bluuebunny/crossref_metadata_2025 huggingface dataset:
Fertilizer Management for Drip-irrigated Vegetables in Florida
Authors: Hochmuth G.J.
Published: December 2018

Fertilizer application by drip irrigation is becoming a common practice for many vegetable crops, especially in Florida. Vegetable producers view drip irrigation as a tool to reduce water use, increase fertilizer efficiency, and improve profits, while simultaneously reducing the potential risk to the environment due to nutrient enrichment of surface and groundwater. This paper presents the current Univ. of Florida recommendations for fertilizer management with drip irrigation for vegetables in Florida. These recommendations are based on more than 15 years of research on water and nutrient management with drip irrigation. Although these recommendations were developed for largely sandy soils from mostly Florida research, they should be easily adaptable for other U.S. vegetable regions on sandy soils.
Maintenance Considerations for Drip Irrigation Systems
Authors: Sanders D.C.
Published: December 2018

Because drip irrigation systems are very susceptible to clogging, maintenance revolves around flushing the system. Both primary and secondary filters and main and lateral lines and drip tubes require flushing on a regular basis. Chlorination and use of acid often are necessary for keeping lines clear of contaminants. Rubber gaskets and diaphragms should be replaced every 2 years. A water meter will assist in assuring that desired application rates are being obtained. The use of air vents assures that air locks do not reduce system efficiency. The calibration of injector pumps should be verified at least two times per season.
Water Budgets to Schedule Irrigation for Vegetables
Authors: Smittle Doyle A. , Dickens W. Lamar
Published: December 2018

Instrumented rainfall- and groundwater-protected irrigation shelters were used to establish relationships (daily crop factors) between pan evaporation and daily water use for several vegetables. Use of these daily crop factors (water use/pan evaporation) and pan evaporation data for scheduling irrigations are described. Snap bean (Phaseolus vulgaris L.) is used to illustrate irrigation scheduling by this method. A table of the model output with columnar headings of age, root depth, date, pan evaporation, crop factor, daily water use, cumulative water use, allowable water use, rainfall, and irrigation is presented. When irrigation was applied according to the model, soil water tension was held below 25 db at 6-inch (15-cm) soil depth. With varying irrigation rates under a line-source irrigation system, marketable pod yields were maximized at 100% of the model rate. Marketable yields of summer squash also were maximized when irrigation was applied at 100% of the model rate. Marketable yields of sweetpotato were not affected by irrigation rates ranging from 1% to 177% of the model rate.
Mechanization, Automation, and Computerization for Greenhouse Production
Authors: Ting K.C.
Published: December 2018

Availability and capability of labor have become dominating factors affecting agriculture's productivity and sustainability. Agricultural mechanization can substitute for human and animal physical power and improve operational uniformity. Automation complements mechanization by implementing the capabilities of automatic perception, reasoning, communication, and task planning. Fixed automation is traditionally cost-effective for mass production of standard items. In addition, flexible automation responds to make-to-order batch processing. The appropriateness of each automation type depends on the situation at hand. Because of their vast memory and high calculation speed, computers are highly effective for rapid information processing. Incorporating state-of-the-art hardware and software, computers can generate status reports, provide decision support, gather sensor signals, and/or instruct machines to perform physical work. It is no surprise, therefore, that computerization is essential to the evolutionary process, from mechanization through fixed automation to flexible automation. Fundamentals of agricultural mechanization, automation, and computerization applied to greenhouse production are discussed. Recent research activities conducted at Rutgers Univ. are presented for illustrative purposes.
Chiles: A Diverse Crop
Authors: Bosland Paul W.
Published: December 2018

Capsicum, a New World genus, has a richness in diversity that has not received much attention. Along with tomato and potato, chile is one of the important New World crops belonging to the Solanaceae family. The Capsicum fruits are popular and used in cuisines from all over the world. There are many different cultivars, forms, and uses of Capsicum. Most cultivars grown in the United States belong to one species, Capsicum annuum. The species is divided into groups based on fruit shape, flavor, and culinary use. Unfortunately, there is confusion about the names associated with the various fruit types. This article attempts to reduce some of the confusion. Whatever the name, there can be no argument that Capsicum is an amazing plant genus.
A Nondestructive Image Analysis Technique for Estimating Whole-tree Leaf Area
Authors: Lindsey Patricia A. , Bassuk Nina L.
Published: December 2018

The development of a rapid, accurate, yet nondestructive technique for expressing whole-tree leaf area would be extremely useful in studying various growth phenomena in trees. The objective of this research was to evaluate the accuracy of an image analysis process adapted for estimating the leaf surface area of four broad-leafed tree species (Amelanchier L. `Robin Hill Pink', Tilia americana L. `Redmond', Sophora japonica L. `Regent', Fraxinus americana L. `Autumn Purple' and Fraxinus pennsylvanica Marsh.). Video images of photographs taken of each tree canopy were quantified by an image analyzer into unitless surface area values or silhouette areas. The relationship between estimated leaf area as calculated from silhouette area and actual leaf area of these trees as determined by a leaf area meter was highly correlated. Use of this technique would enable a researcher, simply from serial photographs of the canopy, to retroactively estimate leaf or canopy area at crucial interim periods.
Scheduling Considerations for Automated Irrigation in the 1990s
Authors: Glen D.M.
Published: December 2018

