bluuebunny/crossref_metadata_2025 huggingface dataset:
Factors Affecting Suppressiveness of Composts to Plant Diseases
Authors: Hoitink H.A.J. , Stone A.G.
Published: February 2019

Many factors affect the potential for composts to provide biological control of diseases caused by soilborne plant pathogens. Heat exposure during composting kills or inactivates pathogens and weed seeds if the process is monitored properly. Unfortunately, most beneficial microorganisms also are killed by this heat treatment. Conditions must be provided after peak heating that enhance natural recolonization of composts by biocontrol agents. The raw feedstock, the environment in which the compost is produced, as well as conditions during curing and utilization, determine the potential for recolonization by this microflora and the induction of disease suppression. Controlled inoculation of compost with biocontrol agents has proved necessary to induce consistent levels of suppression on a commercial scale. Compost stability is another important factor. Immature composts serve as food for pathogens and increase disease even when biocontrol agents are present. On the other hand, excessively stabilized organic amendments, such as highly decomposed peats, do not support the activity of biocontrol agents and disease therefore develops. Finally, salinity, C to N ratio, and other factors affect suppressiveness. Each of these factors will be discussed.
Application of Growth-promoting Rhizobacteria to Transplant Plug and Seed
Authors: Lazarovits George
Published: February 2019

Plant growth-promoting rhizobacteria (PGPR) enhance plant development by many mechanisms. Indirect growth effects result from PGPR activities that displace soilborne pathogens and thereby reduce disease. Direct effects include improved nutrition, reduced disease due to activation of host defenses, and bacterial production of phytohormones. An understanding of the mode of action is essential for exploitation of PGPR for field use. For instance, bacteria that act as biological control agents can only be of benefit at locations where disease occurs. PGPR that stimulate plant growth directly will likely have more universal uses and greater impacts. Thus, we have been developing model systems for identifying PGPR with such traits. In this presentation, the effects of bacterization of tissue culture-grown plants, plug transplants, and seed with a growth-promoting Pseudomonas sp. (PsJN) will be described. Potential uses for this and other PGPR will also be identified. The talk will consider the advantages and limitations of: a) screening methods used for selection of PGPR, b) model systems available for studying the mechanisms of action, and c) why transplants offer an ideal delivery system for rhizobacteria. Results from field trials with PGPR with different modes of action will be presented and their future role in agriculture considered.
Using Entopathogenic Nematodes for the Control of Insect Pests
Authors: Martin W. Randy
Published: February 2019

Recent advances in the development of large-scale, in vitro rearing techniques and formulation technology have prompted the commercialization of entomopathogenic nematodes. The potential for these nematodes as biological control agents is very promising, with proven efficacy against a wide variety of soil-inhabiting insects including root weevils, white grubs, mole crickets, and fungus gnats. Entomopathogenic nematodes are currently marketed in many countries for a variety of horticultural crops, including turfgrass, vegetables, berries, ornamentals, and citrus. Specific examples of successful application of nematodes for the control of insect pests during stand establishment will be discussed.
Effects of Temperature, Light, and Rainfall on Superficial Scald Development in Apples
Authors: Bramlage William J. , Weis Sarah A.
Published: February 2019

Preharvest environmental conditions apparently determine susceptibility of apples to postharvest scald development. Cool temperature, as hours below 10C, can greatly reduce susceptibility, but greater than 30C appears to enhance it. These effects appear to interact, because a high-temperature episode can cause loss of some low-temperature benefit. Shading of fruit increases their scald susceptibility and preharvest light conditions, along with preharvest rainfall, appear to be factors in scald susceptibility in New England. Fruit maturation reduces scald susceptibility. We are constructing models of contributions of these variables to scald susceptibility of fruit grown under different environmental conditions, and in this the relative importance of these variables is being evaluated.
Preharvest Factors Affecting Postharvest Quality of Berry Crops
Authors: Prange Robert K. , DeEll Jennifer R.
Published: February 2019

