bluuebunny/crossref_metadata_2025 huggingface dataset:
(338) Effect of Germanium Supply by Trunk Injection on Tree Growth and Fruit Quality of `Niitaka' Asian Pear (Pyrus pyrifolia)
Authors: Kim Wol-Soo , Jo Jung-An
Published: February 2019

Many trials to supply germanium to fruit have been carried out since tests have confirmed germanium's role as a medical substance. Supplying germanium in orchards by soil and foliar application was not effective because of loss from rainfall. In order to increase germanium absorption by fruit, this study carried out tree trunk injections during the growing season. Two types of germanium, GeO (inorganic type) and Ge-132 (organic type), in concentrations of 5, 10, 25, and 50 mg·L–1 were supplied to `Niitaka' pear trees by trunk injection (1.5 L/tree), four times at 15-day intervals from June 2004. The treatment with 50 mg·L–1 GeO showed decreased fruit weight, but 50 mg·L–1 Ge-132 showed no difference to the control and other treatments. Fruit lenticels were increased in size by all of the Ge treatments in comparison to control fruit. Soluble solids as well as Hunter value `a' of the fruits of all Ge treatments were higher than that of the control. Flesh browning after peeling the fruit was delayed by the germanium treatment, and polyphenoloxidase (PPO) activities were lowered. Postharvest potentials were maintained at high levels for fruit firmness, physiological disorders, and decayed fruit during cold storage at 0 to 1 °C for 2 months.
Fertility and Weed Management Effects on Crop Quality and Disease Variables in a Transitional-organic Processing Cabbage and Tomato System
Authors: Wszelaki Annette , Miller Sally , Doohan Douglas , Amisi Karen , McSpadden-Gardener Brian , Kleinhenz Matthew
Published: February 2019

The influence of organic soil amendments (unamended control, composted dairy manure, or raw dairy manure) and weed treatments [critical period (CP) or no seed threshold (NST)] on diseases, growth parameters, yield, and postharvest quality was evaluated over 3 years in a transitional organic crop rotation of tomato, cabbage, clover, and wheat. More growth, yield, and postharvest quality parameters were affected by amendment treatments in cabbage than in tomato. Significant differences in yield among amendment treatments were found in 2001 and 2003 in cabbage, with higher marketable and total yields in amended vs. control plots. Soil management effects on cabbage varied annually, though amendments were required to maximize crop growth, as head weight, size, and volume and core volume of treatment plots exceeded the control plots in 2002 and 2003. Few differences were found between weed treatments, although in 2001 cabbage heads from the NST treatment were larger than heads from the CP treatment. Similar results were found in tomato in 2003. Also, the CP treatment had a higher Area Under the Disease Progress Curve than the NST treatment in tomato in 2003. Overall, disease pressure was highest in tomato in 2001. But disease levels within years were mostly unaffected by amendment treatments. In cabbage, disease was more common in 2002 than in 2003, although head rot was more prevalent in compost-amended plots in 2003 than in manure-amended or control plots. Tomato postharvest quality parameters were similar among amendment and weed treatments within each year. Soil amendment may enhance crop yield and quality in a transitional-organic system. Also, weed management strategy can alter weed populations and perhaps disease levels.
Organic Vegetable Yield and Economics Show Promise in a Mississippi Trial
Authors: Evans William B. , Hood Kenneth W. , Paridon Keri L. , Hudson Peter M.
Published: February 2019

Yield, input, and economic data from research plots in central Mississippi are being used to test the economic potential of organic vegetable crop production. A six-part, multi-year rotation, including winter and summer cover crops, has been set up to generate yield, cost, and economic return data from vegetables produced in Mississippi using methods allowed by the U.S. Dept. of Agriculture National Organic Standards and accepted by local growers employing pesticide-free and other similar management methods. Data being collected include labor and input costs, yields, and market prices for harvested crops. Marketable produce is being sold through a grower-retailer at a farmer's market. During 2004, the first full year of the rotation, 10 vegetable species were included in the plots. Pest pressure has generally been minimal. With one exception [one of two potato (Solanum tuberosum) cultivars failed to produce a good stand], all crops planted have produced fair to excellent yields. Crops generating high retail prices in this study include potatoes, snap beans (Phaseolus vulgaris), and leaf lettuce (Lactuca sativa). In the future, the yield and price data being generated will be combined with new and existing cost data to create enterprise and production budgets for use by perspective and existing organic vegetable growers.
Organic Transition Strategies for Vegetable Farms Near Urban Areas
Authors: Kleinhenz Matthew D. , Walker Sonia , Cardina John , Batte Marvin , Grewal Parwinder , McSpadden-Gardener Brian , Miller Sally , Stinner Deborah
Published: February 2019

