bluuebunny/crossref_metadata_2025 huggingface dataset:
Impact of Soil Moisture and Mowing Height on Ataenius spretulus (Coleoptera: Scarabaeidae) Selection of Golf Course Turf Habitat in Choice Tests
Authors: Jo Young-Ki , Smitely David R.
Published: February 2019

Ataenius spretulus (Haldeman) (Coleoptera: Scarabaeidae) is the most common grub in golf course fairways in Michigan. Ataenius spretulus grubs are 3- to 10-fold more abundant in golf course fairways (mowed at a height of 1.5 cm) than in the roughs (mowed at a height of 5.0 cm or higher). Predation and infection by Paenibacillus sp. were previously reported to be greater in the rough, and may partially explain outbreaks of A. spretulus grubs in golf course fairways. In addition to natural enemies, cultural practices of irrigation and mowing could also be important factors, especially if A. spretulus prefers to oviposit in the fairway over the rough. In this paper we examine the impact of soil moisture and mowing height on oviposition and habitat selection. In a greenhouse experiment where A. spretulus adults were given a choice of turf maintained at fairway or rough height, no ovipositional preference for one or the other was observed. In three different growth chamber experiments where adults were allowed to choose among fairway or rough turf plugs held in soil at different moisture levels, adults preferred turf plugs in soil at a volumetric moisture content of 13% to 26% over turf plugs in soil at 8% to 9% moisture for their habitat selection. We conclude from these greenhouse and growth chamber experiments that A. spretulus adults do not choose turf habitat based on mowing height, but may be influenced by soil moisture levels.
IMPACT AND MANAGEMENT OF STRAWBERRY BUD WEEVIL (ANTHONOMUS SIGNATUS) ON RASPBERRY IN THE NORTHEAST
Authors: Howard Christina S. , Moran Renae , Handley David
Published: February 2019

The strawberry bud weevil (Anthonomus signatus), “clipper,” is an invasive pest to northeastern U.S. strawberry and raspberry crops. Strawberry is the primary host of clipper, but it has been observed damaging raspberry crops as well. The first objective for this research is to determine the importance of clipper as a pest on raspberries in the northeastern U.S. Raspberry plantings were scouted weekly on 13 grower-cooperator farms in Maine during the late spring and early Summer 2005 for the adult insects and bud injury (clipped or not). 10 canes from each site were then collected and the number of total buds and clipped buds were taken. This data will be correlated with the bud injury data to determine interrelationships between clipper populations and bud injury levels on different varieties of raspberries. The first year of this research has determined that clipper is a pest of raspberry in the northeastern U.S. Up to 55% clipper damage was found on raspberry plants in 2004 and up to 22% clipper damage was found in 2005. The other objective for this research is to develop integrated pest management (IPM) strategies for clipper on raspberry crops in the northeastern U.S. While scouting the farms this past summer, some different scouting techniques were tested for their efficiency and effectiveness at predicting the population levels of clipper on the crop. The scouting method of white sticky traps were hung in the field and provided the most accurate method of scouting for clipper in the field. In addition to this research, the importance of clipper as a pest of raspberries was tested using greenhouse-grown plants. They were analyzed for the ability of raspberry fruit yield to compensate for the loss of flower buds due to clipper damage. The research showed that plants with any clipped buds yielded significantly lower and the mean number of berries is significantly lower than the control plants with no clipped buds. The results also showed that the mean berry size was highest if there were no primaries clipped and significantly lower if primaries or secondaries were clipped concluding that there is little or no compensation in Killarney red raspberries when buds are clipped. This is a thesis project in progress with one more season of data to collect. Concluding the research, this work should improve grower awareness of clipper as a pest of raspberries and provide an IPM program to manage clipper on raspberries in the Northeast.
ANTIOXIDANT ACTIVITY AND PHENOLIC COMPOSITION CHANGES IN SWEETPOTATO ROOT AND LEAF TISSUE DURING DEVELOPMENT
Authors: Padda M.S. , Picha D.H.
Published: February 2019

Antioxidant activity and phenolic content of sweetpotato root and leaf tissues were quantified at different developmental stages. 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical method was used to measure antioxidant activity and total phenolic content was quantified by spectrophotometry using Folin-Denis reagent. Individual phenolic acids were quantified using reversed phase high performance liquid chromatography. Antioxidant activity and phenolic content decreased with root development and leaf maturity. Roots at the initial stages of development (about 4.0 g root weight) had a higher antioxidant activity and phenolic content compared to fully developed roots. Phenolic content in fully developed roots was significantly higher in the cortex tissue than internal pith tissue. The highest total phenolic content and antioxidant activity was found in cortex tissue at the initial stage of development (10.3 mg chlorogenic acid eq/g dry tissue weight and 9.7 mg Trolox eq/gdry tissue weight, respectively). Sweetpotato leaves had a significantly higher phenolic content and antioxidant activity than roots. Immature unfolded leaves had the highest total phenolic content (88.5 mg chlorogenic acid eq/g dry tissue weight) and antioxidant activity (99.6 mg Trolox eq/g dry tissue weight). Chlorogenic acid was the major phenolic acid in root and leaf tissues with the exception of young immature leaves in which the predominant phenolic acid was 3,5-dicaffeoylquinic acid.
TEACHING MASTER GARDENERS HOW TO APPLY IPM PRINCIPLES
Authors: Lamberts Mary , Hunsberger Adrian
Published: February 2019

