bluuebunny/crossref_metadata_2025 huggingface dataset:
Properly Recycled Perlite Saves Money, Does Not Reduce Greenhouse Tomato Yield, and Can Be Reused for Many Years
Authors: Hanna H.Y.
Published: December 2018

A study was conducted to determine if raising tomatoes (Lycopersicon esculentum) in cleaned and disinfected used perlite would be more economical than new perlite and have no negative impact on yield. Cleaning and disinfecting used perlite for recycling saved 56% of the cost to replace the media and reduced salt content to the optimum level recommended for raising container grown plants. Disinfecting used perlite with hot water raised media temperatures above limits necessary to kill several fungi and nematodes. Tomatoes planted in recycled perlite produced greater marketable yield and heavier fruit than those planted in new perlite. Season and year of planting also have significant effects on yield. Used perlite can be cleaned and disinfected as needed and recycled for many years because it is not organic in nature and physically and chemically stable.
Comparison of Flurprimidol to Ancymidol, Paclobutrazol, and Uniconazole for Tulip Height Control
Authors: Krug Brian A. , Whipker Brian E. , McCall Ingram , Dole John M.
Published: December 2018

Preplant bulb soaks of ancymidol, flurprimidol, paclobutrazol, and uniconazole; foliar sprays of flurprimidol; and substrate drenches of flurprimidol, paclobutrazol, and uniconazole were compared for height control of `Prominence' tulips (Tulipa sp.). Height control was evaluated at anthesis in the greenhouse and 10 days later under postharvest conditions. Substrate drenches of ancymidol, flurprimidol, and paclobutrazol resulted in adequate control using concentrations of 0.5, 0.5, and 1 mg/pot a.i. (28,350 mg = 1 oz), respectively. At these concentrations, ancymidol drenches cost $0.06/pot and paclobutrazol drenches $0.03/pot. Since flurprimidol is not yet available and no price is available, growers will need to assess the cost compared to ancymidol and paclobutrazol. Flurprimidol foliar sprays at <80 mg·L–1 (ppm) were ineffective in controlling height during greenhouse forcing, but during postharvest evaluation 80 mg·L–1 resulted in 14% shorter plants than the untreated control. Preplant bulb soaks of flurprimidol, paclobutrazol, and uniconazole at concentrations of 25, 50, and 10 mg·L–1, respectively, effectively controlled plant height. Preplant plant growth regulator soaks are a cost-effective method of controlling plant height of tulips because of the limited amount of chemical required to treat a large quantity of bulbs.
Marketing Trends and Business Management Practices for the Wholesale Nursery Industry in California
Authors: Merhaut Donald J. , Pittenger Dennis
Published: December 2018

A survey of wholesale nurseries in the United States was conducted in 1999, with 169 of the 806 nurseries surveyed responding from the state of California. The survey, consisting of 29 questions related to production practices, products, sales, and marketing, was sent to a random group of nurseries. Based on these results, over 50% of the new nursery businesses in California have been established within the last two decades. While most of the nurseries have computerized business practices, only 21% have implemented the use of computers or other automation in their production practices. Horticulturally, containerized plant production (80% of the industry) is still the primary method of growing and shipping plants in California, and most (90%) of these products are sold within the state. Nevada, Arizona, Oregon, Washington, and Texas are the primary destinations for plant material that is exported out of state. The factors that nursery owners feel influence sales the most include market demand, weather unpredictability, and water supply, while governmental and environmental regulations are perceived to have the least impact. The factors that influence product price include cost of production, market demand, and product uniqueness.
Blueberry Production Trends in North America, 1992 to 2003, and Predictions for Growth
Authors: Strik Bernadine C. , Yarborough David
Published: December 2018

Blueberry production area in North American increased 30% from 1992 to 2003 to 239,818 acres (97,054 ha); most of this increase occurred in Canada. During this period, lowbush blueberry (Vaccinium angustifolium) area increased 33% and highbush 24%. In the United States, the area planted to highbush, which includes northern (V. corymbosum) and southern highbush (Vaccinium sp.) and rabbiteye (V. ashei) blueberries, increased from 48,790 acres (19,745 ha) to 55,898 acres (22,622 ha) from 1992 to 2003, a 15% increase. In 2003, the midwestern region of the U.S. accounted for 35% of the area of highbush blueberries planted. The southern, northeastern, and western regions accounted for 29%, 19%, and 13% of the planted area, respectively. Specific states in the U.S. that had considerable growth from 1992 to 2003 were California, Mississippi, North Carolina, Oregon, and Washington. In Canada, the area planted to highbush blueberries increased 105% to 11,010 acres (4456 ha). Commercial blueberry plantings in Mexico were estimated at 70 acres (28.3 ha) in 2003. In the U.S., total lowbush area increased 6% in 10 years, with Maine accounting for 97% of the area planted. In Canada, lowbush area increased 57% since 1992 with 37% and 34% of the total area present in Quebec and Nova Scotia, respectively. The blueberry industry is still projected to grow considerably in the next 5 to 10 years. Highbush blueberries in the U.S. are expected to increase in area planted by 14% and 31% in the next 5 and 10 years, respectively. In Canada, planted area of highbush blueberries is expected to increase by 22% in 5 years and 26% in 10 years. If projections are correct, planted area in Mexico will increase by almost 30-fold in 10 years. The managed area of lowbush blueberries is expected to increase by 5% to 10% over the next 10 years. Data on typical yields, types of cultivars grown, markets, proportion of machine harvest, major production problems, and changes in production practices are presented.
Historical Perspective on Weed Control and Pest Management in Horticultural Crops
Authors: Ngouajio Mathieu
Published: December 2018

