reduction in treated area from the industry standard of PRE broadcast. In both years, ‘Russet Burbank’ yield was greatest when herbicides were POST in-row banded with cultivation at 15% canopy development; ‘Bannock Russet’ yield was greatest when herbicides were PRE in-row banded with cultivation at 15% canopy development. Cultivar-appropriate weed management systems that band herbicides over the crop row in combination with cultivation would provide a two-thirds decrease in herbicide application from the industry standard without risk of yield loss.
Effects of Short Interval Cyclic Flooding on Growth and Survival of Three Native Shrubs
Authors: Dylewski Katie L. , Wright Amy N. , Tilt Kenneth M. , LeBleu Charlene
Published: December 2018

The effect of short interval cyclic flooding on root and shoot growth of ‘Shamrock’ inkberry holly (Ilex glabra), ‘Henry's Garnet’ sweetspire (Itea virginica), and ‘Winterthur’ possumhaw (Viburnum nudum) was studied in a greenhouse in Auburn, AL. Liners (4.4 inches long) of each species were planted into trade 1-gal pots in 1 pine bark:1 peat by volume (PB:P) or fine textured calcined clay (CC). ‘Shamrock’ inkberry holly and ‘Henry's Garnet’ sweetspire were planted 18 Apr. 2008; the experiment was repeated with the addition of ‘Winterthur’ possumhaw on 16 June 2008. Plants were flooded to substrate level for 0 (non-flooded), 3, or 7 days. Flooding cycles were repeated at least five times with 7 days of draining between each flood cycle. During draining, plants received no irrigation. Non-flooded plants were watered as needed. Flooded plants for all species except ‘Winterthur’ possumhaw showed decreased root dry weight, shoot dry weight, and final growth index when compared with non-flooded plants. Survival was higher in CC than PB:P for both experiments. All plants maintained good visual quality and shoot growth. As a result, overall, these plants seemed tolerant of flooding despite differences in growth.
Effects of 1-Methylcyclopropene on Firmness Loss and the Development of Rots in Apple Fruit Kept in Farm Markets or at Elevated Temperatures
Authors: McArtney Steven , Parker Michael , Obermiller John , Hoyt Tom
Published: December 2018

Many of the apples (Malus ×domestica) grown in the southeastern United States are sold to consumers through direct farm markets and roadside stands. Fruit in these markets may be exposed to high temperatures (>68 °F), which cause the fruit to ripen quickly, limiting their shelf life and consumer appeal and increasing their susceptibility to decay pathogens. Studies were undertaken in 2009 and 2010 to determine the effects of a 1-μL·L−1 postharvest 1-methylcyclopropene (1-MCP) treatment on the maintenance of flesh firmness and the incidence of rots in fruit held at elevated temperatures for up to 8 weeks. 1-MCP-treated fruit of three apple cultivars (Ginger Gold, Gala, and Golden Delicious) held in three retail farm markets in the southeastern United States maintained their firmness for 3 to 5 weeks. The firmness of non-treated ‘Ginger Gold’ fruit declined to less than 12 lbf after 1 week in each market, whereas the firmness of treated fruit remained greater than 16 lbf after 3 weeks. Treated ‘Gala’ fruit maintained their firmness at 14 lbf during 4 weeks in each farm market, whereas the firmness of non-treated fruit declined to less than 12 lbf after 2 weeks. The firmness of non-treated ‘Golden Delicious’ fruit declined to less than 12 lbf after 1 week in each farm market, whereas treated fruit maintained their firmness for up to 4 weeks. ‘Golden Delicious’ fruit treated with 1-MCP exhibited almost no loss of firmness during 4 weeks at 32, 50, or 70 °F, or even up to 8 weeks at 32 or 50 °F. The incidence of fruit rots increased with temperature, and 1-MCP reduced the incidence of fruit rots after 4 weeks at 70 °F in 2009 or after 8 weeks at 70 °F in 2010. These data show that 1-MCP may be of great benefit to producers who sell their fruit directly to the consumer by delaying the loss in firmness and reducing the incidence of rots in fruit kept at elevated temperatures.
Relationship between the Preference and Perceived Restorative Potential of Urban Landscapes
Authors: Abkar Mahdieh , Kamal Mustafa , Maulan Suhardi , Mariapan Manohar , Davoodi Seyed Rasoul
Published: December 2018

