bluuebunny/crossref_metadata_2025 huggingface dataset:
Engineering Principles Impacting High-tunnel Environments
Authors: Giacomelli Gene A.
Published: December 2018

High tunnels are a special type of greenhouse with primary operational goals of season extension, crop quality improvement, and new crop production opportunities to reach unique markets. From an engineering viewpoint, high tunnels have many of the same design concerns as larger, more complex greenhouses. They capitalize on the greenhouse effect as do all enclosed plant growth structures. However, less automated environmental control systems are required for the desired crop production. Tunnel designs are less complex and less expensive than large high-technology greenhouse ranges, but they must be designed and constructed with the fundamental assurance of structural stability, safety, efficient layout, appropriate environmental control, and effective crop management in mind.
Potato Tuber Proteins as Molecular Probes for Tuberization
Authors: Park William D.
Published: December 2018

The potato has tremendous potential as a source of human food. Potato is second only to sugarcane in carbohydrate production and soybeans in protein production per hectare (6). Furthermore, the proteins in potato are of excellent nutritional quality, unlike those of most cereals and legumes (7, 8, 20). The potato combines these properties to produce more nutritious human food per hectare than any of the other major food crops (20).
High Tunnel Tree Fruit Production: The Final Frontier?
Authors: Lang Gregory A.
Published: December 2018

High tunnel production systems typically use horticultural crops that are annually or biennially herbaceous, high in value, short in stature, and quick to produce. At best, tree fruits may fit only one of these criteria–high value. Sweet cherry (Prunus avium) may command high enough values in premium market niches to make high tunnel production strategies worth attempting. Furthermore, sweet cherry production can be a risky endeavor, even in optimal climates, due to the potentially devastating effects of preharvest rain that cause fruit cracking. Consequently, environmental modification by tunnels in regions like the Great Lakes provides a significant risk reduction. Additional potential benefits, such as protection from frosts, diseases, insects, wind scarring, etc., add further production value. Multi-bay high tunnels were constructed in 2005 at two Michigan State University experiment stations, over established and newly planted sweet cherry trees on dwarfing rootstocks, to study and optimize the effects of production environment modification on vegetative and reproductive growth, marketing season extension, and protection of cherries from diseases, insect pests, and/or physiological disorders. Results with tunnels thus far include premium fruit quality and high crop value; increased leaf size and terminal shoot growth; decreased radial trunk growth; decreased chemical pesticide inputs; decreased incidence of cherry leaf spot (Blumeriella jaapii) and bacterial canker (Pseudomonas syringae); increased incidence of powdery mildew (Podosphaera clandestina); inconclusive effects on brown rot (Monolinia fructicola); no or reduced infestation by plum curculio (Conotrachelus nenuphar) or cherry fruit fly (Rhagoletis cingulata); dramatically reduced japanese beetle (Popillia japonica) damage; and increased black cherry aphid (Myzus cerasi) and two-spotted spider mite (Tetranychus urticae) populations.
In Vitro Propagation of Pecan Seedlings
Authors: Hansen Keith C. , Lazarte Jaime E.
Published: December 2018

Single-node cuttings obtained from 2-month-old seedlings of pecan [Carya illinoinensis (Wang.) K. Koch] were induced to break buds and form multiple shoots in liquid, woody plant medium (WPM) and 2% glucose supplemented with 6-benzylamino purine (BA) at 3 mg/liter. In vitro-derived shoots soaked in 1-3 mg/liter indolebutyric acid (IBA) produced adventitious roots in vitro; when soaked for 8 days in 10 mg/liter IBA, they were rooted successfully in soil and acclimated to greenhouse conditions. Etiolation of stock plants did not improve shoot proliferation or rooting under in vitro culture.
A Nondestructive System for Monitoring Gas Evolution from Small-sized Fruits in the Field
Authors: Lang Gregory A. , Martin George C.
Published: December 2018

A nondestructive system for measuring volatile compounds, specifically ethylene, evolved from intact fruit of olive (Olea europaea L.) in the field is described. Polyethylene cans from 35-mm film cartridges are modified with a rubber septum for sampling. The lid is sealed around the fruit peduncle and remains in the field under all conditions. The can is removable to expose the fruit to normal conditions when sampling is not being done. Samples of the atmosphere inside the can are taken with a syringe for gas chromatographic analysis. Background ethylene evolution from the system is low. The system allows repeated monitoring of the same fruit over the duration of a season. Nineteen glues and sealants are evaluated for bonding, phytotoxicity, and ethylene evolution.
Mulched Maple and Oak Leaves Associated with a Reduction in Common Dandelion Populations in Established Kentucky Bluegrass
Authors: Kowalewski Alexander R. , Buhler Douglas D. , Lang N. Suzanne , Nair Muraleedharan G. , Rogers John N.
Published: December 2018