Berry crops can include a wide variety of plant species, with the most important temperate North American species in the genera Fragaria, Rubus, and Vaccinium. The preharvest factors affecting the postharvest quality of berry crops can be divided into abiotic and biotic factors. Amongst the abiotic factors, mineral nutrition, especially calcium and nitrogen, water, temperature, and light play important roles in postharvest quality attributes such as size, color, firmness, acidity, and sweetness. Amongst the biotic factors, several postharvest pathogens, which are also present as preharvest pathogens, can cause very significant reductions in postharvest quality. Grey mold (Botrytis cinera) is considered to be the most important pre- and postharvest pathogen in berry crops, but other preharvest pathogens (e.g., Alternaria, Colletotrichum, and Rhizopus) can become major problems, depending on other preharvest factors. In some growing areas, the presence of fruit fly larvae in the fresh fruit reduces the postharvest quality. Other biotic factors can be more subtle in their effects on postharvest quality, such as cultivar, pruning, and pollination.
The Role of Calcium and Nitrogen in Postharvest Quality and Disease Resistance of Apples
Authors: Fallahi Esmaeil , Conway William S. , Hickey Kenneth D. , Sams Carl E.
Published: February 2019

In several experiments, strong negative correlations were found between fruit and leaf N vs. fruit color and fruit N vs. firmness, but a positive correlation existed between fruit Ca vs. firmness in apples. Based on these relationships, several models were developed to predict postharvest quality using preharvest nutrient status. Quantity and timing of N application to produce optimum-quality fruit in `Delicious', `Fuji', and `Gala' apples have also been investigated. High levels of nitrogen adversely affected fruit quality and increased endogenous ethylene and respiration. In separate experiments, the effects of seven post-bloom CaCl2 applications on various postharvest pathogens were studied in four apple cultivars. Calcium applications did not increase fruit Ca sufficiently enough to reduce colonization or maintain firmness after 4 months of 0C storage, but did slightly reduce infection by these pathogens during the growing season.
Faculty Scholarship and Productivity Expectations—An Administrator's Perspective
Authors: Weiser C.J.
Published: February 2019

An organization can be effective only when its value system is congruent with and complementary to its central mission(s). The value system of a university is most clearly described by its promotion and tenure policies, processes, and the criteria it uses in evaluating a faculty member's performance. Professorial-rank faculty members at universities are required to perform assigned duties in teaching, research, extension, advising, administration, etc., that are unique to their position. All faculty members are required to make scholarly contributions and are encouraged to perform service that is relevant to their assignment and of value to their institution and profession. The balance of emphasis between assigned duties and scholarship varies from one faculty position to another—ranging from faculty with few assigned duties who engage predominantly in scholarship, to faculty with extensive assigned duties who devote a small, but significant, effort to scholarly achievement. A university's effectiveness can be compromised, and its faculty inappropriately evaluated, if this reality is not recognized; if scholarship is too narrowly interpreted; or if undue weight is given to individual achievement rather than to the achievements of individuals—including those that resulted from team efforts. Changes that are evolving at Oregon State Univ. to address these three issues will be described, including: adoption of a broader definition of scholarship as intellectual work that is validated by peers and communicated; a description of four fundamental forms of scholarship: discovery, development, integration, and creation; incorporation of a dynamic description of position responsibilities for each faculty member into annual and promotion and tenure evaluations; and addition of a category entitled, Results of team efforts into the format for faculty documentation of achievements.
Approaching Retirement
Authors: Moser Bruno C.
Published: February 2019

Society sends numerous signals to those of us who reach official senior citizen status at age 55. Both personal and professional decisions and goals begin to adapt to that inevitable retirement date, which may no longer be age 65. Our institutions send mixed signals of early retirement incentives to individuals on the one hand, but loss of position threats to departments on the other. Elimination of a required retirement age allows individuals to plan past 65, with a number of options available. This forces departments to consider the final career years more closely than in the past. Maintaining viability and aggressiveness of faculty members during this phase of an individual's career is a challenge. Issues of deadwood on the one hand, vs. aggressive productivity up to retirement, can affect a department's capabilities. Discussion of this phase in faculty careers will center around both the individual and his/her department head who, hopefully, are on the same track regarding career direction, but often have different plans for the final years, e.g. semi-retirement and disengagement versus productivity to the last day. Faculty in departments with competitive peers and strong professional development programs throughout the career path lead to the latter as individuals approach retirement.
A Simple Method for Estimating Ploidy of in Vitro Watermelon Plantlets
Authors: Compton Michael E. , Harris J.W. , Gray D.J.
Published: February 2019