The risk: reward for a transition to organic vegetable farming near urban areas and changes in soil, crop, and economic parameters during transition are poorly understood. A 4-year study was initiated in 2003 at the Ohio State Univ.–OARDC to document the relative advantages of four transition strategies and their effects on major cropping system variables. Soil previously in a vegetable-agronomic crop rotation has been maintained fallow, planted to a mixed-species hay, used in open field vegetable production, or used in vegetable production under high tunnels, transition strategies with a range of management intensity and expected financial return. Each strategy was replicated four times within the overall experimental area. Half of the soil in each strategy unit was amended with composted dairy manure while the remaining soil was unamended. Field vegetable plots have been planted to potato, butternut squash, and green bean. High tunnels have been planted to potato, zucchini, and a fall–spring rotation of beet, swiss chard, mixed lettuce, radish, and spinach. Data describing the outcomes of the strategies in terms of farm economics, crop yield and quality, weed ecology, plant pest and disease levels, and soil characteristics (physical, chemical, biological) have been recorded. Inputs in the high tunnels have exceeded inputs in all other strategies; however, high tunnel production has widened planting and harvesting windows and increased potato yield, relative to open field production. To date, compost application has increased crop yield 30% to 230% and influenced crop quality, based on analytical and human panelist measures. Weed (emerged seedlings, seedbank) and nematode populations also continue to vary among the transition strategies.
Growth of Young`Minneola' Tangelo Citrus Trees Fertilized with Banded Poultry Litter Overlaid with Wood Chips
Authors: Ferguson James , Ziegler Michael , Hebb Jack
Published: February 2019

Soil incorporation of poultry litter can damage roots of citrus trees grown on shallow soils in southern Florida. Using an alternative application method, young `Minneola' tangelo trees (Citrus reticulata Blanco × C. paradisi Macf.) on Cleopatra mandarin rootstock (C. reticulata Blanco) on bedded groves in southeast Florida were fertilized for 18 months after planting with surface-banded poultry litter (PL) overlaid with wood chips (WC). PL/WC was applied at 142, 284, and 425 kg·ha-1 N in two applications/year in one 0.6-m band within the dripline of trees planted at 278 trees/ha. Other treatments with different N rates included 220 kg·ha-1 N broadcast in the middle of the bed twice a year and 116 kg·ha-1 N as controlled release fertilizer applied within the dripline of trees in three applications per year. Eighteen months after planting, growth of trees receiving PL/WC treatments of 142, 284, and 425 kg·ha-1 N per year and 116 kg·ha-1 N per year was similar and greater than growth of trees receiving PL broadcast in grove middles at 220 kg·ha-1 N per year. Soil P, Ca, and Mg levels beneath the three banded PL/WC treatments were higher than in other treatments; in all treatments leaf N levels were optimum, but leaf P, K, Ca, Mg, and Fe levels were excessive. Banded PL/WC treatments applied at 142 kg·ha-1 N per year and even lower rates may be adequate for growth of young citrus trees, especially in terms of reducing excessive soil and leaf nutrient levels.
Determination of Crop Coefficients (Kc) and Water Use of Spinach and Onion
Authors: Piccinni Giovanni , Leskovar Daniel I. , Marek Thomas
Published: February 2019

Lysimeters are used to measure real-time water use during the growing season. By relating the water use of a specific crop to a well-watered reference crop, such as alfalfa or grass, crop coefficients (Kc) can be developed to assist in predicting accurate crop needs using available meteorological data. Reference evapotranspiration can be obtained from several weather networks; however, without crop coefficients for specific crops, this information is only useful for grass. Three weighing lysimeters, consisting of undisturbed 1.5 m × 2.0 m area by 2.2-m depth cores of soil, comprise the Texas A&M Research and Extension Center–Uvalde lysimeter facility. Two lysimeters, weighing around 15,000 kg, have been placed beneath a linear LEPA irrigation system and used in field production. A third lysimeter measures reference ET values (ETo) and is located in a grassed area near the field lysimeters irrigated by subsurface drip irrigation system. Spinach was grown in one of the two crop lysimeters while onion was grown in the second lysimeter. Daily water use was measured on 5-min intervals. Results show the possibility of saving ≈61 to 74 million m3 of water per year in the irrigated farms of the Edwards aquifer region if proper irrigation management techniques are implemented in conjunction with the newly developed crop coefficients. Crop water requirements, Kc determination, and comparison to existing FAO Kc values will be discussed.
Coreopsis grandiflora `Sunray' Flowers in Response to Short Days or Vernalization
Authors: Padhye Sonali , Runkle Erik S. , Cameron Arthur
Published: February 2019

Coreopsis grandiflora `Sunray' has been reported to flower under long days (LD) following vernalization or short days (SD). The objectives of this study were to characterize the effective duration of vernalization and SD and to determine if photoperiod during vernalization influences flowering. Vegetative cuttings taken from stockplants developed from one seedling were rooted for 2 weeks and grown for 5 weeks. Plants were provided with a 9-hour photoperiod for 2, 4, 6, or 8 weeks or were vernalized at 5 °C under a 16-hour photoperiod for 2, 4, 6 or 8 weeks or under a 9-hour photoperiod for 2 or 8 weeks. Following treatments, plants were grown in a greenhouse at 20 °C under a 16-hour photoperiod. Control plants were grown under constant 9- or 16-hour photoperiod. Leaf development, days to first visible bud (DVB), days to first open flower (DFLW), and height and total number of flower buds at FLW were recorded. No plants flowered under continuous SD. Under continuous LD, two plants flowered on axillary shoots but only after 95 days. All vernalized and SD-treated plants flowered on both terminal and axillary shoots. Photoperiod during vernalization did not affect subsequent flowering. DFLW decreased from 56 to 42 and from 50 to 42 after 2 to 8 weeks of vernalization and SD treatments, respectively. Following 2, 4, 6, and 8 weeks of vernalization, plants had 116, 116, 132, and 204 flower buds, respectively. Plant height at FLW of all SD-treated and vernalized plants was similar. Thus, 2 weeks of 9-hour SD or vernalization at 5 °C followed by LD was sufficient for flowering of our clone of C.`Sunray', although longer durations hastened flowering and increased flower bud number.
Novel Impatiens Genotype with Improved Resistance to Western Flower Thrips Feeding
Authors: Warnock Daniel F.
Published: February 2019

