bluuebunny/crossref_metadata_2025 huggingface dataset:
The Effects of an After-school Garden Club for Fourth Graders Regarding Fruit and Vegetable Nutrition
Authors: O'Brien Suzanne A. , Shoemaker Candice A.
Published: February 2019

An eight-lesson gardening and nutrition curriculum with a hands-on gardening emphasis was taught as an after-school program to determine the effect it had on increasing children's nutrition knowledge, fruit and vegetable (F&V) preference, and improving children's self-efficacy (SE) and outcome expectations (OE) for gardening and for consuming fruit and vegetables. Seventeen fourth-grade students participated in the experimental group as part of an after-school gardening club, and 21 fourth-grade students served as the control group. Nutrition knowledge; F&V preference; SE; OE; as well as demographic measures were obtained at baseline and end-program. There were no differences in nutrition knowledge scores between or within groups at baseline or at end-program. However, baseline scores were high (>7 out of 10 possible) for both groups. Both groups indicated a high preference for fruit at baseline and end-program. Vegetable preference did not increase over the course of the program for either group. At baseline, measurements of gardening SE and OE were significantly different between the groups, and during the length of the study the control group significantly increased in their gardening SE and OE while the experimental group maintained their high SE and OE for gardening. Some possible explanations for these unexpected findings could be recruitment effect and seasonal change. Further research to clarify which aspects of gardening (i.e., season, harvesting, crops grown) have the greatest impact on influencing preference, SE and OE of fourth-grade children is needed.
Service-learning Horticulture Students Benefit through Hands-on Science Activities with Elementary School Students
Authors: Motsenbocker Carl , Smith Leanna
Published: February 2019

A garden-based science curriculum (Junior Master Gardener) was introduced into public elementary schools as an informal education program conducted by Master Gardener volunteers and service-learning university students. The program was held once a week for 2 hours during regular school hours with fifth grade classes. The service-learning students were enrolled in a senior level horticultural science education class. Students were surveyed pre- and post-program with the Science Teacher Efficacy Belief Instrument (STEBI-B, preservice), a background survey instrument, and weekly journals. There were significant differences in the students' perceived teaching efficacy pre- and post-program. Most of the student's STEBI scores either remained the same or increased over the semester. Overall, the service-learning college students had very positive responses to their experiences as teachers and mentors in public elementary schools. In addition, the students were able to use their horticultural skills and knowledge and they also gained an appreciation for the teaching profession.
Children's Garden in Residence Program at the Minnesota Landscape Arboretum
Authors: Kenny Tim , Hoover Emily
Published: February 2019

The Minnesota Landscape Arboretum has been educating urban youth in a garden setting through the Children's Garden in Residence program located in Minneapolis, Minn., for 20 years. The program partners with community groups to teach pre-K to 4th grade students about the wonders of science and nature. The program presently educates between 100 and 120 children each summer. In addition to serving more children, the program curriculum and activities have evolved through the years, developing, trying, redesigning, and trying again curricula to meet the needs of urban children. The result of this process is a program that emphasizes hands-on, garden-based lessons in science, nutrition, and art. We are in the process of documenting the curricula used in the program. This paper will discuss the history of the program, highlight a few units used at the different grade levels, and discuss the documentation process.
The Project Green Reach Summer Program at Brooklyn Botanic Garden: A Case Study
Authors: Conlon Susan L. , Hamilton S. L.
Published: February 2019

Project Green Reach (PGR) is a part of the Children's Gardening Program at Brooklyn Botanic Garden (BBG), a public garden regarded as a model program for garden-based youth education. PGR utilizes the indoor classroom and outdoor laboratory to engage K-8 students and teachers at Brooklyn's Title I schools in informal science learning. Every year, PGR instructors accept a group of students into the summer program where they work in teams on garden projects at BBG. Students who participate in this program often come from challenging home and school environments. Anecdotal evidence reveals that after participating in the summer program, these students quickly develop improved confidence and academic skills, evolving into scientists and gardeners. The purpose of this study is to investigate the effects of a gardening program on inner city youth and to document the PGR summer program as a potential model for informal science youth education in the public garden forum. Field observations of PGR summer program participants and program document collection were conducted during the 2004 Summer Program. This was followed by interviews of adult PGR Summer Program alumni and former staff who discussed their experiences while participating in the program and described the meaning of PGR in their lives. Preliminary results have revealed the positive impact PGR has had on participants' lives, indicating that PGR affected their childhood development, relationships with family members and friends, and their views on BBG, gardening, and science. Findings from the in-depth analysis of the interviews, observations and document review will be presented.
Brooklyn Botanic Garden Children's Gardening Program: A Survey of Alumni
Authors: Smith Emily K. , Hamilton S. L.
Published: February 2019