This study presents the relationship between “perceived restorative potential” (PRP) and “preference” for an environment with respect to their relationship with the restorative components outlined by attention restoration theory (ART) in two categories: urban built landscape (UBL) and urban natural landscape (UNL). In this experimental study, 120 participants from University Putra Malaysia (Serdang, Malaysia) rated four restorative components, the PRP and “preference” of 24 color slides depicting UBL and UNL scenes. The results showed that “preference” and PRP was moderately correlated in UNL and UBL. “Compatibility” was found to be the most influential variable among all the restorative components in explaining PRP and “preference” in both UNL and UBL. However, “fascination” appeared to be the second most significant predictor of “preference” in UNL, whereas “being away” was the second most significant predictor of PRP in UNL. Furthermore, “coherence” predicted “preference” but it did not predict PRP in UNL. “Being away” and “coherence” were distinct components of PRP and “preference” and of UNL and UBL.
Above-grade Planting with Organic Matter Improves Post-transplant Growth of Two Native Shrub Species
Authors: Price Julie Guckenberger , Wright Amy N. , Boyd Robert S. , Tilt Kenneth M.
Published: December 2018

Planting shrubs above-grade with organic matter has shown potential for improving landscape establishment. To further investigate this technique, wax myrtle [Morella cerifera (syn. Myrica cerifera)] (3 gal) and mountain laurel (Kalmia latifolia ‘Olympic Wedding’) (5 gal) were planted on 30 Oct. 2006 (fall planting) and 12 Apr. 2007 (spring planting) in the ground in a shade house in Auburn, AL. At each planting date, plants of each species were assigned one of four treatments. Three of four treatments used a modified above-grade planting technique in which shrubs were planted such that the top 3 inches of the root ball remained above soil grade. Organic matter, either pine bark (PB), peat (PT), or cotton gin compost (CGC), was applied around the above-grade portion of the root ball, tapering down from the top of the root ball to the ground. In the fourth treatment, plants were planted at-grade with no organic matter (NOM). In general, both species had higher shoot dry weight (SDW) and root spread (RS) when planted in the fall than when planted in spring. Among all treatments, plants also typically had larger RS when planted above-grade with PB or PT. For easy-to-transplant species (such as wax myrtle) and especially for difficult-to-transplant species like mountain laurel, fall planting using this modified above-grade planting technique with PB or PT may improve post-transplant root growth and speed establishment in the first growing season.
Assessing Tolerance to Sodium Chloride Salinity in Fourteen Floriculture Species
Authors: Villarino Gonzalo H. , Mattson Neil S.
Published: December 2018

The use of saline irrigation water may be inevitable in the future since the freshwater supply is decreasing over time. In some regions of the United States, producers of both ornamental and agronomic crops are already facing a limited supply of high-quality water. Therefore, it is necessary to determine the salt tolerance of commonly used greenhouse bedding plants to minimize potential salt damage before use of nonpotable water sources is mandated. Research screening several bedding plants has not taken place for more than two decades. Therefore, we undertook experiments to screen popular bedding plants for salt tolerance during greenhouse production. Transplants were exposed to 0 (control), 20, 40, 60, or 80 mm sodium chloride (NaCl) in the irrigation water for 5 weeks resulting in average substrate pour-thru electrical conductivity (EC) values of 4.0 (control), 7.0, 9.8, 12.1, or 14.2 dS·m−1, respectively. Pansy (Viola tricolor) and zinnia (Zinnia angustifolia), the most sensitive species examined, exhibited 100% mortality when exposed to an EC of 14.2 dS·m−1. The least affected species for dry weight (DW) was snapdragon (Antirrhinum majus) with a 54% reduction as EC increased from 4.0 to 14.2 dS·m−1. Only fuchsia (Fuchsia hybrida) and snapdragon were unaffected by an EC of 7.0 dS·m−1, whereas at 9.8 dS·m−1 all of the species had a significantly reduced DW as compared with control plants. Verbena (Verbena ×hybrida), petunia (Petunia ×hybrida), coleus (Solenostemon scutellarioides), and begonia (Begonia hiemalis) were the only species that did not undergo a significant height reduction in comparing 9.8 dS·m−1 to control. A classification of the 14 species is created here on the basis of plant DW to provide guidance as to which species could be irrigated with more saline water while not compromising plant growth and quality.
Effectiveness of Soil Salinity Management Practices in Basin-irrigated Pecan Orchards
Authors: Miyamoto Seiichi , Nesbitt Monte
Published: December 2018