When breeding floriculture plants, one must have a targeted phenotype and genotype in mind before the initial cross-pollination event is performed. In the case of the floriculture breeding program at the University of Illinois, our initial goal was to develop a commercially acceptable, yet novel, Impatienswallerana(bedding plant impatiens) phenotype with improved resistance to the western flower thrips, Franklinella occidentalis, a significant insect pest in production greenhouses. This study describes the process used to obtain a large impatiens phenotype (>61 cm tall and >125 cm wide) with acceptable branching, leaf color, flower size, flower number, flower display, and flower colors with improved resistance to western flower thrips. A reliable and simple evaluation technique, based on the number of leaves expressing western flower thrips feeding damage after inoculation, was developed and utilized to create more resistant impatiens genotypes based on generation means. Using a 1 to 9 scale, mean damage ratings for the original germplasm populations 1, 2, and 3 were 5.18, 6.02, and 6.11, respectively, with the trend for populations 1, 2, and 3 skewed toward susceptible plants. Germplasm with novel phenotypes were derived from crosses with plants in populations 1 and 3 with commercial cultivars. These novel phenotypes had improved levels of resistance with a mean rating of 5.06 and a normal shaped distribution. The potential for improving resistance to western flower thrips feeding exists within available germplasm and the tools necessary for proper evaluations are available.
Freezing Tolerance of Saltgrass (Distichlis spicata) Ecotypes
Authors: Rukavina Hrvoje , Hughes Harrison , Qian Yaling
Published: February 2019

Efforts are ongoing at Colorado State University to develop turf-type saltgrass cultivars. Prior freezing studies have indicated variation in freezing tolerance in saltgrass lines. Therefore, this study was made to examine relative freezing tolerance of 27 saltgrass clones as related to collection sites in three zones of cold hardiness. Furthermore, these lines were evaluated for fall color retention with the intent to determine if there is a correlation with fall color and freezing tolerance. Saltgrass rhizomes were sampled in mid-winter 2004 from lines established in Fort Collins, Colo., and then subjected to a laboratory-freezing test. Saltgrass freezing tolerance was highly influenced by climate zones of clones' origin (P < 0.01) and genotypes within zones (P < 0.01). There was a high negative correlation between color retention in the fall and freezing tolerance (P < 0.01). Average freezing tolerance of saltgrass clones within zones of origin significantly differed among zones. Ranking of zones for least square mean LT50 (OC) was: zone 4 (–17.2) < zone 5 (-14.4) < zone 6 (–11.1). LT50 values in zone 4 ranged from –17.8 (accession 72) to –17.0 (accession 87). Clones in zone 5 showed LT50 values from –17.8 (accession A29) to –11.9 (accession A137). Zone 6 clones had LT50 values that ranged from –9.5 (accession C92) to –12.6 (accession C12). Large intraspecific variation in freezing tolerance may be effectively used in new cold hardy cultivar development. Environmental adaptation inherited by origin of clone is useful in defining clones' adaptation range and may along with fall color retention serve as a selection criterion in saltgrass cold hardiness improvement.
Papaya(Caricapapaya) Transplant Growth and Quality as Affected by Nitrogen and a Soil-applied Seaweed Extract
Authors: Morales-Payan J. Pablo , Stall William M.
Published: February 2019

Experiments were conducted to assess the effects of rate combinations of nitrogen (N) and a soil-applied biostimulant based on seaweed (Ascophyllum nodosum) extract (SSE) on the growth of papaya seedlings for transplant production. Seedlings were grown in 180-mL Styrofoam containers filled with a sphagnum/vermiculite/perlite growing medium. N (0 to 2 g per plant) and SSE (drench, 0 to 1 mL per plant) were applied at sowing and 15 days after emergence. N and SSE rates affected overall growth as well as time to attain adequate size for transplanting. In general, increasing N rates resulted in increased growth, and adding SSE enhanced N effects. In terms of increasing overall transplant growth and decreasing the time required from emergence to adequate transplanting size, the best results were found at the highest N and SSE rates.
Lemon Cultivar Selection Trials in Arizona
Authors: Wright Glenn C.
Published: February 2019