Ploidy of in vitro watermelon plantlets was estimated by painting the lower epidermis of leaves with fluorescein diacetate (FDA) and observing fluorescence of guard cell chloroplasts with a microscope and UV light. Leaves from shoot-tip cultures of known diploid and tetraploid cultivars were used to establish the mean number of chloroplasts per guard cell pair for in vitro plantlets. Leaves from diploid and tetraploid plantlets had 9.7 and 17.8 chloroplasts per guard cell pair, respectively. This method was used to estimate ploidy of shoots regenerated from cotyledon explants of the diploid cultivar Minilee. Approximately 10.6% of regenerated shoots were classified as tetraploid while still in vitro. Putative tetraploids were transplanted to the field and self-pollinated. A majority of polyploids identified in vitro were true breeding, nonchimeric tetraploids. This study demonstrate that FDA can be used to estimate ploidy of in vitro shoots of watermelon prior to acclimatization and transfer of plants to the greenhouse or field.
Interplanted Small Grain Management in Cucumbers
Authors: Zandstra Bernard H. , Chase William R.
Published: February 2019

Small grains are interseeded with several vegetable crops in Michigan to protect them from wind and water erosion. When the vegetable crop is well-established, the small grain is killed with a graminicide. Research was conducted to determine the optimum combination of small grain species, age of kill, and nitrogen application rate for acceptable pickling cucumber yield in a single harvest. In several experiments, barley, oats, rye, and wheat were seeded at 130 seeds/m2 in the field. Cucumbers were seeded 1 week later. The cover crops were treated with sethoxydim at 0.21 or 0.31 kg·ha–1 plus 1.25% COC when they were 7 to 10 or 13 to 16 cm tall. Small grain size at application had no effect on their kill with sethoxydim or on cucumber yields. Barley and rye were the most vigorous small grains up to 3 weeks after seeding, but oats were similar in size by 4 weeks. Wheat was slower to develop, and more difficult to kill with sethoxydim. The optimum nitrogen treatment was 34 kg·ha–1 before planting the cover crop, followed by 45 kg·ha–1 at the two- to three-leaf stage of cucumber.
Evaluation of Color Mulches and Oil Sprays for Yield and Silverleaf Whitefly Control on Tomatoes
Authors: Csizinszky A.A. , Schuster D.J. , Kring J.B.
Published: February 2019

In Fall 1990 and Spring 1991, the effects of four mulch colors, orange, yellow, aluminum, and white or black (fall or spring) were evaluated in the field on yields of `Sunny' tomato and numbers of insect vectors. In additional treatments, plants on the orange mulch were sprayed weekly with 2% mineral oil, and the yellow mulch was sprayed with soybean oil as needed during the season. In fall, plants were tallest (P ≤ 0.05) on the aluminum and yellow + oil treatments. The largest number of whiteflys (Bemisia argentifolii, Bellows and Perring) and the largest proportion of plants with virus symptoms were found on the white and yellow mulches. Fruit size and marketable yields were best with the yellow + oil treatment. In the spring, insect populations were low and only a few plants had virus symptoms. Plant heights, fruit size, and marketable yields were similar with all treatments.
Changes in Storage Reserves of Pecan Somatic Embryos during Maturation and Maturation Enhancement Treatments
Authors: Jeyaretnam Benjamin , Wetzstein Hazel Y. , Phatak Sharad C. , Carlson Russel W.
Published: February 2019

Changes in lipid and total protein content of somatic embryos of pecan (Carya illinoinensis) were estimated during maturation, cold treatment alone (3, 5, or 8 weeks) or cold followed by dessication (3, 5, or 7 days). Triglyceride was estimated colorimetrically and methyl esters of fatty acids were analyzed by GC-MS. Total protein was extracted from the same tissue with 2% SDS in Tris·HCL buffer. Triglyceride content of enlarged somatic embryos was significantly lower than zygotic embryos and further declined after 5 weeks cold treatment. An even greater decline was observed during the desiccation treatment. The most abundant fatty acids in small and enlarged somatic embryos are linolenic > palmitic > oleic > stearic acid. However, the molar ratio of linolenic to oleic reached 1:1 after 5 weeks of cold treatment. During enlargement, protein content increased to levels found in zygotic embryos, with desiccation resulting in further elevation.
Development of a Nutrient Medium for the Growth of Date Palm (Phoenix dactylifera L.) Roots by tTissue Culture
Authors: Dlaigen Yousef I. , Said A. E. , El-Hamady M.A.
Published: February 2019

