bluuebunny/crossref_metadata_2025 huggingface dataset:
Physical Properties of Ground Fresh Rice Hulls and Sphagnum Peat Used for Greenhouse Root Substrates
Authors: Sambo Paolo , Sannazzaro Franco , Evans Michael R.
Published: December 2018

Ground fresh rice (Oryza sativa) hull materials were produced by grinding whole fresh rice hulls and passing the resulting product through a 1-, 2-, 4- or 6-mm-diameter screen to produce a total of four ground rice products (RH1, RH2, RH4, and RH6, respectively). The physical properties and water release characteristics of sphagnum peatmoss (peat) and the four ground rice hull products were evaluated. All of the ground rice hull products had a higher bulk density (Bd) than peat, and as the grind size of the rice hull particle decreased, Bd increased. Peat had a higher total pore space (TPS) than all of the ground rice hull products except for RH6. As grind size decreased, the TPS decreased. Peat had a lower air-filled pore space (AFP) than all of the ground rice hull products and as the grind size of the rice hull products decreased, AFP decreased. Peat had a higher water holding capacity (WHC) than all of the ground rice hull products. Grind sizes RH4 and RH6 had similar WHC, whereas RH1 and RH2 had a higher WHC than RH4 and RH6. Peat, RH4, and RH6 had similar available water content (AVW), whereas RH2 had higher AVW than these materials and RH1 had the highest AVW. However, peat had the lowest AVW and easily available water (EAW) as a percentage of the WHC. The ground rice hull products RH1 and RH2 had the highest AVW and EAW of the components tested. Peat had the highest water content at container capacity. As pressure was increased from 1 to 5 kPa, peat released water more slowly than any of the ground rice hull products. The RH1 and RH2 ground hull products released water at a significantly higher rate than peat, but RH4 and RH6 released the most water over these pressures. For all rice hull products, most water was released between 1 and 2 kPa pressure. The rice hull products RH1 and RH2 had physical properties that were within recommended ranges and were most similar to those of peat.
Application of Floating Culture System on Clonal Propagation of Taiwanese Wild Grape
Authors: Peng Szu-Chin , Chen Iou-Zen , Cheng Cheng-Yung
Published: December 2018

In this study, we built a floating culture system, which could improve the rooting percentage of stem cuttings of taiwanese wild grape (Vitis thunbergii). We took softwood cuttings instead of hardwood cuttings and tested the effects of cutting type, medium type, and auxin concentration on the rooting percentage. In the first experiment, single leaf cuttings (SLC) in 26 °C circulating water (CW26) produced 82% rooting as compared with 48% rooting in the subirrigation medium [SM (3 horticultural perlite : 2 peatmoss, by volume)]. The highest rooting percentage of 88% occurred in 30 °C circulating water (CW30). The same trend was also observed in terminal cuttings (TC) with 62% rooting in CW26 compared with 27% in SM. The highest rooting percentage of 83% occurred in CW30. Besides having the highest rooting percentage, TC and SLC in CW30 formed adventitious roots 7 and 9 d earlier than in 22 °C circulating water (CW22). In the second experiment, SLC in 1.25 μm 1-naphthalenacetic acid (NAA) solution produced 92% rooting as compared with 82% rooting in the untreated group. In addition, SLC in all NAA solution treatments formed adventitious root 6 d earlier than in the untreated group. Based on these results, we suggest that the floating culture system is a practicable system for the clonal propagation of taiwanese wild grape.
Evaluation of Slow-release Fertilizers on Bell Pepper
Authors: Reyes Luz M. , Sanders Douglas C. , Buhler Wayne G.
Published: December 2018

This study was conducted to compare different formulations of a slow-release fertilizer with a conventional fertilizer program to determine their impact on yield and growth of bell pepper (Capsicum annuum). Two formulations of a methylene-urea slow-release fertilizer (Nitamin®) were evaluated on drip-fertigated and plastic-mulched bell peppers during 2006 in the eastern coastal plain and western Appalachian mountains of North Carolina. Liquid slow-release formulations were applied the first 6 or 9 weeks of the growing season and a dry formulation was banded at planting. Treatments were compared with the extension-recommended rate of 200 lb/acre nitrogen (N) (NC-200) and a high-input fertilizer rate of 300 lb/acre N (HI-300) from calcium nitrate injected in 12 weekly applications of drip irrigation. Irrigation was applied twice per week. The slow-release granular formulation at 200 lb/acre N produced the highest marketable yield and better canopy quality in eastern soil. Early marketable yield for this treatment accounted for 46% of the total yield. All slow-release treatments had higher N use efficiency (NUE) values than NC-200 and HI-300 in the eastern study. In loam soil (western study), pepper yield was statistically similar among treatments. Lower rates (150 lb/acre N) of slow-release fertilizer performed as well as NC-200 and HI-300 for marketable yield. Low rates (150 lb/acre N) of one of the liquid formulations performed better in total and marketable NUE than NC-200 and HI-300 in Fletcher, North Carolina. Liquid and dry formulations of slow-release fertilizer showed a potential to be used on bell pepper production across the state at reduced N rates, with greater impact on yield in coarse-textured soils found predominantly in the eastern coastal plain region.
Timing of Drip Irrigation Initiation Affects Irrigation Water Use Efficiency and Yield of Bell Pepper under Plastic Mulch
Authors: Ngouajio Mathieu , Wang Guangyao , Goldy Ronald G.
Published: December 2018