Over the last century, climate change, adoption of new regulations, and changes in cropping systems have significantly impacted weed and pest management in horticultural crops. The objective of this workshop was to provide a critical review of major changes and discuss current and future trends for weed and pest management. Speakers touched on a broad range of topics including climate change and disease dynamics, the use of disease resistance inducers, soil management for pest management, and the role of allelopathy in weed management. Major recommendations included 1) increased grower education related to the impact of climate change on plant diseases; 2) more research directed towards a better understanding of the interaction of plant–pathogen–inducer; 3) use of organic soil amendments, cover crops, crop rotations, and resistant cultivars to enhance the weed and disease suppressive effect of soils; and 4) enhancement of allelochemical production and subsequent weed suppression through conventional breeding and molecular techniques.
History and Current Trends in the Use of Allelopathy for Weed Management
Authors: Weston Leslie A.
Published: December 2018

Allelopathy can be defined as an important mechanism of plant interference mediated by the addition of plant-produced secondary products to the soil rhizosphere. Allelochemicals are present in all types of plants and tissues and are released into the soil rhizosphere by a variety of mechanisms, including decomposition of residues, volatilization and root exudation. Allelochemical structures and modes of action are diverse, and may offer potential for development of future herbicides. In the past, allelopathy was described by the Romans as a process resulting in the “sickening” of the soil; in particular, chickpea (Cicer arietinum) was described as problematic when successively cropped with other species. Other early plant scientists, such as De Candolle in the 1800s, first described the ability of plant roots to produce toxic exudates. More recently, research has focused on development of weed management strategies using allelopathic crop residues, mechanism of allelochemical action, and gene regulation of allelochemical production. This paper briefly describes a variety of weed and crop species that establishes some form of potent allelopathic interference, either with other crops or weeds, in agricultural settings, in the managed landscape, or in naturalized settings. Recent research suggests that allelopathic properties can render one species more invasive to native species and thus potentially detrimental to both agricultural and naturalized settings. In contrast, allelopathic crops offer strong potential for the development of cultivars that are more highly weed suppressive in managed settings. A new challenge that exists for plant scientists is to generate additional information on allelochemical mechanisms of release, selectivity and persistence, mode of action, and genetic regulation. Armed with this specific information, we can further protect plant biodiversity and enhance weed management strategies in a variety of ecosystems.
A Review of Weed Control Practices in Container Nurseries
Authors: Case L.T. , Mathers H.M. , Senesac A.F.
Published: December 2018

Container production has increased rapidly in many parts of the U.S. over the past 15 years. Container production has been the fastest growing sector in the nursery industry and the growth is expected to continue. Weed growth in container-grown nursery stock is a particularly serious problem, because the nutrients, air, and water available are limited to the volume of the container. The extent of damage caused by weeds is often underestimated and effective control is essential. Various researchers have found that as little as one weed in a small (1 gal) pot affects the growth of a crop. However, even if weeds did not reduce growth, a container plant with weeds is a less marketable product than a weed-free product. Managing weeds in a container nursery involves eliminating weeds and preventing their spread in the nursery, and this usually requires chemical controls. However, chemical controls should never be the only management tools implemented. Maximizing cultural and mechanical controls through proper sanitation and hand weeding are two important means to prevent the spread and regeneration of troublesome weeds. Cultural controls include mulching, irrigation methods (subirrigation), and mix type. Nursery growers estimate that they spend $500 to $4000/acre of containers for manual removal of weeds, depending on weed species being removed. Economic losses due to weed infestations have been estimated at approximately $7000/acre. Reduction of this expense with improved weed control methodologies and understanding weed control would have a significant impact on the industry. Problems associated with herbicide use in container production include proper calibration, herbicide runoff concerns from plastic or gravel (especially when chemicals fall between containers) and the need for multiple applications. As with other crops, off-site movement of pesticides through herbicide leaching, runoff, spray drift, and non-uniformity of application are concerns facing nursery growers. This article reviews some current weed control methods, problems associated with these methods, and possible strategies that could be useful for container nursery growers.
A Quantitative Approach to Human Issues in Horticulture: Conjoint Analysis
Authors: Brascamp Wilmien
Published: December 2018

Research on human issues in horticulture focuses on the human dimension of horticulture in an effort to maximize the benefits of plants and nature in general, for human well-being. A key issue is the need for scientific evidence of such benefits and for rigorous research methods to reveal the mechanics of the interaction between people and plants. Conjoint analysis, a methodology with obvious potential for successful application in the area of human issues in horticulture, is widely used in consumer research to estimate the structure of people's reactions to multi-attribute objects or services. This paper discusses the steps involved in implementing conjoint analysis and describes how it can be applied to people–plant research.
Raspberry Variety Performance in Southern Michigan
Authors: Hanson Eric , Berkheimer Steven , Schilder Annemiek , Isaacs Rufus , Kravchenko Sasha
Published: December 2018