Children's gardening programs are growing in popularity. Among public gardens, Brooklyn Botanic Garden (BBG) hosts the oldest children's gardening program in the United States. Founded in 1914, the Brooklyn Botanic Garden Children's Gardening Program (BBG CGP) has succeeded in involving a steady flow of children year after year, creating an environment where children have the opportunity to interact with nature. Over 35,000 children have participated in the BBG CGP since its inception in 1914. A mail survey was conducted of alumni of the BBG CGP to identify how the program has affected their adult lives. A random sample of 700 participants was selected from the BBG CGP alumni records. The survey consisted of five major sections: 1) current gardening interest; 2) involvement with public gardens; 3) current involvement with children's gardening programs; 4) childhood experiences in the BBG CGP; and 5) demographic variables. Preliminary results suggest that the participants' childhood development and learning skills gained from this program have played an important role in their adult lives and that they regard the BBG CGP as having great value in their lives. Additional results and impacts of the program will be presented.
A Survey of Horticulture Graduate Programs and Faculty Salaries at North American Universities
Authors: Arnold Michael A. , Davis Tim D. , Reed David W.
Published: February 2019

Surveys were sent to 53 North American universities offering horticulture curricula to characterize the types of degrees offered, student demographics, participation in distance education, remuneration and assistance available for graduate students, and faculty rank and salary distributions. Twenty-five institutions responded. This represented 10 PhD, 14 MS, and 12 M. Agr. or MS non-thesis professional degree programs in horticulture and 13 PhD, 13 MS, 12 M. Agr. or M. non-thesis degree programs in plant sciences or a closely related area. On average, graduate students were predominantly Caucasian (70.7%), followed by Asian (16.1%), Black (3.2%), Hispanic (2.6%), and Native American (0.2%). Most were supported by research assistantships (56.3%), with the second largest group being self-supported (13.8%). Teaching assistantships were a small source of support (4.6%). Stipends (12-month equivalent) where variable among fellowships ($2000 to $30,000), teaching ($6600 to $25,000), research ($2000 to $25,239), extension ($12,000 to $17,000), or combination assistantships ($900 to $26,000). Most assistantships included a stipend plus in-state and out-of-state tuition waivers: about half included medical insurance. Mean full-time in-state tuition and fees was $6,535, while out-of-state was $13,876. Participation in distance courses was greatest for non-degree students (18.3%), and low for all others (9.2% to 6.4%). The average academic unit had 15.1 professors, 8.9 associate professors, 6.8 assistant professors, 0.3 senior lecturers, and 1.6 lecturers with mean reported average salaries of $85,142; $70,132; $58,918; $55,608; and $37,887, respectively.
The Pros and Cons of Migrating Classes to the Web: Are We Getting What We Truly Want from This Effort?
Authors: McKenney Cynthia B. , Peffley Ellen B.
Published: February 2019

Proponents of distance education encourage the migration of courses and entire degree programs onto the web. To this end, vast amounts of time, energy, and funds are directed to the development of new courses as well as the enhancement of traditionally taught courses. The question now begs to be asked, “Are we getting what we truly want from distance education?” Using a web platform provides a framework with excellent options to develop audio and visually rich courses. Distance programs also provide access to students not able to participate in traditional on-campus degree plans, providing the potential for a boost in enrollment. However, there are serious considerations that need to be balanced, including student satisfaction/dissatisfaction, enrollment management, faculty time commitment, and technical support. In this presentation, some of the benefits and liabilities of web courses will be discussed and program management suggestions will be explored.
A New Horticultural Science Distance Education Graduate Certificate Program
Authors: Sanders Douglas C. , Osborne Dennis J. , Peet Mary M. , Dole John M. , Kornegay Julia L.
Published: February 2019

Many potential students, because of distance from the university campus and/or job requirements, cannot take traditional courses on-campus. This group of learners is “place-bound”—a group of learners who may be employed full-time, most likely married with job responsibilities and/or other situations demanding most of their attention. The Horticultural Science Department and Graduate School at N.C. State University are addressing place-bound limitations in several ways, including the creation and offering of a Graduate Certificate Program in Horticultural Science via distance education (DE). By using DE, high demand, low-seat-available classes can offer additional enrollment for credit. Second, courses can be offered asynchronously or with alternative delivery methods. Also, courses offered collaboratively among institutions can generate a level of interest and enthusiasm that may not exist for “home-grown” courses. Such efforts as these promise to help meet continuing education demands of “non-traditional” students. These include Cooperative Extension's more than 120 Horticultural Crops Extension Agents (“field faculty”) and over 300 other field faculty whose interests include horticultural topics.
CSI Manhattan: Using the Theme of a Popular Television Series to Enhance Student Learning Beyond the Lecture Hall
Authors: Schroeder Kenneth R. , Schroeder Janet E.
Published: February 2019