This work focuses on recent developments and examples of irrigation scheduling that concern where in the root system and when in the plant's phenology water should be applied. Information is provided on using and measuring soil variability to help schedule irrigation. An irrigation model is described that emphasizes the soil water-holding capacity and root distribution in designing irrigation systems and scheduling water application. Recent research is reviewed on the subject of fruit crops that can tolerate severe water stress during specific growth periods of the fruit. Finally, a method of using infrared thermometers and canopy temperature data in cloudy, humid regions is presented that has the potential to extend the use of this technology.
Forecasting Annual Vegetable Plantings
Authors: Guenthner Joseph F.
Published: December 2018

Vegetable producers and marketers make business decisions based on supply estimates. The U.S. Dept. of Agriculture provides estimates of planting intentions for field crops but not for most vegetable crops. This study developed models that can be used to forecast vegetable crop plantings. Multiple linear regression analysis was used to determine the factors that influence plantings of potatoes and onions. Field crop planting intentions, industry structure, lagged values of plantings, prices received, price volatility, and the price of sugar beets were found to be significant factors. The models and/or methods used in this study should be useful to those interested in forecasting vegetable plantings.
A Comparative cost Analysis of Vegetable Irrigation Systems
Authors: Prevatt J.W. , Clark G.A. , Stanley C.D.
Published: December 2018

Three vegetable irrigation systems, semi-closed subirrigation (seepage), fully enclosed subirrigation (seepage), and drip irrigation, were evaluated for use on sandy soils with naturally high water tables to determine comparative irrigation costs for tomato production. Investment, fixed (ownership), and variable (operating) costs were estimated for each irrigation system. The investment costs of the drip irrigation system were significantly greater than those for the semi-closed and fully enclosed irrigation systems. The variable costs, however, for the semi-closed system were considerably less than those for the fully enclosed and drip irrigation systems. The semi-closed irrigation system, therefore, was determined to be the least-cost tomato irrigation system under present fuel cost and nonlimiting water supply conditions.
Notable Women in the History of Horticulture
Authors: Hershey David R.
Published: December 2018

Ten women horticulturists who made important contributions to their science are briefly profiled, since virtually no horticulture textbooks mention notable women horticulturists.
Developing a New Fertilizer for the Greenhouse Market
Authors: Peters John R.
Published: December 2018

The development of the Peters 20-l O-20 water-soluble fertilizer took place at a time when energy and raw materials costs were rising at a double digit rate. Developing a product that could save money for greenhouse crop growers and meet the high performance standards established by the company was the challenge. Product, market, pricing, distribution, and communication issues and strategies were considered in the product development. In 10 years, this new product line became the company's best-selling product line.
Focusing Extension Resources to Diverse Clientele
Authors: Garber M.P.
Published: December 2018

Marketing techniques were valuable in the development of an extension and research support program for the diverse Georgia nursery industry. The support program was developed in three stages: 1) needs assessment and development of industry alliances, 2) initiation of a research program based on priority needs, and 3) technology transfer. The needs assessment was facilitated by the development of a distribution channel map for the Georgia landscape/nursery industry. The industry alliances developed early in the project facilitated conduct of the research program and technology transfer. The research component was identified from an informal needs assessment and qualitative information on industry relations inferred from the distribution channel map. The research results support the contention that landscape architects have a significant influence on demand for nursery crops and that nursery operators should treat this group as important customers. The focus for technology transfer is improved marketing procedures and more efficient working relationships between nursery operators and landscape architects. This includes development of new alliances at the industry/association level, improved marketing practices for nursery operators, and positioning extension publications to benefit multiple industry segments.
Attitudes toward Plants and Gardening
Authors: Relf Diane , McDaniel Alan R , Butterfield Bruce
Published: December 2018

Recently there has been an increased interest in the role of plants in human well-being and in the general public's perception of the value of plants. Knowing the nature and extent of the value of plants to people can affect the way plants are used in public and private landscapes, the amount of money invested in the establishment and maintenance of plants, and the satisfaction derived from the plantings. In conjunction with the annual National Gardening Association consumer market study, a question was asked to determine if observations from previous, limited studies were applicable to a wide range of American households.
Effect of Plastic Mulch Color and Insecticides on Thrips Populations and Damage to Tomato
Authors: Brown Steve L. , Brown James E.
Published: December 2018

In each of 3 years, the average number of thrips in tomato (Lycopersicon esculentum L. cv. Mountain Pride) blooms was greater on tomatoes grown on white plastic mulch than on tomatoes grown on black plastic mulch, aluminum plastic mulch, or bare ground. Early season differences, however, diminished with time as plants grew and shaded a larger portion of plastic mulch. Weekly applications of 12 insecticide treatments failed to reduce thrips populations below that found in the control. No significant differences were found among treatments in the quantity, quality, or earliness of tomato yields. Incidence of tomato spotted wilt (vectored by some thrips species) was too low to detect statistical differences or determine the importance of thrips population in disease epidemiology. Western flower thrips (Frankliniella occidentalis) was the most common species found, followed by eastern flower thrips (F. tritici) and tobacco thrips (F. fusca). Thrips control, in the absence of tomato spotted wilt, is not justified for the thrips populations encountered in this study.
Summer Applications of Plant Growth Retardants Affect Spring Forcing of Hydrangeas
Authors: Bailey Douglas A. , Clark Bernadette
Published: December 2018