Field studies were conducted in 2003 and 2004 to determine effects of withholding irrigation on pepper (Capsicum annuum) plant height, leaf chlorophyll content, yield, and irrigation water use efficiency. Irrigation treatments were initiated at pepper transplanting (S0), after transplant establishment (S1), at first flower (S2), at first fruit (S3), or at fruit ripening (S4). The control treatment received only enough water to apply fertigation (FT). Withholding irrigation did not affect pepper plant height except FT treatment, but increased leaf chlorophyll content. Withholding irrigation until S4 saved 50% and 41% of irrigation water in 2003 and 2004, respectively, without affecting fruit yield compared with the treatment where irrigation started at transplanting. However, yield in the FT treatment was significantly reduced. Irrigation water use efficiency (pepper yield per unit area per millimeter of water applied) was maximum at S4 (59.1 kg·ha−1 per millimeter) and S3 (24.1 kg·ha−1 per millimeter) in 2003 and 2004, respectively. Similar trends in response of pepper to the irrigation treatments were observed in 2003 and 2004 even though there were large differences in rainfall, and pepper yield between years. This suggests that withholding irrigation until first fruit may help to maintain pepper yield while reducing irrigation costs. However, it is important to have adequate soil moisture at transplanting to insure adequate transplant establishment.
Evaluation of Delphinium Cultivars for Resistance to Powdery Mildew
Authors: Wegulo Stephen N. , Vilchez Miguel
Published: December 2018

Powdery mildew caused by Erysiphe aquilegiae var. ranunculi is one of the major diseases affecting field-grown delphiniums (Delphinium spp.). Two lath house and two field experiments were conducted in 2003 and 2004 to evaluate nine delphinium cultivars for resistance to the disease. ‘Blue Bird’, ‘King Arthur’, ‘Cameliard’, and ‘Galahad’ were consistently more resistant [0–1.1 disease severity (ds) on a 0–5 scale] than ‘Casa Blanca’, ‘Blue Shadow’, ‘Belladona’, and ‘Bellamosum’ (2.9–5.0 ds). ‘Oriental Blue’ was moderately resistant (0–3.3 ds). Spearman's coefficients of rank correlation were significant for all pairs of experiments (0.70 ≤ rs ≤ 0.98; P ≤ 0.0354) except for the 2003–04 field experiments (rs = 0.66; P = 0.0525). Pearson correlation coefficients between experiments (0.86 ≤ r ≤ 0.99) were highly significant (P ≤ 0.0027). Disease severity values from lath house evaluations were almost identical to those from field evaluations.
Soluble Solids and Simple Sugars Measurement in Intact Mango Using Near Infrared Spectroscopy
Authors: Delwiche Stephen R. , Mekwatanakarn Weena , Wang Chien Y.
Published: December 2018

A rapid, reliable, and nondestructive method for quality evaluation of mango (Magnifera indica) fruit is important to the mango industry for international trade. The objective of this study was to determine the potential of near-infrared (NIR) spectroscopy to predict soluble solids content (SSC) and individual and combined concentrations of sucrose, glucose, and fructose nondestructively in mango. Mature mangoes at two different temperatures (15 °C and 20 °C) were measured by NIR interactance (750–1088 nm wavelength region analyzed) over an 11-day period, starting when the fruit were underripe and extending to a few days past optimal ripeness. Partial least squares regression was used to develop models for SSC, individual sugar concentration, and the sum of the concentrations of the three sugars. Such analyses yielded calibration equations with R2 = 0.77 to 0.88 (SSC), 0.75 (sucrose), 0.67 (glucose), 0.70 (fructose), and 0.82 (sum); standard error of calibration = 0.56 to 0.90 (SSC), 10.0 (sucrose), 0.9 (glucose), 4.5 (fructose), and 10.4 (sum); and standard error of cross-validation = 0.93 to 1.10 (SSC), 15.6 (sucrose), 1.4 (glucose), 6.9 (fructose), and 16.8 (sum). When the SSC calibration was applied to a separate validation set, the standard error of performance ranged from 0.94% to 1.72%. These results suggest that for assessment of mango ripeness, NIR SSC calibrations are superior to the NIR calibrations for any of the individual sugars. This nondestructive technology can be used in the screening and grading of mangoes and in quality evaluation at wholesale and retail levels.
Response of ‘Desirable’ and ‘Kiowa’ Pecan to a Late-spring Freeze
Authors: Wells M. Lenny
Published: December 2018

This study was established to assess the effects of a severe late spring freeze on flowering, shoot growth, leaf nutrient status, and the retention of fruit developing from secondary buds of pecan [Carya illinoinensis (Wangenh.) K.Koch]. Freeze damage appears to have a significant influence on pecan physiology and fruit retention. ‘Desirable’ produced a crop of pistillate flowers from secondary buds after the freeze; however, many of these flowers were abnormal in appearance. Freeze-damaged ‘Desirable’ trees exhibited shorter shoots, reduced flower and fruit retention, a lower chlorophyll index, and decreased leaf nitrogen concentration compared with nondamaged trees. Leaf zinc concentration was higher in freeze-injured ‘Desirable’ trees than in nondamaged trees. Freeze-damaged ‘Kiowa’ trees had longer shoots and failed to produce a crop of pistillate flowers from secondary buds on most shoots. Freeze damage led to the appearance of mouse-ear leaf symptoms and reduced leaf chlorophyll index, leaf nitrogen, and leaf magnesium concentrations in ‘Kiowa’. Leaf phosphorous and leaf potassium concentrations were higher in freeze-injured ‘Kiowa’ trees than in nondamaged trees. These observations provide insight into the potential response of bearing orchard trees injured by a late spring freeze.
Early Pruning Effects on ‘Florida-47’ and ‘Sungard’ Tomato
Authors: Santos Bielinski M.
Published: December 2018

