bluuebunny/crossref_metadata_2025 huggingface dataset:
Vegetatively Propagated Geraniums Respond Similarly to Drench Applications of Paclobutrazol or Uniconazole
Authors: Whipker Brian E. , Dasoju Shravan K. , Evans Michael R.
Published: December 2018

Drench applications of paclobutrazol or uniconazole were applied at doses of 0, 0.0025, 0.005, 0.01, 0.02, or 0.04 mg a.i./pot (28,350 mg = 1.0 oz) to vegetatively propagated `Aurora', `Medallion Dark Red', and `Pink Satisfaction' geranium (Pelargonium ×hortorum L.H. Bailey). Geranium total plant height, leaf canopy height, and plant diameter responded similarly to drench applications of either paclobutrazol or uniconazole. There was a significant quadratic relationship between plant growth regulator (PGR) dose and total plant height and leaf canopy height for `Aurora' and `Medallion Dark Red', with total plant height and leaf canopy height being shorter as paclobutrazol or uniconazole doses increased up to 0.02 mg. However, doses of ≥0.02 mg had little additional effect on total plant height and leaf canopy height. Most of the total height control achieved by the use of PGRs was primarily due to a reduction of leaf canopy height, rather than inflorescence height. Doses of 0.005 to 0.01 mg of either PGR produced marketable sized potted plants of `Medallion Dark Red' and `Pink Satisfaction'. `Aurora', which was the most vigorous cultivar, required doses of 0.01 or 0.02 mg of either paclobutrazol or uniconazole to produce marketable sized potted plants.
The Quality of Three Table Grape Varieties Fumigated with Methyl Bromide at Doses Recommended for the Control of Mealybugs
Authors: Smilanick J.L. , Mlikota F. , Hartsell P.L. , Muhareb J.S. , Denis-Arrue N.
Published: December 2018

`Ruby Seedless', `Red Globe', and `Prima Red' table grapes were fumigated with the treatment schedule of the USDA-Animal Plant Health Inspection Service recommended for the control of mealybugs. Methyl bromide was applied at 64 g·m-3 (4.0 lb/1000 ft3) for 2 h at 16.1 to 18.3 °C (61 to 65 °F). The grapes were in commercial packages typical for each cultivar. After fumigation and 30 min of aeration, the grapes were stored 2 to 4 weeks at 5 °C (41 °F) and their quality assessed by evaluation of cluster rachis condition, shatter, berry cracking, decay, berry color, internal browning, bleaching injury, and firmness. None of the table grape quality parameters was significantly influenced by methyl bromide fumigation.
Phosphorus Fertilization for Caladium Tuber Production on Organic Soil
Authors: Harbaugh Brent K. , DeVoll David A. , Zalewski R.
Published: December 2018

Phosphorus is considered a major pollutant of lakes in central Florida, and growers producing crops in the Lake Okeechobee watershed are being challenged to reduce use of P fertilizer. Caladium (Caladium×hortulanum Birdsey) tubers are produced on organic soils within this area. This study was done to determine if current commercial P fertilization rates could be reduced or eliminated, since these organic soils have high levels of water extractable P (Pw). Two farms were selected with low (Farm A 19 lb/acre; 21 kg·ha-1) or high (Farm B 59 lb/acre; 66 kg·ha-1) preplant Pw levels. Production of caladium tubers with the standard grower P fertilization practice (Farm A = P at 39.2 lb/acre; 43.9 kg·ha-1, or Farm B = P at 15.9 lb/acre; 17.8 kg·ha-1) was compared to production with either one-half the standard grower rate of P or no P. The percentage of harvested tubers in each of five grades and the estimated harvested tuber value index were similar irrespective of the amount of P fertilizer used on either farm. These results indicate that P could be eliminated from the fertilization program for caladium tuber production on organic soils.
A Ground-based Comparison of Nutrient Delivery Technologies Originally Developed for Growing Plants in the Spaceflight Environment
Authors: Porterfield D. Marshall , Musgrave Mary E. , Dreschel Thomas W.
Published: December 2018

A ground-based comparison of plant nutrient delivery systems that have been developed for microgravity application was conducted for dwarf wheat (Triticum aestivum L. `Yecora Rojo') and rapid-cycling brassica (Brassica rapa L. CrGC#1-33) plants. These experiments offer insight into nutrient and oxygen delivery concerns for greenhouse crop production systems. The experiments were completed over a 12-day period to simulate a typical space shuttle-based spaceflight experiment. The plant materials, grown either using the porous-tube nutrient delivery system, the phenolic foam support system, or a solidified agar nutrient medium, were compared by plant-growth analysis, root zone morphological measurements, elemental composition analysis, and alcohol dehydrogenase enzyme activity assay. The results of these analyses indicate that the porous tube plant nutrient delivery and the phenolic foam systems maintain plant growth at a higher level than the solidified agar gel medium system. Root zone oxygenation problems associated with the agar system were manifested through biochemical and morphological responses. The porous tube nutrient delivery system outperformed the other two systems on the basis of plant growth analysis parameters and physiological indicators of root zone aeration. This information is applicable to the current crop production techniques used in greenhouse-controlled environments.
A Two-component Quarantine Treatment for Postharvest Control of Codling Moth on Apple Cultivars Intended for Export to Japan and Korea
Authors: Hansen James D. , Moffitt Harold R. , Albano Dennis J. , Heidt Millie L. , Drake Stephen R. , Robertson Jacqueline L.
Published: December 2018