When Master Gardeners first begin a training class, their preconceived notions about concepts such as IPM, pests and pest management are usually very similar to those of the general gardening public. Master Gardeners interact extensively with home owners and are often either the first or the only person from an Extension office with whom an individual speaks. We designated part of their initial training to a module aimed at getting them to understand basic concepts about IPM, pests and pest management. Slides were used to review the different types of pests/pesticides and Integrated Pest Management (IPM) principles that apply to a) insects and related organisms, b) diseases and c) weeds. These were accompanied by very simple guidelines for each pest group, stressing that pesticides should not automatically be the home owner's first choice. The pesticide label reading portion of this module started with basic information about pesticide labels themselves. From there, Master Gardener trainees were led through an exercise where they had to find specific information on various labels: Sevin, RoundUp, Daconil 2787, Brush-B-Gon, Phyton 27, Dipel, and Amdro. For fruit and vegetable use, they had to find preharvest intervals and any restrictions on planting. For all products, they looked for rates, timing, Personal Protective Equipment (PPE)—if listed, and noted label variations. Pre-training scores averaged 60% while post-training scores were 90% or higher.
SUSTAINABLE NURSERY PRODUCTION PRACTICES EXTENSION PROGRAMS: IPM AND BMP
Authors: Fulcher Amy , Hayden Dava , Dunwell Winston
Published: February 2019

The objectives of Kentucky's Sustainable Nursery Production Practices Extension Program are for 1) the Kentucky nursery industry to continue sustained growth and 2) Kentucky growers to produce high quality plants, efficiently use pesticides, be stewards of their land and Kentucky's environment. Sustainable Nursery Program Components are 1) Integrated Pest Management (IPM): Nursery Scouting, Scout Training and Scouting Education for growers, Extension workers, and students; 2) Best Management Practice (BMP) Workshops: BMP VI: Disease Demolition Workshop; 3) Production Practice Demonstration: Pruning Training, Pesticide Handling, and Safety and Environmental Stewartship. 4.) Research: Pruning protocols; Media and media amendments; Precision Fertilization and Irrigation. The Kentucky Nursery Crops Scouting Program scouting guidelines were developed and contained: a weekly scouting/trapping guide; a listing of which pests to look for and on what host plants, and a detailed methodology of precisely how to look for the pest, its damage, and how to record this information such that comparisons could be made across nurseries and seasons.
NEXT GENERATION OF SCIENTISTS IS INSPIRED AT AN EARLY AGE
Authors: Peffley Ellen B. , Davis Chad S.
Published: February 2019

The concept that plants and humans in a living system are mutually beneficial was communicated to 2nd to 12th grade students in science educational and outreach programs at Texas Tech University's Center for Space Science. Students traveled to the TTU horticulture greenhouse for a live program, which focused on research in the Engineering Development Unit. The research is funded by NASA's Advanced Life Support. During the program students were presented with the science of growing plants, how plants benefit humans in space, and baseline science vocabulary. A survey instrument was developed to assess student level of understanding of sciences, and their comprehension of living cycles, which work together to support manned space missions. The survey consisted of multiple-choice questions covering topics presented during the program. Likert questions were used to assess student's desire to travel in space, be an astronaut or a scientist, and their enjoyment of science and growing plants. The survey was administered before the program; immediately after the program; and a delayed test was administered in their classroom several weeks after the program. Student performance was scored according to correct responses in the survey. Responses were analyzed for changes over time using an analysis of variance with repeated measures. The results showed there was an overall improvement in knowledge from preprogram survey to postprogram survey and that students recognize science is the main topic to be studied to expand for better space programs. Some elementary education students scored equal to or higher than secondary education students. Enthusiastic science teachers may drive student interest exhibited in the early grades. There is evidence that a teacher's attitude towards science and one's basic science knowledge is important to molding student's attitudes and interests in science.
TEACHER IMMEDIACY/MORE POSITIVE CLASSROOM EXPERIENCE
Authors: Glass Marihelen
Published: February 2019

Most people do not even know the definition of immediacy. It is the perception of physical or psychological closeness: verbal and nonverbal. The practice of immediacy in the class room can help student behavior in the class room. Examples of Teacher Immediacy in the class room areas follows. 1) How the teacher's appearance can affect the student's learning. 2) What the teacher's gestures and movements mean. 3) How facial behavior can be positive or a negative to the student. 4) How eye behavior can affect the student's learning. 5) How the teacher's vocal behavior affects the attentiveness. 6) How the environment in the classroom affects the student's ability to concentrate.
PREVENTING BLOW-OVER OF NURSERY CONTAINERS
Authors: Parish Richard
Published: February 2019