According to brain-based learning theory, learning is enhanced by challenge and inhibited by threat. Effective learning occurs when students are immersed in the educational experience, challenged yet not threatened, and encouraged to actively process information. All of these components are part of simulation or role-play games. With these basic concepts in mind, we approached the challenge of enhancing student learning in a plant identification course taught in a large class setting. Considering that plant identification requires some basic detective skills, and the popularity of criminal investigation television programming, we designed a role-play exercise involving case files, investigation zones, and detective teams. As a spin-off from the television shows “CSI: Crime Scene Investigation” and “CSI: Miami,” the exercise was coined “CSI: Manhattan, Conifer Site Investigation in Manhattan, Kansas.” It was designed to fit into a 50-minute class period. Throughout the exercise, detective teams (students) needed to collectively locate and identify plants based on previous knowledge and clues within the case files and at the sites. Upon completion, plant specimens were checked in and identification logs discussed in order to provide immediate feedback and reinforcement of learning. Students enjoyed the exercise, offering positive feedback and conversations about the exercise throughout the balance of the semester. Six months later, while walking past one of the investigation sites, students remembered the site, exercises performed, and the plant name. The exercise includes both interactive and experiential learning components. This session will discuss the “CSI” exercise and its value in linking action to information.
Market of Colored Bell Peppers and an Estimated Profitability for the Production in Greenhouses in Florida
Authors: Jovicich Elio , VanSickle John J. , Cantliffe Daniel J. , Stoffella Peter J.
Published: February 2019

The uninterrupted supply of high quality colored peppers to the U.S. is mainly from imports of greenhouse-grown fruits. Average year-round wholesale market price of these imports was $4.80/kg when U.S. field-grown fruit price was $1.60/kg for colored and $0.91/kg for green. High market prices and a suitable environment for growing colored peppers in inexpensive protected structures led to construction of 25 ha of greenhouses currently growing peppers in Florida. Greater demand for specialty vegetable crops, loss of methyl bromide, and an increase in urban sprawl and price of arable land may result in growers considering greenhouses to produce high value peppers. We estimated the profitability of a greenhouse enterprise with a budget analysis and calculated the returns to capital and management. We assumed use of current technology applied in commercial greenhouse crops in Florida, and in experimental crops at the Univ. of Florida. Revenues per square meter were estimated from current yields and historical fruit price data. Plants were grown in perlite in a high-roof polyethylene-covered greenhouse (0.78 ha) located in north central Florida. Transplanting occurred in August and fruits were harvested from November to May for a yield of 13 kg·m-2 with a total cost of production of $41.09 and an estimated return of $17.89. The return on investment was 17%. Only yields greater than 7.8 kg·m-2 generated positive returns using the average wholesale fruit price during the season ($5.29/kg). For this price, a range of possible yields (5–17 kg·m-2) led to returns ranging from $–9.52 to $30.84, respectively. The estimates indicated that production of greenhouse-grown peppers could represent a viable production alternative for Florida vegetable growers.
Consumer Preference among Three Cold-climate Strawberry Production Systems
Authors: Stevens Matthew D. , Abbott Judith A. , Lea-Cox John D. , Black Brent L.
Published: February 2019

Three cold-climate strawberry production systems, conventional matted row, advanced matted row, and cold-climate annual hill plasticulture, were compared for consumer preference in a pick-your-own (PYO) setting. Replicated 6 × 15 m plots were established in 2002 in Maryland and cropped in 2003 and 2004. To simulate PYO marketing, volunteers were recruited to harvest 3.6-m plots in each of the three production systems and to complete a five-part questionnaire. The questionnaire collected demographic information and allowed volunteers to compare the three systems both prior to and after their harvesting experience. Harvests were carried out twice weekly, with 75 participants in 2003 and 45 participants in 2004. The 2003 season was cool and wet, with frequent rainfall and a high incidence of fruit rot. Spring 2004 was unseasonably hot, resulting in an unusually short harvest season. Consumer preference differed between years and among harvests within a season. The annual hill system was favored early in the 2003 season, with preference shifting to the other systems as the season progressed. The advanced matted row was favored early in the 2004 season. Many of the participants' comments, both positive and negative, were directed at the plastic mulch and raised beds. In several cases, participants indicated that their preferences after picking from each system did not match their initial impressions. Implications of this research to the social components of sustainability will be discussed.
The Changing Face of the American Gardener
Authors: Dennis Jennifer H. , Behe Bridget K.
Published: February 2019

As the diversity of the American population increases, so should efforts to understand gardening behavior of different subcultures. Businesses need this information to effectively target these consumer groups, and improve their level of product satisfaction. An Internet study of gardening activities was conduced in Sept. 2004, with a sample of 1591 individuals, but over sampled for African-, Hispanic-, and Asian-Americans. Results showed many differences in the purchases, enjoyment, expenditures, and product satisfaction for these groups compared to the Caucasian sample. More Caucasians had mowed their own lawn in the year prior to the study (60.2%) than African-Americans (47.1%), Hispanics (50.4%), or Asians (50.5%). More Caucasians (58.2%) had participated in flower gardening than African-Americans (33.5%) or Hispanics (44.1%), but similar to the percentage of Asian-Americans (50.9%). However, a similarly high percentage of Asians had participated in fruit, vegetable, or herb gardening (33.8%), compared to Caucasians (33.5%). Both groups participated in fruit, vegetable, or herb gardening more than African-Americans (16.3%) or Hispanics (26.7%). Hispanic gardeners spent 7.3 hours in the garden on average each week, compared to 6.7 hours for Caucasians, 6.5 for Asians, and 4.7 for African-Americans. Yet, Hispanic (3.8) and Asian (3.8) gardeners rated their level of outdoor gardening enjoyment (7-point Likert scale) higher than African-Americans (3.1) but lower than for Caucasians (4.0). This first glimpse of non-Caucasian gardeners shows businesses should target these groups for specific gardening products and may have some extra work to do to improve their level of satisfaction and enjoyment.
Improving the On-farm Productivity and Supply of Capers to Processors in Morocco
Authors: Rahmani Mohamed , Humpal Donald S.
Published: February 2019