Confirmatory tests were performed on a two-component quarantine treatment against the codling moth (Cydia pomonella L.) (Lepidoptera: Tortricidae) for seven apple [Malus sylvestris (L.) var. domestica (Borkh.) Mansf.] cultivars ('Delicious,' `Golden Delicious,' `Braeburn,' `Fuji,' `Gala,' `Jonagold,' and `Granny Smith') intended for export to Japan and Korea. Treatment consists of a 55-day cold storage at 40 °F (2.2 °C) or below, followed by a 2-hour methyl bromide fumigation (0.056 oz/ft3 or 56 g·m-3) at 50 °F (10 °C). No eggs or larvae survived this treatment. Comparison tests were conducted on all cultivars to demonstrate no difference in insect responses between a previously accepted cultivar and proposed cultivars. Concentration-mortality responses were determined for each of the components and no statistical differences were found in the regression slopes of pest mortality with controlling variable (either cold exposure or fumigation) among all cultivars. Descriptive mathematical models, developed for the effects of cold storage on egg mortality and for methyl bromide fumigation on larvae mortality, were sigmoid curve equations.
Methyl Bromide Fumigation of Five Cultivars of Sweet Cherries as a Quarantine Treatment against Codling Moth
Authors: Hansen James D. , Drake Stephen R. , Moffitt Harold R. , Albano Dennis J. , Heidt Millie L.
Published: December 2018

A quarantine treatment was developed against codling moth (Cydia pomonella L.) (Lepidoptera: Tortricidae) for the sweet cherry (Prunus avium L.) cultivars ('Garnet,' `Brooks,' `Tulare,' `Lapins,' and `Sweetheart') exported to Japan. Specific procedures were required to demonstrate treatment efficacy. Dose-mortality responses were measured for each cultivar at regularly incremented concentrations of methyl bromide for 2 hours at 43 °F (6 °C) compared to the dose-mortality curve of an approved cultivar under the same conditions. Based on the overlap of confidence limits, there were no significant differences between new and approved cultivars in group comparisons. In a confirmation test of efficacy, fumigation with methyl bromide at 0.064 oz/ft3 (64 g·m-3) for 2 hours at 43 °F resulted in complete mortality for all codling moth larvae in the treated cultivars. By convention, fumigation at this or the following concentrations [0.048 oz/ft3 (48 g·m-3) for 2 h at 54 to 63 °F (12 to 17 °C); 0.040 oz/ft3 (40 g·m-3) for 2 h at 63 to 72 °F (17 to 22 °C); 0.032 oz/ft3 (32 g·m-3) for 2 h at 72 °F (22 °C) or above] were considered as an efficacious quarantine treatment against the codling moth in sweet cherries. Except for `Brooks,' fumigation did not significantly influence fruit firmness, soluble solids, or titratable acids. Reduction in fruit and stem quality was more associated with temperature than with methyl bromide concentration. `Tulare,' `Lapins,' and `Sweetheart' could be fumigated with minimal change in fruit quality.
Response of Potted Sunflower Cultivars to Daminozide Foliar Sprays and Paclobutrazol Drenches
Authors: Whipker Brian E. , McCall Ingram
Published: December 2018

Plant growth retardant (PGR) foliar sprays of daminozide at 4,000 or 8,000 mg·L-1 (ppm) and paclobutrazol drenches of 2 or 4 mg a.i. per pot were applied to `Big Smile', `Pacino', `Sundance Kid', `Sunspot', and `Teddy Bear' pot sunflowers (Helianthus annuus L.) to compare their chemical height control. Plant height varied among the cultivars due to genetic variation. The percentage reduction in plant height from the untreated control only was significant at the PGR level, indicating similar responses of all five cultivars to each PGR rate. Paclobutrazol drenches at 2 mg and daminozide foliar sprays at 4,000 or 8,000 mg·L-1 reduced plant height by about 24% when compared to the control. Paclobutrazol drenches at 4 mg produced plants that were 33% shorter than the control. Plant diameter of `Big Smile', `Pacino', or `Sundance Kid' was unaffected by daminozide, whereas `Sunspot' plants were smaller than the controls. Paclobutrazol drenches at 2 or 4 mg decreased plant diameter for all cultivars except `Teddy Bear', with the reduction being greater as paclobutrazol drench rates increased. The number of inflorescence buds increased by ≥18% with the use of daminozide sprays, while paclobutrazol drenches at 2 or 4 mg had no effect when compared to the untreated control. Paclobutrazol drenches of 2 or 4 mg offer the economic advantage to growers of increased plant density on greenhouse benches, while plants treated with daminozide had an increased bud count but would require a greater amount of bench space.
1997 Spring and Fall Cabbage Cultivar Trials in Pennsylvania
Authors: Orzolek M.D. , Lamont W.J. , Otjen L.
Published: December 2018