Soil salinity management is a factor for successful production of pecan (Carya illinoinensis) in arid southwestern United States. An exploratory study was performed to evaluate the effect of various soil management practices on salt leaching in basin-irrigated orchards developed on alluvial soils (Torrifluvents, Entisols) of the middle Rio Grande Basin. The practices evaluated were ripping, minimum-till chiseling, and soil profile modification. For ripping, parabolic shanks were passed through the center section (4 to 8 ft wide) between each tree row to a depth ranging from 18 to 36 inches. Minimum-till chisels included 7- and 30-inch shanks, equipped with coulters to reduce break up of the ground surface. Soil profile modification consisted of trenching with a backhoe and profile mixing with a large excavator. The effectiveness of these methods was evaluated by measuring soil salinity and moisture in treated and untreated zones at 17 test sites. Both ripping and minimum-till deep chiseling helped improve salt leaching, and the effectiveness of salt leaching increased as working depths approach the thickness of the clayey layer. However, annual ripping of the center section of each tree row space may not provide wide enough zones to alleviate salt stress to the trees. Straight shanks prune but do not lift tree roots, thus appearing to be better suited for chiseling closer to tree rows. Soil profile modification was highly effective in leaching salts. From the view of minimizing soil aggregate destruction and of maintaining a leveled floor, minimum-till deep chiseling, followed by the use of sand-topdressing and minimum-till shallow chisels for maintenance may prove to be more desirable than conventional ripping, especially in soil types consisting of silty clay loam.
Allotment Gardening and Other Leisure Activities for Stress Reduction and Healthy Aging
Authors: Hawkins Jemma L. , Thirlaway Kathryn J. , Backx Karianne , Clayton Deborah A.
Published: December 2018

This study explored the potential benefits of allotment gardening for healthy aging, focusing on the opportunities for outdoor physical activity, social support, and contact with nature that allotment gardening provides. Participants included 94 individuals aged between 50 and 88 years who were members of various indoor and outdoor activity groups. The participants completed physiological measures and psychometric scales of self-rated health, perceived stress, physical activity level, and perceived social support. A significant difference in perceived stress levels was observed between the activity groups. Allotment gardeners reported significantly less perceived stress than participants of indoor exercise classes (P < 0.05). As there were no significant differences in reported levels of social support and physical activity, explanations for the allotment gardeners' lower stress levels focus on the potential contribution of engagement with nature and psychological restoration. These findings represent a step toward understanding the benefits of allotment gardening activity as a health-promoting behavior in later life.
Tank Mix of Saflufenacil with Glyphosate and Pendimethalin for Broad-spectrum Weed Control in Florida Citrus
Authors: Singh Megh , Malik Mayank , Ramirez Analiza H.M. , Jhala Amit J.
Published: December 2018

Citrus (Citrus spp.) is one of the most important crops in Florida agriculture. Weed control is a major component in citrus production practices. If not controlled, weeds may compete with citrus trees for nutrients, water, and light and may also increase pest problems. Herbicides are an important component of integrated weed management program in citrus. Saflufenacil, a new herbicide registered for broadleaf weed control in citrus, can be applied alone or in a tank mix with other herbicides to improve weed control efficacy. A total of six field experiments were conducted in 2008 and 2009 to evaluate the efficacy of saflufenacil applied alone or in a tank mix with glyphosate and pendimethalin for weed control. In addition, experiments were also conducted to evaluate phytotoxicity of saflufenacil applied at different rates and time intervals in citrus. The results suggested that saflufenacil applied alone was usually effective for early season broadleaf weed control; however, weed control efficacy reduced beyond 30 days after treatment (DAT) compared with a tank mix of saflufenacil, glyphosate, and pendimethalin. For example, control of weeds was ≤70% when saflufenacil or glyphosate applied alone compared with tank mix treatments at 60 and 90 DAT. Addition of pendimethalin as a tank mix partner usually resulted in better residual weed control compared with a tank mix of saflufenacil and glyphosate, and this herbicide mixture was comparable with grower's adopted standard treatment of a tank mix of glyphosate, norflurazon, and diuron and several other tank mix treatments. Saflufenacil applied once in a season at different rates or even in sequential applications did not injure citrus trees when applied according to label directions. It is concluded that with its novel mode of action, saflufenacil tank mixed with glyphosate and pendimethalin would provide citrus growers with another chemical tool to control broadleaf and grass weeds.
Postharvest Treatments for Degreening of ‘Villa franca’ Lemons
Authors: Mayuoni Lina , Porat Ron
Published: December 2018