A study was conducted in 2004 comparing commercial plant restraint systems with a grower standard consisting of a steel rod driven through the container into the soil. Commercial systems included wire baskets, aboveground plastic pot-in-pot, trellis with straps, and brackets on individual posts. This test was conducted on 15-gallon containers. Costs and efficacy of the systems were recorded. All of the commercial systems worked well, but the annualized cost of the grower standard was much less even though more blow-over occurred with the grower standard. A different system consisting of a horizontal rod over the top of containers and held down with J-stakes was tested on 4-gallon containers. Not enough stakes were used and the system was less effective than vertical stakes in each pot. A new study was initiated in 2005 to refine the grower standard through the use of one or two stakes per container, longer stakes, and the use of rebar instead of smooth rod. More stakes, longer stakes, and rebar were also evaluated with the horizontal rod system. The 2005 test was lost due to Hurricane Katrina. It will be repeated in 2006.
ORGANIC VEGETABLE CULTURE IN MISSISSIPPI: GROWING AND PROFITABLE
Authors: Evans William B. , Hood Kenneth W. , Hudson Peter M. , Paridon Keri L.
Published: February 2019

Yield and economics of vegetable crops are being evaluated in non-adjacent organic (OG) and nonorganic (NOG) vegetable production field areas in Crystal Springs, Mississippi. Each production area has six sections in which crops are rotated over several seasons and years. Production techniques and management are as similar in timing and methodology as possible between the systems without compromising either system. Production methods, timing, and costs are recorded for each operation. These are combined with yield data to create budgets and estimated returns for each production system/crop combination. When possible, harvested produce is marketed by a cooperating grower-retailer at a local mid- to up-scale farmers market. Three years into the study, positive returns have been found for several crops including potato (Solanum tuberosum L.), lettuce (Latuca sativa L.), summer squash (Cucurbita pepo L.), cucumber (Cucumis sativa L.), and others. Marketable new potato yields in 2005 were under 10,000 lb/acre for Yukon Gold and Red Lasoda in either production system. Estimated net returns, based on an actual $2.00/lb market price, were positive for all system/cultivar combinations although final budget numbers are not firm. Significant differences in yield among cultivars were seen in potato, lettuce, summer squash, and cucumber. Organic production budgets for other crops in the study are also being developed.
2005 PERSONAL SIZE “MINI” TRIPLOID WATERMELON VARIETY TRIAL
Authors: Horgan Thomas , Snyder Richard , Hudson Peter , Vinson Edgar , Kemble Joseph
Published: February 2019

Ten “mini” or personal size seedless watermelons were evaluated at three locations: north and central Mississippi and in central Alabama. `Betsy', `Bobbie', `Demi-Sweet', `Extazy', `Mini Yellow', `Petite Treat', `Solitaire', `Valdoria', `Vanessa', and `Wonder' were the cultivars trialed. Seedlings were started, in a greenhouse, four weeks before planting. All locations used drip irrigation and black plastic mulch and were fertilized according to soil testing lab recommendations. A personal size diploid (seeded) variety, `Jenny', was used as the pollinator. One pollinator was planted, and interspaced evenly, for every three triploid plants. Four harvests were made at each location on 7-day intervals. Yields reported are based on 2,074 triploid plants per acre and 1,037 pollinizer plants per acre. Only the triploid yield reported. Plant spacing was 14 ft2 per plant. For total yield (lb/acre) the cultivars `Petite Treat' (27,210), `Valdoria' (25,700), and `Demi-Sweet' (26,400) were among the top producers at each location. `Mini Yellow' was a top producer at all locations averaging 22,480 lb/acre. For total yield (fruit/acre) the cultivars `Valdoria' (3,380), `Petite Treat' (3,470), `Bobbie' (3,470), `Betsy' (3,380), and `Vanessa' (2,740), were among the top producers at each location. For total yield (lb/fruit) `Betsy' (6.9), `Wonder' (6.7), and `Vanessa' (6.1) had the overall lowest individual fruit weights. `Demi-Sweet' had the highest individual fruit weight in central Alabama (10.0) and north Mississippi (8.8). One problem observed was that a number of melons among cultivars were above or below size class. Also determining melon ripeness was a challenge. Melon quality was good. The soluble solids concentration (sweetness) of all melons was excellent. `Demi-Sweet' had the highest incidence of hollowheart. `Wonder' and `Extazy' had no incidences of hollowheart at any location. Rind thickness had no significant differences, however in both locations measured `Mini Yellow' had the thinnest rind. Rind necrosis was not encountered.
TESTING ANTIFUNGAL COMPETENCY OF COMPOUNDS AGAINST SOME POSTHARVEST PATHOGENS USING THE DISC ASSAY METHOD
Authors: Narciso J. , Baldwin E. , Plotto A.
Published: February 2019

There are many methods to test the efficiency of antimicrobial compounds. Our goals were to perform screens of several natural, experimental compounds and evaluate their effects on postharvest pathogenic fungi isolated from fruit. This screen was the first test in series that would allow us to see if these experimental compounds had potential use as components in a coating or as a preharvest treatment to help insure postharvest fruit quality. The disc assay method was chosen as a preliminary method for our screen as most of our compounds are water soluble and this method is straightforward, efficient and easy to interpret. This poster describes the testing of natural compounds against problematic postharvest fungi using the disc assay as a screening method. The results of various compounds are shown via the formation of a prominent zone of inhibition. Comparisons are also shown of non-responsive compounds to Penicillium digitatum and Geotrichum citri-aurantii. The clarity of using this method for step-wise dilutions of the anti-fungal compounds is shown.
POSTHARVEST TREATMENTS FOR EXTENDING MARKET LIFE OF FRESH HORSERADISH
Authors: Picha D.H.
Published: February 2019