Morocco is the world's leading caper producer. Its export position has declined as worldwide production increases. Farm gate prices have declined as market prices have diminished. A joint program among the Moroccan Federation of Food Processors (FICOPAM), the Institut Agronomique et Veterinaire Hassan II (IAV Hassan II), and DAI was supported by USAID to examine how to improve industry competitiveness. Field surveys and workshops with farmers, buyers, and processors in Morocco's three main caper growing regions were used to inform a national conference to arrive at a consensus action plan. The plan focuses on a shift from weight-based to grade-based buying practices. Supporting changes were identified to modify on-farm practice; equip and regulate buying floors at major markets; institute minimum traceability requirements; and establish HACCP programs for caper processors in collaboration with Moroccan export authorities. Training programs to support these changes were completed with farmers and extension personnel in 2004.
Onion Seed Quality
Authors: Taylor Alan G.
Published: February 2019

High seed quality is required to obtain optimal plant stands and to achieve maximum yield potential. Onion seeds are commonly coated and treated with an insecticide and fungicide to control early season insects and diseases. The seed treatments may cause phytotoxicity in standard germination tests, and thus reduce the percent germination of a seed lot. The objective of this study was to examine the effect of seed quality on seed storage, stand establishment and yield. Two seed lots of two long-day onion varieties were pelleted and treated with the seed treatments Trigard and Pro-Gro. Standard germination and saturated salt aging tests were performed on each seed lot, indicating a high and lower quality seed lot for each variety. Aging was conducted by equilibrating pelleted seeds at 35% relative humidity and aging at 25 °C for up to 12 months. Aging decreased germination with time, especially for the lower quality lots. Field studies were conducted in two locations in upstate New York. The plant stand was greater in the high compared to the lower quality lots in both varieties at both locations. Yield was reduced in the lower quality than high quality lot; however, the response differed by variety and location. Overall, the initial seed quality had an impact on seed storagability, stand establishment and yield.
Evaluation of Chill Models in `Bing' Sweet Cherry Rest-breaking Trials in California from 1994 to the Present: Validation of the Dynamic Model
Authors: Glozer Kitren , Grant Joseph A. , Coates William W.
Published: February 2019

Moderate California winters often result in delayed, erratic or extended bloom, inadequate overlap with pollenizers, poor leafing-out, low fruit set, and irregular fruit maturity. In recent years, use of rest-breaking agents has become commonplace in California sweet cherry (Prunus avium L.) culture, mainly to promote earlier bloom and fruit maturity, but also to promote uniform flowering and overcome lack of marginal chilling. Variable responses by different cultivars and in different seasons may be due to different chilling requirements, despite little variation in genetic background for chill requirement in California's commercial cultivars. Other sources of variation include the activity of the rest-breaking agent used, concentration and carrier volume. A minimum amount of effective chill appears to be required for a given cultivar before rest-breaking agents can be effectively applied. This threshold, as exhibited by degree of response to treatment, can be an important indicator of when to spray. Method of measuring chill accumulation, and thus, timing of applications, varies by region and historic acceptance. California's tree fruit industry typically uses the 45 °F “chill hour” model. The Utah Chill Unit Model and the Modified 45 °F Chill Hours Model had not been thoroughly tested under California conditions nor with the rest-breaking chemicals that are in use today in California. We tested our research results against these models and the Dynamic Model developed in Israel and concluded that the Dynamic Model provided the best explanation of responses in our experimental trials. We have been developing recommendations for application of rest-breaking chemicals based on Dynamic Model chill portion accumulation.
The Effect of Kaolin on Walnut (Juglans regia) Quality in California
Authors: Anderson Kathleen M. Kelley , King Mitchell
Published: February 2019

The effect of kaolin (Surround™) on walnut quality parameters, including edible yield, reflected light index, insect damage, off grade, price per pound, and the incidence and severity of sunburn, were evaluated over a 4-year period in `Vina' and `Chandler' walnut orchards. Results indicate that applications of kaolin significantly improved edible yield, reflected light index, price per pound, and the incidence and severity of sunburn in most orchards in most years. Improvements in these parameters were more consistent with the `Vina' cultivar. Off-grade was not significantly reduced by the use of kaolin. Codling moth damage levels were too low to detect in all orchards in all years.
Tomato Production in the Hot-wet Season using Grafting and Rainshelter Technology
Authors: Palada Manuel , Wu Deng Lin
Published: February 2019