Previous research has shown that maple (Acer spp.) leaf litter resulted in fewer common dandelions (Taraxacum officinale) when mulched into established turfgrass. However, the leaves used in that research may have contained herbicide residues and were separated by genus, not species. Our research compared the effects of pesticide-free mulched maple and oak (Quercus spp.) leaves on dandelion populations in an established kentucky bluegrass (Poa pratensis) stand maintained as a residential lawn on sandy loam soil. The objectives of this study were to quantify the effectiveness of maple or oak leaf mulches as an organic common dandelion control method and to identify which maple species and rates (particle size and rate per unit area) provided the most effective control. The experimental design was a randomized complete block with treatments arranged as a 5 × 2 × 2 + 1 factorial, with tree leaf species, leaf particle size, leaf application rate, and control as main factors. Leaf species were red maple (Acer rubrum), silver maple (A. saccharinum), sugar maple (A. saccharum), high sugar content sugar maple, and red oak (Quercus rubra). Particle sizes were coarse (0.4–1.0 inch2) and fine (≤0.2 inch2), and application rates were low (0.5 kg·m−2) and high (1.5 kg·m−2). Mulch applications were made in Fall 2003 and 2004 and data were collected beginning in Spring 2004 on kentucky bluegrass spring green-up, and common dandelion plant counts. The high application rate, regardless of tree genus or species, resulted in the highest green-up ratings. Common dandelion plant counts after one (2003) and two (2003 and 2004) mulch applications at the high rate showed that up to 80% and 53% reduction was achieved, respectively. Results indicate that mulching leaves regardless of genus (oak or maple) or maple species into established turfgrass as a leaf litter disposal method will increase spring green-up and contribute to a reduction in common dandelion population.
AR Hale’s Best Jumbo, AR 5, and AR Topmark: Melon Aphid-resistant Muskmelon Breeding Lines
Authors: McCreight J. D. , Kishaba A. N. , Bohn G. W.
Published: December 2018

The melon (or cotton) aphid (Aphis gossypii Glover), an economically important pest throughout the world (1), is an important vector of muskmelon viruses (6), and often causes damage by feeding large populations on this favored host (7). Resistance to the melon aphid was found in muskmelon PI 371795 from India (4).
Influence of Cultivar, Growing Media, and Cluster Pruning on Greenhouse Tomato Yield and Fruit Quality
Authors: Hanna Hanna Y.
Published: December 2018

Cultivars and growing media are important components of a successful greenhouse tomato (Solanum lycopersicum) operation. Two studies were conducted simultaneously and independently in two 30 × 96-ft greenhouses in Spring 2006 and 2007 (January–July) to assist producers in selecting appropriate cultivars and reducing production cost. The first study was conducted to evaluate yield, fruit weight, fruit quality, and shelf life of ‘Geronimo’, ‘Quest’, and ‘Trust’ tomatoes planted in perlite and pruned to three or four fruit per cluster. The second study was conducted to determine the initial cost of perlite, pine bark, and rockwool growing media and their effect on yield of ‘Quest’ pruned to three or four fruit per cluster. ‘Geronimo’ produced the highest total marketable yield and ‘Trust’ produced the lowest. ‘Trust’ produced more cull yield and lower fruit weight than ‘Geronimo’ or ‘Quest’. Pruning clusters to three fruit increased total marketable yield and fruit weight, and reduced cull yield of all cultivars. Only ‘Geronimo’ produced higher early marketable yield at four fruit per cluster. All cultivars produced higher early marketable yield in 2007 than in 2006. Tested cultivars had similar fruit content of potassium and sodium and similar concentration of soluble solids. ‘Trust’ fruit had a higher pH than the other two cultivars. About 92% of ‘Quest’ tomatoes remained marketable after storage at 67 °F for 1 week. ‘Geronimo’ and ‘Trust’ had only 83% and 78% marketable fruit, respectively, under the same conditions. Initial costs to grow greenhouse tomatoes in perlite were higher than in rockwool, and were the lowest in pine bark. Plants grown in perlite produced higher total marketable yield than plants grown in either of the other media. They produced lower cull yield than plants grown in rockwool, but produced similar cull yield to plants grown in pine bark. Pruning clusters to three fruit increased total marketable yield and fruit weight in both studies. Pruning clusters to four fruit increased cull yield in both studies regardless of planting year.
Pecan Nutrient Element Status and Orchard Soil Fertility in the Southeastern Coastal Plain of the United States
Authors: Wells M. Lenny
Published: December 2018

This survey addresses the current nutritional status of orchards typical of a large portion of the United States pecan (Carya illinoinensis) industry. A leaf nutrition and soil fertility survey was conducted for commercial orchards in a major production area of the U.S. pecan belt, which is located in southern Georgia. The study sampled pecan orchards from 18 July to 5 Aug. 2005 and 17 July to 3 Aug. 2008. All orchards had a history of commercial level orchard management, and represented a wide range of orchards typical of the region. Results indicate that southeastern U.S. pecan producers should focus their nutrient inputs on nitrogen (N), potassium (K), sulfur (S), and copper (Cu) as needed. The survey results show that leaf N can vary widely by season and among orchard locations. Evidence indicates that many growers could likely forego the soil application of phosphorous (P) and zinc (Zn) until leaf or soil analysis indicates a need. Orchard soil organic matter (SOM) in 2008 averaged 3.63%, and ranged from 1.74% on coarse-textured sandy soils to 5% on sandy loam soils. Both SOM and soil nitrate-N were higher in orchards using clover (Trifolium spp.) as a cool-season orchard groundcover than those using a grass sod only. The mean carbon:S ratio of Georgia pecan orchard soils was 504:1, which may further reduce tree uptake of S from low-S soils.
The Effects of Reflective Film on Fruit Color, Quality, Canopy Light Distribution, and Profitability of ‘Mondial Gala’ Apples
Authors: Iglesias Ignasi , Alegre Simó
Published: December 2018