Horseradish (Armoracia rusticana) has one of the highest rates of postharvest weight loss among all vegetable crops. Postharvest studies were conducted to identify improved methods of extending the market life of fresh horseradish roots. Postharvest treatments included submerging or coating thoroughly washed and dried roots in chlorine (150 ppm), hydrogen dioxide (Storox), 2,6-dichloro-4-nitroaniline (Botran), carnauba-based wax, shellac-based wax, paraffin wax, and polyolefin shrink film (75–100 micron thickness). Two treatments, shrink wrapping and paraffin waxing, were superior in reducing postharvest weight loss and extending horseradish root market life. Roots from the non-paraffin waxed and nonshrink-wrapped treatments lost an average of 20% weight after only 4 days of ambient temperature storage. This resulted in significant root shriveling and unacceptable market appearance. Roots from the shrink wrapped treatments lost an average of 1% weight after 4 days of ambient temperature storage, while paraffin waxed roots lost about 3% weight. It is important to thoroughly dry the roots before shrink wrapping, to avoid moisture condensation on the inner surface of the film and subsequent microbial growth. All of the shrink-wrapped roots and paraffin waxed roots were marketable after 14 days of ambient storage, and no surface mold was detected. Less than 3% weight loss occurred after 14 days of ambient storage in all shrink-wrapped roots, while paraffin-waxed roots lost about 9% weight. Weight loss in the unwrapped roots from the other postharvest treatments ranged from an unacceptably high 44% to 48% after 14 days.
GREENHOUSE-TOMATOES: A NEW E-LIST FOR COMMERCIAL GROWERS
Authors: Snyder Richard G.
Published: February 2019

The greenhouse-tomatoes list was created to provide a method for commercial greenhouse tomato growers to communicate with each other to learn from others' experiences. Its purpose is to connect growers with vendors of greenhouses, fertilizers, seeds, and other supplies, and to facilitate networking among growers, agents, specialists, and researchers. The goal of the greenhouse-tomatoes list is to develop high quality discussion that benefits commercial growers and the entire greenhouse tomato industry. This is accomplished by promoting the list to growers; keeping the list small so that the traffic is manageable; avoiding promotion to hobbyists so the list does not become cluttered; avoiding SPAM. Excellent majordomo software has been 100% effective in the latter. The list was first offered to growers at the 2004 Greenhouse Tomato Short Course (GHSC) in Jackson, Miss. Then, it was promoted through other e-lists for vegetable specialists, new crops, greenhouse growers, hydroponics, etc. The final phase was to promote it at various grower meetings around the U.S., through trade magazines, and at the 2005 GHSC. Currently, the list consists of 141 members. Subscribers are from the U.S., Argentina, Australia, Canada, England, Germany, Newfoundland, Pakistan, Romania, South Africa, Virgin Islands, and Thailand. Demographics are 31% university, 15% suppliers, 34% growers, 20% unknown. The greenhouse-tomatoes list is housed on a server at Mississippi State University with nearly all functions handled seamlessly by majordomo software. To subscribe: send e-mail to majordomo@lists.msstate.edu with the following message: subscribe greenhouse-tomatoes. You will get a confirmation email telling you that you must reply. You must be subscribed to send anything to the list. Once subscribed, to communicate with the whole group, address an email message to greenhouse-tomatoes@lists.msstate.edu and everybody on the list will receive it. To make this easy, the user can save that address to a nickname, such as ght or greenhouselist. More information can be found at http://www.greenhousetomatosc.com.
GIS ON THE CHEAP: DIVA–GIS AND OTHER FREE DATA VISUALIZATION TOOLS FOR RESEARCH
Authors: Villordon A.
Published: February 2019

Geographic information system (GIS) tools allow the visualization of research data that have a strong spatial component. Currently, several proprietary desktop GIS tools are available that enable researchers to generate maps and perform spatial analysis. However, these packages often require licensing agreements and do not provide specific options that enable rapid and uncomplicated analysis of biological diversity data. As an alternative, publicly available GIS applications that perform basic GIS as well as specialized functions are available. For example, DIVA–GIS was developed specifically to allow analysis of genebank and herbarium databases as well as to assess genetic, ecological, and geographic patterns in the distribution of crops and wild species. It is potentially useful for researchers who do not have the time to learn how to use proprietary GIS software, or who cannot justify purchasing a license to perform very basic GIS operations like creating and modifying maps. This presentation describes the basic features as well as some advanced functionality of DIVA–GIS and other publicly available GIS applications.
Thin Films of Liquid Media for Heterotrophic Growth and Storage Organ Development: Turmeric (Curcuma longa) as a Model Plant
Authors: Adelberg Jeffrey , Cousins Matthew
Published: February 2019