The effects of early pruning on the growth and yield of ‘Florida-47’ and ‘Sungard’ tomato (Solanum lycopersicum) were assessed in west-central Florida. Each cultivar was established in separate experiments. The four pruning treatments consisted of leaving one, two, and three main stems in the tomato plants below the first flower cluster, and a nonpruned control. Pruning shoots had significant effects on the plant height of ‘Sungard’ and ‘Florida-47’ at 4 and 3 weeks after transplanting, respectively. Tomato plants with a single stem were 13% and 10% taller than the ones in the nonpruned control, respectively. However, this effect disappeared 1 and 2 weeks later in both cultivars. Regardless of the cultivar, early pruning did not influence foliar disease incidence or early and total tomato marketable yield. This cultural practice did not affect the partitioning to different fruit categories in either cultivars. This data showed that early pruning can temporarily change the plant architecture of ‘Sungard’ and ‘Florida-47’ tomato, explaining the perceived increased plant vigor in comparison with the nonpruned control. However, the effect disappeared during the growing season and did not reflect on marketable yields of either tomato cultivars. If no pruning were performed in these cultivars, growers would be able to save an estimated $40/acre of tomato.
Consumer Knowledge of Nutritional Attributes of Pecans and Factors Affecting Purchasing Behavior
Authors: Lombardini Leonardo , Waliczek Tina M. , Zajicek Jayne M.
Published: December 2018

A study was conducted among the attendees of the Annual Texas Master Gardener Conference held in College Station, TX, in May 2006. Participants were asked to complete a 31-question survey to understand their knowledge of the nutritional attributes and storage guidelines of pecans (Carya illinoinensis). A total of 177 attendees completed the survey, corresponding to 32.2% of the total number of conference attendees. Participants were asked to complete the survey to test their nutritional knowledge, purchasing attitude, consumption, and storage preferences of pecans (23 questions). The remaining eight questions requested biographical and demographical information. Results revealed that taste was the main reason people ate pecans followed by the perception of eating something healthy. Over four-fifths of survey respondents knew that pecans contain heart-healthy fats and proteins. Approximately one-half of the respondents were aware that pecans are a source of minerals and antioxidants. However, 86.9% of the respondents believed that consuming pecans could lead to an increase in the levels of low-density lipoprotein (“bad”) cholesterol, which is opposite of what was reported by clinical studies. Over one-third of the respondents did not think that pecans require refrigeration to maintain flavor. Moreover, over half of the respondents did not believe that pecans store better if kept in the shell. Although the sample was limited because it was one of convenience, in general, respondents had good eating habits and a very positive attitude toward pecans. However, more educational programs are necessary to inform them about the health properties and proper storage methods of pecans.
Consumer Attitudes for Asian Vegetables in Direct Markets
Authors: Walters S. Alan , Range Kurt T. , Taylor Bradley H. , Moon Wanki
Published: December 2018

Because the demand for Asian vegetables is rapidly increasing in the United States, these crops may provide local market growers new revenue opportunities with high returns per acre. However, consumer attitudes and purchasing habits regarding Asian vegetable crops are poorly understood. Therefore, consumers were surveyed in two direct-market venues (on-farm and farmers market) to measure their familiarity and preferences for Asian vegetables. Attributes that may influence buying decisions such as purchase frequency, consumption behavior, and knowledge of preparation and use were measured. Respondents were generally not familiar with fresh Asian vegetables. Although greater than 80% consumed less than 5 lb per year and less than once per month, the consumers surveyed expressed a strong interest to learn more about these vegetables. Consumers purchased Asian vegetables most often at supermarkets (29.4%) and restaurants (28.1%), and much less at local direct markets (12.5%). Results also indicated that Asians as well as consumers with higher income levels were most likely to consume these vegetables. Thirty-eight percent of consumers strongly indicated that the availability of recipes for various Asian vegetables at direct markets would increase the likelihood for purchase; thus, the opportunity exists to add these vegetables to local production and marketing systems, if recipes were made available at the point-of-purchase.
Economic Returns Using Risk-rated Budget Analysis for Rabbiteye Blueberry in Georgia
Authors: Fonsah Esendugue Greg , Krewer Gerard , Harrison Kerry , Stanaland Danny
Published: December 2018