Summer spray applications of 5000 ppm daminozide (1× or 2×), 62 ppm paclobutrazol (1× or 2×), or 5 ppm uniconazole (1× or 2×) were applied to seven cultivars (Böttstein, Enziandom, Kasteln, Mathilde Gütges, Merritt's Supreme, Red Star, and Schenkenburg) of florists' hydrangea [Hydrangea macrophylla subsp. macrophylla var. macrophylla (Thunb.) Ser.] to evaluate cultivar response to plant growth retardants (PGRs). Both daminozide treatments and the 2× uniconazole treatment effectively reduced plant height for all cultivars during the summer growth period; cultivars varied in response to the paclobutrazol treatments and the 1× uniconazole treatment. Daminozide and uniconazole treatments resulted in less elongation than all other treatments during forcing for most cultivars tested. Paclobutrazol treatments had no residual effect on shoot elongation during forcing of the cultivars tested. The 2× treatments of all PGRs decreased inflorescence diameter of some of the cultivars tested compared with nonsprayed controls. Results from this study indicate that 1) summer application of PGRs can have a residual effect on plant height and inflorescence diameter of hydrangeas during the spring greenhouse forcing phase; and 2) hydrangea cultivars differ significantly in response to the PGRs tested. Therefore, the need for height control during the spring forcing period of hydrangeas will vary with cultivar, and it will depend on how plants were treated the previous summer growing season. We recommend that producers of dormant hydrangeas provide records of their summer height control program to forcers so that height control programs during spring forcing can be adjusted appropriately.
Retaining Master Gardener Volunteers
Authors: Stouse Larry , Marr Charles
Published: December 2018

Master Gardeners are volunteers who assist local cooperative extension horticulture and related program efforts by receiving training and conducting educational activities and projects. Participants generally receive training and volunteer within a 1-year period. The emphasis has shifted to longer retention of trained, experienced Master Gardeners. There are several advantages in retaining volunteers. Volunteers with established knowledge who “know the ropes” serve as spokespersons for the program to recruit additional volunteers and as mentors for new class members. Since 1980, Master Gardeners in Johnson County, Ran., have served the 300,000 population base of the southwestern Kansas City suburban area through the county extension horticulture program. About 35% of the members of the first classes are still active volunteer participants after 10 years. Retention is encouraged by emphasizing that volunteer time is an opportunity for continued learning, rather than a “payback” for training received. An advisory board and committee structure encourages “ownership” of the program, and an advanced training program is offered to retained volunteers. Developing ideas for quality volunteer activities is continuously stressed. As new volunteers start the program, their abilities and skills in nonhorticultural areas that may be useful are assessed, such as woodworking, photography, speaking, leadership, and art. Applicants are screened to limit class size to 20 to 25 participants.
Sources of Information and Channels of Communication used in Transfer of Gardening Technologies
Authors: Patel Ishwarbhai C. , Okai Milton N.
Published: December 2018

This study revealed that cooperative extension education usually requires a combination of communication channels or teaching methods. One channel or method supplements and complements another. It is the cumulative effect on people of repeated exposure to an innovation that results in action. The differential adoption behavior of the gardeners in relation to 10 gardening technologies suggests that the adoption of one technology does not depend on another. Adoption of a gardening technology is a major consequence of communication. Furthermore, the relative influence of sources and channels decreased with the increase in the number of technologies adopted.
Master Gardeners and Horticultural Therapy
Authors: Flagler Joel S.
Published: December 2018

Horticultural therapy programs can benefit from the services of Master Gardeners. Trained through the U.S. Cooperative Extension Service, Master Gardeners are skilled in practical plant sciences and committed to volunteerism. A nationwide survey has determined that 374 Master Gardeners in 21 states are helping to bring structured horticultural activities to individuals in nursing homes, hospitals, rehabilitation centers, prisons, and other special service facilities.
Assessing and Influencing Attitudes toward Water-conserving Landscapes
Authors: Lohr Virginia I. , Bummer Lenore H.
Published: December 2018

Implementing water-conserving landscapes is one action that many individuals can take to help ease the nation's water crisis, but few people seem to be exercising this option. Some horticulturists attribute this to a negative attitude toward such landscapes. Our research was designed to assess these attitudes and to see if they could be improved with information. Questionnaires were administered to people in treatment or control groups. Those in the treatment group viewed a short videotape about water issues and water-conserving landscapes. Initial attitudes in both groups were neutral or positive, not negative as predicted. Viewing the videotape was associated with significantly improved attitudes. People in the treatment group described water-conserving landscapes as less hot, more colorful, and more attractive three weeks after viewing the videotape than they had initially.
Heat Treatments for Improved Postharvest Quality of Horticultural Crops
Authors: Klein Joshua D. , Lurie Susan
Published: December 2018