‘Villa franca’ is the main lemon (Citrus limon) variety in Israel, also cultivated in several other citrus-growing countries. In winter, the fruit turns yellow naturally, but during the summer and autumn, it remains green on the tree and requires postharvest ethylene treatment to stimulate color change from green to yellow. However, ‘Villa franca’ lemons are very sensitive to ethylene, which enhances development of reddish/brown peel blemishes known as red blotch. In the present study, we provide three different methods for postharvest degreening of ‘Villa franca’ lemons without causing red blotch. First is a slow process, involving natural degreening during 4–5 weeks of storage at 13 °C without ethylene exposure. Second is a moderate “under-degreening” process, involving a short 48-hour exposure to ethylene followed by 2 weeks of storage at 13 °C. Third is a fast process involving degreening with ethylene for up to 4 days at a constant high conditioning temperature of 30 °C or a combination of 24 hours of ethylene treatment at 30 °C followed by additional 72 hours of exposure to ethylene at 25 °C. Overall, ‘Villa franca’ lemon growers, packers, and exporters may now choose to use any of these proposed degreening procedures, according to commercial needs and market demands.
Economic Contributions of the Green Industry in the United States in 2007–08
Authors: Hodges Alan W. , Hall Charles R. , Palma Marco A.
Published: December 2018

Economic contributions of the green industry in each state of the United States were estimated for 2007–08 using regional economic multipliers, together with information on horticulture product sales, employment, and payroll reported by the U.S. Economic Census and a nursery industry survey. Total sales revenues for all sectors were $176.11 billion, direct output was $117.40 billion, and total output impacts, including indirect and induced regional economic multiplier effects of nonlocal output, were $175.26 billion. The total value added impact was $107.16 billion, including employee compensation, proprietor (business owner) income, other property income, and indirect business taxes paid to state/local and federal governments. The industry had direct employment of 1.20 million full-time and part-time jobs and total employment impacts of 1.95 million jobs in the broader economy. The largest individual industry sectors in terms of employment and value added impacts were Landscaping services (1,075,343 jobs, $50.3 billion), Nursery and greenhouse production (436,462 jobs, $27.1 billion), and Building materials and garden equipment and supplies stores (190,839 jobs, $9.7 billion). The top 10 individual states in terms of employment contributions were California (257,885 jobs), Florida (188,437 jobs), Texas (82,113 jobs), North Carolina (81,113 jobs), Ohio (79,707 jobs), Pennsylvania (75,604 jobs), New Jersey (67,993 jobs), Illinois (67,382 jobs), Georgia (66,042 jobs), and Virginia (58,677 jobs). The total value added of the U.S. green industry represented 0.76% of U.S. Gross Domestic Product (GDP) in 2007, and up to 1.60% of GDP in individual states. On the basis of a similar previous study for 2002 (Hall et al., 2006), total sales of horticultural products and services in 2007–08 increased by 3.5%, and total output impacts increased by 29.2%, or an average annual rate of 5.8% in inflation-adjusted terms.
Selecting the Right Nutrient Rate: Basis for Managing Fertilization Programs
Authors: Santos Bielinski M.
Published: December 2018

Selecting the “right” nutrient rate for fertilization programs is one of the most important decisions growers face. On one hand, increasing fertilizer prices and environmental concerns have increased the awareness of accurately managing fertilization programs, thus reducing fertilizer amounts during cropping seasons. By contrast, many growers fear not obtaining the desired crop performance and economic returns, especially when fertilization is assumed as “inexpensive insurance” to improve yields, thus leading to overfertilization. The objective of this paper was to provide general principles for selecting and monitoring the right nutrient rate within the framework of the “4R” nutrient management concept (right rate, right source, right placement, and right timing) to protect environmental quality while maintaining productivity. Some methodologies to determine, apply, and adjust fertilization rates during the growing season were discussed, including in-season monitoring procedures, such as petiole sap testing, plant diagnostic analysis, leaf color evaluation, and plant growth index.
Root Piece Planting in Sweetpotato—A Synthesis of Previous Research and Directions for the Future
Authors: George Nicholas A. , Pecota Kenneth V. , Bowen Blake D. , Schultheis Jonathan R. , Yencho G. Craig
Published: December 2018