Rabbiteye blueberry (Vaccinium ashei) is the most important type of blueberry grown in Georgia. This species is classified as a highbush blueberry type, but is distinctively different from highbush blueberry (V. corymbosum) in its ability to withstand high temperatures and low-organic–matter soils. However, rabbiteye blueberries, like other fruit crops, are subject to price and yield fluctuation. These volatilities depend on several factors, including the cultivar produced and sold, locality, aggregate productivity, targeted market, and timing. As a result, profit margin is hard to determine. The objective of this study was to estimate economic returns using risk-rated budget analysis for rabbiteye blueberry under Georgia conditions. The first-year establishment and maintenance cost of growing rabbiteye blueberry in Georgia was estimated at $5022.04/acre. Total harvesting and marketing cost in the second year was $719.44/acre. In the third year, total variable and fixed cost was $3487.50/acre. In the full production year (fourth year), the cost was estimated at $4671.17/acre. The compounded and recaptured establishment annual cost was $2736.11/acre. The risk-rated expected returns over total costs 63% of the time were $679.00/acre. The chances of making a profit were 77% and the base budgeted net revenue was $369.00/acre. The total budgeted cost was $0.94/lb. The estimated annual total fixed machinery cost was $698.00/acre. The total annual cost of drip irrigation was $161.15/acre.
Curriculum Evaluation: An Outcomes Assessment of the Department of Horticulture at Iowa State University
Authors: Duncan Elizabeth , VanDerZanden Ann Marie , Haynes Cynthia , Esters Levon
Published: December 2018

The Iowa State University undergraduate horticulture program has been nationally ranked as one of the best in the nation. Regular and systematic outcomes assessment is one means to evaluate the program for purposes of sustaining this level of excellence. The purpose of this study was to conduct a survey of horticulture graduates to determine preparedness when entering the workforce, departmental effectiveness, and to evaluate how well graduates met departmental learner outcomes. A 59-question survey instrument was distributed electronically to a proportional sample of 221 horticulture alumni who graduated between 2000 and 2006. The response rate was 47%. Results showed that graduates found jobs quickly, and a majority (76.7%) noted that their first and current jobs were highly related to their degree. Furthermore, 41.8% rated themselves as adequately prepared, 37.9% as more than adequately prepared, and 15.5% as exceptionally well prepared for their first job. Respondents also ranked their abilities related to the 33 learner outcomes questions as good to excellent.
Effectiveness of Pasteurized Poultry Litter as a Partial Substitute for Controlled-release Fertilizers in the Production of Container-grown Ornamental Plants
Authors: Broschat Timothy K.
Published: December 2018

In two experiments, pasteurized poultry litter (PPL) was evaluated as a potential substitute for controlled-release fertilizers in the production of container-grown downy jasmine (Jasminum multiflorum), chinese hibiscus (Hibiscus rosa-sinensis), and areca palm (Dypsis lutescens). Downy jasmine and chinese hibiscus generally grew better when provided with PPL as a micronutrient source than with no micronutrients or with an inorganic micronutrient blend (MN). However, areca palm grew poorly with PPL as a fertilizer supplement compared with MN-fertilized areca palm. PPL provided high levels of ammonium nitrogen, phosphorus, and potassium during the first few weeks, but soil solution levels of these elements dropped off rapidly in subsequent weeks. The large amount of phosphorus leached from the containers fertilized with PPL is an environmental concern.
Economic Evaluation of Methyl Bromide Alternatives for the Production of Tomatoes in North Carolina
Authors: Sydorovych Olha , Safley Charles D. , Welker Rob M. , Ferguson Lisa M. , Monks David W. , Jennings Katie , Driver Jim , Louws Frank J.
Published: December 2018

Partial budget analysis was used to evaluate soil treatment alternatives to methyl bromide (MeBr) based on their efficacy and cost-effectiveness in the production of tomato (Solanum lycopersicum). The analysis was conducted for the mountain tomato production region based on 6 years of field test data collected in Fletcher, NC. Fumigation alternatives evaluated included 61.1% 1,3-dichloropropene + 34.7% chloropicrin (Telone-C35™), 60.8% 1,3-dichloropropene + 33.3% chloropicrin (InLine), 99% chloropicrin (Chlor-o-pic), 94% chloropicrin (TriClor EC), 42% metam sodium (4.26 lb/gal a.i., Vapam), and 50% iodomethane + 50% chloropicrin (Midas). The MeBr formulation was 67% methyl bromide and 33% chloropicrin (Terr-O-Gas). Chloropicrin applied at 15 gal/acre provided the greatest returns with an additional return of $907/acre relative to MeBr. Telone-C35 provided an additional return of $848/acre and drip-applied metam sodium provided an additional return of $137/acre. The return associated with broadcast applied metam sodium was about equal to the estimated return a grower would receive when applying MeBr. Fumigating with a combination of chloropicrin and metam sodium; shank-applied chloropicrin at 8 gal/acre; drip-applied chloropicrin, Midas, or InLine; and the nonfumigated soil treatment all resulted in projected losses of $156/acre, $233/acre, $422/acre, $425/acre, $604/acre, and $2133/acre, respectively, relative to MeBr. Although technical issues currently associated with some of the MeBr alternatives may exist, results indicate that there are economically feasible fumigation alternatives to MeBr for production of tomatoes in North Carolina.
Causes and Consequences of Overfertilization in Orchards
Authors: Weinbaum Steven A. , Johnson R. Scott , DeJong Theodore M.
Published: December 2018