Geophytes store carbohydrates in modified underground shoot systems protected by a broad array of biologically active chemistry. In vitro formation of storage organs requires months in the lab instead of years in the field, when water and nutrients are correctly supplied. Liquid and agar systems in large and small vessels were compared for sugar and water use with turmeric (Curcuma longa) as a model plant. Small jars on a shaker were compared with large, flat-bottomed vessels containing thin films of liquid media, intermittently tilted at slight inclines that allow the advantages of liquid phase transfer with gentle agitation. Liquid culture in small vessels on a shaker yielded the most plants and liquid culture on a thin-film rocker in a large vessel yielded the largest plants. Increased and improved biomass (fresh and dry) in liquid culture compared to agar was based on greater sugar use. When large vessels of liquid media were grown for 5 and 6 months on a rocker, 400 mL of media yielded 150 to 200 g (fresh weight) of plants. Similarly, 13 to 16 g (dry weight) of plant tissue was derived from 24 g of sugar. Plants were about one-third rhizome by fresh mass. Rhizomes had greater dry and fresh weight than leaves or roots, indicating solute actively accumulated in the rhizome. The rhizomes had normal morphology, characteristic pigments and fragrance, and rhizome extracts had strong antioxidant potential. The gentle rocking action of plantlets in sugar-containing liquid medium was demonstrated to produce functional storage organs.
Production and Verification of Hydrangea arborescens `Dardom' × H. involucrata Hybrids
Authors: Jones Keri D. , Reed Sandra M.
Published: February 2019

Previous attempts to use interspecific hybridization to combine flower color and cold hardiness in Hydrangea have not produced the desired results, with confirmed hybrids being weak, sterile or aneuploid. In all cases, H. macrophylla (Thumb.) Ser. was used as the source of flower color. This work investigates the use of H. involucrata Sieb. as an alternative source of flower color in Hydrangea interspecific hybridizations. Controlled reciprocal pollinations of H. involucrata with two cultivars of H. arborescens L. and three cultivars of H. paniculata Sieb. were made. Hybridity of progeny was verified using RAPD markers and confirmed with chromosome counts and morphological comparisons of hybrids and parents. Plants were obtained only when H. involucrata was used as the pollen parent. No hybrids between H. paniculata or H. arborescens `Annabelle' and H. involucrata were produced. Seven H. arborescens `Dardom' × H. involucrata progeny showed either a sum of the RAPD bands of both parents or banding patterns that matched those of H. involucrata. Leaf blade length and length/width ratio of the hybrid were intermediate to its parents. Chromosome number in the hybrid (2n = 34) was also intermediate between H. arborecens (2n = 38) and H. involucrata (2n = 30). One `Dardom' × H. involucrata plant flowered in 2005. While pollen staining indicated a very low level of fertility, we will continue to evaluate the possibility of using the hybrid for producing advanced filial or backcross progeny.
Optimum Stand Density for Maximum Essential Oil Yield in Commercial Fennel Crops
Authors: Falzari Linda M. , Menary Robert C. , Dragar Valerie A.
Published: February 2019

Fennel (Foeniculum vulgare Mill.) is grown commercially in Tasmania for the production of a steam-distilled essential oil, which is high in trans-anethole. Often, only the generative canopy is harvested since this contains the bulk of the oil and further this oil is higher in anethole than oil from other parts of the plant. Regardless of whether the whole crop is forage harvested or the generative canopy alone is removed using a combine-harvester, the most efficient oil production occurs when the greatest proportion of the canopy is generative, giving maximum oil yield from a minimum of fresh weight to be processed. A trial was conducted to examine the relationship between stand density and the various yield components of fennel in order to predict the likely effect on yield of increasing stem density as the short term perennial crop matures. As for most crops, planting density and biomass yield are closely related and the optimum planting density was predicted using a mathematical model. The results suggest that an initial stand density of 10 to 12 plants/m2, in a square layout, would produce the greatest yield of essential oil per unit area by maximising the production of the generative canopy. This density also maximises the yield of oil relative to the weight of material to be distilled.
Overhead and Drip-tube Irrigation Affect Twospotted Spider Mites and their Biological Control by a Predatory Mite on Impatiens
Authors: Opit George P. , Fitch Greg K. , Margolies David C. , Nechols James R. , Williams Kimberly A.
Published: February 2019

The effects of overhead and drip tube irrigation on twospotted spider mite (TSMs) (Tetranychus urticae Koch) and predatory mite (PMs) (Phytoseiulus persimilis Athias-Henriot) populations, as well as the biological control of TSMs by PMs, were investigated on Impatiens wallerana Hook. f. `Impulse Orange'. To determine the effects of the two irrigation methods on TSM populations, plants were inoculated with female TSMs 6 weeks after seeding. Plants were then irrigated twice every three days, and TSM counts were taken 3 weeks later. To assess the effects of irrigation method on PMs, plants were inoculated with TSMs 6 weeks after seeding, PMs were released 10 days later, plants were irrigated about once per day, and the number of predatory mites on plants was counted 3 weeks after release. To assess the effects of irrigation method on the biological control of TSMs by PMs, plants were inoculated with TSMs and PMs were released as before, but then plants were irrigated either three times every 2 days or three times every 4 days using either drip or overhead irrigation. The number of TSMs on plants and the number of leaves showing TSM feeding injury were measured 3 weeks after predator release. Overhead watering significantly reduced TSM and PM populations as much as 68- and 1538-fold, respectively, compared to drip irrigation with microtubes. Perhaps more important, overhead watering with or without predators significantly reduced the number of leaves sustaining TSM feeding injury as much as 4-fold compared to drip irrigation. These results confirm the common observation that TSM infestations and injury may be reduced by irrigation systems that wet plant foliage. However, predators still reduced TSMs even though overhead irrigation had a suppressive effect on predatory mites. Predators are particularly useful for reducing TSM injury when plants are watered infrequently. Overhead watering could be used in tandem with biological control as a component of an integrated crop management program for TSMs in ornamental greenhouses by rapidly lowering TSM population levels in hot spots before PMs are released.
Differential Response of Weeds and Vegetable Crops to Aqueous Extracts of Hairy Vetch and Cowpea
Authors: Hill Erin C. , Ngouajio Mathieu , Nair Muraleedharan G.
Published: February 2019