Sweetpotato (Ipomoea batatas) is traditionally grown for fresh consumption, particularly in developed nations, but it is increasingly being used for alternative markets such as processed foods and industrial products. Sweetpotato is well suited for these end uses but its utilization is limited due to high production costs. These costs are primarily the result of high labor inputs. As a vegetatively propagated crop, sweetpotato is typically planted using unrooted plant cuttings, or “slips,” which requires hand labor at several stages. Consequently, planting costs can be as high as 20% of total production costs. As an alternative to slips, sweetpotato can be established using root pieces, similar to the seed piece system used for potato (Solanum tuberosum). This system can be readily mechanized and therefore has the potential to reduce labor demands. Root piece planting has been investigated several times since the 1940s but is not reported to be in large-scale commercial use anywhere in the world. In this work, we review the research literature relating to root piece planting in sweetpotato. This literature demonstrates that it is possible for sweetpotato root pieces to produce yields comparable to slips, but that in most cases yields from root pieces are usually lower than from slips. We conclude that given suitable cultural management and appropriate varieties, it may be possible to successfully produce sweetpotato using root pieces. More work is necessary to develop root piece planting as a viable alternative to slips in sweetpotato production. This work should include the selection and breeding of adapted varieties, evaluation of the economics of sweetpotato production using root pieces, development of planting equipment suited to sweetpotato root pieces, and examination of chemical treatments to improve success of root piece planting.
Drought Resistance of Warm-season Turfgrasses Grown in Mediterranean Region of Turkey
Authors: Severmutlu Songul , Mutlu Nedim , Gurbuz Ercan , Gulsen Osman , Hocagil Murat , Karaguzel Osman , Heng-Moss Tiffany , Shearman Robert C. , Gaussoin Rock E.
Published: December 2018

There is a dearth of information about turfgrass drought resistance and adaptation in the Mediterranean region of Turkey. Turfgrass managers in this region need this information to help them make informed decisions regarding turfgrass selection and management. This research was conducted to assess the drought resistance of bermudagrass (Cynodon dactylon), buffalograss (Buchloe dactyloides), bahiagrass (Paspalum notatum), seashore paspalum (Paspalum vaginatum), zoysiagrass (Zoysia japonica), centipedegrass (Eremochloa ophiuroides), and tall fescue (Lolium arundinaceum) under Mediterranean conditions of Turkey. The study was conducted at two locations, Antalya and Mersin, and was repeated in 2006 and 2007 at both locations. One year after establishment, the turfs were subjected to drought stress for 90 days, which was followed by resumption of irrigation for recovery of the turf. Percentage leaf firing, turfgrass quality, and percent green shoot recovery were recorded. There were inter and intraspecies differences detected for percentage leaf firing and shoot recovery. Bermudagrass, bahiagrass, and buffalograss exhibited superior drought resistance as demonstrated by lower leaf firing and better shoot recovery values when compared with other species studied. Centipedegrass and zoysiagrass demonstrated a high leaf firing and very poor shoot recovery, whereas zoysiagrass and tall fescue were unable to recover from the drought stress in the sandy soil. Results showed that ‘SWI-1045’ (Contessa®) and ‘SWI-1044’ bermudagrass and ‘Cody’ buffalograss possessed superior drought resistance with acceptable turfgrass quality up to 30 days under drought stress that can be used for water-efficient turf management under the Mediterranean environment.
A Method for Assessing Drift Potential of a Citrus Herbicide Applicator
Authors: Vanella Giuseppe , Salyani Masoud , Balsari Paolo , Futch Stephen H. , Sweeb Roy D.
Published: December 2018

The main objective of this study was to evaluate the suitability of the DEIAFA drift test bench system (Dipartimento di Economia e Ingegneria Agraria, Forestale e Ambientale; University of Torino, Italy) for assessing drift potential of a citrus (Citrus sp.) herbicide applicator. The study involved testing the effects of spray drift shield, nozzle type, and ground speed on drift potential of the applications. It was carried out in randomized block design within a split-split-plot experiment with five replications. A computational analysis procedure for evaluation of deposit values, measured along the test bench, was developed to compare the treatments in terms of a drift potential index (DPI). The methodology provided repeatable results. Among the treatments, ground speed was the main factor affecting the DPI. Both nozzle types tested [flat fan extended range nozzle (XR) and wide-angle deflector nozzle (TT)] showed higher DPI at faster speed. Decreasing the ground speed from 6.0 to 3.0 km·h−1 decreased the drift potential on average ≈35%. The performance of XR nozzle was improved by the presence of spray drift shield (27% reduction in DPI). However, the shield did not affect the drift potential of the TT nozzle significantly. The results were significantly affected by the wind velocity normalized by its direction relative to the sprayer travel; therefore, the tests should be carried out in relatively calm wind conditions, as much as possible.
Effect of Healing Chamber Design on the Survival of Grafted Eggplant, Tomato, and Watermelon
Authors: Johnson Sacha J. , Miles Carol A.
Published: December 2018