Over-fertilization (i.e., the application of fertilizer nitrogen (N) in excess of the tree or vine capacity to use it for optimum productivity) is associated with high levels of residual nitrate in the soil, which potentially contribute to groundwater and atmospheric pollution as a result of leaching, denitrification, etc. Overfert-ilization also may adversely affect productivity and fruit quality because of both direct (i.e., N) and indirect (i.e., shading) effects on flowering, fruit set, and fruit growth resulting from vegetative vigor. Pathological and physiological disorders as well as susceptibility to disease and insect pests also are influenced by the rate of applied N. Over-fertilization appears to be more serious in orchard crops than in many other crop species. The perennial growth habit of deciduous trees and vines is associated with an increased likelihood of fertilizer N application (and losses) during the dormant period. The large woody biomass increases the difficulty in assessing the kinetics and magnitude of annual N requirement. In mature trees, the N content of the harvested fruit appears to represent a large percentage of annual N uptake. Overfertilization is supported by a) the lack of integration of fertilizer and irrigation management, b) failure to consider nonfertilizer sources of plant-available N in the accounting of fertilizer needs, c) failure to conduct annual diagnosis of the N status, and d) the insensitivity of leaf analysis to over-fertilization. The diversity of orchard sites (with climatic, soil type, and management variables) precludes the general applicability of specific fertilization recommendations. The lack of regulatory and economic penalties encourage excessive application of fertilizer N, and it appears unlikely that the majority of growers will embrace recommended fertilizer management strategies voluntarily.
Rowcovers Accelerate Fruiting and Increase Productivity in Primocane-fruiting Red Raspberries
Authors: Pritts Marvin , Hanson Eric , Fiola Joseph , Kelly Mary Jo
Published: December 2018

Studies were conducted over eight location-years to evaluate the effects of rowcover material, time of application, and time of removal on `Heritage' red raspberry cane growth, flowering, and fruiting. We anticipated that rowcovers would accelerate fruit maturity so that more of the crop could be harvested before the onset of cold temperatures in autumn. In seven of the eight experiments, rowcovers either increased yields or accelerated harvest. With a March application, harvest began 3 weeks earlier, and August yields of covered plants were 42 times higher than those of noncovered plants. Responses were observed with spunbonded polypropylene and polyester covers, but not with polyethylene covers. Rowcovers placed over the row before primocane emergence and removed when canes were ≈50 cm tall resulted in the greatest plant response. The use of polyester or polypropylene rowcovers with primocane-fruiting raspberries appears to be economically feasible in most years in northern climates.
Control of Humidity in Small Controlled-environment Chambers using Glycerol-Water Solutions
Authors: Forney Charles F. , Brandl David G.
Published: December 2018

Solutions of glycerol and water provide a convenient and inexpensive system to control the relative humidity (RH) in small controlled-environment chambers. The relationship between the specific gravity (SG) of a glycerol-water solution and its equilibrium RH is described by the equation SG = [-0.189 (RH) + 19.9]0.0806. Gas can be humidified by bubbling it through jars containing solutions of glycerol-water with the desired equilibrium RH. The effects of flow rate, volume of solution, temperature, and pressure on the equilibrium RH are discussed.
Scheduling Collard Planting Dates Regionally to Lengthen the Production Period
Authors: Dufault Robert J. , Batal K. Dean , Decoteau Dennis , Garrett J. Thomas , Granberry Darbie , McLaurin Wayne , Nagata Russell , Perry Katharine B. , Sanders Douglas
Published: December 2018

The experiment screened two spring and two fall planting dates in six regions within North Carolina, South Carolina, and Georgia. The objective was to extend the production over the southeastern United States rather than at a single location. Spring harvests lasted from mid-April to early July. Summer-to-winter harvests lasted from mid-August to late January. Collards were not harvested in any of the locations from late January to mid-April or from early July to mid-August. More extensive planting dates may further increase the longevity of production.
Horticulture Hiring People with Disabilities
Authors: Davis Steven H. , De Riso Mary S.
Published: December 2018

Since 1982, the American Horticultural Therapy Assn. (AHTA) has devoted a significant portion of its organizational energies to promoting the employment of people with disabilities in the horticultural industry. Since then, the AHTA has administered five federal grants, resulting in the employment of 2269 people with disabilities. This paper summarizes the data generated through these activities and presents program findings.
Market Segmentation and Product Targeting at the Conceptual level
Authors: Behe Bridget K.
Published: December 2018

Firms have limited resources that cannot be allocated efficiently to the market as a whole, but can be targeted to selected customer groups. Market segmentation is the process of dividing a market into distinct customer components. Selected products and services that best meet the needs of a selected customer group are targeted to that particular segment in a marketing strategy. Market segmentation and product-targeting concepts help management efficiently allocate scarce resources as part of a comprehensive strategy to expand revenues and profits.
Recruiting Students by Marketing Horticulture
Authors: Balbach Margaret
Published: December 2018

The traditional content in introductory horticulture courses emphasizes plant structure, physiology, and production. At Illinois State Univ., however, the course work has been designed to meet University Studies requirements as well as departmental needs. The students taking the course are viewed as a market, and basic principles of marketing are used to gain and keep the interest of a wide variety of students, few of which have had any previous contact with horticulture. Extensive coverage is given to the historical, social, and economic status of horticulture in the United States. This nontraditional approach has been successful in the view of students and faculty. Postcourse surveys found that 98% of students felt that they had gained a good working knowledge of horticulture, and that 95% believed they would be a more knowledgeable consumer. Some departments use the University Studies program as a means of recruiting new majors, and this potential was not ignored in designing a marketing approach to the course content.
Use of Near-Infrared video for Localizing Nitrogen Stress in Peach Orchards
Authors: Stutte G.W. , Stutte C.A.
Published: December 2018