Twenty-two cabbage cultivars were evaluated in the spring and 26 cabbage cultivars evaluated in the fall of 1997. The cultivars were evaluated for uniformity of maturity, marketable yield, percent cull, stem core length, and head firmness. In addition, three heads of each cultivar were tasted at harvest by the summer farm crew and responses noted on the data collection forms. The highest yielding cultivars were not necessarily the best performing ones evaluated in the trial. Average head weight was significantly different between spring and fall plantings. Data from this trial suggests that multiple cultivars should be grown in Pennsylvania based on whether it is a spring or fall cabbage crop.
Physical Discomfort May Be Reduced in the Presence of Interior Plants
Authors: Lohr Virginia I. , Pearson-Mims Caroline H.
Published: December 2018

A well-known research report showed that being in a hospital room with a view of trees rather than a view of a building was linked to the use of fewer pain-reducing medications by patients recovering from surgery. The experiment reported here was designed to further examine the role of plants in pain perception. We found that more subjects were willing to keep a hand submerged in ice water for 5 min if they were in a room with plants present than if they were in a room without plants. This was found to be true even when the room without plants had other colorful objects that might help the subject focus on something other than the discomfort. Results from a room assessment survey confirmed that the room with colorful, nonplant objects was as interesting and colorful as the room with plants present, but the presence of plants was perceived as making the air in the room fresher.
Interactions between Elderly Adults and Preschool Children in a Horticultural Therapy Research Program
Authors: Predny Mary L. , Relf Diane
Published: December 2018

This report examines the behavior of elderly adults and preschool children during horticultural therapy (HT) activities to determine if combining intergenerational groups would complement or detract from the HT goals for each group separately. During a 10-week observation period, data were collected on video documenting attendance, participation time and pattern during separate age group and intergenerational activities. These data were used to determine if interactions changed over time or in response to different activities. Participation appeared to be affected by activity design, difficulty level, individual ability, and availability of assistance from volunteers. Children's participation during separate age group activities appeared to be affected mainly by the difficulty level and activity design. Elderly adults' participation during separate age group activities appeared to be affected by individual ability limitation and availability of assistance. Children's intergenerational participation scores appeared to show an increase in the category of “working with direct assistance”, while elderly adults' intergenerational scores appeared to show an increase in the categories of “no participation” and “independent participation”. In part, the change in intergenerational participation appeared to be due to a decrease in assistance available from volunteers for each individual. For some individuals, the introduction of intergenerational groups appeared to detract from personal participation in horticulture activities. If the goal of the HT is directly related to the individual's activity in horticulture (i.e., increased self-esteem from successfully designing and building a terrarium), the intergenerational element appears to reduce the potential for that benefit. The percentage of total social interaction time between the generations during activities increased over time. The intergenerational activities involving plant-based activities seemed to be more successful at increasing intergenerational exchange than the craft-type activities. Therefore, horticulture may be a useful activity for programs with a goal of increased intergenerational interaction.
Using a Web-based Survey to Research the Benefits of Children Gardening
Authors: Waliczek Tina M. , Lineberger R.D. , Zajicek J.M. , Bradley J.C.
Published: December 2018

A survey, targeting adults working with youth in garden situations, was designed for delivery on the KinderGARDEN World Wide Web site. The goal of this survey was to investigate adults who are actively involved in gardening with children in school, community or home gardens on their perceptions of the benefits of children participating in gardening. Three hundred-twenty completed surveys were returned via e-mail during a period of 9 months. Fourteen questions were included on the survey requesting information concerning what types of gardening situations in which children were participants and the demographics of the children involved in gardening. Results of the study cover 128,836 children (youth under 18 years old) involved in gardening, primarily with teachers in school gardens. The children involved were generally 12 years of age or under and were growing food crops. Adults gardening with children reported benefits to children's self-esteem and reduction in stress levels. Adults were also interested in learning more about the psychological, nutritional and physical benefits of gardening. Comparisons between those adults involved in gardening found that parents' and teachers' ideas differed concerning the most important aspects of the gardening experience. Parents viewed food production as most important while teachers thought socializing and learning about plants were most important.
Optimum Plant Population for Fresh-market Sweet Corn in the Northeastern United States
Authors: Morris Thomas F. , Hamilton George , Harney Sara
Published: December 2018

There is little published data to support current recommended plant populations of 11,500 to 17,500 plants/acre (28,600 to 34,600 plants/ha) for fresh market sweet corn (Zea mays L.) in the northeastern United States. The plant population likely affects marketable yield and recovery of nitrate. Residual soil nitrate is of concern because of the potential for nitrate contamination of water supplies. Our objectives were to determine the effect of plant population on the yield of sweet corn grown for fresh market without irrigation and on the amount of nitrate in the surface 1 ft (30 cm) of soil at harvest. Seven main-season sweet corn varieties were planted in a total of eight experiments in 1995, 1996, and 1997. Seven experiments were in Connecticut and one was in New Hampshire. All but one of the varieties were standard (su) or sugary enhanced (se) varieties. The experimental design was a randomized complete block with four replications, and the treatments consisted of 12,000, 16,000, 20,000, 24,000, and 28,000 plants/acre (29,600, 39,500, 49,400, 59,300, and 69,200 plants/ha). The yield of marketable ears was classified based on the length of the ears. The results suggest that the current recommendations for plant population in the Northeast US may be too low. Populations of 20,000 and 24,000 plants/acre produced consistently greater yields of ears greater than 7.0 inches (178 mm) long. Soil nitrate-N concentrations at harvest were about 8 mg·kg-1 lower with 16,000 plants/acre or greater, compared with 12,000 plants/acre, which suggests that populations of 16,000/acre or greater should decrease the potential for nitrate contamination of water supplies in the fall, winter, and early spring.
Microclimates, Peach Bud Phenology, and Freeze Risks in a Topographically Diverse Orchard
Authors: Logan Joanne , Mueller Marcella A. , Searcy Michael J.
Published: December 2018