Seven primocane-fruiting and 15 floricane-fruiting raspberry varieties (Rubus idaeus) were compared for three fruiting seasons on a loamy sand soil in southwest Michigan. The earliest primocane-fruiting varieties (`Autumn Bliss', `Autumn Britten', `Polana') began ripening 3 weeks before the standard variety, `Heritage'. `Autumn Bliss' was the most productive early primocane-fruiting variety. `Caroline' and `Dinkum' ripened about 1 week earlier than `Heritage', and `Ruby' was 2 days later. `Caroline' was the most productive of this group and also had large fruit that were somewhat resistant to rot caused by Botrytis cinerea. `Caroline' also received the greatest leaf feeding from rosechafer beetles (Macrodactylus subspinosus). Most primocane-fruiting varieties were fairly resistant to leaf spot (Sphaerulina rubi), while `Dinkum' was highly susceptible to spur blight (Didymella applanata). Floricane-fruiting varieties were evaluated based on fruit production and quality as well as winter injury to canes, disease resistance, and feeding injury from two-spotted spider mites (Tetranychus urticae). The floricane-fruiting varieties showing minimal winter injury were `Boyne', `Killarney', `Latham', `Nova', and `Prelude'. `Canby', `Encore', `Glen Ample,', `Qualicum', `Reveille', `Titan', and `K 81-6' were moderately hardy; while `Tulameen', `Malahat', and `Lauren' were not hardy enough for this location. `Reveille', `Killarney', `Boyne', and `Prelude' were the most productive floricane-fruiting varieties. `Nova' and `Qualicum' had low levels of botrytis rot. `Nova' was most resistant to leaf spot and also had resistance to spur blight. Injury from mites was greatest on `Glen Ample' and lowest on `Malahat', `Prelude', `Qualicum', and `Tulameen'. `Caroline' (primocane-fruiting), `Prelude', and `Nova' (floricane-fruiting) were promising newer varieties.
Hydroponic Greenhouse Production of “Baby” Squash: Selection of Suitable Squash Types and Cultivars
Authors: Shaw Nicole L. , Cantliffe Daniel J.
Published: December 2018

Mini or “baby” vegetables have become increasingly popular items for restaurant chefs and retail sales. Squash (Cucurbita pepo) are generally open-field cultivated where climate, insect, and disease pressures create challenging conditions for growers and shippers who produce and market this delicate, immature fruit. In order to overcome these challenges, in Spring 2003 and 2004, 18 squash cultivars, including zucchini, yellow-summer, patty pan/scallop, and cousa types, were grown hydroponically in a passively ventilated greenhouse and compared for yield of “baby”-size fruit. Squash were graded as “baby” when they were less than 4 inches in length for zucchini, yellow-summer, and cousa types and less than 1.5 inches diameter for round and patty pan/scallop types. In both seasons, `Sunburst' (patty pan) produced the greatest number of baby-size fruit per plant, while `Bareket' (green zucchini) produced the least. The zucchini-types produced between 16 and 25 baby-size fruit per plant in 2003. The yellow summer squash-types produced on average 45 baby fruit per plant. The production of the patty pan/scallop types ranged from 50 to 67 baby-size fruit per plant depending on cultivar. The cousa types produced approximately 30 baby-size fruit. Total yields were lower in 2004 due to a shortened season. Squash plants will produce numerous high quality baby-sized fruit when grown hydroponically in a reduced pesticide environment of a greenhouse where they can be harvested, packaged, and distributed to buyers daily. The cultivars Hurricane, Raven, Gold Rush, Goldy, Sunray, Seneca Supreme, Supersett, Butter Scallop, Sunburst, Patty Green Tint, Starship, Magda, and HA-187 could be used for hydroponic baby squash production.
Effects of Slope and Underlay on Surface Runoff of Irrigation from Woven Polypropylene Groundcloth
Authors: Million Jeff , Yeager Tom , Bryant Henry , Larsen Claudia , Shook Joe , Albano Joseph
Published: December 2018

Woven polypropylene groundcloth is used extensively in plant nurseries as a permeable and durable surface for container plant production. To better understand the fate of overhead sprinkler irrigation water, we designed and constructed runoff platforms (2.7 m2) to measure runoff and leachate from single irrigation events as affected by slope and underlay substrates. Groundcloth-covered platforms at slopes of 1.5% and 11% were tested with each of five underlay treatments: no underlay, coarse sand, 50% coarse sand and 50% no underlay (CS50), gravel, and native sandy soil. We applied 0.9 cm of irrigation at 1.8 cm·h-1 and determined runoff and leachate volumes. Runoff percentage [runoff × 100%/(runoff + leachate)] increased at the 11% slope for each underlay treatment. Mean (n = 10) runoff percentages (RP) for the 1.5% and 11% slopes were 0.5% and 15.7%, respectively, for no underlay, 0.1% and 1.1% for coarse sand, 0.1% and 0.7% for CS50, 0.7% and 2.5% for gravel, and 0.1% and 3.1% for native sandy soil. The low RP observed indicate that a high percentage of nutrients and agrichemicals associated with container leachate would move into the underlying substrate or soil rather than directly running off into surface waters.
Evaluation of Organic Strawberry Runner Production
Authors: Walter Monika , Snelling Cath , Boyd-Wilson Kirsty S.H. , Langford Geoff I. , Williams Graeme
Published: December 2018