The effects of covering the orchard floor with Extenday™ or Solarmate™ reflective films on fruit color, fruit quality, canopy light distribution, orchard temperature, and profitability of ‘Mondial Gala’ apples (Malus ×domestica) were evaluated over a 3-year period (2000–02) at Lleida (northeastern Spain). Reflective film was laid down 5 weeks before commercial harvest. Photosynthetically active radiation in the lowest part of the tree (1 m aboveground level) increased by 34% and 56%, for Solarmate™ and Extenday™ films, respectively, compared with the control. Fruit color, measured with a portable tristimulus colorimeter, significantly increased on both sides of the fruit (with lower values of L* and hue) when using the film. A higher proportion of red blush over the fruit surface was observed for the fruit in the film treatments. Based on the fruit size and color required to meet European Union grade standards, the use of Extenday™ or Solarmate™ resulted in an increase of 26% and 17%, respectively, when compared with the control, for the number of fruit picked at first harvest. Season clearly affected fruit color development, whereas harvest date, fruit firmness, fruit size, soluble solid concentration, titratable acidity, and maturity were not consistently affected by the use of reflective film. Despite the advance in fruit color, the starch score did not appear to be affected by the use of film. Based on current fruit prices for the study period, both types of film increased orchard profitability compared with the control, but the long-term benefit of this technique will largely depend on fruit prices.
Improving the Evaluation of Public Garden Educational Programs
Authors: Steil Aaron , Lyons Robert E.
Published: December 2018

Professional staff at public gardens often overlook educational program evaluation for a variety of reasons, but it remains important for program funding and development. This study developed an original, six-step evaluation approach specific to educational programs at public gardens. Interviews subsequently were conducted with 11 executive directors and/or directors of education at 10 public gardens in the United States with proven, high-quality educational programs. Interviews examined the feasibility, practicality, perceived effectiveness, and merits of the original evaluation approach developed in this study. Interview data added clarification to what is known about the current state of educational program evaluation at public gardens and supported and further improved the original evaluation approach to create an improved version.
Transplanting Palms
Authors: Hodel Donald R. , Downer A. James , Pittenger Dennis R.
Published: December 2018

The optimum time to transplant palms (Arecaceae) is at the beginning of the warm season in temperate climates or at the beginning of the rainy season in tropical climates if irrigation is unavailable. Careful and proper handling, including covering and protecting the leaves and root ball during transplanting to protect them from injury and drying out and immediate planting upon arrival at the new site, helps to ensure rapid and successful establishment. A root ball extending out from the trunk for 30 cm appears to be adequate for most solitary-stemmed species. Larger root balls may be necessary for multistemmed or unusually tall or large specimens. Tying up leaves facilitates handling during digging, transport, and planting, but it is best to untie them after planting. In most instances leaf removal during transplanting does not appear to be advantageous, and it is probably best to remove leaves only when they die and turn brown. Too deep or too shallow planting lowers transplant success and stresses palms, making them susceptible to diseases, disorders, and pests. Amending the backfill when transplanting palms is not beneficial in most cases. However, mulch applied around the base of the palm after transplanting can enhance growth. Keeping the soil, backfill, and surrounding site soil evenly moist helps to ensure successful establishment.
Estimating Water Needs of Landscape Palms in Mediterranean Climates
Authors: Pittenger Dennis R. , Downer A. James , Hodel Donald R. , Mochizuki Maren
Published: December 2018

The responses of five landscape palm species [king palm (Archontophoenix cunninghamiana), mediterranean fan palm (Chamaerops humilis), queen palm (Syagrus romanzoffiana), chinese windmill palm (Trachycarpus fortunei), and california fan palm (Washingtonia filifera)] to three levels of irrigation [50%, 25%, and 0% (no irrigation) of reference evapotranspiration] were evaluated in a coastal mediterranean climate in Irvine, CA. Cumulative leaf production varied greatly among the species, but only king and chinese windmill palms produced more leaves with additional irrigation. All species maintained at least minimally acceptable visual quality at the no-irrigation treatment. Mediterranean fan and california fan palms expressed near optimum performance with no irrigation. Many established landscape palms can maintain at least minimally acceptable appearance for an extended period with little or no supplemental water in coastal mediterranean climates. However, when rainfall plus irrigation is less than 50% of reference evapotranspiration, sensitive landscape palms could be expected to appear less attractive and grow less. Responses of palm species in this study were similar to those of many other landscape tree and shrub species, but the water needs of landscape palms are considerably less than those of commercial date palm (Phoenix dactylifera), oil palm (Elaeis guineensis), or coconut palm (Cocos nucifera).
Present Status and Future Prospects of Cut Rose Production in Punjab, Pakistan
Authors: Ahmad Iftikhar , Dole John M. , Khan M. Aslam , Qasim M. , Ahmad Tanveer , Khan A.S.
Published: December 2018