Peach [Prunus persica (L.) Batsch.] production in the southeastern United States. has suffered a decline in the past several decades due to late and severe spring freezes. Much of the peach production in Tennessee is located on topographically diverse sites. Peach producers do not have adequate information about the effects of microclimates within their orchards on peach bud development and subsequent freeze risk. Such information may help them select the best adapted cultivars based on microclimate. The objectives of this study were to use a `Redhaven' peach bud development model to compare and contrast the phenology and freeze risks at five sites within the orchard, and to study the freeze characteristics (advective vs. radiative) of these same sites. Automated weather stations were located in topoclimatically different areas of a peach orchard in Dandridge, Tenn., from October 1990 to April 1992. Hourly weather data included average air temperature, chill units (CUs), growing degree hours (GDHs), and wind speed. The data show that the microclimatic factors that affect peach bud development and freeze risk, such as CUs, GDHs, and minimum temperatures, can vary in a topographically diverse orchard, but the effects are not as straightforward as previously reported. For instance, peach buds at a site at a lower elevation may break dormancy later due to slower accumulation of CUs, which could be beneficial to the grower. Then the buds may develop more slowly due to cold air drainage to the lower elevations, which would also be desirable. However, the lower temperatures due to cold air drainage could be damaging to the bud and cause more problems with injuries. Over the two seasons, there were more radiative freezes than advective freezes, but the advective freezes were more severe. Small differences in wind speed can account for surprisingly different freeze conditions during radiative situations. Any improvement in cold air drainage should help decrease the duration and severity of radiative freezes.
Boron Fertilizer Product and Concentration Influence Spray Water pH
Authors: Peryea Frank J. , Lageschulte Jennifer M.
Published: December 2018

Farmers often mix fertilizers, pesticides and other agricultural chemicals together in a spray tank to allow applications of multiple products in a single spray. Because polyborate-based B fertilizers may increase solution pH, adding B to tank-mixed sprays may impair the stability and efficacy of alkalinity-sensitive pesticides and growth regulators if an acidifier is not included. We conducted a laboratory experiment to determine the influence of 10 commercial B fertilizer sources in factorial combination with B concentrations ranging from 0 to 4 lb/100 gal (4.8 g·L-1) on solution pH values of distilled water and two natural waters. Two boric acid-based compounds produced acidic reactions relative to background water pH at all tested B concentrations. Their pH responses were influenced by initial water composition. Seven B products produced moderately to strongly alkaline reactions at all but the highest B concentration, regardless of the form of B (polyborate vs. boric acid) initially present in the formulated products. One polyborate product formulated with an acidifier showed intermediate pH behavior. The dependence of solution pH on B rate of the polyborate-containing products was identical in all three waters. The maximum pH values generated by all products occurred in the B concentration range <0.1 to 0.25 lb/100 gal (0.12 to 0.3 g·L-1). Solution pH values declined with increasing B concentration above this range. The pH responses qualitatively conformed to known aqueous chemical behavior of B and the product additives. The complexity of the interaction between initial water chemistry, B concentration, and B fertilizer product reinforces the need to measure the pH of B-amended spray water before adding pH-sensitive compounds.
Canopy Development and Spray Deposition in Highbush Blueberry
Authors: VanEe Gary , Ledebuhr Richard , Hanson Eric , Hancock Jim , Ramsdell Donald C.
Published: December 2018

Most highbush blueberries (Vaccinium corymbosum L.) in Michigan are treated annually with fungicides and insecticides with several types of sprayers. The goal of this study was to determine how sprayer type, pruning severity, and canopy development interact to affect spray deposition patterns. Deposition was measured as the percentage of the surface area of card targets that was covered following applications of black dye. Light measurements indicated that the canopy of blueberry bushes, regardless of pruning treatment, closed by the middle of June, and light levels within the canopy changed little from then until fruit harvest in August. A standard airblast sprayer that pushed spray up and through bushes provided acceptable deposition in all parts of the canopy early in the season, but later in the season, coverage was poor in the top and sides furthest from the sprayer. An above-row sprayer with fan-driven micronozzles also provided acceptable coverage throughout the bushes early in the season, but once the canopy had closed, coverage was poor in the bottom of the bush. Both sprayers were operated in bushes receiving light, moderate, and heavy pruning. The more severe pruning regimes increased the amount of spray deposited from the above-row sprayer, but not from the airblast sprayer.
A Comparison of Early Field Results of White Pine Blister Rust Resistance in Sugar Pine and Western White Pine
Authors: Sniezko Richard A. , Bower Andrew , Danielson Jude
Published: December 2018

Seedlings from 12 sugar pine (Pinus lambertiana Dougl.) and 13 western white pine (Pinus monticola Dougl.) families were planted at Happy Camp, Calif., in 1996. Assessment in Summer 1999 indicated moderate levels of white pine blister rust (Cronartium ribicola Fischer) infection. This paper focused on the species differences and showed that sugar pine had a higher incidence of stem infection (active and inactive cankers) and more stem infections per tree than western white pine. An unexpected result was the very high percentage of infections that were bark reactions (completely inactivated infections), despite the fact that only some of the families of both species were selected for this mechanism. Assessments in subsequent years will track the future performance of the two species and of the individual families.
Canadian Breeding Program for White Pine Blister Resistance in Black Currants
Authors: Luffman Margie
Published: December 2018