Computer analysis of airborne, broad-band, near-infrared (NIR, 710 to 1100 nm) video imagery of peach tree canopies was used to determine spatial variability of cumulative stress in two peach orchards. A significant quadratic correlation was found between leaf-N content and the normalized mean pixel intensity (MPI) of the digital imagery of NIR canopy reflectance. This correlation was used to establish MPI estimates of N-stressed trees in the orchard. The relationship was used to localize site-specific spatial variability in a commercial peach orchard. The underlying soil type was found to be closely associated with the spatial variability in NIR imagery in the commercial peach orchard. Assessing spatial variability in the orchard with NIR video permits early localization of potentially low productivity regions within an orchard.
Automation in the Greenhouse: Challenges, Opportunities, and a Robotics Case Study
Authors: Simonton Ward
Published: December 2018

The commercial greenhouse operation, with a controlled and structured environment and a large number of highly repetitive tasks, offers many advantages for automation relative to other segments of agriculture. Benefits and incentives to automate are significant and include improving the safety of the work force and the environment, along with ensuring sufficient productivity to compete in today's global market. The use of equipment and computers to assist production also may be particularly important in areas where labor costs and/or availability are a concern. However, automation for greenhouse systems faces very significant challenges in overcoming nonuniformity, cultural practice, and economic problems. As a case study, a robotic workcell for processing geranium cuttings for propagation has been developed. The robot grasps randomly positioned cuttings from a conveyor, performs leaf removal, trims the stems, and inserts the cuttings into plug trays. While the system has been shown to process effectively many plants automatically, the robot is not equipped to handle successfully the wide variety of cuttings that a trained worker handles with aplomb. A key challenge in greenhouse automation will be to develop productive systems that can perform in a reliable and cost-effective way with highly variable biological products.
A Consumer Horticulture Computer Network for Extension Agents
Authors: Relf Diane , Silva Ellen , Nathan Virginia
Published: December 2018

In 1985 an extension consumer horticulture computer information system (HORT) was initiated on the Virginia Tech mainframe computer to mitigate the demands on agents' time while providing monthly professional updates and accurate, timely information for use in their local programs. Agents access the information through their office microcomputers, which are linked to the Virginia Tech mainframe computer. Agents can transfer the needed information onto a diskette for reference, immediate use, or further editing or print a hard copy on campus to be mailed to them. Slide sets or videotapes can be ordered from the Virginia Tech Learning Resource Center (LRC) on this system. The monthly releases are available at no charge to anyone in the land-grant system with a BITNET or Internet user identification number.
Research on Human Issues in Horticulture Motivates Students to Learn Science
Authors: Lohr Virginia I.
Published: December 2018

Many undergraduates major in horticulture because they love working with plants. When they hear research that documents how people respond-to plants, some students -begin to understand why they have responded positively to plants, and they want to learn more about the topic. This paper 1) discusses the potential to use students' excitement about human issues in horticulture to teach principles that educators consider important components of a baccalaureate degree, and 2) presents the case of one student to demonstrate how it can be done.
Modified Atmosphere and Vacuum Packaging to Extend the Shelf Life of Respiring Food Products
Authors: Gorris L.G.M. , Peppelenbos H.W.
Published: December 2018

There has been a recent upsurge in the application of modified atmosphere and vacuum packaging to extend the shelf life of food products that rapidly deteriorate. Although these techniques are mostly used with nonrespiring products, both offer considerable prospects for respiring products as well. Because not all commodities respire at the same pace, packaging conditions, such as the initial gas atmosphere applied, the type of packaging material used, and the storage temperature, require special consideration. Choosing the wrong packaging conditions may lead to loss of product quality and also may impair the microbiological safety normally associated with fresh fruits and vegetables. This paper stresses the importance of these considerations with modified atmosphere and vacuum packaging systems.
Influence of Seed Hydration on Seedling Performance
Authors: Taylor A.G. , Prusinski J. , Hill H.J. , Dickson M.D.
Published: December 2018

Water is pervasively involved in the life cycle of seeds. Water in the environment, either as a vapor or liquid, directly affects seed moisture status. This article is devoted to the study of seed moisture status in postharvest events. Two topics are discussed: imbibitional chilling injury and upgrading of primed seeds. Imbibitional chilling injury is a physiological disorder that occurs in large-seeded legumes as well as other important agronomic seeds. Imbibitional chilling injury has been shown to reduce the survival rate of seedlings. Surviving seedlings have less emergence force per seedling and require a longer period to generate maximum force. Rapid hydration has been shown to induce injury at a particular seed moisture level. Methods of regulating the hydration rate were explored to alleviate chilling injury in snap beans (Phaseolus vulgaris L.) Plant breeding lines with the semihard seed characteristic delayed the onset of imbibition when the initial moisture level was low (8%). Coating seeds with polymeric films to complement the permeable testa retarded the imbibition rates. Both approaches alleviated chilling injury and improved seedling establishment under stressful conditions. Seed priming is a technique for elevation of seed moisture content before sowing. Primed seeds generally emerge more quickly than nonprimed seeds, especially under stressful environmental conditions. An additional merit of this technique is that it gives access to seeds with elevated moisture content. Various approaches may be employed to condition seeds after priming, but before redesiccation. Discarding the low-density fractions of primed tomato and lettuce seeds improved the percentage of germination compared with nonprimed seeds. Physiological mechanisms are presented to explain the association of density with seed viability in lettuce (Lactuca sativa L.).
Postharvest Quality and Storage of Scab-resistant Apple Cultivars
Authors: DeEll Jennifer R. , Prange Robert K.
Published: December 2018