Commercial, ecological, and agrotechnical considerations have recently renewed interest in the use of physical rather than chemical means to maintain postharvest quality of horticultural crops. This review discusses prestorage heat treatments that protect against physiological disorders, enhance natural resistance to pathogen infection, reversibly inhibit fruit ripening, and permit flexibility in storage temperatures.
Mistletoe: Its Role in Horticulture and Human Life
Authors: Paine Laura K. , Harrison Helen C.
Published: December 2018

Parasitic flowering plants represent a unique ecological adaptation, having evolved away from independent function and toward an increasing dependence on other higher plants for survival. Mistletoe, a common evergreen parasite of woody plants, has played a significant role in human culture for centuries. Throughout history, mistletoe species were nurtured and revered as medicinal herbs and religious symbols. But the role of mistletoe has changed. Its importance in western culture has dwindled to a minor, though enduring, association with the Christmas holiday. In contrast, its significance as a parasite of tree crops and woody ornamentals has increased in recent years. Mistletoe species are studied in efforts to control their pathogenic effects and to gain insight into the evolutionary role played by this family of parasitic flowering plants. The unique characteristics of mistletoe that challenge horticultural researchers have contributed to its enduring role in human life.
Cultivar, Packaging, and Storage Temperature Differences in Postharvest Shelf Life of Okra
Authors: Perkins-Veazie P. , Collins J.K.
Published: December 2018

Okra stored at 3C in 12.7-pm high-density polyethylene (HDPE) bags developed less chilling injury than fruit stored in plastic boxes. Okra held in HDPE bags at 12.5C for 8 days had more decay and reduced overall appearance than fruit held in plastic boxes. `Emerald Green' okra lost more weight in storage than the other four cultivars regardless of temperature or storage duration, while `Blondy' had the most decay. `Annie Oakley' and `Clemson Spineless' had better shelf life than the other cultivars.
Rapid Testing of Films for Modified Atmosphere Packages Using an Active Modification Technique
Authors: Gong Sannai , Corey Kenneth A.
Published: December 2018

It frequently takes days or weeks to determine if desired steady state concentrations of gases are reached in modified atmosphere packages of produce when atmospheres are modified by commodity respiration. We present a rapid method for testing packaging films and designs with active modification of atmospheres by vacuum and N2 infusion. Reduction of O2 concentration in produce packages and commodity tissues was completed within minutes by using several cycles of vacuum and N2 infusion treatments. Produce packages were placed in a desiccator and subjected to repeated partial vacuums, each followed by infusion of N2 to one atmosphere. Resulting O2 concentrations in packages (polyethylene + ethyl-vinyl acetate additive) were dependent on the extent of vacuum and the number of evacuations. Within packages of tomatoes, O2 concentrations of 8.3% ± 0.5% and 5.0% ± 1.0% were measured following two evacuations at 460 and 360 mm Hg, respectively. Three evacuations of cabbage and muskmelon packages at 460 mm Hg resulted in O2 concentrations of 5.1% ± 1.4% and 5.0% ± 1.4%, respectively. Maintenance or deviation from actively established atmospheres by the film was determined within hours.
Textural Changes of Asparagus in Relation to Delays in Cooling and Storage Conditions
Authors: Hernández-Rivera Luis , Mullen Robert , Cantwell Marita
Published: December 2018

Asparagus (Asparagus officinalis L.) spears (cv. UC 157) trimmed to 20 cm were cooled 0, 4, 8, 12, 16, and 20 hours after harvest and evaluated for resistance to shear at 5 and 10 cm above the cut end immediately after cooling and during storage at 0.5, 2.5, and 5C. Resistance to shear increased during cooling delays and with time in storage. Initial cooling delays and simulated marketing conditions (transfer to 15C for 1 day) were the principal causes of increased resistance to shear. A 4-hour cooling delay resulted in an average 40% increase in resistance to shear. Transfer to 15C for 1 day resulted in a greater increase in shear force in the rapidly cooled than in the delayed-cooled spears. Increases in resistance to shear during storage varied from 0% to 50% and depended on the storage temperature, time, and the initial cooling delay. Spears trimmed to a green base showed less increase in shear force after storage than did spears trimmed to a white base. The visual quality of asparagus stored for 14 days was similar (excellent) among spears from different storage temperatures and between green- and white-base spears. Storage quality after 24 days had decreased more in spears stored at 5C than at 2.5 or 0.5C, and more in the green-base than the white-base spears.
Management of Nitrogen and Calcium in Pear Trees for Enhancement of Fruit Resistance to Postharvest Decay
Authors: Sugar David , Righetti Timothy L. , Sanchez Enrique E. , Khemira Habib
Published: December 2018

Management of pear (Pyrus communis L.) trees for low N and high Ca content in the fruit reduced the severity of postharvest fungal decay. Application of N fertilizer 3 weeks before harvest supplied N for tree reserves and for flowers the following spring without increasing fruit N. Calcium chloride sprays during the growing season increased fruit Ca content. Nitrogen and Ca management appear to be additive factors in decay reduction. Fruit density and position in the tree canopy influenced their response to N fertilization. Nitrogen: Ca ratios were lower in fruit from the east quadrant and bottom third of trees and from the distal portion of branches. High fruit density was associated with low N: Ca ratios. Nutritional manipulations appear to be compatible with other methods of postharvest decay control.
An Effective System for Brushing Vegetable Transplants for Height Control
Authors: Baden Sherrod A. , Latimer Joyce G.
Published: December 2018