Two lemon [Citrus limon (L.) Burm.] cultivar selection trials are being conducted at the Yuma Mesa Agriculture Center in Somerton, Ariz. Some selections in these trials include: `Allen Eureka', `Berna', `Cook Eureka', `Cascade Eureka', `Cavers Lisbon', `Strong Lisbon', `Femminello Comune', `Lapithkiotiki', `Limoneira 8A Lisbon', `Limonero Fino 49', `Monroe Lisbon', `Primofiori', `Santa Teresa', `Walker Lisbon', and `Villafranca'. Selections that have had superior yields include `Cascade Eureka', `Cook Eureka', `Strong Lisbon', `Limoneira 8A Lisbon', `Limonero Fino 49', `Primofiori', `Femminello Comune', and `Villafranca'. Fruit size data suggest that `Limonero Fino 49' has consistently good fruit size, and consistently larger fruit than `Limoneira 8A', the industry standard. `Cavers Lisbon' and `Femminello Comune' also have good fruit size. `Lapithkiotiki' also had large fruit size, but its shape was unacceptably elongated. We also found significant differences in peel thickness and juice pH among the selections. `Santa Teresa' had significantly lower juice pH and a thinner peel than some of the other selections under evaluation.
A Marketing Feasibility Study of Incorporating Worm Castings into a Substrate Mix for Home Gardening
Authors: Kaiser Kris-Ann E. , Williams Patrick N.
Published: February 2019

Ferry-Morse Seed Company is trying to market worm castings to their customers. Murray State University was asked to compare different percentages of worm castings for use with both bedding plants/vegetables and houseplants. Recommended application rates for worm castings was not to exceed 30%. Two plants were chosen to represent the plant categories deemed important to the consumer: tomato (Lycopersicon esculentum `Rutgers') and spider plant (Chlorophytum comosum). Treatment percentages for worm castings were 0% for a control and 10%, 20%, and 30% were incorporated into a soilless media substrate. Treatment 1 consisted of worm castings/soilless media alone and Treatment 2 consisted of worm castings/soilless media with the addition of Peters Professional All-Purpose 20–20–20 fertilizer at 100 ppm nitrogen. Tomatoes were grown from seed and the spider plant propagules were harvested from greenhouse stock plants and sized into small, medium, and large depending on weight. Tomatoes were harvested at 6 weeks and spider plants at 10 weeks. All tomatoes in Treatment 1 had poor visual consumer quality. Visual quality for Treatment 2 tomatoes was best in 20% and 30%. No significant differences were found in Treatment 1 regarding shoot and root weights. Treatment 2 showed significant differences in dry and fresh weight between the control and 20% and 30%. There were visual quality differences with spider plants in Treatment 2 and also significant differences in shoot and root weights between control and all percentages of worm castings in Treatment 2. Based on plant performances, a recommendation to Ferry-Morse Seed Company was to market worm castings in conjunction with a regular fertilizer schedule for maximum plant quality.
Gardening in the Zone: Educational Programming using Mass Media Outlets
Authors: VanDerZanden Ann Marie , Haynes Cynthia
Published: February 2019

The 2004 report from the National Gardening Association showed that 84 million people (78% of the U.S. population) participated in one or more types of do-it-yourself lawn and garden activities. This creates a substantial consumer group, and an important audience for Cooperative Extension to reach with educational programming. In 2003, a collaborative project between the Iowa State University (ISU) Extension Service, a regional gardening magazine, and regional television stations began as a new avenue to deliver educational programming related to horticulture. Gardening in the Zone is a series of 35 two-minute segments that are broadcast weekly March through October during local morning and evening news programs. Currently, the segments are shown on television stations across the state, resulting in over 95% coverage and reaching viewers in southwestern Wisconsin, northwest Illinois, southern Minnesota, and eastern Nebraska. In just 1 year, the number of stations carrying the segments has doubled. The segments are hosted by a broadcast professional and done in a question and answer format with an introduction, content on the particular topic, and a close. To close the segment the host refers viewers to the ISU Extension Gardening in the Zone website (http://129.186.89.193/gardening/) and the magazine website, which appear on the screen. This format provides a minimum of three potential contacts with the viewer including the real time broadcast, reference to the website, and ultimately, links to Extension publications from the website. These segments provide research-based information to a large audience that traditional Extension programming methods might not otherwise reach.
Molecular Marker Development and High Throughput with Microarrays using Diversity Array Technology (DArT)
Authors: Stevens Mikel R. , Chrisensen Shawn A. , Marshall Ammon B. , Stevens JoLynn J. , Wenzl Peter , Hunter Eric , Carling Jason , Killian Andrzej
Published: February 2019

Recently, a technology known as DArT (diversity array technology) has been developed to increase throughput in marker assisted selection (MAS). DArT utilizes microarray technology as a method to potentially compare thousands of molecular markers in one test to a single DNA sample. We used DArT on two sets of interspecific tomato [Solanum lycopersicum (Fla 7613) × S. pennellii (LA 716 or LA 2963)] segregating populations (BC, F2, and F1). We compared over 300 segregating plants to 3840 random tomato genomic fragments. After the 3840 markers were prepared, it took about 2 weeks of laboratory time to perform the experiments. With experience, this time can be reduced. We identified a total of 654 polymorphic markers usable for developing a DArT tomato genetic map. Depending on the particular cross, 13 to 17 linkage groups were identified (LOD 3) per population. Most recently, the amplified polymorphic DNA (AFLP) technique has been used for rapid genetic mapping of large numbers of anonymous genomic fragments. Besides the additional effort and reagents using AFLPs compared to DArT, a desired AFLP polymorphic band is often difficult to clone and process into a PCR based marker, whereas in DArT all markers are already cloned and immediately available for such experiments. A drawback to DArT is that it requires specialized software and equipment and is technically demanding. However, once the equipment and software are secured, techniques are optimized, and segregating populations developed, marker throughput is increased by orders of magnitude. Although challenging, the application of DArT can dramatically increase MAS throughput, thus facilitating quantitative trait and saturated mapping research.
Influence of Honey Bee Pollination on Triploid Watermelon Fruit Set and Quality
Authors: Walters S. Alan
Published: February 2019