This paper reports preliminary results on the postharvest quality and storage characteristics of several scab-resistant apple cultivars. `Novaspy', `Moira', `Priscilla', `Novamac', `Nova Easygro', `Prima', and `Macfree' were stored for 3 months at 3C in air or standard controlled atmosphere (CA; 4.5% CO2 and 2.5% O2) in 1990 and for 4 months at 0C in air, standard CA, or low-O, CA (LO; 1.5% CO2 and 1.5% O2) in 1991. `Moira', `Prima', and `Priscilla' had very limited storage life. `Moira' was susceptible to bitterpit, scald, core browning, vascular breakdown, and storage rots. `Prima' was susceptible to core browning and vascular breakdown and had a high incidence of storage rots in air storage. `Priscilla' had several defects as a result of insect damage and was susceptible to bitterpit and scald. `Novaspy' stored very well and had virtually no physiological disorders or storage rots. `Novamac, `Nova Easygro', and `Macfree' developed few storage rots and were essentially at the end of their storage life after 4 months, regardless of storage conditions. Firmness in `Novamac' decreased substantially in all storage atmospheres, while `Nova Easygro' and `Macfree' were susceptible to core browning and scald.
Postharvest Performance of Southern Highbush Blueberry Fruit
Authors: Lang Gregory A. , Tao Jiaxun
Published: December 2018

The postharvest performance of early ripening southern highbush blueberries `Sharpblue' and `Gulfcoast' was evaluated under storage and simulated retail conditions. In general, `Gulfcoast' fruit were 28% heavier than those of `Sharpblue', which had a higher percent soluble solids concentration (SSC) and lower titratable acidity (TA). Quality loss, as indexed by fresh weight, percent decayed fruit, or changes in SSC, pH, or TA, was insignificant in first-harvest fruit of either cultivar when kept in storage (2C) for up to 7 days. Transfer of fruit stored at 2C for 3 days to simulated retail conditions at 21C for 4 days significantly increased fresh weight loss and decay, but not beyond levels deemed unmarketable. Second-harvest fruit were smaller than first-harvest fruit, and those of `Sharpblue' fruit were more prone to decay. However, storage quality of both cultivars was acceptable through 11 days at 2C. Retail quality, as influenced by decay incidence, was acceptable after 3 days at 2C plus 4 days at 21C, but not after 3 days at 2C plus 8 days at 21C. Overall, fruits of these early ripening southern highbush blueberry cultivars performed well under postharvest conditions and are suitable for expanding production of premium fresh blueberries by growers in the Gulf coastal plains.
A Simple Method to Measure On-farm Pan Evaporation for Scheduling Irrigation
Authors: Simonne Eric , Mills Harry A. , Smittle Doyle A.
Published: December 2018

Measurements of daily, 3-day, and 6-day cumulative pan evaporation using a #2 wash tub or a modified steel drum and a ruler provided an accurate, easy, and inexpensive way to schedule irrigation. Pan factors for these containers, which were covered with a 5-cm-mesh wire under humid climatic conditions, were 1.0 and 1.1, respectively.
Grading Criteria for Judging Potatoes for Chip Quality and Yield
Authors: Evensen Kathleen B. , Russo Joseph M. , Braun Harriet
Published: December 2018

Grading criteria are proposed for judging potatoes (Solanum tuberosum) for chip quality and yield. The criteria were derived from a decision-making scheme developed from expert opinions, U.S. Dept. of Agriculture grades, and a statistical evaluation of stored potatoes. The criteria are presented as ranges of acceptable values for a limited set of variables found to be important for chip quality and yield. These variables include bruising, cracks, cuts, fusarium dry rot, lesions, and scab. The proposed criteria, besides being a practical decision-making tool for processors, could serve as a knowledge base for potato expert systems and the development of mechanized sorting equipment.
Soil Properties Pertinent to Horticulture in Florida
Authors: Harris W.G. , Chrysostome M. , Obreza T.A. , Nair V.D.
Published: December 2018

Horticulture is an important industry in Florida despite formidable soil limitations. Favorable climate often makes the expense of overcoming these limitations economically feasible. Challenges arise from high water tables and/or sandy textures, both of which limit plant-available water and nutrient retention. High water tables of flatwoods (Spodosols) and marshes (Everglades Histosols) restrict root proliferation and commonly require artificial drainage. Upper zones of these soils are dominated by uncoated sand (Spodosols) or organic matter (Histosols) that has minimal sorption capacity for phosphorus (P) such that its transport poses an environmental risk without careful management. Nitrogen can be lost via denitrification under prolonged near-surface water saturation. At the other extreme but also prevalent in Florida are excessively well-drained sandy “sandhills” soils with limited water and nutrient retention. Nitrogen leaching from the latter soils can result in nitrate contamination in groundwater. Soil morphology is an important consideration in gauging nutrient and moisture retention. For example, each is enhanced by the presence of sand-grain coatings. Some amendments show promise in reducing P and moisture loss from sandy soils. Precarious balance between horticultural production and environmental risks for Florida soils has spurred development of approaches providing for a more accurate determination of the safe soil P storage capacity. Testing and refinement of these approaches are needed.
Best Management Practices for Temperate and Tropical/Subtropical Fruit Crops in Florida: Current Practices and Future Challenges
Authors: Williamson Jeffrey G. , Crane Jonathan H.
Published: December 2018