The search for appropriate white pine blister rust (WPBR) (Cronartium ribicola J.C. Fischer) resistant germplasm to use in black currant (Ribes nigrum L.) breeding programs began in 1935 in Ottawa. Crosses were made in 1938 and 1939 with three different Ribes L. species and two standard black currant cultivars. The resulting seedlings from these crosses were evaluated for rust resistance. Three promising selections resulted from this program and were named `Coronet', `Crusader' and `Consort'.
Commercial Production of Currants and Gooseberries in the Inland Northwest and Intermountain West of the United States: Opportunities and Risks
Authors: Barney Danny L.
Published: December 2018

During the 1800s and early 1900s, red and white currants (Ribes L. subgenus Ribes), black currants (Ribes subgenus Coreosma), and gooseberries (Ribes subgenus Grossularia) were grown commercially in the United States. Because Ribes serve as alternative hosts of white pine blister rust (Cronartium ribicola J. C. Fischer) (WPBR), which was introduced from Europe, the federal government and many states either banned or severely restricted currant and gooseberry production beginning about 1933. The development of WPBR resistant pines and black currants (the most susceptible cultivated Ribes) renewed interest in commercial Ribes production. Climatic and soil conditions in selected areas of the U.S. inland northwest and intermountain west (INIW) are favorable for commercial currant and gooseberry production. Challenges to the establishment of a Ribes industry are labor, marketing, diseases, and pests. Careful site and cultivar selection are critical for successful commercial production. This article describes Ribes opportunities and risks associated with currant and gooseberry production in the INIW. The region includes Idaho and surrounding areas in Montana, Nevada, Oregon, Utah, Washington, and Wyoming.
School Gardens: Can a Hands-on Teaching Tool Affect Students' Attitudes and Behaviors Regarding Fruit and Vegetables?
Authors: Lineberger Sarah E. , Zajicek Jayne M.
Published: December 2018

Nutrition in the Garden is a garden program designed to help teachers integrate nutrition education into their classroom using a hands-on tool, the garden. The objectives of this research project were to 1) develop a garden activity guide to help teachers integrate nutrition education, specifically as it relates to fruit and vegetables, into their curricula, 2) evaluate whether students developed more positive attitudes towards fruit and vegetables by participating in the garden program, and 3) evaluate whether students developed better nutritional behavior by eating more fruit and vegetables after participating in the garden program. Students' nutritional attitudes regarding fruit and vegetables were measured with a fruit and vegetable preference questionnaire divided into three sections targeting vegetables, fruit, and fruit and vegetable snacks. Students' nutritional behaviors regarding fruit and vegetables were evaluated through 24-hour recall journals. After gardening, students' attitudes towards vegetables became significantly more positive. In contrast, no differences were detected in attitudes towards fruit. Students also had more positive attitudes towards fruit and vegetable snacks after gardening, with female students and younger students having the greatest improvement in snack attitude scores. Even though school gardening improved students' attitudes towards vegetables, fruit and vegetable consumption of students did not significantly improve due to gardening. Overall, the average daily fruit and vegetable consumption of the students participating in the Nutrition in the Garden study was 2.0 servings per day. This falls short of the estimated national average for daily fruit and vegetable consumption for this age group (3.4 servings) and extremely short of the nationally recommended 5.0 servings per day.
Phytotoxicity and Longevity of Twenty-two Preemergent Herbicides used on Three Species of Container-grown Palms
Authors: Broschat Timothy K.
Published: December 2018

Twenty-two preemergent herbicides were applied at their maximum labeled rates and twice those rates to determine their safety and effectiveness on areca palm [Dypsis lutescens (H. Wendl.) Beentje & Dransf.], pygmy date palm (Phoenix roebelenii O'Brien), and mexican fan palm (Washingtonia robusta H. Wendl.). Two products, dichlobenil and metolachlor showed consistent phytotoxicity on all three species. Several of the remaining products caused death of the apical meristem in mexican fan palms and reduced growth rates in pygmy date palms, but most caused little damage to areca palms. Herbicides applied as sprays generally remained effective for 2 to 4 months, whereas granular products, especially those containing oxyfluorfen plus another chemical, were effective for up to 8 months.
Reasons for Becoming Involved as a Master Gardener
Authors: Schrock Denny S. , Meyer Mary , Ascher Peter , Snyder Mark
Published: December 2018

Current and former Missouri Master Gardeners were asked to respond to each of 30 reasons (an adaptation of the Volunteer Functions Inventory [VFI]) for doing volunteer work. Principal factor analysis confirmed the presence of six principal components of volunteer motivation. Master Gardener functions related to new learning experiences (understanding) were equally as important as functions related to altruism (values). Satisfactions related to self-esteem (enhancement) ranked next in motivational importance. Motivations concerning relationships with others (social), protecting the ego (protective) and functions related to preparation for a new career (career), concluded the list. In addition, respondents were asked to indicate whether they were presently volunteering as a Master Gardener, how many years they had been active in the program, and level of volunteer time commitment to the program in the past year. In most cases, no correlations or statistical differences were found among respondents belonging to different demographic categories, making demographic information a poor predictor of motivation for volunteering. However, those who volunteered more time during the past year were more likely to highly rate certain motivational factors.
Precocious, Dwarfing, and Productive—How Will New Cherry Rootstocks Impact the Sweet Cherry Industry?
Authors: Lang Gregory A.
Published: December 2018