Production of tomato (Lycopersicon esculentum) during the hot-wet season in the lowland humid tropics can be increased using grafted plants and rainshelter. This technology can reduce soil-borne diseases, improve the ability of tomato plants to tolerate high temperatures and flooding due to high rainfall, and protect the crop from the impact of heavy rains. AVRDC has developed tomato lines that are resistant to virus diseases and high temperatures. This experiment was conducted to evaluate the performance of these lines in the hot-wet season, with and without rainshelter protection. Tomato lines (CHT501, TLCV15, and FMTT847) were grafted onto eggplant (Solanum melongena cv. EG203) rootstock and grown under rainshelter and open field. Nongrafted plants of three lines were also grown under two rainshelter treatments. The experimental design was a split-plot with four replications. Plants were managed using AVRDC standard practices for summer tomato production. TLCV15 and FMTT847 were highly resistant to tomato leaf curl virus (ToLCV), whereas CHT501 was greatly infected by the virus disease. All nongrafted plants died from bacterial wilt, whereas grafted plants survived the disease and outyielded nongrafted plants by 233% in the open field and 143% under rainshelters. Plants under rainshelters had a slightly lower yield than in the open field, but the difference was nonsignificant. Due to lack of frequent high rainfall during the season, the benefit of rainshelter was not detected and realized. It was concluded that TLCV15 and FMTT847 are well suited for grafted tomato production during the hot-wet season.
Influence of Rainshelter and Irrigation Method on Yield, Water, and Fertilizer Use Efficiency of Chili Pepper
Authors: Palada Manuel , Wu Deng Lin
Published: February 2019

Chili pepper (Capsicumannuum cv. Delicacy) was grown in single- and double-bed rainshelters and irrigated using furrow and drip irrigation to determine effect on yield and efficiency of water and nutrient application in the lowland tropics of southern Taiwan during the hot wet season. The experiment was laid out using a split-plot design with four replications. The main plots were rainshelters (single, double, open field) and the two irrigation methods (furrow and drip) were the subplots. Grafted chili seedlings were transplanted in double rows on raised beds at row spacing of 80 cm and plant spacing of 50 cm. The furrow-irrigated crop was applied with basal N-P2O5-K2O at the rate of 180–180–180 kg·ha-1 and 240–150–180 kg·ha-1 of N-P2O5-K2O as sidedressing. The drip-irrigated crop received half of the total rate applied for the furrow-irrigated crop. Significant differences (P < 0.05) in marketable yield were observed between rainshelter treatments. Highest yield (42.2 t·ha-1) was produced from the single-bed rainshelter, and crops grown under double-bed rainshelters produced the lowest marketable yield. Irrigation method did not significantly influence marketable yield, but crops grown under drip irrigation produced a higher yield than furrow-irrigated crops. Nutrient uptake by plants grown under drip irrigation was also higher (P < 0.05) than for furrow-irrigated crops. Water use efficiency was 60.7% higher in drip-irrigated plots. Results indicate that in high rainfall vegetable production areas, drip irrigation minimizes nutrient loss through leaching and maximizes efficiency of fertilizer use.
High Tunnels or a Poor Man's Greenhouse?
Authors: Lamont William , Orzolek Michael
Published: February 2019

After being interviewed by a newspaper reporter on high tunnels and explaining in great detail what a high tunnel is and how it is different from a greenhouse, you can guess my shock to read the headline “High Tunnels—A Poor Man's Greenhouse.” High tunnels do not offer the precision of conventional greenhouses for environmental control, but they do sufficiently modify the environment to enhance crop growth, yield, and quality and provide some frost protection, but their primary function is to elevate temperatures a few degrees each day over a period of several weeks. In addition to temperature control, there are benefits of wind and rain protection, soil warming, aid in control of insects, diseases, varmints, and birds. They are relatively inexpensive, about $1.30/sq. ft., excluding labor. This system is particularly appealing to new-entry growers with limited capital who utilize retail-marketing channels. High tunnels like plastic-covered greenhouses are generally quonset-shaped with a peak, constructed of metal bows that are attached to metal posts, which have been driven into the ground about 2 feet deep. They are covered with one layer of 6-mil greenhouse-grade polyethylene, and are ventilated by manually rolling up the sides each morning and rolling them down in early evening. There is no permanent heating system, although it is advisable to have a standby portable propane unit to protect against unexpected below-freezing temperatures. There are no electrical connections. The only external connection is a water supply for trickle irrigation.
Influence of Preharvest AVG Application on the Activity of Sorbitol Dehydrogenase in Apple Fruit
Authors: Sigal-Escalada Valeria , Archbold Douglas D.
Published: February 2019

Sorbitol dehydrogenase (SDH) is a key enzyme in apple fruit converting sorbitol into fructose. SDH activity in `Fuji' apple was reported to increase close to harvest, perhaps as part of the ripening process. Aminoethoxyvinylglycine (AVG) is used to delay fruit ripening and prevent fruit drop, though its effect on sorbitol metabolism is not known. To determine if the late season increase in SDH activity is common among apple cultivars and if AVG use affects SDH expression and activity, AVG was applied to `Lodi', `Redchief Delicious', and `Red Fuji' trees 4 weeks before harvest. Control and AVG-treated fruit were collected 1 week prior to, at, and 1 week after the normal harvest date for assessment of ethylene production over time after harvest and SDH presence and activity at harvest. Ethylene production in control fruit increased after harvest and AVG reduced it in all cultivars. `Redchief Delicious' fruit had the highest ethylene production of the treated samples. The levels of SDH activity in controls were similar across dates for `Redchief Delicious' and showed no consistent pattern in the other cultivars. `Redchief Delicious' and `Red Fuji' showed the highest and lowest levels of SDH activity, respectively. AVG did not affect SDH activity in `Redchief Delicious', and substantially increased SDH activity in `Red Fuji' on each of the three harvest dates, and, in `Lodi', only 1 week after normal harvest. SDH presence was confirmed through immunoblotting for all cultivars and harvest dates. Overall, fruit with the greatest reduction in ethylene production in response to AVG also showed changes in SDH activity.
Synergistic Effects of the Combined Application of MCP and Low O2 on Apple Fruit Ripening
Authors: Asif Mehar , Trivedi Prabodh , Solomos Theophanes , Mattoo Autar
Published: February 2019