A brushing system for vegetable transplants that is adjustable, easy to use, and provides uniform brushing action was designed and constructed. Using this system, the height of several species and cultivars of vegetable transplants was reduced 15% to 50%. Quality and uniformity also were improved, and edge effects on growth were reduced.
High-temperature Inhibition of Seed Germination and Seedling Emergence of Broccoli
Authors: Elson Marshall K. , Morse Ronald D. , Wolf Dale D. , Vaughan David H.
Published: December 2018

High summer temperatures may reduce plant stands of direct-seeded fall broccoli (Brassica oleracea var. italica Plenck). The influence of constant and diurnally alternating temperatures in the range of 5 to 42C on germination and emergence of `Packman' broccoli was evaluated. Germination was defined as protrusion of the radicle from the seedcoat, and emergence as 10 mm elongation of the radicle. The range of constant temperatures from 10 to 30C for 14 days was satisfactory for 90% germination and 75% emergence. However, alternating temperatures extended the acceptable emergence range to 5/17 through 20/32C. Since soil temperatures in warm climates often exceed 20/32C during the summer, high-temperature inhibition of seed germination and seedling emergence is a potentially important factor limiting direct-seeded broccoli stands.
Freeze Survival Survey of 21 Palm Species in New Orleans and Vicinity
Authors: Doughty Severn C. , Gill Daniel J. , Blouin David C.
Published: December 2018

Landscape palms were surveyed for cold damage 8 to 10 months after the coldest weather episode recorded this century in the New Orleans, La., area. Fourteen genera and 21 species of palms totaling 9039 individuals were surveyed and assigned to one of three condition categories within six geographic areas. Area 1, north of Lake Pontchartrain, was not a reliable area for the majority of the 21 species found. South of Lake Pontchartrain, areas 2-6 were considered statistically better for overall palm survival, with area 3 best followed by areas 4, 2, 5, and 6. Although species survival depended somewhat on area, 10 species were found to be statistically reliable south of Lake Pontchartrain: Brahea armata, Chamaedorea microspadix, Phoenix canariensis, Rhapidophyllum hystrix, Sabal mexicana, S. minor, S. palmetto, Sabal spp., Sabal spp. seedlings, and Trachycarpus fortune;. Two species, Phoenix reclinata and Phoenix spp., were found to be marginal and seven species were found to be unreliable: Butia capitata, Chamaerops humilis, Livistona chinensis, Rhapis excelsa, Syagrus romanzoffiana, Washingtonia filifera, and W. robusta. Due to low individual numbers, survival for three species could not be reliably estimated: Arenga engleri, Phoenix dactyfifera, and Serenoa repens.
Rapid Moisture Content Determination of Macadamia Nuts with an Electronic Moisture Meter
Authors: Tsang Marcel M.C. , Fujii Jack K.
Published: December 2018

An electronic moisture meter (Dole Model 400) was calibrated for rapid determination of moisture content of macadamia (Macadamia integrifolia Maiden and Betche) nuts. The meter was found suitable to measure the moisture content (from 9.5% to 21.5% on a wet-weight basis) of macadamia nuts with sufficient accuracy for routine use by farmers and processors. On average, the meter readings were about 0.21% ± 0.08% se lower compared to readings obtained from the standard forced-air oven technique. A moisture analysis with the meter required <5 minutes compared to 72 hours by conventional oven-drying.
Florida Vegetable Transplant Producers Survey, 1989-1990
Authors: Vavrina Charles S. , Summerhill William
Published: December 2018

Thirty-four operators produced > 1.15 billion vegetable transplants in Florida in the 1989-90 season. Sales, concentrated in the winter and spring, were estimated at $30 million. Firms in the industry also made additional sales of ornamental and agronomic plants. Nine large firms accounted for 88% of all transplants produced. More than 109 acres (44 ha) of greenhouse area are allocated to containerized vegetable production. The majority (83%) of Florida s vegetable transplants were from three crops--tomatoes (45%), peppers (28%), and cabbage (10%). Only 36% of the transplants produced in the state were shipped out-of-state. This report discusses various facets of production, marketing, labor, and general business conditions of the containerized vegetable transplant industry.
Turf Nutrient Leaching and Best Management Practices in Florida
Authors: Trenholm Laurie E. , Sartain Jerry B.
Published: December 2018