Successful grafting of vegetables requires high relative humidity (RH) and optimal temperatures for ≈1 week following grafting to reduce transpiration of the scion until rootstock and scion vascular tissue are healed together and water transport is restored. This study evaluated the effect of three healing chamber designs on the survival of grafted eggplant (Solanum melongena), tomato (Solanum lycopersicum), and watermelon (Citrullus lanatus). The three healing chamber designs were 1) an industry design, which was hand-misted, 2) a research design, which contained a humidifier, and 3) a simplified design, which was shadecloth only and hand-misted. All plants were self-grafted using the splice grafting technique, placed in the healing chamber for 7 days after grafting and evaluated for signs of wilting and graft failure from day 6 to day 14 after grafting. During the 7-day healing period, the industry design had the greatest fluctuation in temperature, the research design had the greatest fluctuation in RH, and the shadecloth only design had the least fluctuation in both temperature and RH. When the healing chambers were closed on day 2 after grafting, the industry healing chamber had higher mean temperature and RH (24.9 °C, 98%) than both the research (23.4 °C, 81%) and shadecloth only (23.3 °C, 52%) healing chambers. These results suggest that a humidifier may not be necessary to maintain high RH. Mean graft survival rates in the industry (69%) and research (66%) healing chambers were similar, and both were higher than that in the shadecloth only healing chamber (52%). Tomato had the highest rate (98%), eggplant was intermediate (82%), and watermelon had the lowest mean survival rate (7%); there was no interaction between healing chamber and crop. The very low survival rate of watermelon was most likely due to the grafting technique used in this study, which is not optimal for watermelon. Tomato graft survival was high in all three healing chambers (96% to 98%), suggesting that high RH is not essential for tomato graft survival. Eggplant graft survival decreased from 90% to 60% when RH was decreased, suggesting that high RH is essential for eggplant graft survival.
Winter 2011 Low-temperature Injury to Stone Fruit Flower Buds in New Mexico
Authors: Yao Shengrui
Published: December 2018

Twelve peach (Prunus persica) cultivars, six apricot (Prunus armeniaca) cultivars, two japanese plum (Prunus salicina) cultivars, three european plum (Prunus domestica) cultivars, four sweet cherry (Prunus avium) cultivars, and three tart cherry (Prunus cerasus) cultivars were monitored for winter damage at New Mexico State University's Sustainable Agriculture Science Center in Alcalde, NM (main site), and the Agricultural Science Center in Los Lunas, NM (minor site), in 2011. Uncharacteristically low temperatures on 1 Jan. and 3 Feb. were recorded as −7.2 and −11.3 °F, respectively, at Alcalde, and 4.8 and −13.9 °F, respectively, at Los Lunas. On 10 Jan. at Alcalde, live peach flower bud percentage varied by cultivar, ranging from 11% for Blazingstar to 25% for PF-1, and 85% to 87% for Encore and China Pearl. Apricot flower buds were hardier, with 70% survival for ‘Perfection’, 97% for ‘Sunglo’, and 99% for ‘Harglow’ on 10 Jan. By 10 Feb., almost all peach flower primordia were discolored, with no cultivar showing more than 1% survival. Based on this information, the 10% kill of flower buds for most peach cultivars occurred at temperatures equal to or slightly higher than −7.2 °F, and 90% kill occurred between −7.2 and −11.3 °F. On 10 Feb., 0% to 15% of apricot flower buds on spurs or shoots of the middle and lower canopy had survived. For vigorous shoots in the upper canopy, apricot flower buds on 1-year-old shoots had a higher blooming rate than those on spurs of 2-year-old or older wood. Flower buds of japanese plum were also severely damaged with less than 0.2% survival for ‘Santa Rosa’ and 4.8% for ‘Methley’, but european plum were relatively unaffected with over 98% flower bud survival for ‘Castleton’ and ‘NY6’, and 87% for ‘Stanley’ after −11.3 °F at Alcalde. Cherry—especially tart cherry—survived better than peach, apricot, and japanese plum after all winter freezes in 2011.
Responses of Lettuce Cultivars to Insect Pests in Southern Florida
Authors: Lu Huangjun , Wright Alan L. , Sui David
Published: December 2018