Present status and future prospects of cut rose (Rosa ×hybrida) flower production and postharvest management in Punjab, Pakistan, were investigated. Cut roses were the leading flower crop in the area under study, but production systems and practices were outdated and primitive, resulting in cut stems that were not acceptable in international markets. The majority of growers (65%) had only basic education (grade 10 or less) and 57% had small landholdings (<1 ha); therefore, they did not have modern production techniques and resources for high-quality cut rose production. Moreover, lack of production and postharvest facilities, ignorance of both public and private resources, and poor production and postharvest practices were prevalent. Growers' training regarding production and postharvest management would be required to lift the quality standards of this industry up to the international level. However, a positive trend was observed in cut rose businesses as more than half of growers (52%) entered into the business during last 5 years. In addition, 30% of growers were in business over 10 years, indicating that cut rose production can provide a sustained income for producers. This analysis of the cut rose industry in Punjab can serve as a model for other countries whose cut flowers industries are at a similar stage of development.
In Vitro Propagation of Dierama latifolium
Authors: Page Yvonne M. , Van Staden J.
Published: December 2018

Dierama latifolium N.E. Br. was propagated in vitro using corm cultures. Shoots were induced from corm explants when grown on solidified Murashige and Skoog (MS) medium supplemented with 30 g/liter sucrose, 100 mg/liter meso-inositol, and 0 or 0.5 mg/liter NAA. Shoot proliferation was not improved by the addition of BA to the initial culture medium. Multiple shoots were induced by transferring those produced in vitro, to a modified MS medium supplemented with 0.5 or 1.0 mg/liter BA. Rooting of these shoots was induced by subculturing single excised shoots, 5-10 mm in height, either a hormone-free basal medium or a BM supplemented with 0.5 or 1.0 mg/liter NAA. Utilizing this technique, about 90 plants could be produced from a single corm within 12 months. Chemical names used: 1-napthalenacetic acid (NAA); N-(phenylmethyl)-1H-purin-6-amine(BA).
Performance of Sweetpotato Foundation Seed after Incorporation into Commercial Operations in Louisiana
Authors: Clark Christopher A. , Smith Tara P. , Ferrin Donald M. , Villordon Arthur Q.
Published: December 2018

Because sweetpotato (Ipomoea batatas) is vegetatively propagated, viruses and mutations can accumulate readily, which can lead to cultivar decline. Sweetpotato foundation seed programs in the United States maintain the integrity of commercial seed stock by providing virus-tested (VT) foundation seed to commercial producers. A survey was conducted in Louisiana from 2007 to 2009 to examine the performance and quality of the foundation seed after it had been integrated into commercial sweetpotato operations. G1 seed [grown 1 year after virus therapy in the foundation seed production field at the Sweet Potato Research Station, Louisiana State University Agricultural Center (LSU AgCenter), at Chase, LA] was used as a reference to compare the yield and virus incidence of growers' generation 2 (G2) and generation 3 (G3) seed roots (grown in the growers' seed production fields 1 or 2 years following the year of foundation seed production). Although yields of plants grown from G2 and G3 seed were 86.3% and 86.1% for U.S. No. 1 and 83.3% and 86.0% for total marketable, respectively, compared with the yields from G1 seed, they were not significantly different. Yield and virus incidence data suggest that seed quality may vary from year to year and from location to location. Results from this study suggest that producers are realizing yield benefits by incorporating VT foundation seed into their production schemes, but further benefits could be attained if ways to reduce re-infection with viruses can be found.
Effect of Water Additives on Fraser Fir Needle Retention
Authors: Hinesley L.E. , Blankenship Sylvia M.
Published: December 2018

Several floral and tree preservatives were evaluated to determine their effect on postharvest needle retention of Fraser fir [Abies fraseri (Pursh) Poir.], an important Christmas tree species. Clorox (sodium hypochlorite) and aspirin (salicylic acid) caused massive needle loss, and three of the six commercial additives increased needle loss significantly, No treatment was better than water alone.
Hazelnut Pollination
Authors: Olsen J.L. , Mehlenbacher S.A. , Azarenko A.N.
Published: December 2018

Hazelnuts, (Corylus avellana L.), are wind-pollinated, monoecious, mostly dichogamous, and self-incompatible. About 90% of the cultivars studied are protandrous. Anthesis of the pistillate flower is temperature-dependent and occurs December through February, peaking in January. Stigmatic surfaces may remain receptive for up to 3 months. Four to 5 months separate pollination and fertilization of the ovule; the latter usually occurring between mid-May and the end of June in Oregon. A 10% pollinizer density has been the standard, with a recommended distance of 66 ft (20 m) or less between the main cultivar and the nearest pollinizer. Two or three different pollinizer cultivars, with different times of pollen shed, are recommended. The Oregon hazelnut industry is presently combating the fungal disease, eastern filbert blight, caused by Anisogramma anomala (Peck). Current management recommendations suggest reducing risk of infection are to reduce the most susceptible pollinizer cultivars to a density 5%, then gradually replace those left with immune or more resistant genotypes.
Pollination of Almonds: Practices and Problems
Authors: Connell Joseph H.
Published: December 2018