Best management practices (BMPs) for Florida's green industries have been established since 2002. BMPs for nonagricultural industries such as commercial lawn care were developed in 2002 by the Florida Department of Environmental Protection (FDEP), the University of Florida Institute of Food and Agricultural Sciences (UF/IFAS), and other parties. The BMP educational program, delivered primarily by UF/IFAS extension in partnership with the FDEP, began in 2003 as a voluntary program. As a result of increasing concerns regarding lawn fertilization and potential harmful effects on ground and surface waters, several local governments throughout the state require commercial fertilizer applicators to have a certificate of completion in a BMP educational program. The BMP program emphasizes appropriate fertilization practices to reduce nonpoint source pollution, including proper rates, timings, and application of fertilizers. Research done on fate of fertilizer applied to turfgrass demonstrates that a properly maintained lawn provides an effective means for uptake of nutrients. Some of the factors that have been shown through research to increase the opportunity for nutrient leaching include nitrogen (N) application at higher than recommended rates, excess rainfall after fertilization, and fertilization at a time when turf is not actively growing. Research results vary regarding N source and the difference in nitrate leaching resulting from N source. To provide concise research-based information for lawmakers and elected officials in Florida, there is currently a large research project underway to further quantify nutrient leaching under a variety of circumstances. Results of this research should form the basis for future regulations regarding fertilizer applications.
Effect of El Niño–Southern Oscillation on the Number of Leaching Rain Events in Florida and Implications on Nutrient Management for Tomato
Authors: Fraisse Clyde W. , Hu Zhengjun , Simonne Eric H.
Published: December 2018

Most of the winter vegetable production in the southeastern United States is located in Florida. High-value vegetable crops are grown under intensive fertilization and irrigation management practices using drip, overhead, or seepage irrigation systems. Rainfall events may raise the water table in fields irrigated by seepage irrigation resulting in leaching of nutrients when the level is lowered to remove excess water. The objective of this study was to assess the effect of El Niño–Southern Oscillation (ENSO) phases on rainfall distribution and leaching rain occurrences during the fall, winter, and spring tomato (Solanum lycopersicum) growing seasons using long-term weather records available for main producing areas. Differences in fall growing season mean precipitation during El Niño, La Niña, and neutral years were found to be nonsignificant. Winter and spring mean precipitations during El Niño, La Niña, and neutral years were found to be significantly different. Winter and spring average rainfall amounts during La Niña and neutral years were lower than during El Niño years. During El Niño years, at least one leaching rainfall event of 1.0 inch or more in 1 day occurred at all locations and all planting seasons and two of these events occurred in more than 9 of 10 years except during the winter and spring planting seasons at the Tamiami Trail station located in Miami–Dade County. During the fall growing season of El Niño years, three to four 1.0 inch or more in 1-day leaching rainfalls may be expected at least 4 of 5 years at all locations. In the case of larger leaching rainfall events (3.0 inches or more recorded in 3 days or 4.0 inches or more recorded in 7 days), the probability of having at least one event was mostly less than 0.80. Based on these results, nitrogen fertilizer supplemental applications of 30 to 120 lb/acre could be applied during the fall growing season of all ENSO phases and during all planting seasons of El Niño years. Using current fertilizer prices, one supplemental fertilizer application of 30 lb/acre nitrogen and 16.6 lb/acre potassium costs $55/acre. Assuming a median wholesale price of $12 per 25-lb box, this additional cost may be offset by a modest yield increase of 4.6 boxes/acre (compared with a typical 2500 25-lb box/acre marketable yield). These results suggest that ENSO phases could be used to predict supplemental fertilizer needs for tomato, but adjustments to local weather conditions may be needed.
Use of Irrigation Technologies for Vegetable Crops in Florida
Authors: Dukes Michael D. , Zotarelli Lincoln , Morgan Kelly T.
Published: December 2018

Major horticultural crops in Florida are vegetables, small fruit, melons, and tree fruit crops. Approximately half of the agricultural area and nearly all of the horticultural crop land is irrigated. Irrigation systems include low-volume microirrigation, sprinkler systems, and subsurface irrigation. The present review was divided into two papers, in which the first part focuses on vegetable crop irrigation and the second part focuses on fruit tree crop irrigation. This first part also provides an overview of irrigation methods used in Florida. Factors affecting irrigation efficiency and uniformity such as design and maintenance are discussed. A wide range of soil moisture sensors (e.g., tensiometers, granular matrix, and capacitance) are currently being used in the state for soil moisture monitoring. Current examples of scheduling tools and automated control systems being used on selected crops in Florida are provided. Research data on the effect of irrigation scheduling and fertigation on nutrient movement, particularly nitrate, are reviewed. Concluding this review is a discussion of potential for adoption of irrigation scheduling and control systems for vegetable crops by Florida growers and future research priorities.
Seed Coating and Seeding Rate Effects on Turfgrass Germination and Establishment
Authors: Leinauer Bernd , Serena Matteo , Singh Devesh
Published: December 2018