Banded cucumber beetle [BCB (Diabrotica balteata)], serpentine leafminer [SL (Liriomyza trifolii)], and aphids (Homoptera: Aphididae) are among the major insect pests that cause significant economic damage to lettuce (Lactuca sativa) in southern Florida. Four romaine cultivars and three iceberg cultivars, currently used in Florida's lettuce production, were evaluated from Oct. 2010 to Jan. 2011 in separate field experiments for their responses to insect infestation. Lettuce cultivars differed significantly in their responses to infestations of BCB and aphids. Cultivar 70096 had the lowest percent (3.7%) of BCB feeding damage among the romaine cultivars. Romaine cultivar Manatee also had significantly lower BCB feeding damage (12.1%) than the susceptible cultivars Okeechobee (19.8%) and Terrapin (19.1%). The lowest level of infestation of aphids was observed on ‘Manatee’, followed by ‘70096’, whereas ‘Okeechobee’ and ‘Terrapin’ had severe infestation of aphids. The iceberg cultivars were similar to one another in their responses to BCB and SL but not in their response to aphid infestation. Yield was decreased from 3% to 37% for six of the seven cultivars grown under the adverse environmental conditions of insect infestations and cold weather in Dec. 2010, but the yield of ‘70096’ did not decline. The cultivars identified as resistant to insects can play an important role in integrated pest management (IPM), which may decrease pesticide application, reduce production costs, and protect the environment.
Shoot Regeneration and Plantlet Formation by Cascade Huckleberry, Mountain Huckleberry, and Oval-leaf Bilberry on a Zeatin-containing Nutrient Medium
Authors: Debnath Samir C. , Barney Danny L.
Published: December 2018

A plant regeneration protocol was developed for cascade huckleberry (Vaccinium deliciosum), mountain huckleberry (V. membranaceum), and oval-leaf bilberry (V. ovalifolium) clones. The effects of zeatin concentrations (0, 4.6, 9.1, and 13.7 μM) and explant type (leaf or stem segment) on adventitious shoot regeneration were studied on a nutrient medium of low ionic concentration. Adventitious bud and shoot regeneration was greatly influenced by clone, explant type, and zeatin concentration. Zeatin at 9.1 to 13.7 μM supported the best bud and shoot regeneration. At low concentrations (2.3 to 4.6 μM), zeatin enhanced shoot elongation and produced usable shoots after one additional subculture. The three clones differed significantly with respect to multiplication rate of adventitious shoots. Oval-leaf bilberry and mountain huckleberry clones produced six to seven 5-cm-long shoots per explant and cascade huckleberry clone produced five 3-cm-long shoots per explant, when 2.3 μM zeatin was used in the medium. Increasing the concentration of zeatin in the culture medium increased shoot number per explant, but decreased shoot height, leaf number per shoot, and shoot vigor. Proliferated shoots were rooted on the same medium but without any plant growth regulators (PGRs). Rooted plantlets were transferred to a 2 peat:1 perlite (v/v) medium for acclimatization and eventually established in the greenhouse with 75% to 90% survival rate. This in vitro protocol will be useful for micropropagation, in vitro selection, and genetic manipulation of Vaccinium species.
Augmentation of Antioxidant Constituents by Drought Stress to Roots in Leafy Vegetables
Authors: Koyama Ryohei , Itoh Hiromichi , Kimura Syuji , Morioka Ai , Uno Yuichi
Published: December 2018

Plants can synthesize some antioxidants, including L-ascorbic acid (AsA) and polyphenol, in response to environmental stresses. Antioxidants detoxify reactive oxygen species in plants and also aid in human health. In this study, we demonstrate that a novel hydroponic treatment can increase leafy vegetable nutritional quality without retarding growth. Leaf lettuce (Lactuca sativa) was grown hydroponically and subjected to rhizosphere drought stress by lowering the water level in the solution tub before harvesting. Appropriate drought stress using this method could increase AsA, polyphenol, and sugar content by 24%, 50%, and 17%, respectively, and decrease nitrate nitrogen content by 18% without reducing yield. Similar effects of drought stress on AsA content were observed in four other plant species. This hydroponic method has a universal potential to increase leafy vegetable quality without reducing yield in controlled environments such as plant factories.
Pre- and Postemergence Herbicide Tolerance of Tropical Fimbry, a Native Hawaiian Sedge with Potential Use for Roadside Revegetation
Authors: Baldos Orville C. , DeFrank Joseph , Sakamoto Glenn
Published: December 2018