System requirements for organic strawberry (Fragaria × ananassa) runner production under cover were determined during the 2001-02 and 2002-03 seasons. In the field, yield and fruit quality were assessed for organically produced runners (plug and bare-rooted transplant) in comparison with barerooted conventionally produced runners under organic, BioGro certified production conditions. The preferred organic production system was the enhanced suspended system, where mother plants grew on benches in the tunnel house and the first two runners were potted into growth substrate. This system produced approximately 50 plug transplants/mother plant or 200 plug transplants/m2. The least preferred system was the nursery bed, where mother plants were allowed to produce runners that yielded approximately 100 bare-rooted runners or 100 transplants/m2. Tunnel house production of runners (plug transplants and bare-rooted) allowed earlier planting (March vs. May) compared to field-produced bare-rooted runner plants. The earlier planting date increased yield by approximately 181 g/plant. Under organic production conditions, organically produced runners (plug and bare-rooted transplants) performed at least as well as bare-rooted conventionally produced runners. Our results show that indoor production of organic strawberry runners is possible. We also showed that organically produced runners (bare-rooted and plug transplants) perform similarly in the field compared to bare-rooted conventionally produced runners. Generally, there were no differences in yield or fruit quality among runner sources.
A Comparison of Sanitation Systems for Fresh-cut Mango
Authors: Narciso Jan , Plotto Anne
Published: December 2018

A comparison of sanitizers for fresh-cut mango (Mangifera indica cv. Keitt) was made. Mangos were obtained from a farm in Homestead, Fla., and stored at 15 °C until processed. Before cutting, fruit were dipped in solutions of either sodium hypochlorite (NaOCl) (200 ppm) or peroxyacetic acid (100 ppm). The cut pieces were dipped in acidified sodium chlorite (NaClO2) (200 ppm, pH 2.6) or dilute peroxyacetic acid (50 ppm) for 30 seconds. Resulting cut slices were placed in polystyrene clamshell food containers and stored at 5 °C for 21 days. Samples in the clamshells were tested for changes in microbial stability and for quality parameters every 7 days. Results showed that even though the fruit slices were sanitized after cutting, cut fruit microbial populations were related to the method of whole fruit sanitation. After 15-21 days in storage at 5 °C, cut slices from whole fruit sanitized with peroxyacetic acid that were subsequently treated with dilute peroxyacetic acid or acidified NaClO2 had less contamination [<1 colony-forming unit (cfu) per gram] than samples cut from whole fruit sanitized with NaOCl (<1000 to 3700 cfu/g). These data demonstrate that the method of whole fruit sanitation plays a role in determining the cleanliness of the cut fruit. These sanitizer systems (peroxyacetic acid on whole fruit followed by peroxyacetic acid or acidified NaClO2 on cut slices) effectively reduced microbial growth and kept microbial counts low on cut fruit surfaces for 21 days when compared to cut fruit slices from NaOCl-treated whole fruit.
Apple Scab Management Assisted by Postharvest Tree Defoliation with Vegetable Oil Emulsion
Authors: Curry Eric , Ju Zhiguo , Duan Yousheng
Published: December 2018

Vegetable oil emulsion (VOE) was applied to `Gala' and `Fuji' apple (Malus ×domestica) trees after harvest to hasten defoliation and reduce apple scab (Venturia inaequalis). Applied at 2%, 4%, or 6%, VOE applied to whole trees in the fall induced leaf drop, with the highest concentration causing the most defoliation. At the same concentration, VOE applied in early, mid, or late October had similar effects on leaf drop. VOE treatment reduced respiration and stimulated ethylene production in shoot tissue within 24 hours of application. None of the treatments affected tree hardiness during the winter, or shoot growth the following spring. Return bloom density was unaffected; however, VOE tended to delay anthesis by 2 to 5 days. Under controlled conditions, `Gala' and `Fuji' trees inoculated with scab spores developed 48% and 65% scab, respectively. VOE-induced defoliation reduced scab by 50% to 65%. VOE-induced defoliation plus manual leaf removal from the orchard floor, or VOE-induced defoliation in late fall (15 Oct.-15 Nov.) plus application of 5% lime sulfur in early spring, controlled scab to <5% on both leaves and fruit. Neither lime sulfur nor urea applied in late fall at 2% induced defoliation or controlled scab. VOE at 4% plus 2% lime sulfur and/or 2% urea applied in late fall, however, defoliated `Gala' trees effectively and controlled scab on fruit to <7% the following spring. In the `Fuji' planting, the combination of 4% VOE plus 2% lime sulfur and 2% urea reduced scab on fruit from 21% in controls to 0%.
Focus Groups and Staff Surveys: Tools to Assess the Future Direction of Volunteer Involvement
Authors: Jutila Stephanie G. , Meyer Mary Hockenberry , Hoover Emily
Published: December 2018

Focus groups and surveys were used to align volunteers' work with the mission and organizational objectives of the Minnesota Landscape Arboretum (MLA) at the University of Minnesota. In focus groups, a cross-section of volunteers discussed several issues, including how they could more directly contribute to the mission and organizational objectives of the institution. Staff were surveyed on their perceptions of the volunteer workforce, including their current use of volunteers. Focus groups and surveys proved to be valuable tools to approach programmatic changes in volunteer involvement at the MLA by providing a platform to discuss the areas where change is needed, as well as what kind of change should occur. Focus groups can be a key tool in involving volunteers, by allowing them to provide input on changes that directly affect them, in addition to furthering the understanding of volunteer needs and motivations.
Yield and Quality of Vegetable Soybean Cultivars for Production in North Dakota
Authors: Duppong Lisa M. , Hatterman-Valenti Harlene
Published: December 2018