We have studied the effects of MCP and low O2, applied singly and in combination, on apple fruit ripening at 1, 7, and 18 °C. The single application of 2 ppm MCP is more effective in delaying the onset of the C2H4 climacteric than is 1% O2. However, the combined application has a much larger effect than the single applications of either MCP or 1% O2. For instance, at 7 °C, the onset of the C2H4 climacteric occurs at 15, 50, and 90–95 days for the controls, 1% O2 and 2 ppm MCP, respectively, whereas the combined application of 2 ppm MCP and 1% O2 suppressed the initiation of the C2H4 climacteric for 200 days, the duration of the experiment. The retardation of the climacteric onset by the treatments is associated with the suppression of ACC-synthase (ACS1) and the putative receptor ERS1. The accumulation of their transcripts is critically dependent on the rate of C2H4 evolution. As expected, the combined application of MCP and 1% O2 completely suppressed the expression of both genes. Yet when the fruits were transferred to 18 °C in air, they ripened normally. A similar pattern of inhibition in response to the above treatments was also observed with a C2H4-dependent MAPK. The expression of ETR1, ETR2 and ACC-oxidase was not affected by the treatments. The nature of this strong effect of the combined application of MCP and low O2 is not clear. It should be pointed out that MCP does not inhibit the induction of hypoxic proteins such as ADH.
Apple Scald Development and Regulation
Authors: Solomos Theo , Trivedi Prabodh , Asif Mehar
Published: February 2019

We have studied scald development by comparing changes in gene expression, C2H4 evolution, and α-farnesene and conjugated trienol contents in scald-resistant cultivars, i.e., `Gala' and `Braeburn', and scald-sensitive cultivars, i.e., `Red Delicious' and `Granny Smith'. We also carried out similar comparisons between controls and treatments that diminished scald symptoms in sensitive cultivars. The data show that scald development is critically dependent on the initiation of the climacteric rise in C2H4 evolution, since treatments that suppress the latter inhibit scald development at low temperatures coincident with a suppression of α-farnesene and conjugated trienols. However, in scald-resistant cultivars, there is an increase in α-farnesene and conjugated trienols, although to a lower degree than in the sensitive cultivars. This indicates that factors other than the auto-oxidation of α-farnesene are also involved in scald development. Analytical data show that malonyl dialdehyde (MDA) increases only in scalded areas, which, in turn, suggests that oxidative reactions are involved in scald development. Storage of `Granny Smith' at temperatures above 7 °C prevents the development of scald without affecting the accumulation of α-farnesene and conjugated trienols. This in turn suggests that chilling temperatures induce as yet unknown enzymes that contribute to scald development. In short, the data show that in addition to cultivars, low temperature stress and the induction of the C2H4 climacteric play a crucial role in scald development. Preliminary data show that treatment of `Granny Smith' apples with olive oil emulsions suppress scald development symptoms.
Diphenylamine and Diphenylamine Derivative Content of `Granny Smith' Peel: Influence of Ethylene Action and Regular or Controlled Atmosphere Storage Duration
Authors: Rudell David , Mattheis James , Fellman John
Published: February 2019

Diphenylamine (DPA) is used for superficial scald control in apple fruit. A number of DPA derivatives resulting from C-nitration, C-hydroxylation, O-methylation, and N-nitrosation can be present in DPA-treated apple fruit after storage. The presence of the compounds may be indicative of metabolic processes that lead to scald development. Therefore, apple peel DPA and DPA derivative content in fruit treated at harvest with DPA or DPA plus 1-methylcyclopropene (1-MCP) was assayed upon removal of fruit from controlled atmosphere (CA) and regular atmosphere (RA) storage and during a 14-d post-storage ripening period. Apples were also treated at harvest with different concentrations of DPA and assayed after 6 months CA storage to confirm recovery of DPA and DPA derivatives is linear over a wide concentration range. Harvest maturity notably affected peel DPA and 4-hydroxydiphenylamine (4OHDPA) content. Post-storage ripening, 1-MCP treatment, and CA storage had varied affects on DPA derivative content, suggesting reactive oxygen or nitrogen species, such as •OH, •NO, and •NO2, or enzyme catalyzed reactions may be generated during ripening and senescence related physiological processes. Consistent correlations between scald incidence and content of specific derivatives were not observed.
BiofumigationwithMuscodoralbus Pads for Controlling Decay in Commercial Table Grape Cartons
Authors: Mercier Julien , Walgenbach Paul , Jiménez Jorge I.
Published: February 2019