California almonds [Prunus dulcis, (Mill.) D.A. Webb, syn. Prunus amygdalus Batsch] are self-incompatible requiring cross-pollination to produce a commercial crop. Within seven known pollen groups, they also display cross-incompatibility. Coincidence of bloom between compatible cultivars is essential for cross-pollination. Since almonds are pollinated primarily by honeybees [Apis mellifera L.], arranging pollinizers in close proximity to one another promotes maximum pollen transfer. Almonds are frequently subject to inclement weather during their February bloom period. Strong honeybee colonies are better able to forage during marginal weather conditions than are weak colonies. Honeybee management can encourage pollen foraging and placement of colonies can affect flight activity and ultimately nut-set. Weather permitting vigorous honeybee flight activity is the most important factor for setting a good crop. Temperature also affects anther dehiscence, pollen germination, and pollen tube growth. The sooner an almond flower is cross-pollinated after opening, the greater the chance of fertilization and nut-set. Optimizing all of these pollination factors is therefore essential to achieve maximum production in almond orchards.
Pollination Characteristics of Pecan Trees and Orchards
Authors: Wood Bruce W.
Published: December 2018

There is increasing evidence of substantial pollination related crop losses by pecan [Carya illinoensis (Wangenh.) K. Koch] orchards. These most likely occur in block-type orchards consisting of only one or two cultivars, but can also occur at locations with a great number of different genotypes nearby. Main crop cultivars should generally be within about two rows of pollinizers to ensure cross-pollination. Thus, block widths exceeding about four rows between pollinizers are especially likely to exhibit serious pollination problems. Scattered trees of off-type genotypes are potentially of major importance as backup orchard pollinizers. Tree age/size and spring temperatures influence the characteristics of flower maturity windows and are probably primary factors contributing to pollination-related fruit-set losses in many block-type orchards. Flower maturity tends to be earlier in older/larger trees while warmer springs accelerate catkin development relative to that of pistillate flowers. Because of substantial variability in relative differences associated with initiation and duration of flower maturity windows within either protandrous or protogynous flowering types (i.e., Type I or II), selection of complementary pollinizers should be based on the relatively high resolution 30-class flowering classification system rather than the traditional low resolution 2-class system. Other factors sometime causing pollination related crop losses are either abnormally wet weather or strong dry winds during the pollination period or abnormally warm or cool springs. Pollination problems can be visually detected by noting premature non insect related post pollination fruit drop or diminishing fruit set with increasing distance from pollinator trees or off-type genotypes within the orchard.
Education, Research, and Use of Human-Horticulture Relationships in Japan and Korea
Authors: Matsuo Eisuke
Published: December 2018

Plants and horticulture play an integral role in the cultural heritage of eastern societies. Plants are deemed as important in many ways besides being a source of food and shelter. The present study summarizes information on research and trends in the value and application of horticulture collected from professionals in Asian countries, focusing on the work in human-horticulture relationships in Korea and Japan.
Using Nitrogen Balance to Calculate Fertilization in Strawberries
Authors: Gariglio N.F. , Pilatti R.A. , Baldi B.L.
Published: December 2018

In Santa Fe, Argentina, strawberries (Fragari ×ananassa Duch.) are cultivated in the area of Coronda where N fertilization usually exceeds crop requirements. The objective of this work was to test four types of fertilization methodology to optimize fertilizer use efficiency. Experiments were carried out at the horticultural center of the Facultad de Agronomía y Veterinaria, in Esperanza, Santa Fe, 31.15° S latitude, on a typical argiudol soil. `Chandler' was planted 13 Mar. 1996. Nitrogen demand was related to the dry matter production with N content decreasing to increment of biomass (W), soil N mineralization was estimated according to the program EDAFO version 3. Using previous data, a monthly balance was calculated and four treatments were devised: control (T0) = without fertilization; treatment 1 (T1) = N fertilization covering the accumulated monthly deficit, 53 kg·ha-1 (47 lb/acre); treatment 2 (T2) = N fertilization covering the monthly deficit 66 kg·ha-1 (58 lb/acre); treatment 3 (T3) = N fertilization covering the total crop demand 117 kg·ha-1 (104 lb/acre). All N treatments significantly increased yields over the control. Yield increased to increasing N rates from 0 to 53 kg·ha-1. This response was due to an increase in fruit number but not in fruit weight. High N rates promoted runner growth without increasing fruit yield. The use N balance method for strawberry fertilization showed satisfactory results. Accumulated N balance (T1), required the least amount of N fertilizer while producing good yield, thus it should be the method adopted to reduce costs and environmental risks of N fertilization.
Leaf Zinc and Copper Concentrations of Mature Pistachio Trees in Response to Fertigation
Authors: Kallsen C.E. , Holtz Brent , Villaruz Lou , Wylie Chris
Published: December 2018