Cucurbit vegetable crops, such as watermelon (Citrullus lanatus), require insect pollination for fruit set, which is usually achieved by placing honey bee (Apismellifera) colonies in a field or relying upon natural bee populations. Pistillate (or female) watermelon flowers require multiple honey bee (or other bee) visitations after visiting staminate (or male) flowers for fruit set, and pollination is even more of a concern in triploid watermelon production since staminate flowers contain mostly nonviable pollen. Six honey bee visitation treatments, 1) no visitation control, 2) two visits, 3) four visits, 4) eight visits, 5) 16 visits, and 6) open-pollinated control, were evaluated to determine the effect of honey bee pollination on `Millionaire' triploid watermelon fruit set, yield, and quality utilizing `Crimson Sweet' at a 33% pollinizer frequency. No differences (P> 0.05) between honey bee pollination treatments were observed for `Millionaire' quality characters (hollow heart disorder or percent soluble solids). The lowest pistillate flower abortion rate (20%) and subsequently the greatest triploid watermelon yields (fruit numbers and weights per hectare) occurred with the openpollinated control compared to all other honey bee visitation treatments. Fruit abortion rates decreased linearly, while fruit numbers and weights per hectare increased linearly as number of honey bee visits to pistillate flowers increased from 0 (no visit control) to the open-pollinated control (≈24 visits). This study indicated that >16 honey bee visits are required to achieve maximum triploid watermelon fruit set and yields, which is twice the number of honey bee visits required by diploid watermelons to achieve similar results.
QTL Associated with Day-neutrality in Strawberry
Authors: Weebadde Cholani K. , Hancock James F.
Published: February 2019

While it is of great significance for strawberry breeders to know the genetics of day-neutrality (DN), evidence for inheritance of the trait is still contradictory. A linkage mapping approach is being used to determine how many QTL regulate DN and the proportion of the variability explained by each. A preliminary genetic linkage map was constructed for 125 individuals of the day neutra× short day (SD) cross `Tribute' × `Honeoye' using single dose restriction fragments (SDRFs) of amplified fragment length polymorphic (AFLP) markers. Over 500 SDRFs from 55 AFLP primer combinations were used to build the map using the software tool Join Map 3.0 at a LOD score of 3.0. Single marker analysis using WinQTL cartographer software previously determined 27 SDRF markers to co-segregate with DN for 57 individuals of the mapping population phenotyped in the field for the years 2002 and 2003, indicating putative QTL for DN. These markers were included in the linkage analysis and seven of them mapped to five different linkage groups that may indicate the quantitative nature of the trait. For determining QTL and percentage of phenotype governed by each QTL, however, accurate phenotypic evaluation is critical. Therefore, controlled environment (growth chamber) studies were used to obtain flowering response data under SD and long day (LD) conditions with two day/night temperatures. This study was conducted for the entire mapping population (over 400 individuals) so that QTL detected can be confirmed by fine mapping the QTL regions. We will also test how robust the QTL detected are, by analyzing the same segregating population at six different field locations in the United States (California, Maryland, Michigan, Minnesota, New York, and Oregon) for their flowering response under SD and LD conditions.
Apple Root stocks and Pre-plant Soil Treatments Alter Soil Microbial Community Composition in a New York Orchard
Authors: Yao Shengrui , Merwin Ian A. , Thies Janice E.
Published: February 2019

Apple (Malu ×domestica) replant disease (ARD) is a soil-borne disease syndrome of complex etiology that occurs worldwide when establishing new orchards in old fruit-growing sites. Methyl bromide (MB) has been an effective soil fumigant to control ARD, but safer alternatives to MB are needed. We evaluated soil microbial communities, tree growth, and fruit yield for three pre-plant soil treatments (compost amendment, soil treatment with a broad-spectrum fumigant, and untreated controls), and five clonal rootstocks (M7, M26, CG6210, CG30, and G16), in an apple replant site at Ithaca, N.Y. Molecular fingerprinting (PCR-DGGE) techniques were used to study soil microbial community composition of root-zone soil of the different soil treatments and rootstocks. Tree caliper, shoot growth, and yield were measured annually from 2002–04. Among the five rootstocks we compared, trees on CG6210 had the most growth and yield, while trees on M26 had the least growth and yield. Soil treatments altered soil microbial communities during the year after pre-plant treatments, and each treatment was associated with distinct microbial groups in hierarchical cluster analyses. However, those differences among fungal and bacterial communities diminished during the second year after planting, and soil fungal communities equilibrated faster than bacterial communities. Pre-plant soil treatments altered bulk-soil microbial community composition, but those shifts in soil microbial communities had no obvious correlation with tree performance. Rootstock genotypes were the dominant factor in tree performance after 3 years of observations, and different rootstocks were associated with characteristic bacterial, pseudomonad, fungal, and oomycetes communities in root-zone soil.
Interdisciplinary Teaching: Taking the Fear out of the Unknown
Authors: Kamp-Glass Marihelen
Published: February 2019