Tropical fimbry (Fimbristylis cymosa) is a salt, wind, and drought tolerant sedge under consideration as a native roadside revegetation species in Hawaii. Multiple rate studies were conducted on transplanted tropical fimbry plugs to identify pre- and postemergence herbicides that are safe for selective weed control during plant establishment. The response of newly transplanted tropical fimbry plugs to applications [1 and 44 days after transplanting (DAT)] of oxadiazon (2.0 and 4.0 lb/acre), oryzalin (2.0 and 4.0 lb/acre), and oxadiazon + oryzalin (2.0 + 2.0 and 4.0 + 4.0 lb/acre) were evaluated at 212 DAT through visual vigor ratings and seedhead counts. Response of established transplants to the postemergence broadleaf herbicides, aminopyralid (0.06 and 0.11 lb/acre) sulfosulfuron (0.06 lb/acre), prepackaged mixes of carfentrazone-ethyl + (4-chloro-2-methylphenoxy)acetic acid (MCPA) + mecoprop + dicamba (0.02 + 1.11 + 0.22 + 0.11 lb/acre), and carfentrazone-ethyl + 2,4-D + mecoprop + dicamba (0.02 + 0.77 + 0.24 + 0.07 lb/acre) were evaluated through visual vigor ratings 35 days after spraying (DAS). Results of the preemergence study indicate that low rates of oxadiazon and oryzalin provided an acceptable level of growth suppression to the sedge (>60% visual vigor). Postemergence applications of the prepackaged formulations of carfentrazone-ethyl resulted in moderate to high foliar injury (46% to 74%) and plant mortality (17% to 23%). Plants treated with sulfosulfuron showed signs of stunting (visual vigor of 36%), but exhibited the least foliar injury (16%) and no mortality. Plants treated with high and low recommended rates of aminopyralid exhibited very low injury ratings (1% to 2%) at 35 DAS. Results obtained from these preliminary studies identified oxadiazon, oryzalin, and aminopyralid as potentially safe for controlling weed species in transplanted tropical fimbry.
Winter-applied Glyphosate Effects on Spring Green-up of Zoysiagrasses and ‘Yukon’ Bermudagrass in a Transition Zone
Authors: Rimi Filippo , Macolino Stefano , Leinauer Bernd
Published: December 2018

In transitional environments, turf managers and sod producers of warm-season grasses face the issue of winter annual weeds that can dominate dormant turf stands through the winter until late spring. The use of glyphosate to control weeds in dormant bermudagrass (Cynodon dactylon) has been well documented, but information is lacking about its effect on spring green-up of other warm-season grasses. A field study was conducted on two commercial sod farms in northern Italy (Expt. 1) to evaluate the effects of glyphosate applied on two different winter dates on weed control and spring green-up of ‘Zeon’ manilagrass (Zoysia matrella). A second study was carried out at the experimental agricultural farm of Padova University (Expt. 2) to assess the effects of a winter application of glyphosate on weed control and spring green-up of ‘Yukon’ bermudagrass and ‘Companion’ zoysiagrass (Zoysia japonica). Each experiment was conducted from Jan. to June 2011, and glyphosate was applied at 1.1 kg·ha−1 on 8 and 21 Feb. in Expt. 1 and on 8 Feb. in Expt. 2. Spring recovery was evaluated by periodical visual ratings of green turf cover and by collecting normalized difference vegetation indices (NDVIs). Weed injury was visually evaluated on all plots 7 weeks after the 8 Feb. glyphosate application. The visual ratings of green cover were strongly and positively correlated with NDVI measurements. Glyphosate applied in February as a single treatment effectively controlled winter weeds in ‘Zeon’ manilagrass (Expt. 1) and ‘Yukon’ bermudagrass (Expt. 2) without negatively affecting spring green-up. In contrast, spring green-up of ‘Companion’ zoysiagrass (Expt. 2) was delayed by the application of glyphosate.