A wide variety of temperate, subtropical, and tropical fruit crops are grown commercially in Florida. Farm size ranges from large commercial operations exceeding 100 acres to small 1- or 2-acre “estate” farms. Irrigation and fertilization practices vary widely with crop, soil type, and management philosophy. However, many growers are adopting practices such as microirrigation, fertigation, and other technologies, which, if properly used, should reduce water and fertilizer inputs and minimize leaching and runoff of fertilizers and pesticides. Although fertilizer and irrigation recommendations exist for major crops such as avocado (Persea americana), mango (Mangifera indica), and blueberry (Vaccinium spp.), there is little research-based information specific to Florida for many minor crops, including muscadine (Vitis rodundifolia), blackberry (Rubus spp.), sapodilla (Manilkara zapota), guava (Psidium guajava), papaya (Carica papaya), and others. Even where recommendations exist, refinement of irrigation and fertilization practices is needed because of changes in technology.
Two Reproductive Bud Thinning Alternatives for Cactus Pear
Authors: Zegbe Jorge A. , Mena-Covarrubias Jaime
Published: December 2018

Cactus pear (Opuntia spp.) is an important Mexican fruit crop cultivated extensively (about 51,000 ha) in the semiarid highlands of Mexico. Fruit exports have increased in the last decade, but to fulfill these markets, fruit size must be enhanced. However, current hand thinning reduces yield, thus making it uneconomical for growers. The objective was to evaluate two reproductive bud (RB) thinning protocols in an effort to increase export fruit size without depressing cactus pear yield. Two experiments were conducted during the 2004 growing season with two cactus pear types: Cristalina (Opuntia albicarpa) and Rojo liso (Opuntia ficus-indica). In the first experiment, the treatments were no thinning (control) or keeping 4, 8, or 12 RBs per cladode. In the second experiment, the treatments were no thinning (control), thinning every other bud along the cladode, and thinning two of every three buds along the cladode. In the first experiment, yield of Cristalina was reduced by 10.4% and 51.8% when eight or four RBs per cladode were retained, respectively. Mean fruit weight of Cristalina decreased with the most severe thinning treatment. Yield of Rojo liso was reduced when four RBs were retained per cladode. In the second experiment, yield of both cactus pear types was unaffected by the thinning treatments. Therefore, we recommend thinning every other bud along the cladode because it does not reduce yield and tends to improve marketable fruit in both cactus pear types. However, this thinning alternative should be tested in other commercial cactus pear types if growers are interested in export markets.
Application of Paraquat Can Injure Field-grown Narcissus
Authors: Miller Timothy W. , Libbey Carl R.
Published: December 2018

Mid-summer, foliar-applied paraquat is often used to control weeds and desiccate foliage of field-grown narcissus (Narcissus pseudonarcissus) prior to bed reshaping in the autumn. Paraquat-treated narcissus plants sometimes display chlorotic foliage the subsequent growing season. A trial was conducted to determine if paraquat causes that injury and if so, under what conditions paraquat may be safely applied to narcissus. Narcissus (‘Flower Carpet’ hybrid) was treated with two rates of paraquat at three summer application timings and was then evaluated for damage to new foliar growth the following spring. Flower number and flower stem length was also measured and bulb yield was determined. Narcissus foliage displayed 50% to 77% chlorosis in February after half-green foliage was treated with paraquat at 0.47 or 0.78 lb/acre, respectively, the previous summer. Foliage was still 13% to 63% chlorotic, respectively, at flowering. Paraquat at both rates applied to half-green foliage also reduced flower number and flower stem length in one of two iterations, as well as reducing average bulb weight 18% to 33%. If applied when leaves were 75% dry, foliar damage and reduction in average bulb weight was limited to the 0.78 lb/acre rate, while flower number and stem length were not affected at either rate. When desiccating late-season narcissus foliage and weeds with paraquat, therefore, growers are advised to delay application until narcissus foliage is about 75% dry and most of the flower stems have fallen, and to use a maximum of 0.47 lb/acre.
Potential Economic Impact of Laurel Wilt Disease on the Florida Avocado Industry
Authors: Evans Edward A. , Crane Jonathan , Hodges Alan , Osborne Jason L.
Published: December 2018

This article describes and provides preliminary estimates of the potential economic losses that could result from an incursion of the recently discovered exotic laurel wilt disease caused by Raffaelea lauricola, in the main avocado (Persea americana) growing area of Florida. Estimates are provided for the direct losses as well as the indirect or “spillover” losses that could occur across the rest of the regional economy. The Impact Analysis for Planning (IMPLAN) input-output multipliers were used in assessing the regional impacts. The results of the investigation indicate that the direct loss to the industry in terms of lost sales, property damage, and increased management costs could range from $356 million in a do-nothing situation to about $183 million if damage control measure were 50% effective. If increased management costs and decreased property values are ignored, the adverse impact on the regional economy could range from $54 million in a do-nothing situation to $27 million in a case in which the treatments result in only a 50% reduction in avocado production.