The volatile-producing fungus Muscodoralbus is being developed as a biological fumigant for postharvest use, as it can kill storage pathogens and control fungal decay in various commodities. A wettable pad or sachet system made of teabag paper containing desiccated rye grain culture of M. albus was designed for the biofumigation of individual fruit containers. The fungus is reactivated before use by a brief immersion of the pad in water. This research was conducted to determine the potential of the pad system for controlling decay of table grapes in commercial cartons. Individual pads containing 24 or 86 g of grain culture (to achieve a 1:10 ratio of fumigant to box volume or a 1:100 ratio of fumigant to fruit weight, respectively) were added to Styrofoam cartons containing 8.6 kg of freshly harvested `Thompson Seedless' (TS) or `Ruby Seedless' (RS) grapes, which were then placed in cold storage at –1 to 0 °C. Control cartons exposed to SO2 were placed in a separate storage room and SO2 fumigation was performed once for TS and weekly for RS. After 8 to 9 weeks, the grapes were taken out of storage and rated for decay. In the experiment with TS, the 24-g and 86-g pads provided significant control of gray mold rot when compared to untreated cartons and were not statistically different from cartons exposed to a single SO2 fumigation. In the experiment with RS, only the 86-g pads provided significant decay control. Measurements of the three most abundant volatile compounds in empty cartons containing 10 g of the biofumigant revealed that partial coverage of holes mimicking obstruction by packed fruit achieved levels of isobutyl alcohol, 2-methyl-1-butanol, and isobutyric acid of 0.7, 1.6, and 11.2 ppb, respectively.
Smart Fresh™ in Combination with Film Coatings Reduces Sugar Spots and Extends “Yellow Life” of Bananas
Authors: Siller-Cepeda Jorge , Baez-Sañudo Manuel , Contreras-Martinez Rosalba , Contreras-Angulo Laura , Velez Rosabel , Muy-Rangel Dolores
Published: February 2019

Banana fruits `Cavendish' type were obtained from a warehouse at color green stage. At arrival, fruits were taken out of boxes, dipped into a thiabendazole solution for 5 minutes, dried at room temperature and separated into three lots. One lot was sprayed with Fresh Seal™ (FS) at 3 °Brix, a second lot was treated with Semper Fresh™ (SF) at 1.2%, and the third was left as a control. After that, all fruits were packed again inside the plastic bags within the original carton boxes. Film-coated and control fruits were ethylene treated for 24 hours at 150 ppm, and vented for 24 hours until they reached color 3 (more green than yellow). After that, film-coated and control fruit boxes were collected inside 238-L airtight containers to apply Smartfresh™ (SMF) treatments at 0 and 300 ppb for 12 hours at 22 °C, complementing six different treatments. Later, fruits were stored at 22 °C and 80% to 90% relative humidity for 5 days to follow up changes. Quality evaluations were registered every day, including weight loss, firmness, color, CO2, ethylene, pH, titratable acidity, °Brix, and sugar spots. SF alone and the combinations SF + SMF and FS + SMF reduced weight loss as compared with the other treatments. SMF alone or in combination with FS or SF maintained higher firmness and delayed yellow color development as compared with the other treatments. Combinations of SF or FS with SMF delayed and reduced the incidence of sugar spots as compared with control fruits. Chemical characteristics were not significantly affected by the treatments, but SF + SMF had higher acidity and a lower pH. All treatments reached between 20 and 21 °Brix after 5 days. The data show that combined treatments of SMF and film coatings reduce sugar spot incidence, improving appearance and extending yellow life of fruits.
Developing a Tree Fruit Code [Prunus persica (Batch.)] for Cultivars According to Their Organoleptic Characteristics
Authors: Crisosto Carlos H. , Crisosto Gayle M. , Echeverria Gemma , Puy Jaume
Published: February 2019

Cultivar segregation according to their organoleptic perception was attempted by using trained panel data evaluated by principal component analysis in four sources of 24 peach and 27 nectarine cultivars as a part of our program to develop minimum quality indexes. Source significantly affected cultivar ripe soluble solids concentration (RSSC) and ripe titratable acidity (RTA), but it did not significantly affect sensory perception of flavor, sourness and aroma by the trained panel. On two out of 51 cultivars tested, source played a role on sweetness perception. In all of these cases, when source fell out of the proposed cultivar organoleptic group it could be explained by fruit being harvested outside the commercial physiological maturity (immature or overmature). The perception of the four sensory attributes was reduced to three principal components that explain 92% for peach and 94% for nectarine of the variation in the sensory characteristics of the cultivars tested. Season did not affect significantly the classification of three cultivars that were evaluated during these two seasons. By plotting organoleptic characteristics in PC1 and PC2 (∼76%), cultivars were segregated into groups (balanced, robust, sweet, peach or nectarine aroma, and/or peach or nectarine flavor) with similar sensory attributes; nectarines were classified into five groups and peaches into four groups. Based on this information, we recommend that cultivars should be clustered in organoleptic groups and a development of a minimum quality index should be attempted within each organoleptic group rather than proposing a generic minimum quality index based on RSSC. This organoleptic cultivar classification will help to match ethnic preferences and enhance the current promotion and marketing programs.
The Implications of Temperature and Mesophyll Response Functions in a Biochemically-based Model of Photosynthesis: Effects on Whole Crown Carbon Exchange Estimates
Authors: Bauerle William L. , Wang G. Geoff , Rajaraman Nilakantan S. , Anantharamu Shruthi
Published: February 2019