If we want our students to engage in complex intellectual tasks to interrogate the insights of different disciplines, then let's join them in the task, modeling it and sharing the difficulties and richness of its possibilities. Interdisciplinary study is not rejection of the disciplines. It is firmly rooted in them, but offers a corrective to the dominance of disciplinary ways of knowing and speculation. We need the depth and focus of disciplinary ways of knowing, but we also need interdisciplinarity to broaden the context and establish links to other ways of constructing knowledge. It is this dialogue between analysis and synthesis that provides the creative tension from which we will all benefit in a world in which crossing intellectual boundaries is increasingly the norm.
Urban Residents Rate the Benefits of Trees in Cities Highly and Are Unconcerned with Problems Associated with Trees
Authors: Lohr Virginia I. , Pearson-Mims Caroline H.
Published: February 2019

In a survey, residents of the largest metropolitan areas in the continental United States rated the social, environmental, and practical benefits from trees in urban areas highly. They ranked the ability of trees to shade and cool surroundings highest. The potential of trees to help people feel calmer was ranked second highest. Survey respondents were not very concerned about potential problems with trees in cities, and felt that trees should be planted in cities regardless of any annoyance. Practical problems with trees, such as causing allergies, were bigger concerns than were financial issues. Responses varied slightly, based on childhood background and current demographic factors. For example, people who grew up with a garden near their home or actively worked with plants during childhood were more likely to appreciate the potential benefits of trees than were those who did not have such early experiences. People who strongly agreed that trees were important to their quality of life and those who did not strongly agree ranked the tree benefits and problems similarly, however. Those who strongly agreed that trees were important to their quality of life rated the benefits of trees more highly than people who did not strongly agree.
Enhancing Horticulture Students' Reasoning and Thinking Skills: Applying the Perry Theory to Horticulture
Authors: Lavis Catherine
Published: February 2019

This study explored students' cognitive complexity as defined by William Perry (1970) as influenced by teaching methods promoting active involvement at a higher level of interchange than traditional lecture. Two components of this research are: 1) an understanding of Perry's theory to serve as a guide for curricula development incorporating activities to influence intellectual growth by considering the student's current Perry positions in order to encourage upward movement according to Perry's Scheme; and 2) to investigate the reliability of using the student's Learning Environment Preference Inventory (LEP) (Moore, 1987) as a tool to understand the student's cognitive growth. The qualitative portion of this research examined cognitive complexity using the LEP instrument. LEP would give instructors an approximate idea of how to construct their courses to deliver information encouraging higher-order thinking. It is a mistake to assume students in upper division courses are all operating in upper Perry positions. It is difficult to make significant gains in intellectual development during one semester, but it is particularly challenging if instructors are unaware of where students are initially in respect to cognitive complexity. The utilization of a reliable instrument may also help explain some perplexing incidents that occur in classrooms. Instructors can be comforted knowing that what frequently transpires in a class might be motivated more by where students are in their cognitive development than by what is said or done by the instructor.
Comparison of Direct Seed versus Transplant Yield and Fruit Quality of Processing Tomatoes in the Southern Sacramento Valley
Authors: Miyao Gene M. , Bryant Dennis C. , Kochi Mark S. , Herrera Israel G.
Published: February 2019

Canning tomato transplants were compared to direct seed in field trials to evaluate fruit yield and quality. Trials were conducted either at the University of California at Davis Long Term Research on Sustainable Agriculture field facility or in a commercial direct-seeded tomato field near Woodland. To closely match harvest dates of both propagation methods, transplants were mechanically planted after direct-seeded plants approached the 2 to 3 true-leaf stage. Trial design was replicated, factorial with propagation method and with plant population comparisons. Populations were 8712, 6534, 5227, and 4356 planting units per acre. Direct-seeded plots were thinned to clumps of three plants centered on 12, 16, 20, or 24 inches between clumps within the seed line. Transplants were 6-week-old, commercial, greenhouse-grown plants that were mechanically planted to match the direct-seed spacing. Plant rows were single lines per bed centered on 5 feet. The entire 100-foot plot length was mechanically harvested into specially designed portable weigh trailers to measure yield. Fruit yield between direct-seed and transplants were similar in two of the 3 years. In one of the 3 years, production problems were encountered resulting in low overall yield, but significantly lower with the transplants. `Halley', a cultivar common in the region, was used in all of the test years. Transplant yields were slightly reduced linearly as spacing between plants increased while yield from direct seed was less affected. Fruit quality tended to be similar among the treatments.
Integration of Precision Agriculture and Systems Modeling in Pistachio
Authors: Rosenstock Todd , Brown Patrick
Published: February 2019