Several experiments were conducted in this investigation with the objective of determining the chemical components and the physical state of an optimal medium for the growth and elongation of excised date palm, cv Sukkari, roots. The chemical tests carried out included: Comparison of (MS)-salts with “White's”-salts mixture and different concentrations of (MS)-salts and its chelated iron; sugars; Modified White's Organics; inositol; adenine sulfate; growth regulators; and some antioxidants. The physical tests, on the other hand, included comparison of the growth and elongation of cultured roots in a liquid or on solidified nutrient media. The effects of various pH values were also tested. Roots were cultured in basal nutrient media composed of: (MS)-salts mixture, and (in mg·liter–1): NaH2PO4·H2O, 170; sucrose, 30,000; inositol, 200; Modified White's Organics; adenine sulfate, 120; activated charcoal, 1500; (2,4-D), 1; kinetin, 2. pH was adjusted at 5.7 ± 01. (MS)-salts mixture was found to be superior to “White's”-salts. No significant difference was observed between (1/2MS) and full-strength (MS)-salts. However, twice the concentration was found to be inhibitory. The normal concentration of (MS)-Fe was found to be optimum for root growth and elongation. The optimal concentration most suitable for the growth and elongation of excised date palm roots has been determined for each of: sugars; Modified White's Organics; inositol; and adenine sulfate. The only growth regulator that needs to be added to the nutrient medium is 2,4-D at 0.1–1.0 mg·liter–1. The study showed the importance of the inclusion of activated charcoal to the nutrient medium. The growth and elongation of roots were both stimulated at all concentrations tested. (PVP), on the other hand, was inhibitory at all concentrations tested. Shaken liquid media was recommended for better root growth and elongation at pH 7.0–8.0. Incidentally, the medium developed was found to support the growth and elongation of roots excised from two other cultivars, namely `Khudri' and `Khaias'.
Micropropagation of Achimenes Hybrids for Winter Production
Authors: Vlahos J.C. , Dragassaki M. , Assargiotaki I.
Published: February 2019

Achimenes is a summer-flowering pot plant commonly propagated by shoot tip cuttings taken from rhizomes released from dormancy. Micropropagation was used in this study in order to establish a protocol for producing plants in winter when Achimenes are not usually available. Leaf segments, taken in August 1993, from hybrids `Flamenco', `Rosenelfe', `Bella', and `Sandra' grown in a greenhouse, were cultured on a modified Murashige and Skoog (MS) medium supplemented with 0.1 mg·liter–1 BA and 0.5 mg·liter–1; shoots proliferated without callus formation. Leaf explants taken from the proliferated shoots were placed on MS medium with 0.5 mg·liter–1 BA and 0.1 mg·liter–1 NAA for 8 weeks for further shoots proliferation. `Bella' showed vigorous growth and produced the most shoots (82) with no rhizomes, whereas `Flamenco' had the least shoots (28) along with rhizomes. Shoot tips were then transferred on MS medium supplemented with 0.5 mg·liter–1 NAA for 6 weeks where more vigorous shoots developed along with roots. Microcuttings were directly stuck ex vitro under moisture and rooted well in 4 weeks before planting in individual culture and flowered normally. These results provide the basis for a successful production of Achimenes hybrids for growth and flowering in winter months provided optimal temperature and irradiance levels are given.
A Computer-based Diagnostic System for Diseases, Disorders, and Pests of Subtropical and Tropical Fruits
Authors: Thomas M.B. , Beck H.W. , Crane J.H. , Ferguson J.J. , Noling J.W.
Published: February 2019