A field experiment was conducted at New Mexico State University to investigate the effect of seeding rates and ZEBA polymer [starch-g-poly (2-propenamide-co-propenoic acid) potassium salt] seed coating on the germination and establishment of warm- and cool-season grasses, and cool-season blends and mixtures. Grasses were established at recommended and reduced (50% of recommended) seeding rates with coated and uncoated seeds under two irrigation regimes (98% and 56% reference evapotranspiration). With the exception of ‘Bengal’ creeping bentgrass (Agrostis stolonifera), the polymer coating did not improve germination of the turfgrasses tested 22 days after seeding (DAS). However, at the end of the establishment period (92 DAS), plots established with ‘Bengal’, Dunes Mix [mixture of ‘Hardtop’ hard fescue (Festuca longifolia), ‘Baron’ kentucky bluegrass (Poa pratensis), ‘Barok’ sheep fescue (Festuca ovina)], ‘Panama’ bermudagrass (Cynodon dactylon), and Turf Sense™ [mixture of ‘Baronie’ kentucky bluegrass, ‘Barlennium’ perennial ryegrass (Lolium perenne), and ‘Barcampsia’ tufted hairgrass (Deschampsia cespitosa)] achieved greater coverage (based on visual estimations) when coated seed was used compared with uncoated seed. Establishment was greater for ‘Bengal’, Dunes Mix, ‘Panama’, Turf Sense™, and Turf Saver™ [blend of ‘Barlexas II’, ‘Barrington’, and ‘Labarinth’ tall fescue (Festuca arundinacea)] when normal seeding rates were applied compared with reduced seeding rates. ‘Barleria’ crested hairgrass (Koeleria macrantha) plots did not establish, regardless of the treatments applied. Results showed that seed coating has the potential to improve establishment at recommended and reduced seeding rates and can compensate for less favorable conditions such as reduced irrigation, reduced seeding rate, or for a combination of both. At the end of the establishment period, not all grasses achieved coverage greater than 50%. Further research over a longer establishment period is needed to determine if coated seed can be beneficial in achieving full coverage.
Graduate Student Use of Campus Green Spaces and the Impact on Their Perceptions of Quality of Life
Authors: McFarland A.L. , Waliczek T.M. , Zajicek J.M.
Published: December 2018

Students' perception of their overall academic experience and the campus environment is related to academic accomplishment, and research has found that the designed environment of the university can influence the degree of stress students may feel. Past research found that undergraduate student use of campus green spaces and perceptions of quality of life were related to each other. The main objective of this study was to investigate the relationship between graduate student use of campus green spaces and their perceptions of quality of life at a university in Texas. A total of 347 of 3279 (≈10%) of the graduate student body received e-mails with information regarding the incentive for participation and instructions on accessing an on-line survey. The survey included questions that related to student use of campus green spaces, overall quality of life statements, an instrument to measure the quality of life of university students, and demographic questions. A total of 79 (22.8% response rate) graduate student questionnaires were collected and analyzed to compare perceptions of quality of life of university students and the level of individual usage of campus green spaces. Descriptive statistics determined that, unlike undergraduates who were primarily “high users” of campus green spaces, graduate students were about equally split between being “low,” “medium,” and “high users” of campus green spaces. However, graduate students still ranked their quality of life highly. Finally, this study found that, unlike undergraduates, graduate students did not have a statistically significant relationship between green-user scores and perception of quality of life scores. It may be that graduate students have less time to spend in outdoor spaces, yet still meet their quality of life needs through other means such as academic achievements.
Diagnostic Nutrient Testing
Authors: Mylavarapu R.S.
Published: December 2018

Recommendations made for nutrient applications have traditionally focused on economic yield and quality. However, present-day testing procedures and recommendations are required to simultaneously ensure economical and environmental sustainability of agricultural production systems. A soil test is a calibrated index relating crop response to applied nutrients. Any application rate devoid of an economical response in yield or quality is deemed unnecessary. Therefore, a soil test becomes the first step in any nutrient best management practice (BMP) development, implementation, and monitoring activity. Certain significant areas in Florida, such as calcareous soils, require development of calibrated soil tests rather urgently. Nutrient sufficiency of perennial crops and deficiency diagnostics can be gauged through in-season plant tissue testing. Nutrient delivery for correcting the deficiency through foliar sprays is not always effective, and may require multiple applications. Spectral reflectance methods show significant promise as an alternative to traditional wet chemistry analyses with regard to ease, costs, and speed with wider range of applications, including natural resources. Additional research is needed to develop this technology for field-scale applications. Current research is focusing on environmental nutrient management to include nutrient sources, application rates and timing, nutrient uptake efficiency, retention capacity of soils, estimating and minimizing nutrient losses to the environment, etc. Nutrient loss assessments tools such as the Florida phosphorus (P) index and bahia (Paspalum notatum) and citrus (Citrus spp.) tests for P are now being made possible in Florida through integration of soil and tissue testing methods. Development and improvements of such analytical methods and tools specific to Florida to include other nutrients, heavy metals, soil capacity, and ecosensitive regions, is vital to ensure sustainability to the state's tourism, agriculture, and urban-rural balance.
Vegetative Growth Responses of Citrus Nursery Trees to Various Growth Retardants
Authors: Roux Smit le , Barry Graham H.
Published: December 2018