Alternate bearing exerts economic and environmental consequences through unfulfilled yield potential and fertilizer runoff, respectively. We will discuss a systematic biological–statistical modeling management integration approach to address the concert of mechanisms catalyzing alternate bearing. New engineering technologies (precision harvesting, spatially variable fertigation, and mathematical crop modeling) are enabling optimization of alternate bearing systems. Four years of harvest data have been collected, documenting yield per tree of an 80-acre orchard. These results have shown variability within orchard to range from 20–180 lbs per tree per year. Results indicate irregular patterns not directly correlated to previous yield, soil, or tissue nutrient levels, or pollen abundance. Nor does significant autocorrelation of high or low yields occur throughout the orchard, suggesting that genetically dissimilar rootstocks may have significant impact. The general division of high- and low-yielding halves of the orchard may infer a biotic incongruency in microclimates. This orchard does not display a traditional 1 year-on, 1 year-off cyclic pattern. Delineation of causal mechanisms and the ability to manage effectively for current demands will empower growers to evaluate their fertilization, irrigation, male: female ratio, site selection, and economic planning. In comparison to annual crops, the application of precision agriculture to tree crops is more complex and profitable. When applied in conjunction, the aforementioned methods will have the ability to forecast yields, isolate mechanisms of alternate bearing, selectively manage resources, locate superior individuals, and establish new paradigms for experimental designs in perennial tree crops.
Regionalizing Agent Training with the Greenhouse Tomato Short Course
Authors: Snyder Richard G. , Rowell A. Brent , Koske Thomas J. , Straw R. Allen
Published: February 2019

The protocol for agent training has always been for extension specialists to train agents within the same state in each aspect of agriculture. However, with ubiquitous cutbacks among universities, and extension in particular, it is no longer feasible for every state to provide expertise in each field. Consequently, agents cannot receive training in some specialized fields. With a partnership agreement from the USDA Risk Management Agency, the Greenhouse Tomato Short Course in Jackson, Miss., provided training for five to seven agents from each state in the region: Louisiana, Tennessee, Kentucky, and Mississippi. Funding was made available to cover travel expenses, registration, and a resource notebook for 25 agents. As a result, these agents took part in 3 days of intensive training seminars, as well as a 1-day tour of greenhouses. Invited speakers from around the United States spoke to these agents, as well as current and prospective commercial growers from all over the United States. Topics included basics of producing a commercial crop of hydroponic greenhouse tomatoes, budget for establishing and operating a greenhouse business, marketing and promotion, principles of risk management, pest and disease identification and management, grower's point of view, heating, cooling, and ventilation of greenhouses, new technologies, diagnostics, recent research in greenhouse production, and alternative crops (lettuce, peppers, mini-cucumbers, galia melons, baby squash) for the greenhouse. With this training, agents from throughout the south-central region returned to their offices with the skills to assist growers in their counties to succeed in the hydroponic greenhouse tomato business. Complete information on the short course can be found at www.greenhousetomatosc.com.
Citrus Shoot Age and Flowering Potential
Authors: Albrigo L. Gene
Published: February 2019

Three hurricanes in Florida starting in late Summer 2004 caused severe leaf loss, which stimulated many fall shoots. Flush occurred after each hurricane and by December, shoots were 6- to 12-weeks-old when cool temperatures capable of causing flower bud induction started. To evaluate the potential for these flushes to mature buds that could be induced to flower, flushes that were stimulated on potted trees in a greenhouse were allowed to mature 4, 6, 8, or 10 weeks before moving trees to flower-inducing conditions for 6 weeks (15 °C day/10 °C night). Plants were then returned to the greenhouse, which was kept at 20 °C or higher (ambient), until buds sprouted. Only 1% of sprouting buds on shoots that matured for 4 weeks had flowers. In shoots that matured for 6 weeks, 18% of sprouting buds had flowers. After 8 weeks of growth, 57% of the buds that sprouted were flower buds, while after allowing 10 weeks for shoots to mature, induction resulted in 76% of the sprouting buds producing flowers. Consequently, 8 weeks of development were necessary for citrus shoots to develop mostly mature buds that responded to flower inductive conditions. This is about the same amount of time required for new citrus leaves to fully mature.
Candidate Gene Analysis of Internal Breakdown in Peach
Authors: Peace Cameron P. , Crisosto Carlos H. , Bliss Fredrick A. , Gradziel Thomas M.
Published: February 2019

Candidate gene (CG) analysis can be an efficient approach for identifying genes controlling important traits in fruit production. Three chronological steps have been described for determining candidate genes for a trait—proposing, screening, and validating—and we have applied these to the problem of internal breakdown of peach and nectarine. Internal breakdown (IB), also known as chilling injury, is the collective term for various disorders that occur during prolonged cold storage and/or after subsequent ripening of stone fruit. Symptoms include mealiness, browning, and bleeding. Candidate genes for IB symptoms were proposed based on knowledge of the biochemical or physiological pathways leading to phenotypic expression of the traits. Gene sequences for proposed CGs were obtained primarily from the Genome Database for Rosaceae. Screening the CGs involved identifying polymorphism within a progeny population, relying mainly on simple PCR tests. Several polymorphic CGs were located on a peach linkage map and compared with phenotypic variation for IB susceptibility. A major QTL for mealiness coincided with the Freestone-Melting flesh locus, which itself is likely to be controlled by a CG encoding endopolygalacturonase, an enzyme involved in pectin degradation. Further gene sequences positioned on the consensus linkage map of Prunus by other researchers were co-located with QTLs for IB traits. Validation of the role of identified CGs will require detailed physiological or transgenic studies.
(23) Sorbitol Transport, Sorbitol, and Watercore in Apple Cultivars Differ in Watercore Susceptibility
Authors: Loescher Wayne , Johnson Tad , Beaudry Randolph , Jayanty Sastry
Published: February 2019