Sweet cherries (Prunus avium L.) can be one of the most profitable tree fruits cultivated in temperate climates. While cherry trees grow naturally to relatively tall heights (≈35 ft [≥10 m]), new size-controlling cherry rootstocks similar to those used in high-density apple (Malus domestica Borkh.) orchards are now a reality. The Gisela (GI.) and Weiroot (W.) series from Germany, the Gran Manier (GM.) series from Belgium, the P-HL series from Czech Republic, `Tabel Edabriz' from France, and others of international origin are at various stages of scientific and field testing in North America, with some now being used for commercial fruit production. These stocks confer several advantageous traits besides vigor control, including precocious fruiting and high productivity. While these beneficial traits are exciting, serious problems also have been documented on occasion, such as small fruit size and tree decline. As many of these rootstocks are interspecific Prunus L. hybrids, might there be significant limitations for fruit quality and orchard longevity? What is known about their tolerance to various soil types and/or climatological stresses? What is known about their susceptibilities to pathogens and pests? Further, with the U.S. and worldwide orchard area planted to fresh-market sweet cherries already expanding to record levels throughout the 1990s and a time-honored agricultural tendency toward overproduction until grower profits are minimized (e.g., recent international apple markets), what might be the future impact of such precocious, productive rootstocks on sweet cherry profitability and sustainable production? This overview addresses these topics, providing some answers and some areas for future scientific investigation and industry discussion.
Processes Influencing Floral Initiation and Bloom: The Role of Phytohormones in a Conceptual Flowering Model
Authors: Davenport Thomas L.
Published: December 2018

The reproductive phenologies of temperate fruit tree species are briefly introduced and compared to the reproductive phenologies of three tropical and subtropical fruit tree species. The impact of leaf and fruit development and the phytohormones they may produce on the reproductive or vegetative fate of bourse buds in apple spurs serves as the model to discuss temperate fruit flowering. In contrast, conceptual models of citrus (Citrus L.), mango (Mangifera indica L.), and lychee (Litchi chinensis Sonn.) flowering are described which propose physiological mechanisms for both flowering and vegetative flushing in trees grown in subtropical and tropical environments. Possible roles for auxin and cytokinins in shoot initiation and for gibberellins and a putative florigenic promoter in induction are discussed as they relate to the physiology of flowering and vegetative flushing of tropical species. Successful application of these conceptual flowering models through the use of growth regulators and other horticultural management techniques to control flowering of citrus, mango, and lychee is described.
Shade Influences Propagation of Golden Barberry `Bailsel'
Authors: Murphree Brian H. , Sibley Jeff L. , Eakes D. Joseph , Williams J. David
Published: December 2018

The influence of three shade levels on propagation of golden barberry (Berberis koreana Palib. × B. thunbergii DC.) selection `Bailsel' was evaluated in studies initiated 29 Apr. and 18 Sept. 1998. After 57 days, root ratings were higher in plants under 70% and 80% shade treatments than 60% shade for both studies. In study one, viability was lower among plants under the 60% shade level than those under 70% or 80% shade levels. Viability among treatments was similar in study two. Based on visual observations, leaf retention appeared greater under the 70% and 80% shade treatments than the 60% shade treatment for both studies. Cuttings rooted under 70% and 80% shade levels generally had a uniform golden hue, whereas the foliage of those rooted under 60% shade often had a red hue and showed signs of desiccation for both studies. Root dry weights were greater for cuttings under the 60% shade levels than 70% or 80% shade.
Evaluation of Forty-seven Cultivars of Lisianthus as Cut Flowers
Authors: Harbaugh Brent K. , Bell Michelle L. , Liang Rongna
Published: December 2018

Lisianthus [Eustoma grandiflorum (Raf). Shinn.] is emerging as an important cut flower in the United States while in European and Asian markets it is already listed among the top ten cut flowers. Many new cultivars have been released in the United States within the last 5 years, but comparative performance trials of these cultivars have been lacking. This trial evaluated 47 cultivars of lisianthus representing series (cultivar groups) that were marketed in the United States in 1998. Evaluations were made for rosetting, plug performance, cut-flower characteristics (vegetative and flowering attributes) as well as postharvest longevity of cut flowers. Significant differences among cultivars were found for all of the attributes evaluated. `Malibu Purple', `Catalina Blue Blush', and `Alice Pink' were selected as the best performers in the seedling (plug) stage since they had less than 5% rosettes, large leaves and a vigorous root system. Cultivars were placed in classes based on flower color, flower size, and number of petals (single or double flowers). Cultivars were ranked for each of the attributes and the total rank sum of all attributes (TRS) was used to select the best in class. Cultivars selected as best in class were `Malibu Purple', `Malibu Blue Blush', `Alice Purple', `Balboa Blue', `Avila Blue Rim', `Mellow Pink', `Flamenco Wine Red', `Flamenco Rose Rim', `Alice Pink', `Avila Rose' and `Echo Pink', `Alice White', and `Mariachi White'.
Susceptibility of Forty-six Lisianthus Cultivars to Fusarium Crown and Stem Rot
Authors: Harbaugh Brent K. , McGovern R. J.
Published: December 2018