Laboratory experiments were conducted to study the effect of aqueous extracts of hairy vetch (Vicia villosa Roth) and cowpea (Vigna unguiculata (L.) Walp) cover crops on germination and radicle elongation in seven vegetable and six weed species. Lyophilized aqueous extracts of the cover crops were dissolved in reverse osmosis (RO) water to produce seven concentrations: 0.00, 0.25, 0.50, 1.00, 2.00, 4.00, and 8.00 g·L–1. Each treatment had 4 replications and the full experiment was repeated. Experiment 1 (E1) and Experiment (E2) were conducted under similar conditions. In general, seed germination was not affected by extracts of both cover crops. However, radicle growth of all species tested (except common milkweed exposed to cowpea extract) was affected by the cover crop residue extracts. Low concentrations of hairy vetch extract stimulated the radicle growth of carrot, pepper, barnyardgrass, common milkweed, and velvetleaf. Likewise, low concentrations of cowpea extract stimulated the growth of corn, barnyardgrass, and velvetleaf. At higher concentrations all species tested were negatively affected. The order of species sensitivity to the hairy vetch extract, as determined by the IC50 (concentration required to produce 50% radicle inhibition) values, was common chickweed > redroot pigweed> barnyardgrass E1 > carrot E1 > wild carrot > corn > carrot E2 > lettuce > common milkweed > tomato > onion > barnyardgrass E2 > velvetleaf > pepper > cucumber (most sensitive to least sensitive). For cowpea the order was common chickweed > redroot pigweed > corn > tomato > lettuce > wild carrot > pepper > carrot > cucumber > onion> barnyardgrass and velvetleaf. Results suggest that the susceptibility of weeds and vegetable crops to aqueous extracts of hairy vetch and cowpea is dependent on both species and extract concentration.
Effects of Insecticides on Gas Exchange, Vegetative and Floral Development, and Overall Quality of Gerbera
Authors: Spiers James D. , Davies Fred T. , He Chuanjiu , Bográn Carlos E. , Heinz Kevin M. , Starman Terri W. , Chau Amanda
Published: February 2019

This study evaluated the influence of insecticides on gas exchange, chlorophyll content, vegetative and floral development, and plant quality of gerbera (Gerbera jamesonii Bolus `Festival Salmon'). Insecticides from five chemical classes were applied weekly at 1× or 4× their respective recommended concentration. The insecticides used were abamectin (Avid), acephate (Orthene), bifenthrin (Talstar), clarified hydrophobic extract of neem oil (Triact), and spinosad (Conserve). Photosynthesis and stomatal conductance were reduced in plants treated with neem oil. Plants treated with neem oil flowered later—and at 4× the recommended label concentration had reduced growth, based on lower vegetative dry mass (DM) and total aboveground DM, reduced leaf area, thicker leaves (lower specific leaf area), higher chlorophyll content (basal leaves), and reduced flower production. Plants treated with acephate at 4× the recommended label concentration were of the lowest quality due to extensive phytotoxicity (leaf chlorosis). Plants treated with 1× or 4× abamectin or spinosad were of the highest quality due to no phytotoxicity and no thrips damage (thrips naturally migrated into the greenhouse). The control plants and plants treated with 1× bifenthrin had reduced quality because of thrips feeding damage; however gas exchange was not negatively affected.
Visualization of the Distribution Pattern of Citrus Tristeza Virus in Leaves of Mexican Lime
Authors: Lin Youjian , Powell Charles A.
Published: February 2019

The distribution pattern of citrus tristeza virus (CTV) T-36 isolate in leaves of infected mexican lime [Citrus aurantifolia (Christm.) Swingle] plants was visualized using a whole-leaf-blot immunoassay (WLBIA) procedure in combination with a computer scanning imaging technique and CTV-specific monoclonal antibody 17G11 (CTV MAb 17G11). The distribution pattern of CTV T-36 in leaves varied with the age of the leaves and shoots of infected plants. In the young leaves, especially the about 5-day-old leaves and the completed expanded leaves, CTV T-36 was easily detected in most of the leaf veins, the main veins and the large and small primary veins. In the old leaves, CTV T-36 only was detected in the main veins, sometimes in a few of the large primary veins with weak signals, and seldom in the small primary veins. The distribution density and immunoassay reaction signals of CTV T-36 reacted to CTV MAb 17G11 in leaves from new shoots were much higher than that in leaves from old shoots. ELISA test results using leaves with different ages from different shoots of the same mexican lime plants infected with CTV T-36 supported the visualized-test results obtained by the WLBIA in combination with computer scanning imaging technique. This is the first reported visual analysis of the distribution pattern of CTV in leaves of infected citrus plants. The results indicate that the WLBIA in combination with computer scanning imaging technique is a useful tool for studying the distribution of plant viruses in leaves of virus-infected plants.
Effects of Carbon Source and Explant Type on Somatic Embryogenesis of Four Cacao Genotypes
Authors: Traore Abdoulaye , Guiltinan Mark J.
Published: February 2019