Vegetable soybeans (Glycine max), the same species as field-dried soybeans, have similar production requirements and good market potential for commercial producers in upper midwestern United States. Five vegetable soybean cultivars were tested for yield and quality characteristics and to assess the necessity of field irrigation during 2003 and 2004 in North Dakota. Cultivars of different maturity dates were evaluated for stand densities, pod production, seed weight, and marketable yield. Total marketable yields varied between the years, ranging from 5773 to 10,118 lb/acre. Lower yields in 2003 were attributed to significantly lower population stands caused by poor germination conditions. `Envy', the earliest maturing cultivar, produced a significantly smaller seed size, while `Sayamusume' produced a greater seed size than the other cultivars both years. `Butterbean', `IA1010', and `IA2062' yielded greater percentages of three-bean pods than the other two cultivars each growing season. Irrigation did not increase the marketable pod yield or the quality variables examined each season; thus it appears that rainfall during the growing season may be adequate for vegetable soybean production in this region.
Evaluation of Selected Raspberry and Strawberry Cultivars in Southern Idaho
Authors: Robbins Jo Ann
Published: December 2018

The growth, yield, and berry weight of nine June-bearing strawberry (Fragaria ×ananassa) cultivars (`Allstar', `Cavendish', `Honeoye', `Jewel', `Kent', `Mesabi', `Mira', `Northeaster', and `Winona') and six floricane fruiting (summerbearing) raspberry (Rubus idaeus) cultivars (`Algonquin', `K-81-6', `Lauren', `Nova', `Qualicum', and `Reveille') grown in southern Idaho were compared. `Cavendish', `Mesabi,' and `Winona' established quickly and maintained their spring vigor. Strawberry cultivars grew well during the summer but some cultivars had low spring vigor ratings. The most reliable yielding cultivars were `Cavendish' and `Mesabi' in spite of spring frosts, which damaged blossoms. `Mesabi' yielded best during a season where plants suffered spring freeze injury. Only `Mesabi' yielded above 6 tons/acre (2001). Spring freezing and relatively low yields are limiting factors in strawberry production in southern Idaho. Berry weight averaged 5.5 to 8.8 g in the second year of the study and may be too small for consumer acceptance and other commercial competition. `Cavendish' and `Mesabi' fruited earliest and `Honeoye' and `Winona' were latest. Raspberry shoot and cane growth was strong in all years. Over the course of the study, highest yielding in 2001 was `Nova' (7.65 tons/acre) and in 2002 `K-81-6' (10.4 tons/acre). In the second year of harvest (2002), all cultivars produced greater than the projected commercial production requirement of 3 tons/acre. Raspberry bloom occurred after the spring frosts. Berry weight was largest in `K-81-6' (3.3 and 2.5 g in 2001 and 2002, respectively) and smallest in `Algonquin' (1.8 and 1.5 g in 2001 and 2002, respectively). Early fruiting cultivars were `Nova' and `Reveille'.
Variability in Plant Growth in Retail Potting Media
Authors: Wiberg Amanda , Koenig Richard , Cerny-Koenig Teresa
Published: December 2018

There is extensive variability in physical and chemical properties among brands of retail potting media. The purpose of this study was to assess variability in seed germination and plant growth responses among and within brands. Twenty-four different brands of media, and multiple bags of five brands, were purchased at nine retail stores. Tomato (Lycopersicon esculentum) seeds were germinated in 11 different brands of media and in media from different bags of four of the same brands. Marigold (Tagetes erecta) and petunia (Petunia×hybrida) were grown to flowering in 10 brands of media. Germination varied significantly among media brands and among bags of one of the brands. Plant performance also varied significantly, with several of the brands producing plants with few flowers, long times to flowering, and low shoot and root dry weights even though all treatments received uniform applications of a complete fertilizer solution three times per week. Few relationships could be discerned between individual physical and chemical properties of the media and plant performance. Results indicate improvements in quality among brands and quality control within brands are needed in the retail potting media industry. Quality assessment tools emphasizing plant performance could improve overall media quality.
Effects of Aminoethoxyvinylglycine, Ethephon, and 1-Methylcyclopropene on Apple Fruit Quality at Harvest and after Storage
Authors: Drake S.R. , Elfving D.C. , Drake M.A. , Eisele T.A. , Drake S.L. , Visser D.B.
Published: December 2018

This study was conducted over two crop seasons using `Scarletspur Delicious' and `Gale Gala' apple trees (Malus ×domestica). The bioregulators aminoethoxyvinylglycine (AVG), ethephon (ETH), and 1-methylcyclopropene (MCP) were applied at various times before or after harvest. Fruit response was evaluated at harvest and after regular atmosphere (RA) and controlled atmosphere (CA) storage [2.0% oxygen (O2) and <2.0% carbon dioxide (CO2) at 0 °C] and quality of whole and juice apple products evaluated. AVG reduced starch loss and ethylene production, enhanced firmness, and reduced cracking in `Gale Gala,' but reduced sensory acceptance of apples and apple juice. ETH intensified starch loss, ethylene production, and reduced firmness, but did not affect `Gale Gala' fruit cracking. AVG followed by ETH reduced starch loss, ethylene production, and cracking and maintained firmness. This combination also aided in sensory acceptance of apples but reduced sensory preference of apple juice. Exposure to postharvest MCP improved flesh firmness retention and reduced ethylene production after both RA and CA storage. MCP either favored or reduced sensory acceptance of whole apples, depending on the particular season, but reduced sensory preference of apple juice. Sensory scores for `Scarletspur Delicious' apples were more strongly modified by bioregulators than were `Gale Gala' apples.
Nitrogen Availability from High-nitrogen-containing Organic Fertilizers
Authors: Hartz T.K. , Johnstone P.R.
Published: December 2018