Mature `Kerman' pistachio (Pistacia vera L.) trees, located on the west side of the San Joaquin Valley of California on an alkaline clay-loam soil, were fertigated in 1997 and 1998 with three combinations of zinc (Zn) and copper (Cu) sulfate. Seasonal applications of Zn and Cu were injected at three separate times starting in spring and ending in summer. Efficacy of the treatments were compared by measuring the concentration of Zn and Cu in leaf tissue. Fertigated treatments were compared to trees receiving no supplemental Zn or Cu and to trees receiving a single foliar treatment of Zn and Cu each year. Soil Zn and Cu concentrations increased in the fertigated plots. Plots receiving the highest rates of Zn and Cu showed the greatest increase. However, at the recommended August leaf sampling period, only the foliar treated pistachio trees showed a significant increase in leaf Zn and Cu. The results demonstrate that after two seasons, a foliar application of Zn and Cu in April, two to three weeks after flowering, increased leaf-tissue concentrations of Zn and Cu to sufficiency levels. These foliar applications were more effective than fertigating with Zn and Cu sulfate.
Cell Size and Pretransplant Nutritional Conditioning Influence Growth and Yield of Transplanted `Jubilee' Watermelon
Authors: Graham Charles J. , Payne James T. , Molnar Eric J.
Published: December 2018

Increasing cell volume or pretransplant nutrient conditioning (PNC) reduced the time to flowering for staminate and pistillate flowers in watermelon [Citrullus lanatus (Thunb.) Matsum. & Nakai]. Larger cell volumes increased the number of early harvested watermelons and average watermelon weight in two of three studies. Similarly, larger cell volume increased the early and total yield per area of watermelons harvested in 1995 and 1998, but not in 1997. Effect of transplant cell volume on soluble solids varied seasonally. PNC increased the number of melons and the yield per area harvested early in 1995 and soluble solids in early harvested fruit in 1997, but had no significant effect on total `Jubilee' watermelon size or total production in Louisiana for 1995, 1997, or 1998. PNC offers the transplant grower little advantage, while increasing transplant cell size provides a grower with a better opportunity to produce increased early and total yields.
An Overview of the Current State of Human Issues in Horticulture in the United States
Authors: Lohr Virginia I. , Relf Paula Diane
Published: December 2018

Throughout history, plants have been used to benefit people. In the United States, formal research to document the impacts of plants on people was not published until the 1970s, when papers from social and medical scientists began to appear. In the 1990s, symposia, including the first on “The Role of Horticulture in Human Well-being and Social Development,” brought people together from around the world to share and expand their knowledge in this emerging field. Symposium participants have included researchers in the social sciences and plant sciences, practitioners in horticultural therapy, teachers in colleges and public gardens, industry representatives applying the knowledge, and more. This has formed the basis for current activities in research, teaching, and practice throughout the United States. Examples from research that now documents a variety of beneficial impacts of plants on people are discussed.
Perceived Benefits to Human Well-being of Urban Gardens
Authors: Dunnett Nigel , Qasim Muhammad
Published: December 2018

Private gardens occupy a significant proportion of the total surface area of a British city. For many people, the garden represents their only contact with nature and their chance to express themselves creatively. Yet relatively little research has been carried out on the role and value of such gardens to human well-being. We report in this paper on a major survey on the role of private, urban gardens in human well-being, conducted with a wide cross-section of randomly selected garden owners from the city of Sheffield, England, over the summer of 1995. In particular, we discuss the perceived value that gardens have to the well-being of people, both individually through the enjoyment of their own gardens and collectively through the contribution of city gardens to environmental enhancement. We relate these values to age, gender and social demographics.
The Transition from State to Local Funding for Virginia Master Gardener Volunteer Management
Authors: Dorn Sheri , Relf Paula Diane
Published: December 2018

Management changes brought about by 1996 budgetary action shifted local Master Gardener (MG) program management from state-funded local agents to a structure of coordinators consisting of locally funded agents, locally funded nonagent coordinators, and volunteers willing to take on additional responsibilities. The Virginia Cooperative Extension (VCE) MG volunteer program is currently available in 76 unit offices. The unit programs are managed by 46 MG coordinators, including 8 locally funded agents, 8 locally funded technicians, and 30 volunteers. Currently, there are 2747 MG volunteers (trainees, interns, and MGs). To provide consistent, state-level direction and leadership to this less experienced group of local coordinators and to prepare them for their jobs as MG program managers, current management materials were extensively revised and expanded and new resources were developed. These efforts to ensure that everyone understood the purpose and focus of the VCE MG program resulted in revision of MG program policies, development of new volunteer training materials, establishment of a state-level MG planning and work team, new management guidelines, in-service training for coordinators, an administrative website and electronic discussion listserv available only internally to agents and coordinators, and a state MG newsletter focused on the role of MGs as community leaders and educators.
Using Chat Rooms in a Plant Nutrition Course: Bane or Boon?
Authors: Paparozzi Ellen T. , Williams Kimberly A.
Published: December 2018