Fusarium crown and stem rot, caused by Fusarium avenaceum (Fr.: Fr.) Sacc., is a serious disease of lisianthus [Eustoma grandiflorum Raf. (Shinn.)]. While more than 80 new cultivars of lisianthus have been released for sale in the United States in the last decade, there is a lack of information on their susceptibility to this pathogen. Forty-six cultivars of lisianthus were evaluated for their response to infection by F. avenaceum. Cultivars were grouped according to blue/purple, pink, or white flower colors and evaluated within their color class. Although some plants of all cultivars were susceptible to F. avenaceum, partial resistance was observed as indicated by differences in the length of time to symptom expression and in the frequency of diseased plants within each color group. In 21 of the 46 cultivars, 80 to 100% of the plants expressed symptoms within 55 days after inoculation. The lowest frequencies of diseased plants 55 days after inoculation were found in `Ventura Deep Blue' and `Hallelujah Purple' (25%), `Bridal Pink' (23%), and `Heidi Pure White' (53%) for the blue/purple, pink, and white flower color groups, respectively. Screening cultivars for resistance to F. avenaceum is the first step in breeding resistant cultivars. The methods we developed for these studies should be useful in screening for resistance. These results also may help growers select cultivars that are less susceptible to F. avenaceum, which should aid in the management of this disease.
Biological Assessment of Herbicide Use in Apple Production I. Background and Current Use Estimates
Authors: Derr Jeffrey F.
Published: December 2018

Weed management is an important concern for apple producers. Weeds compete with fruit trees for water, nutrients, light and pollination by insects. Weed competition can dramatically reduce apple tree (Malus domestica Borkh.) growth and yield. Weed control practices can impact rodent populations, and insect and disease management in orchards. Use of cultivation can increase soil erosion. Mulches are too expensive for use in orchards and can increase rodent problems. Weeds are generally controlled within the row using herbicides while a grass sod is often used in row middles for erosion control. The most commonly used postemergence herbicides in apples are glyphosate, paraquat, and 2,4-D. Simazine is the most commonly used preemergence herbicide.
Production Unit Trends and Price Characteristics within the United States Pecan Industry
Authors: Wood Bruce W.
Published: December 2018

The United States pecan [Carya illinoinensis (Wangenh.) K. Koch] industry is based on about 10,107,170 trees (about 15% nonbearing) comprising about 492,137 acres (199,168 ha) of orchards (34% in Texas, 27% Georgia, and 17% Oklahoma) dispersed among about 19,900 farm operations (36% in Texas, 16% Georgia, and 7% Oklahoma) in 24 states. Fifty-six percent of this acreage is on farms with ≥100 acres (40.5 ha) of trees (i.e., 5% of total farms). An evaluation of production related changes over the last decade indicate fundamental changes occurring in the nature of the U. S. industry. These include a) movement toward agricultural industrialization as reflected by fewer small-farms and more large-farms; b) reduced percentage of young (i.e., nonbearing) trees in most major producing states; c) substantial decline in number of farms and acres in the southeastern regionhistorically the primary production area-yet substantial growth in the northern region of production; d) a national 3% increase in the number of pecan farms and 14% increase in acreage; and e) substantial demographic changes, such as the enhanced importance of the southwestern region including New Mexico with diminished importance of many southeastern states. States also drastically differ in degree of biennial bearing, as measured by the biennial bearing index (i.e., K = 0.04 - 0.73; where 0 = no production variation and 1 = maximum variation), average production efficiency of both orchards [Epa = 192 - 1,224 lb/acre (215 - 1,374 kg·ha-1)] and trees [Ept = 19 - 60 lb/tree (8.6 kg/tree)], variation in grower prices (cv = 18 - 36%), and relationship between price and national supply of pecan (r2 = 0.94 - 0.03). For the pecan industry as a whole, average price received for nut-meats is as closely associated with national supply of pecan nut-meats as that of almond and pistachio and is far better than that of walnut-pecan's primary competitor. The supply of pecan meats on-hand at the beginning of the season, plus supply from the current season's crop, plus the price of walnut meats accounts for 80% of price variation in average United States pecan meat price.
Graphics for Horticulture Students
Authors: Hurley-Kurtz Pauline
Published: December 2018

This paper discusses the benefits of including the visual and graphic arts in a horticultural curriculum, as a means for fostering creativity and reading the landscape. It describes the curricular sequence in the graphic communication seminar and studio—a joint studio for horticulture and landscape architecture students at Temple University, Ambler, Pa. This sequence begins with freehand drawing, and progresses to mechanical drafting, drawing construction and rendering.
Trehalose Delays Senescence in Cut Gladiolus Spikes
Authors: Otsubo Mayuko , Iwaya-Inoue Mari
Published: December 2018