Limited soil nitrogen (N) availability is a common problem in organic vegetable production that often necessitates in-season fertilization. The rate of net nitrogen mineralization (Nmin) from four organic fertilizers (seabird guano, hydrolyzed fish powder, feather meal, and blood meal) containing between 11.7% and 15.8% N was compared in a laboratory incubation. The fertilizers were mixed with soil from a field under organic management and incubated aerobically at constant moisture at 10, 15, 20, and 25 °C. Nmin was determined on samples extracted after 1, 2, 4, and 8 weeks. Rapid Nmin was observed from all fertilizers at all temperatures; within 2 weeks between 47% and 60% of organic N had been mineralized. Temperature had only modest effects, with 8-week Nmin averaging 56% and 66% across fertilizers at 10 and 25 °C, respectively. Across temperatures, 8-week Nmin averaged 60%, 61%, 62%, and 66% for feather meal, seabird guano, fish powder, and blood meal, respectively. Cost per unit of available N (mineralized N + initial inorganic N) varied widely among fertilizers, with feather meal the least and fish powder the most expensive.
Phytoavailability of Zinc in Postbloom Zinc Sprays Applied to `Golden Delicious' Apple Trees
Authors: Peryea Frank J.
Published: December 2018

Postbloom zinc (Zn) sprays are replacing dormant and postharvest sprays as the primary means for applying Zn in commercial apple (Malus ×domestica) orchards. We conducted a multiyear field study comparing the phytoavailability of Zn in 11 commercially available Zn spray products, plus reagent-grade Zn nitrate and a water-sprayed control, applied postbloom at identical Zn concentrations to `Golden Delicious' apple trees. Two sprays were applied per season (mid-May and mid-June), at per-spray rates of either 0.5 lb/acre in 2000 or 1.0 lb/acre in 2001 and 2002. No sprays were applied in 2003 in order to evaluate carry-over effects. The Zn sprays had no effect on fruit number, bitter pit or russeting, or on leaf green color. Zinc concentrations of detergent plus acid-washed leaves (a procedure used to remove surface residues of the Zn sprays) sampled in August and of unwashed winter buds sampled the following January were used as indices of tree Zn status. Leaf Zn concentration generally increased in the order: Zn phosphate < Zn oxide = Zn oxysulfate < chelated/organically complexed Zn ≤ Zn nitrate. There was little consistent difference among chelated and organically complexed Zn products. Leaf Zn concentration varied considerably between seasons, and was not related to Zn application rate. All of the Zn sprays increased leaf Zn concentrations to desirable levels. Because the inorganic Zn-based products typically are substantially less expensive per unit of Zn, it may be less costly and just as effective to use a higher rate of an inorganic Zn product as to use a lower rate of a more expensive chelated or organically complexed Zn product. On the other hand, use of low rates of highly phytoavailable Zn products minimizes release of the nutritionally essential but potentially ecohazardous metal into the environment. There was no detectable lasting effect of the three previous seasons of Zn sprays on leaf Zn in 2003. Similarly, there was no detectable effect in any year of the Zn spray treatments on bud Zn concentration the following winter. These results suggest that the amount of Zn supplied by the sprays at the tested rates was insufficient to promote substantial Zn accumulation within the trees, thereby validating the recommendation for annual application of Zn nutritional maintenance sprays.
Mechanical Removal of Summer Dodder Infestations and Impacts on Cranberry Yield
Authors: Hunsberger Laura K. , Autio Wesley R. , DeMoranville Carolyn J. , Sandler Hilary A.
Published: December 2018

Over a 2-year period, 11 cranberry (Vaccinium macrocarpon) farms in southeastern Massachusetts were selected to evaluate mechanical removal of swamp dodder (Cuscuta gronovii) with a conventional hand-held bamboo rake. This technique consisted of breaking and removing large strands of the parasite that connected host plants; embedded and encircled portions of the parasite were not removed. Differences in dodder biomass, cranberry yield, and berry weight were determined in plots that received zero, one, or two weed-removal events. Removing dodder one time per season reduced percentage of weed cover by more than 74% in both years. Impacts on dodder fresh and dry weight were not as discernible. Removal initially decreased dodder biomass, which remained 20% to 40% lower than the baseline values, but removal treatments did not differ statistically from the control. No additional benefits were obtained by removing the weed cover more than once. Biomass per berry was not affected by mechanical weed removal and fruit of marketable size were produced in the treated area. Substantial yield loss was largely attributable to the dodder infestations, but multiple removals may eventually reduce yield to levels below those associated with infestations alone.
Survey of Japanese Beetle Management Practices in Michigan Highbush Blueberry Production
Authors: Szendrei Zsofia , Isaacs Rufus
Published: December 2018