The effects of five carbon sources (glucose, fructose, maltose, sorbitol, and sucrose) and two explant types (petals and staminodes) on cacao somatic embryogenesis was studied. No growth was observed on both types of explants cultured on sorbitol containing media and slow growth was obtained on media supplemented with maltose. Depending on the genotype, the percentage of explants producing one or more embryos ranged from 6% to 99%, 18% to 98%, and 3% to 82% on media containing glucose, fructose and sucrose respectively. Explants cultured continuously on maltose or sorbitol-containing media failed to produce embryos. Staminode explants produced 3 to 10 times more somatic embryos than petals. A strong genotypic effect on somatic embryogenesis was observed. Staminode explants of the Forastero clones Laranja and PSUSca 6 produced 2 to 30 times more somatic embryos than the Trinitarios UF 613 and ICS 16. During embryo maturation and conversion, no significant differences were observed among glucose, fructose, maltose, or sucrose for embryo weight, total shoot and root production. However, we found that all plantlets produced on glucose had shoots with normal cacao leaves while the other carbon sources sometimes produced plantlets with cotyledon-like leaves.
Seasonal Changes in Root Metabolic Activity and Nitrogen Uptake for Two Cultivars of Creeping Bentgrass
Authors: Xu Qingzhang , Huang Bingru
Published: February 2019

Roots play important roles in plant responses to environmental changes. The objective of this study was to investigate seasonal changes and cultivar variation in root growth, respiratory activity, nitrogen uptake, and carbon allocation in relation to turf performance for two cultivars of creeping bentgrass [Agrostis stolonifera L. var. palustris (Huds.)] under field conditions. Two cultivars, `Penncross' and `L-93', were managed under USGA-specification putting green conditions, with daily irrigation and mowing at a 3-mm height from May to November in 1999 and 2000. Turf quality of both cultivars declined from the highest rating of 7 to 9 in May to 4 to 5 in August and September, and recovered to above 7 in October and November in both years. This corresponded to seasonal changes in root dry weight, dehydrogenase activity, nitrate reductase (NR) activity, carbon allocation to roots, and 15N uptake. Compared to Penncross, L-93 generally maintained better turf quality, as well as higher root dry weight, 15N uptake, NR activity, and carbon allocation during summer months. Previous studies often emphasize the important of a large, extensive root system. The results in the present study demonstrated that root metabolic activities followed the same seasonal pattern and cultivars variation as turf performance, and suggested that decline in root metabolic activities could be contributed to summer decline in turf quality for creeping bentgrass.
Conversion of Introductory Plant Biology Course and Lab to Web-Based Distance Ed Course
Authors: Bradley Lucy , Towill Leslie , Stutz Jean , Roberson Robert
Published: February 2019

Conversion of the introductory plant biology course for non-majors from a lecture/lab format to a web-based course was a collaborative project between the Department of Plant Biology and the Instructional Support group at ASU. This course provides an introduction to biology through the world of plants by including lectures and laboratory activities that examine plant systems. The project was undertaken to provide students with an asynchronous opportunity to participate in either the course, the lab, or both. There were three distinct phases of implementation of the multimedia website: Design, Development, and Delivery. The design phase was driven by the faculty, who, along with graduate assistants, developed the course outline and content. They gathered images, identified concepts to be animated, and created storyboards to layout the sequence in the animation. The development stage was driven by the Instructional Designers who selected the appropriate media for animations and worked with developers to create them. The delivery phase was again driven by the professors. They implemented the website as a teaching tool, gathered feedback from students and teaching assistants, and worked with instructional designers and multimedia developers to improve the site. A wide variety of on-line multimedia components were incorporated into the website, including illustrations, images, animations, interactive modules, video and text. Three separate media packages were used: MacroMedia Flash (Macromedia, 2000), Director Shockwave (Macromedia, 2000), and QuickTime (Apple, Inc. 2000). Findings from surveys of students, faculty, and staff identified positive regard for the site as a whole. Several technological and logistical challenges were encountered and addressed.
Stoller's Root Feed Applied to Drip-irrigated Cantaloupes Enhances Productivity and Pest Tolerance
Authors: Liptay Albert , Stoller Jerry H. , Salzman Ron
Published: February 2019

Root Feed is a product developed by Stoller Enterprises, Inc., to enhance crop productivity and quality. Weekly application of Root Feed in drip-irrigated crops was found to be the most effective frequency of application. Root Feed increased the number of the largest melons and total melons by over 50% and also increased fruit °Brix (soluble solids). Moreover, it was observed that a number of pests were suppressed with Root Feed, namely, whiteflies, a cucurbit virus, and downy mildew.
Drip Irrigation Effect on Yield and Fruit Size of Jack-o-lantern Pumpkins
Authors: Maynard Elizabeth T.
Published: February 2019