As part of a larger study to improve rind color of citrus (Citrus spp.) fruit, this initial study was conducted to determine the concentration of various gibberellin-biosynthesis inhibitors required to elicit a biological response in citrus trees, as measured by vegetative growth. Paclobutrazol and GA3 were included as control treatments at concentrations known to elicit growth-retarding or growth-promoting effects, respectively. Repeated (×4) foliar applications of GA3 (at 64 ppm) increased growth of ‘Eureka’ lemon (Citrus limon) shoots by 63%, with no significant effect on rootstock and scion diameters. Repeated foliar applications of prohexadione-calcium (ProCa) at various concentrations (100, 200, 400, or 800 ppm) as well as uniconazole (at 500 or 1000 ppm) and paclobutrazol (at 0.25%) had no effect on rootstock or scion diameters 8 months after the first application. The high concentrations of ProCa (800 ppm) and uniconazole (1000 ppm), and the paclobutrazol treatment (0.25%) reduced shoot length compared with the control. Uniconazole at 1000 ppm resulted in the most growth retardation, which resulted in 34% shorter shoot length than the control. Although the number of nodes on the longest shoot did not differ from the untreated control, internode length differed significantly among treatments. ProCa at 400 and 800 ppm, uniconazole at 1000 ppm, and paclobutrazol at 0.25% significantly reduced internode length relative to the control by 31%, 56%, 50%, and 28%, respectively. Vegetative growth of ‘Eureka’ lemon nursery trees was retarded following the repeated (×4) foliar application of gibberellin-biosynthesis inhibitors. ProCa at 400 to 800 ppm and uniconazole at 1000 ppm were identified as prospective treatments for further field studies to test their effects on rind color enhancement of citrus fruit.
The Effects of Colored Plastic Mulches and Row Covers on the Growth and Yield of Okra
Authors: Gordon Garry G. , Foshee Wheeler G. , Reed Stewart T. , Brown James E. , Vinson Edgar L.
Published: December 2018

Okra (Abelmoschus esculentus ‘Clemson Spineless’) was grown on an Orangeburg sandy loam soil in Shorter, AL. Okra was direct-seeded in single rows. Treatments consisted of five mulch colors: black, white, red, silver, and blue installed either with or without spun-bonded row cover. Soil temperatures were 4 to 7 °C lower than air temperatures in all treatments. The use of darker (black, blue, red) -colored plastic mulches increased early and total yield of okra compared with bare soil with and without row cover. Increased soil and air temperatures did not always correlate to an increase in yield. It can be concluded that the use of dark plastic mulch is advantageous to growers of okra in climates that do not have cool springs, but the added use of row covers to plastic mulch has no effect on growth and yield. The profit of marketable okra produced using a row cover was $1.37 versus $1.35 per pound without a cover in 2003 and $1.28 versus $1.29 per pound in 2004. Blue plastic mulch is ≈$0.08 per foot more expensive than black plastic. Our data do not show an economic advantage for blue over black mulch for okra, but the positive effect cited by other authors may be more pronounced with leafy vegetables.
Precise Placement and Variable Rate Fertilizer Application Technologies for Horticultural Crops
Authors: Schumann Arnold W.
Published: December 2018

Fertilizer spreaders capable of variable rate application are increasingly important for enhancing nutrient management in horticultural crops because they improve placement and increase nutrient uptake efficiency. Matching applied fertilizer to fertilizer requirements represents a significant input cost saving for the grower and a reduction in potential pollutant loading to ground and surface water. Variable rate fertilization (VRF) is a precision agriculture technology made possible by embedded high-speed computers, accurate Global Positioning System (GPS) receivers, Geographic Information Systems (GIS), remote sensing, yield or soil maps, actuators, and electronic sensors capable of measuring and even forecasting crop properties in real time. For tree crops like Florida citrus (Citrus spp.), the most important function of the VRF spreader is to detect and avoid fertilizing spaces of the orchard not occupied by trees. Treeless spaces are becoming more common in Florida as diseases such as citrus greening (Candidatus Liberibacter asiaticus) and canker (Xanthomonas axonopodis) cause the removal of thousands of trees every year. VRF works best under those conditions. Because VRF exploits crop and soil variability, it has no value in a perfectly uniform field. VRF enables smaller trees including resets to be fertilized at lower, most appropriate rates, thus minimizing any excess application. This article examines the existing knowledge on using precision agriculture and variable rate technology to keep water and nutrients in the root zone of horticultural crops, thus facilitating maximum uptake efficiency.
Use of Irrigation Technologies for Citrus Trees in Florida
Authors: Morgan Kelly T. , Zotarelli Lincoln , Dukes Michael D.
Published: December 2018

Florida is the most important center of processed citrus (Citrus spp.) production in the United States, and all of the crop is irrigated. Irrigation systems include low-volume microirrigation, sprinkler systems, and subsurface irrigation. This review details the relative irrigation efficiencies and factors affecting irrigation uniformity such as design and maintenance. A wide range of soil moisture sensors (e.g., tensiometers, granular matrix, and capacitance) are currently being used for citrus in the state. The use of these sensors and crop evapotranspiration estimation using weather information from the Florida Automated Weather Network in irrigation scheduling are discussed. Current examples of scheduling tools and automated control systems being used on selected fruit crops in Florida are provided. Research data on the effect of irrigation scheduling, soluble fertilizer injection, and soil nutrient movement, particularly nitrate and the use of reclaimed water in Florida, are also reviewed. Concluding this review is a discussion of the potential for adoption of irrigation scheduling and control systems for citrus by Florida growers and future research priorities.