Michigan higbush blueberry (Vaccinium corymbosum) growers were surveyed during Winter 2003 to gather information on the extent of the pest status of japanese beetle (Popillia japonica, Coleoptera: Scarabaeidae) within this crop, and their responses to this pest management challenge. The survey was mailed to 215 highbush blueberry farms in southwestern, central, and southeastern Michigan. Ninety-nine surveys were completed and returned. Our results revealed that this pest was of concern to the majority of growers who returned the survey (84%), causing average additional costs of $72/acre. Increased insecticide use was the major cause of the economic loss due to this pest, and the main methods for controlling japanese beetle were insecticides and clean cultivation. More farms had permanent sod coverage than clean cultivation in individual fields. The acreage of clean-cultivated farms was higher because larger farms tend to have clean cultivation. Japanese beetle has driven changes in row-middle management, indicated by growers who have switched to clean cultivation recently. Fifty percent of growers considered the changes they implemented to control japanese beetle to be effective, and most growers were not planning any further changes to their pest management programs to address this pest. Many growers were willing to try new cover crops if they are shown to be effective against japanese beetle.
Ethylene Treatment Promotes Early Ripening Capacity in Mature `Comice' Pears
Authors: Sugar David , Basile Sally R.
Published: December 2018

`Comice' pears (Pyrus communis) harvested early in the maturity range needed 25-31 days of storage at 0 °C to develop the capacity to ripen to an average firmness of 5 lbf within 5 days after being moved to 20 °C. After 24 h exposure to 100 ppm ethylene at 20 °C applied immediately after harvest, 17-27 days additional chilling were needed to develop ripening capacity, while ethylene exposure for 48 hours required an additional 7-17 days chilling. After 72 h ethylene exposure, ripeness was achieved within 5 days following 3 days cold storage, the minimum duration tested. Similar results were obtained when the sequence of ethylene treatment followed by cold storage was reversed. This technique may be applied to reduce the amount of time that `Comice' pears must be stored after harvest before marketing fruit with the capacity to ripen.
Narcissus Response to Plant Growth Regulators
Authors: Krug Brian A. , Whipker Brian E. , McCall Ingram , Dole John M.
Published: December 2018

Three experiments were conducted to determine the effectiveness of plant growth regulators (PGRs) on `Tete a Tete', `Dutch Master', and `Sweetness' narcissus (Narcissus pseudonarcissus). Ethephon foliar sprays (500 to 2500 mg·L-1) and substrate drenches of flurprimidol and paclobutrazol (0.25 to 4 mg/pot a.i.) did not control height during greenhouse forcing of `Tete a Tete' at any concentration trialed. Stem stretch was controlled during postharvest evaluation with ethephon foliar sprays ≥1000 mg·L-1, flurprimidol substrate drenches ≥0.5 mg/pot a.i., and paclobutrazol substrate drenches of 4 mg/pot a.i. A second experiment investigated preplant bulb soaks of flurprimidol (10 to 40 mg·L-1) applied to `Dutch Master' and `Tete a Tete' narcissus bulbs. Flurprimidol preplant bulb soaks controlled postharvest stretch on `Tete a Tete' and `Dutch Master' at concentrations ≥15 and ≥10 mg·L-1, respectively. A third experiment was conducted with paclobutrazol (75 to 375 mg·L-1) on `Tete a Tete' and `Dutch Master' and three concentrations of flurprimidol on `Sweetness' to determine optimal soak recommendations. Paclobutrazol preplant bulb soaks ≥75 mg·L-1 controlled postharvest stretch of `Tete a Tete' and `Dutch Master', while 37.5 mg·L-1 of flurprimidol controlled postharvest stretch of `Sweetness'. Based on the results of these experiments, growers can now select a PGR to help control excessive plant growth.
Screening Winter-sown, Intermediate-day Onion Cultivars for Resistance to Fusarium Basal Rot
Authors: Gutierrez Jessica A. , Molina-Bravo Ramon , Cramer Christopher S.
Published: December 2018

Fusarium basal rot (FBR), caused by Fusarium oxysporum f.sp. cepae, is a soilborne fungal disease that affects bulb onions (Allium cepa) worldwide. Winter-sown onion cultivars that are resistant to FBR are lacking. The goal of this project was to screen winter-sown onion germplasm for FBR resistance using a mature-bulb field screening at harvest and after 4 weeks in storage. The project was conducted for 2 years, and in each year, 22 winter-sown onion lines were grown in a field known to produce a high incidence of FBR-infected bulbs. At maturity, the basal plates of 20 randomly selected bulbs were cut transversely and each plate was scored for disease severity on a scale of 1 (no diseased tissue) to 9 (70% or more diseased tissue). Bulbs were stored and scored again at 4 weeks after harvest. Severity and incidence increased in storage for both years. NMSU 99-30, `NuMex Arthur', and `NuMex Jose Fernandez' showed the lowest disease severities and incidences in both years. For fields that produce a high incidence of FBR-infected bulbs, these cultivars could be grown with less loss to FBR at harvest and after storage than more FBR-susceptible cultivars. When developing FBR-resistant cultivars, breeding lines should be evaluated over multiple years and bulbs should be stored for 4 weeks before being screened.
Fruiting Responses and Economics of Containerized and Bare-root Strawberry Transplants Established with Different Irrigation Methods
Authors: Hochmuth George , Cantliffe Dan , Chandler Craig , Stanley Craig , Bish Eric , Waldo Eric , Legard Dan , Duval John
Published: December 2018