Chat rooms and their use in everyday life are becoming increasingly common, and the technology may be a useful tool to link students with experts of a given subject material and each other. In our shared course Plant Nutrition and Nutrient Management, we experimented with using a chat room to link students with experts in the field of plant nutrition. Our main goal was to enhance the learning experience of the students by providing them with access to national and international plant nutrition researchers. Web CT was used to create and conduct the chat rooms and a chat etiquette evolved to prevent crosstalk and control the flow of the discussions. Positive outcomes of the chat room use included exposure of students to the technology and beneficial interaction between students and experts. Negative aspects of chat room use included the time involved to coordinate the overall effort and train experts to use the technology; the slow pace of some chats; effective grading; and the superficial coverage of some topics. We are developing modifications for future sessions to allow subjects to be explored in more depth and to improve networking between students and experts.
Chestnut Production in the Northwestern United States
Authors: Olsen J.L.
Published: December 2018

The chestnut (Castanea Mill.) industry in the northwestern United States is in its relative infancy, with most orchards being less than 10 years of age. Currently there are an estimated 300 acres (121 ha) in Oregon and Washington. California has about 500 acres (202 ha) in chestnuts. Current worldwide production is over 500,000 tons (435,600 t). China is the leading producer with 40%, followed by Korea at 15%. Italy, Turkey and Japan grow 10% each, while France, Greece and Spain grow 4% each. The United States, Chile, Argentina, New Zealand and Australia each grow less than 1%. The value of chestnuts imported into the United States is estimated to be $10 to 15 million annually. Domestic producers hope to displace some of the imported chestnuts in the marketplace. The leading variety being grown in the western United States is `Colossal,' a hybrid between european chestnut (C. sativa Mill.) and japanese chestnut (C. crenata Gillet). `Dunstan' hybrids are chestnut blight (Cryphonectria parasitica Murr.) resistant, and were bred in Florida using chinese chestnut (C. mollisima Blume) and american chestnut (C. dentata Marsh. Borkh.) parentage. Prices received by chestnut producers in the northwestern United States have ranged from $1.20 to $7.00/lb ($2.64 to $15.40/kg). The marketing of chestnuts has been through brokers into wholesale markets, farmers markets, mail order and direct sales through catalogues and World Wide Web sites.
Pecan Production in the Northern United States
Authors: Reid William , Hunt Kenneth L.
Published: December 2018

More than 93% of pecans [Carya illinoinensis (Wangenh.) K. Koch] produced in the United States are grown in the southeastern and southwestern states. However, the native range of the pecan tree extends northward into Kansas, Missouri, and Illinois. In these northern states, commercial pecan production is expanding as additional acres of native trees are brought under cultivation and orchards of short-season, cold-hardy cultivars are established. Native nut production dominates the northern pecan industry accounting for over 95% of nuts produced in the region. Cultural practices for native pecans have been developed for northern groves that feature low inputs and good yields. Pecan cultivars adapted to the north ripen their fruit in a climate that provides 155 to 200 frost-free days. Few generalizations can be made about northern cultivars. The nuts produced by these cultivars vary in size from small [4 g (0.14 oz)] to medium [8 g (0.28 oz)] with shelling percentages ranging from 44% to 59%.
Geographic Information Systems Show Impact of Field Placement on sh2 Sweet Corn Stand Establishment
Authors: Barr Amy , Bennett Mark , Cardina John
Published: December 2018

The objective of this study was to ascertain if stand establishment of sh2 sweet corn (Zea mays L.) would benefit from variable planting depths determined by the use of geographic information systems (GIS). Spring and fall research plots were established in a field [80 × 20 m (262 × 66 ft)] containing Crosby silt loam and Kokomo silty clay loam soil series in Columbus, Ohio. Three sh2 sweet corn cultivars (Starship, Skyline, and Confection) were planted at three depths on the two soil types in the fall study, with an additional transition soil added in the spring. Emergence counts as well as soil moisture and temperature were monitored. In the spring, sites were also sampled for nutrient levels and soil compaction. Significant variability was found within the field with respect to soil moisture, temperature, nutrient levels, and compaction. Seedling emergence fluctuated with average soil moisture increasing in blocks with up to 24% moisture and then leveling off. Daily minimum soil temperatures impacted stand establishment. Although heat units accumulated faster on the Crosby soil, emergence was slower and less complete on these soil series than on Kokomo soil series. Further investigation determined that although temperatures of the Crosby soil were 3 to 4.5 °C (5.4 to 8.1 °F) warmer during the day than the Kokomo soil, temperatures on the Crosby soil averaged 2 °C (3.6 °F) cooler at night. Analysis of emergence patterns and field variability was performed on ArcView mapping software. Although `Skyline' planted at 2 cm (0.8 inches) had the best emergence overall, final stand would have been increased with `Skyline' planted variably at 2 and 4 cm (1.6 inches). Mapping the field under these different scenarios showed that although area with less than 70% stand would exist with a 2-cm uniform planting depth, the entire field would have a stand of 70% or greater with variable planting depth using a high vigor seedlot.
Sprinkler Spacing Does Not Affect Carrot Yield and Quality
Authors: Mitchell J.P. , Allaire-Leung S.E. , Sanden B.L. , Wu L.
Published: December 2018