Sorbitol is the major carbohydrate translocated into apple fruit where it is normally metabolized to fructose. In watercored apple fruit tissues, however, the intercellular spaces become flooded and sorbitol content is consistently higher than in nonwatercored apples, suggesting a defect in sugar alcohol metabolism or transport. Our previous results have identified and characterized two sorbitol transporters, MsSOT1 and MsSOT2, in apple fruit tissues. Sorbitol transporter gene expression has been implicated in development of watercore with MsSOT expression diminished or absent in certain watercored fruit tissues. To explore this further, we have investigated the relationships between watercore, fruit maturation, fruit composition, and MsSOT expression in a number of apple cultivars that differ in watercore susceptibility. We also compared transporter expression between affected (watercored) and healthy parts of the same fruit and between watercored and nonwatercored fruits throughout the maturation and ripening processes. The MsSOT expression was often dramatically reduced in fruit tissues exhibiting watercore. Thus, in susceptible cultivars, maturing (ripening) fruit parenchyma cells lose the ability to transport sorbitol, and this in turn leads to sorbitol accumulation in the apoplastic free space and subsequent flooding of these spaces. These results are consistent with a relationship between watercore and sorbitol transport and also with a genetic susceptibility to the disorder.
(25) Characterization of Volatile Biosynthesis in `Jonagold' Apples (Malus ×domestica Borkh.) during the Ripening Process
Authors: Sugimoto Nobuko , Beaudry Randy
Published: February 2019

The objective of the experiment was to determine developmental changes in major aroma profiles in `Jonagold' apple (Malus ×domestica Borkh.) and analyze climacteric fruit characteristics. Changes in internal ethylene production, respiration, skin color, texture, and aroma concentration were measured during maturation and ripening of `Jonagold' apple fruit. Patterns for skin color, starch, and internal ethylene content were typical for the variety. Volatile compounds and CO2 increased after a rapid increase in ethylene production. Total ester emission peak coincided with fruit softening. Hexyl acetate, 2-methylbutyl acetate, butyl acetate, and hexyl 2-methylbutanoate were found to be the major volatile compounds detected by GC/MS. Long chain esters, such as hexyl acetate and butyl acetate, contributed during the early stages of ripening and short chain esters such as n-propyl acetate and butyl propanoate increased later. Esters are formed by combining alcohol moiety with CoA derivative of fatty acid moiety by the action of alcohol acyl transferase (AAT). The alcohols butanol, 2-methylbutanol, propanol, and hexanol increased at an earlier developmental stage than the esters for which they acted as substrates.
(27) Peel Browning Development of Bananas Treated with SmartFresh™ and Film Coatings Stored under Low Humidity Conditions
Authors: Baez-Sañudo Manuel , Siller-Cepeda Jorge , Contreras-Martinez Rosalba , Contreras-Angulo Laura , Velez Rosabel , Muy-Rangel Dolores
Published: February 2019

Bananas are usually harvested at the “all green” maturity stage in the country of origin and exported to main markets. Upon arrival, fruits are forced to ripen with ethylene and moved to market conditions to accelerate color change and ripening. Fruits exposed to low relative humidity conditions at market frequently induce browning of the peel and diminish quality. To protect fruits marketed under those conditions and to reduce peel browning, SmartFresh™ (1-MCP) alone or combined with two film coatings was evaluated. Banana Cavendish type fruits obtained from a warehouse at all green color stage were applied with two film coatings: 1) SemperFresh™ (1.2%); or 2) FreshSeal™ (3 °Brix). Additionally, a set of fruits were left as a control without coatings. Coated and control fruits were then exposed to 150 ppm of ethylene for 24 hours at 20 °C. When fruits reached color stage 3 (more green than yellow), 0 and 300 ppb of 1-MCP were applied for 12 hours at 22 °C. Fruits from all six treatments were stored at 22 °C and 30% to 40% relative humidity for 5 days to follow quality changes and browning development. Weight loss, firmness, color, pH, acidity, °Brix and appearance were evaluated daily. Control fruits, SmartFresh™ alone, FreshSeal™ + SmartFresh™ and both film coatings alone lost more than 10% of weight after 5 days. Only fruits treated with SemperFresh™ + SmartFresh™ reduced weight loss below 10%. Firmness tests indicated a higher force penetration due to dehydration of peel. Pronounced browning was observed on control fruits. SemperFresh™ + SmartFresh™ delayed yellow color appearance, sugar spot incidence, and peel browning development, extending shelf-life. No significant changes were observed on chemical characteristics.