Strawberry (Fragaria ×ananassa) crops were transplanted in two seasons in central Florida with bare-root and containerized (plug) plants under three transplant establishment-period irrigation methods to evaluate crop fruiting responses and production economics associated with the various establishment systems. Irrigation was not required to establish plug transplants in the field. Early (first 2 months) fruit yield with nonirrigated plug plants was greater than early yield with sprinkler-irrigated bare-root plants (the current commercial system) in one of two seasons and equal in a second season. Total-season yields were similar in each season between the two establishment systems. Large or medium plug plants led to greatest early fruit yields in one season while large plug plants resulted in greatest early yield in a second season. Total yield was greatest with medium plants in one season and large plants in another season. The extra cost for the plug plant system was $1853/acre. In one out of two seasons there was increased net income amounting to $1142/acre due to greater early yield associated with the plug plant cultural system. Strawberry plug transplants showed promise for earlier and more profitable crops in addition to substantial savings in water used for plant establishment in the field. The ability to establish strawberry crops without irrigation will be important in areas where growers are required to reduce farm water consumption.
Response of Selected Nursery Crop Plants to Inoculation with Isolates of Phytophthora ramorum and Other Phytophthora Species
Authors: Linderman R.G. , Davis E.A. , Marlow J.L.
Published: December 2018

Many nursery crops are susceptible to root and foliage diseases caused by numerous species of Phytophthora. Phytophthora ramorum causes sudden oak death of trees and ramorum leaf blight and shoot dieback on numerous nursery plants, including rhododendron (Rhododendron spp.), viburnum (Viburnum spp.), pieris (Pieris spp.), and camellia (Camellia spp.) in Europe, the United States, and British Columbia, Canada. We sought to evaluate relative susceptibility of a selection of ornamental nursery crops by inoculating detached leaves with several species of Phytophthora known to infect rhododendrons, and to compare the relative virulence on those species to isolates of P. ramorum. The results indicated that many plants were susceptible under these experimental conditions, while others were not. On a given host, symptoms caused by all species of Phytophthora were identical except for differences in pathogen virulence. Plant species were identical except for differences in pathogen virulence. Plant species within genera or cultivars within species varied in susceptibility to isolates of P. ramorum and other species of Phytophthora. Phytophthora ramorum, P. citricola, P. citrophthora, and P. nicotianae were the most virulent pathogens on most of the host plants inoculated. Some plants were susceptible to several species of Phytophthora, while others were susceptible only to P. ramorum. Inoculation of detached leaves of `Nova Zembla' rhododendron, lilac (Syringa vulgaris), or doublefile viburnum (Viburnum plicatum var. tomentosum) under controlled conditions with different species of Phytophthora or isolates of P. ramorum (both mating types) indicated significant relative differences in species or isolate virulence.
Residential Landscapes, Homeowner Attitudes, and Water-wise Choices in New Mexico
Authors: Hurd Brian H. , St. Hilaire Rolston , White John M.
Published: December 2018

Residential landscapes are responsible for a large share of the water use of New Mexico communities. Water conservation plans and programs are being promulgated throughout New Mexico and the western U.S. as concern grows over the sufficiency and variability of present supplies, sustainability of current population growth rates, and desire for enhanced economic development. Household attitudes, choices, and behaviors ultimately underlie the success and performance of community water conservation programs. Homeowners in three New Mexico cities were surveyed concerning their attitudes and behavior toward water use, water conservation, and residential landscapes. Findings suggest that New Mexico's homeowners are mindful of the water resource challenges faced by communities, and are prepared to shoulder responsibility for stewarding the state's water resources. There is broad community support to limit traditional turfgrasses [e.g., kentucky bluegrass (Poa pratensis)] and to increase the areas planted to native, natural, and water-conserving landscapes; for example, 92% favored limiting turfgrass to less than 25% of the area around public buildings. Evidence showing that 40% are not “content” with their current landscape suggests that significant impediments remain and limit still greater adoption of water-conserving landscapes and subsequent potential for increased household water savings.
Chlorine Disinfection of Tomato Surface Wounds Contaminated with Salmonella spp.
Authors: Felkey K. , Archer D.L. , Goodrich R.M. , Schneider K.R. , Bartz J.A.
Published: December 2018

This study examined the efficacy of chlorine treatments of flume water for eliminating Salmonella spp. from inoculated wounds and intact surfaces of tomatoes (Lycopersicon esculentum). Water in a scale-model flume was chlorinated to 150 mg·L-1 of free chlorine at pH 6.5 and maintained at a temperature of 25 or 35 °C, depending on the test. Viable Salmonella were recovered from all of the inoculation sites (intact fruit surface, punctures, shaves, and stem scars) even after treatment with chlorinated water for up to 120 seconds at either 25 or 35 °C. Generally, the highest Salmonella recovery came from puncture wounds and the lowest from the intact surfaces. After 120 seconds at 25 °C, 4.9 to 5.8 log10 units were recovered from the wounds. Populations recovered after the 30-second treatment at 35 °C ranged from 4.1 log10 cfu/mL for intact surfaces to 6.0 log10 cfu/mL in the puncture wounds. At 60- and 120-second treatment times, all wounds had higher mean populations than tomatoes with intact surfaces. Although greater Salmonella survival was associated with shorter exposure to the chlorine, water chlorination cannot completely eliminate contamination of tomato fruit by Salmonella, even on intact surfaces. Stem scars, in this study, were not readily disinfected with sodium hypochlorite.