A computer-based diagnostic system that can assist commercial producers, extension agents, and homeowners in the diagnosis of diseases, disorders, and pest damage for citrus, avocado, `Tahiti' lime, mango, carambola, lychee, and papaya was developed. The program was written in C++ and runs under MS-DOS. The system design was based on the diagnostic reasoning process of experts by identifying the location of symptoms, tree vigor, and occurrence within a grove. Full-screen color images link symptoms to possible diseases, disorders, and/or pest damage. Users can also refer to expert knowledge, graphic displays, pop-up menus, dialogue boxes, and retrieve information via hypertext from extension publications as well as current control methods. The program is available on CD-ROM, contains over 800 digital color images, and includes a glossary of terms.
Using Fax-on-demand to Disseminate Agricultural Production Information
Authors: Nitzsche Peter J. , Rabin Jack , Barbour Bruce
Published: February 2019

Fax-on-demand is a new system of communications that combines computer, fax, and telephone technologies. Corporate use of fax-on-demand has shown it to be a rapid, user-friendly, economical way to disseminate technical support information. A project was initiated to evaluate the usefulness of fax-on-demand for disseminating “time-sensitive” crop management information to growers. The system, named the “RCE FaxInfo Line,” has made extension newsletters, pesticide label updates, market price summaries, IPM insect counts and treatment thresholds, etc. available to callers 24 hours a day. While most of the producers surveyed felt the system fit their needs, there has not been widespread use. A limiting factor has been the lack of producers with fax machines. A recent survey revealed that only 8% of New Jersey farmers own fax machines. If this technology is to be effective for extension, the percentage of growers utilizing fax machines must increase.
The Influence of Nitrogen Rate and Timing on `Beauregard' Sweetpotato Yield and Quality
Authors: Schultheis Jonathan R. , Jester W.R. , Averre Charles W.
Published: February 2019

Sweetpotato yield and quality are influenced by a N fertilization program. These studies were conducted to evaluate the effect that different N rates and application times had on the yield and quality of Beauregard roots. Three experiments were conducted in separate locations in North Carolina: One in 1992 to evaluate N rates of 28 to 56 kg·ha–1; and two in 1994 that evaluated nitrogen rate and time of N application. In 1994, N timing using single applications (21, 28, and 35 days after planting) were compared with split applications (10–21 and 21–35 days after planting). Also, in 1994, N rates for the season was varied from 0 to 42 kg·ha–1 comparing single and split applications. No yield differences were detected when N rate was varied from 14 to 56 kg·ha–1. However, the application of at least 14 kg N/ha increased yield when compared with the control (0 kg N/ha). The highest yield of US #1 marketable roots was obtained when all N was applied at 21, 28, or 35 days compared with split applications made at 10 and 21 days after planting. Roots tended to be shorter with single vs. split N applications.
A Model Describing rRelease of Flower Bud Dormancy in `Prize' and `Gloria' Azaleas
Authors: Womack William M. , Barrett James E. , Nell Terril A.
Published: February 2019

`Prize' and `Gloria' azaleas were budded at 29C day/24C night without growth regulators. Dormant-budded plants were held at 2, 7, 13, or 18C for 0, 0.5, 1, 2, 4, 6, 8, or 10 weeks and then forced in walk-in growth chambers (29C day/24C night). A model was developed to describe the effect of cooling temperature and duration on days to marketability (eight open flowers) and percent of buds showing color. Holding at temperatures below 7C, increases days to marketability up to 7 days. Extended cooling (beyond 6 weeks) at temperatures <7C increases percent of buds showing color. Extended holding at temperatures >7C decreases buds in color due to development of bypass shoots during cooling and increased bud abortion. Plants not receiving a cool-treatment or cooled for <2 weeks do not flower uniformly. Furthermore, the percentage of plants reaching marketability dramatically decreases for plants held longer than 6 weeks at temperatures >7C. Both cultivars show similar trends, but `Gloria' has greater variability.
Changes in Chrysanthemum Meristem and Lateral Bud Development at Elevated Temperatures
Authors: Schoellhorn Richard K. , Barrett James E. , Nell Terril A.
Published: February 2019