The estimate of the photosynthetic response to temperature is important for accurate growth predictions in process-based models designed to respond to broad variation in environmental conditions. Several studies have attempted to decipher the temperature and mesophyll response functions for use in the widely used Farquhar et al. (1980) biochemically based photosynthesis model. Unfortunately, published values of Rubisco kinetic properties (Kc and Ko) differ among species. To compound the problem, the methodology used to estimate Kc and Ko has not been consistent. We compared the variation in carbon gain estimates of a whole tree by incorporating the different temperature parameter estimates of Bernacchi et al. (2001, 2003) and Medlyn et al. (2002) into a three-dimensional biological process-based model. In addition, we also investigated the contribution of mesophyll conductance by incorporating Rubisco enzyme kinetics parameters reported by Bernacchi et al. (2002). Temperature parameters substantially influenced our whole tree carbon gain estimates. The variation among model estimates of aboveground net carbon gain was ≈11% for 3-year-old red maple saplings. Variation was even greater when mesophyll conductance was incorporated. The different parameter estimates, if not validated at the whole plant scale, can introduce inaccuracies and exacerbate carbon gain estimates of single plants, stands of plants, and entire ecosystems.
Photosynthetic Response of Carrots to Varying Irradiances, CO2 Concentrations, Moisture, and Nutrition
Authors: Lada Rajasekaran R. , Pettipas F. Christine , Kyei-Boahen Steve , Gordon Robert , Astatkie Tess
Published: February 2019

Genotypes and environmental parameters interactively act on plants and modify their yield responses through modifying photosynthetic processes. In order to optimize yield, it is critical to understand the photosynthetic behavior of the crop as altered by genotypes and environment. Leaf gas exchange parameters of carrot (Daucus carota L.) cultivars Cascade, Carson, Oranza, and Red Core Chantenay (RCC) were examined in response to various irradiances, fertility levels, moisture regimes, and to elevated CO2 concentrations. Leaf net photosynthetic rate (PN), stomatal conductance (gs), and transpiration rate (E) were measured. Cultivars responded similarly to increasing PAR and CO2 concentrations and did not differ in photosynthetic parameters. Increasing PAR from 100 to 1000 μmol·m-2·s-1 increased PN, which did not reach saturation. The gs and E increased to a peak between 600 and 800 μmol·m-2·s-1, then rapidly declined, resulting in a sharp increase in water use efficiency (WUE). Increasing CO2 concentrations from 50 to 1050 μmol·mol-1 increased PN until saturation at 650 μmol·mol-1. The gs and E increased to a peak at 350 μmol·mol-1 and then declined. WUE increased linearly with increasing CO2. Carrots exposed to drought over a period of 5 days decreased PN and E. The PN decrease was cultivar specific. Nutrient concentrations of 0 to 400 ppm gave a similar pattern of decrease for PN, E, and gs. Treatment of 50 ppm had the highest PN, E, and gs. The WUE generally increased with increasing nutrient concentration.
Effect of Annual Defoliation on Yield, Juice Quality, Leaf Net Gas Exchange, Leaf Size, and Number in `Hamlin' and `Valencia' Orange Trees
Authors: Yuan Rongcai , Garcia-Sanchez Francisco , Alferez Fernando , Kostenyuk Igor , Singh Shila , Zhong Guangyan , Syvertsen James , Burns Jacqueline
Published: February 2019

The effect of annual defoliation over two consecutive years on fruit yield, juice quality, leaf size, and number was examined in 11-year-old `Hamlin' and 13-year-old `Valencia' orange [Citrus sinensis (L.) Osb.] trees. Removal of up to 50% of the leaves in late November had no effect on fruit number, fruit weight, fruit yield, soluble solids yield, juice °Brix, and °Brix: acid ratio of juice in `Hamlin' oranges. In `Valencia' oranges, removal of up to 50% of the leaves in late March also did not affect °Brix or the °Brix: acid ratio of the juice, but decreased fruit yield and soluble solids yield. Leaf size was reduced by removal of 50% of the leaves in both cultivars. Removal of up to 50% leaves in late November had no significant influence on net CO2 assimilation (aCO2) of the subsequent spring flush leaves in early May in `Hamlin' oranges, whereas aCO2 of `Valencia' spring flush leaves in early May increased linearly with increasing levels of defoliation in late March. The results indicate that fruit yield, fruit quality, leaf size, and number were not negatively impacted when annual defoliations did not exceed 25% of the total canopy leaf area for `Valencia' and `Hamlin' oranges for two consecutive years. Overall, in whole `Hamlin' or `Valencia' orange trees, fruit weight increased linearly with increasing ratio of leaf area to fruit, suggesting that fruit enlargement depends on available photosynthate and can be limited by leaf area.