Optimal water management is essential in irrigated agricultural regions to sustain productivity, conserve water resources and protect groundwater quality. The southern San Joaquin Valley (SJV) of California is a major irrigated production region in which solid set sprinkler systems are commonly used to grow such crops as carrots (Daucus carota L.), potatoes (Solanum tuberosum L.), garlic (Allium sativum L.) and onions (Allium cepa L.) in predominantly sandy soils. Water and fertilizer use efficiencies are important concerns in this region. In 1996 and 1997, we evaluated the effects of three sprinkler spacings [32.2, 38.6 and 45 ft (9.8, 11.8 and 13.7 m)] and irrigation uniformity within these spacings on carrot yield, quality and nitrogen content. Applied water and soil nitrate and ammonium contents were monitored at four locations within each sprinkler lateral spacing throughout both seasons. Neither sprinkler spacing nor location within a given sprinkler spacing affected carrot production or quality. Distributions of soil nitrate and ammonium resulting from the different sprinkler spacings were also not correlated with carrot yields. These results suggest that any of the three spacings can be used for high carrot quality and productivity.
Evaluation and Yield Trials of Tomatillo in New Hampshire
Authors: Freyre Rosanna , Loy J. Brent
Published: December 2018

Five tomatillo (Physalis ixocarpa Brot. ex Hornem) cultivars available from commercial seed companies (`De Milpa', `Puebla Verde', `Purple Tomatillo', `Tomatillo' and `Toma Verde') and four Physalis L. accessions (PI 197691, PI 270459, PI 291560, and PI 309812) were grown in 1997 and 1998 at Kingman Research Farm, Durham, N.H. Three manual harvests per plot were performed each year, recording data of total fruit weight, number of fruit and average fruit weight for each genotype. There were statistically significant differences between tomatillo genotypes for all three traits. Statistically significant differences between the 2 years were found for fruit number and average fruit weight per genotype. Over both years, total fruit weight varied from 29.7 to 63.7 t·ha-1 (13.3 to 28.4 ton/acre). Fruit numbers per plant varied from 83 to 330, and average fruit weight varied from 18.0 to 38.3 g (0.6 to 1.3 oz). PI 197691 and PI 270459 performed better than some of the commercial cultivars indicating their potential to be used as germplasm for breeding. A basket-weave trellising system which kept plants upright was tested. This made harvest easier and potentially can be used for tomatillo culture.
An Evaluation of a Childrens Garden in Developing a Greater Sensitivity of the Environment in Preschool Children
Authors: Midden Karen Stoelzle , Chambers Jessica
Published: December 2018

A childrens' garden was designed and installed in a preschool facility to determine if the garden was effective in increasing the children's respect and knowledge of a garden ecosystem. Evaluation of the children's involvement with the garden revealed it to be effectively incorporated into a multidisciplinary curriculum. The children's experience with the garden was a first step in developing environmental sensitivity while providing an opportunity for the staff to experience a garden as an educational tool.
Precision Agriculture Technology for Horticultural Crop Production
Authors: Roberson Gary T.
Published: December 2018

Precision agriculture is a comprehensive system that relies on information, technology and management to optimize agricultural production. While used since the mid-1980s in agronomic crops, it is attracting increasing interest in horticultural crops. Relatively high per acre crop values for some horticultural crops and crop response to variability in soil and nutrients makes precision agriculture an attractive production system. Precision agriculture efforts in the Department of Biological and Agricultural Engineering at North Carolina State University are currently focused in two functional areas: site-specific management and postharvest process management. Much of the information base, technology, and management practices developed in agronomic crops have practical and potentially profitable applications in fruit and vegetable production. Mechanized soil sampling, pest scouting and variable rate control systems are readily adapted to horticultural crops. Yield monitors are under development for many crops that can be mechanically harvested. Investigations have begun to develop yield monitoring capability for hand harvested crops. Postharvest controls are widely used in horticultural crops to enhance or protect product quality.
Using Site-specific Approaches to Advance Potato Management in Irrigated Systems
Authors: Davenport Joan R. , Hattendorf Mary J.
Published: December 2018

Potatoes (Solanum tuberosum L.) are grown extensively throughout the Pacific northwestern United States as a high value crop in irrigated rotations with other row crops such as wheat (Triticum aestivum L.) and both field and sweet corn (Zea mays L.). Center pivots are the predominant irrigation systems. Soil texture ranges from coarse sands to finer textured silt loams and silts and can vary within one field, particularly in fields with hilly topography. Site specific management is being evaluated as an approach to help to optimize inputs (water, seed, agricultural chemicals) to maintain or enhance yield and reduce potential negative environmental impacts from these farming systems. Currently, variable rate fertilizer application technology and harvest yield monitoring equipment are commercially available for potato. Variable rate seeding and variable rate irrigation water application technologies are developed but not fully commercialized and variable rate pesticide application equipment is in development. At the Irrigated Agricultural Research and Extension Center in Prosser, Wash., we have a team of research scientists, interested individuals from local industry, and other key organizations (e.g. local conservation districts) who are working together to evaluate different site specific technologies, improve the ability to use available tools, and to improve decision-making ability by conducting research both on farm and in research plots.