Florets of cut gladiolus (Gladiolus ×grandiflora hort. cv. Fujinoyuki) spikes kept at 25 °C under 14 h light/10 h dark condition showed severe wilting 4 days after flower opening. Treatment with 0.1 m trehalose prolonged vase-life 2 days, whereas inhibitors and other sugars had no effect. The upper florets also opened properly in trehalose-treated spikes, but not in cycloheximide-treated ones. After 4 days, the first florets of trehalose-treated spikes maintained water content more effectively than did controls or spikes treated with other sugars. The parenchyma adjacent to vascular bundles in the petals of trehalose-treated spikes maintained viability for 4 days. These results suggest that trehalose preserves cell viability in gladiolus spikes, thereby enhancing water uptake into petal tissues.
Biological Assessment of Herbicide Use in Apple Production II. Estimated Impacts following Loss of Specific Herbicides
Authors: Derr Jeffrey F.
Published: December 2018

Assessing herbicide impacts are difficult due to the indirect effects of weeds on apple (Malus domestica Borkh) growth and development. Herbicide loss will increase potential for development of herbicide-resistant weeds. A limited number of alternatives exist for herbicides currently used in apple production. Switching to certain herbicides increases potential for crop injury. Certain alternatives have higher acute toxicity or are more expensive. No alternatives exist to 2,4-D for broadleaf control in grass alleyways. Nonselective herbicides are alternatives to 2,4-D within the row but pose a greater risk of crop injury. It is difficult to assess long-term impact of 2,4-D loss due to impact on pollination and pest management. Loss of glyphosate will result in yield losses in apple production. Most alternatives to glyphosate are less effective on perennial weed species. Paraquat, one alternative to glyphosate, poses greater hazard to the applicator due to its higher acute toxicity. Diuron is important for rotation with simazine to prevent the development of herbicide-resistance weeds. Norflurazon has an important use in recently planted orchards, where few alternatives exist for yellow nutsedge (Cyperus esculentus L.) control. Oryzalin is commonly used for newly planted orchards and certain alternatives can only be used on nonbearing trees. Alternatives to paraquat pose greater risk of tree injury, although there would be increased worker safety with alternative products. Glyphosate would be the predominate alternative if paraquat was no longer available. Simazine would be the predominate replacement if diuron were no longer available and diuron would be the predominant alternative if simazine was no longer registered for use. Resistance management would be negatively impacted if growers relied on simazine or diuron as their primary preemergence herbicide.
Evaluation of Compost as an Amendment to Commercial Mixes used for Container-grown Golden Shrimp Plant Production
Authors: Wilson S.B. , Stoffella P.J. , Graetz D.A.
Published: December 2018

Growth of golden shrimp plant (Pachystachys lutea Nees.) transplants was evaluated in media containing 0%, 25%, 50%, 75%, or 100% compost derived from biosolids and yard trimmings. A commercial coir- or peat-based media was amended with compost. As compost composition in the peat or coir-based media increased from 0% to 100%, carbon/nitrogen ratios decreased; and media stability, nitrogen mobilization, pH, and electrical conductivity increased. Bulk density, particle density, air-filled porosity, container capacity, and total porosity increased as more compost was added to either peat- or coir-based media. Plants grown in media with high volumes of compost (75% or 100%) had less leaf area and lower shoot and root dry weight compared to the controls (no compost). Regardless of percentage of compost composition in either peat or coir-based media, all plants were considered marketable after 8 weeks.
Vegetation-free Area Surrounding Newly Planted `Niagara' Grapevines Affects Vine Growth
Authors: Zabadal Thomas J. , Dittmer Thomas W.
Published: December 2018

Varying amounts of vegetation-free area (VFA) were established around newly planted `Niagara' (Vitis labrusca L. × Vitis vinifera L.) grapevines to determine their influence on vine growth during the first growing season. VFAs were either circular with radii from 0 to 5 ft (0 to 152 cm) in one experiment or in bands from 0 to 8 ft (0 to 244 cm) in width in a second experiment. VFAs were maintained with biweekly manual weeding for the entire growing season. Leaf, shoot and root dry weights as well as the number of primary shoots and the length of the longest root were measured at the end of their first growing season. The thresholds for maximum vine dry weight biomass accumulation occurred with a circular VFA of 4 ft (122 cm). When banded VFAs were used, total vine dry weight biomass continued to increase up to the widest treatment of 8 ft (244 cm). Therefore, no threshold was attained. These are greater VFAs than typically established around vines in commercial plantings. Therefore, growers who desire to maximize vine growth of newly planted vines, should consider larger VFAs around vines than has been traditional unless such a practice is likely to cause surface soil erosion.
Effect of Microsprinkler Irrigation on Pear Fruit Growth and Postharvest Quality
Authors: Chen C. , Roseberg R.J. , Sugar D. , Selker J.S.
Published: December 2018

A study was undertaken to determine if microsprinkler irrigation (MI) can provide sufficient water and produce similar yield and quality of pear (Pyrus communis L.) fruit as flood irrigation (FI) in a cracking (shrinking-swelling) clay soil. Soil water content and fruit quality attributes were measured under MI and FI in 2 years. Water potential of the upper 120 cm (47 inches) of soil was maintained at 0.1 to 0.3 MPa (14.5 to 43.5 lb/inch2) through most of the growing season in both MI and FI treatments. MI and FI treatments did not differ in their effect on fruit size, yield, or firmness decline during cold storage. No consistent effect on fruit susceptibility postharvest fungal decay related to irrigation treatment was observed. MI has the potential to reduce chemical and water movement to groundwater, while providing sufficient water to produce satisfactory yield and fruit quality in a cracking clay soil.