Benefits of drip irrigation for jack-o-lantern pumpkins (Cucurbita pepo) in the midwestern United States are not documented. Field trials were conducted on a sandy loam soil to compare yield and fruit size of unirrigated pumpkins (NONE) with pumpkins irrigated when in-row soil water tension (SWT) 30 cm deep reached 20 kPa (HIGH) or 60 kPa (MED). The 2004 trial included two planting methods, direct seed (SD) and transplant, and two cultivars, `Gold Medal' (GM) and `Magic Lantern' (ML). GM typically has larger and more vigorous vines than ML. In 2005 the trial included only SD ML. Rainfall June through August totaled 38.4 cm in 2004 and 28.2 cm in 2005. In 2004 HIGH increased yield 13% compared to NONE (42.1 vs. 37.2 t·ha-1). MED (39.0 t·ha-1) did not differ from NONE. Neither planting method nor cultivar influenced the yield response to irrigation. The effect of irrigation on average weight per pumpkin depended on cultivar. In 2004, ML with HIGH averaged 7.76 kg per pumpkin, 16% heavier than NONE at 6.67 kg. MED averaged 7.17 kg. Irrigation did not affect average weight of GM: HIGH, MED and NONE averaged 12.6, 12.8 and 12.3 kg, respectively. For SD ML, combined analysis of 2004 and 2005 data showed an 18% increase in average pumpkin weight for HIGH vs. NONE (7.94 vs. 6.72 kg), but no significant effect of irrigation on yield (33.6, 29.8 and 28.4 t·ha-1 for HIGH, MED and NONE, respectively). Irrigation did not affect the number of pumpkins produced per hectare for either cultivar in either year. Results suggest that compared to no irrigation, maintaining SWT less than 20 kPA with drip irrigation may lead to 1) yield increase on the order of 10% or less, 2) 16% to 18% increase in average pumpkin weight for ML.
Drip Irrigation Configuration Influences Growth in Young Highbush Blueberries
Authors: Bryla David R.
Published: February 2019

A study was done to determine the effects of irrigation with different drip configurations on growth of newly planted highbush blueberries (Vaccinium corymbosum L. `Duke'). Plants were grown on raised beds mulched with sawdust. Different configurations included two laterals of drip tubing placed on the soil surface on each side of the plants, two laterals buried 0.1 m deep on each side of the plants, and one lateral suspended 1.2 m above the plants. Each treatment was irrigated three times per week (when needed) with enough water to replace 100% of the estimated crop evapotranspiration requirements. During the first 2 years after planting, plants irrigated by buried drip were larger and produced significantly more whips than those irrigated by drip placed at the soil surface. The size and whip number of those irrigated by suspended drip were intermediate. Subsurface drip eliminated water runoff and bed erosion observed with both surface drip configurations. It also maintained lower soil water content near the plant crown. Since plants tested positive for phytophthora and pythium root rot, lower soil water content may have reduced problems with the disease. As plants mature, the next objective will be to determine the effects of each drip configuration on fruit production.
(132) Study on Morphological Characteristics and Essential Oil Constituents Bulgarian Oil-bearing Rose
Authors: Kovacheva Natasha , Rusanov Krasimir , Jeliazkov (Zheljazkov) Valtcho , Nedkov Nedko
Published: February 2019

Bulgaria is famous for its 330-year-old-tradition in rose oil production, which is based on the Kazanluk rose (Rosa damascena Mill. f. trigintipetala Dieck.). The Bulgarian rose oil (otto) is recognized as the ultimate rose oil. For successful selection and breeding work of oil-bearing roses, information is needed on the variation of morphological and phenological characteristics and essential oil composition of locally available genotypes. We estimated the correlation coefficients between yields and morphological characteristics of 15 genotypes of Bulgarian oil-bearing rose. It was found that rose yields depended mostly on the number of flowers, the number of flower branches per bush, and the weight of individual flowers (r = 0.99, 0.88, and 0.84, respectively). Also, we established correlations between the concentrations of various essential oil constituents of the Bulgarian rose oil. Generally, higher concentration of citronellol + nerol was associated with lower concentration of geraniol and stereo-terpens (r = –0.76 and –0.59, respectively). Also, higher concentration of citronellol + nerol was positively correlated to increased concentration of terpene aldehydes (r = 0.63) and esters (r = 0.48). The geraniol concentration was positively correlated to stearoptenes (r = 0.57). Both morphological characteristics and essential oil constituents should be used for further selection of high-yielding cultivars with desirable essential oil composition.
(133) Growth and Development of Introduced Leuzea in the Rose Valley, Bulgaria
Authors: Dzhurmanski Anatoli , Dzhurmanski Georgi , Jeliazkov (Zheljazkov) Valtcho
Published: February 2019

Leuzea, or Maralroot, is a perennial medicinal plant originating from Siberia, and is characterized with significant metabolic and tonic effects. A 3-year study was conducted at the Research Institute for Roses, Aromatic and Medicinal Plants Kazanluk, Bulgaria, on the introduction of various genotypes of Leuzea (Rhaponticum carthamoides Willd/Iljin.) from the Altai region, Russia. Phenological observations, and up to 11 morphological indices were characterized for 1-, 2-, and 3-year-old plants. Generally, it was found that the climatic and soil conditions in the region were not very favorable for the growth and development of Leuzea. Also, for the tested region, Leuzea should be grown only under irrigation. Yields of Leuzea roots and rhizomes reached 7.19 t/ha in the 2nd year, and up to 8.62 t/ha in the 3rd year. Yields of aboveground herbage were up to 8.73 t/ha when plants were harvested at the beginning of blossoming. Second cut of the above-ground herbage of Leuzea was not satisfactory under the climatic conditions of the region. When grown for seed production, seed yields during the 3rd year were up to 128 kg/ha. Leuzea may have a potential as a cash crop for the region if grown for seed production.