`Improved Mefo' chrysanthemums were grown at 22C/18C and 34C/28C day/night temperature regimes to evaluate the failure of lateral bud development following pinching of this temperature sensitive cultivar. The number of viable buds on plants at the high temperatures was 40% of number at low temperature. Loss of bud viability was categorized as those buds that were: 1) absent, or 2) those in which growth was present, but inhibited. Inhibited buds were visible swellings surrounded by dense masses of secondary cell wall material. Anatomical studies were completed to verify the absence of lateral buds and determine what cellular changes imposed inhibition on those buds that did develop. A second group of experiments demonstrated that moving low-temperature plants to the high temperature caused production of viable buds to decline. Plants were moved from high temperatures to low, and reciprocally to high from low temperature. Anatomical sampling of apical meristems began at time of shift and at 1, 2, 4, and 8 days after temperature shift. High-temperature meristems possessed predominantly non-viable lateral buds, with few viable buds present.
Regulation and Function of a Pollen-specific ACC Synthase Gene from Petunia
Authors: Lei Chih-Hsien , Lindstrom Jon T. , Woodson William R.
Published: February 2019

At anthesis, petunia pollen contains large amounts of the ethylene precursor 1-aminocyclopropane-1-carboxylic acid (ACC). This ACC is thought to contribute to the rapid burst of ethylene produced by the pistil following pollination. An analysis of ACC content in developing anthers revealed that ACC began to accumulate the day before anthesis, indicating its synthesis was a late event in pollen development. We employed degenerate DNA primers to conserved amino acid sequences of ACC synthesis to amplify a cDNA from anther mRNA by RT-PCR. The resulting cDNA (pACS2) was sequenced and found to represent ACC synthase. Use of pACS2 as a hybridization probe revealed an increase in ACC synthase mRNA concomitant with the increase in ACC content. Further analysis indicated the ACC synthase mRNA was localized specifically to the haploid pollen grain. In an attempt to determine the function of ACC in pollen maturation or pollen–pistil interactions, we have generated a series of transgenic petunias designed to inhibit the accumulation of ACC in pollen. For these experiments, we have employed a pollen-specific promoter (LAT52) from tomato to drive the expression of antisense pACS2 or the coding region of ACC deaminase. The results of the experiments will be discussed.
Does Quality Pay?
Authors: Kippen Laura Sue , Rhodus W. Timothy
Published: February 2019

Quality is extremely important to the processors of horticultural and agricultural commodities. It is important from the standpoint of producing high-quality end-products as well as resulting in lower costs and higher profits. However, producers of commodities receive few benefits from the production of higher quality for several reasons. One important reason is that producers lack information about the qualities processors require. In addition, producers are uninformed of the end-user quality their crops manifest. Presently, little incentive exists for producers to improve quality, other than that provided by USDA Grades and Standards. Using experimental economics, empirical evidence is provided demonstrating that increased awareness of crop quality requirements of processors by producers influences market efficiency, pricing efficiency, and crop quality management strategies of producers.
Integration of a Crop Growth Model in a Greenhouse Management Software System
Authors: Zekki Hassan , Gosselin André , Gauthier Laurent
Published: February 2019

In greenhouses, computerized climate control systems can be used to dynamically and automatically regulate climatic and environmental parameters. To support such a mode of operation, a crop growth model that was developed for greenhouse tomato plants (TOMGRO) was chosen. The model describes the phenological development and increase in dry weight of various organs from planting till maturity under variable environmental conditions. The assimilate partitioning is based on sink strength. A FORTRAN version of TOMGRO was converted to the Smalltalk object-oriented programming environment. This model was integrated into GX, a dynamic climate management software system that was developed at Laval Univ. GX defines a general architecture that may accommodate different decision-making modules based on mathematical models and rule bases. The TOMGRO model is being used to evaluate different production scenarios and will be used to calculate and predict crop growth rates, development, and yields. The model can be used to perform real-time and seasonal cost–benefit analysis and for the dynamic optimization of greenhouse climatic parameters.
Split-plot Analysis—Now and Then
Authors: Fernandez George C.J.
Published: February 2019

Split-plot design is a very popular experimental design in analyzing factorial treatments in horticultural experiments. Two different sizes or types of experimental units are assigned to main plot and the split-plot treatments. The SAS procedure GLM with the TEST option is commonly used to analyze the split-plot data by assigning the correct error term to test the main plot factor. In SAS GLM, no option is available to compare the two main factors within a split-plot factor. The CONTRAST tests and LSMEAN comparisons are valid only for comparing split-plot factors within a main plot treatment. The main factor standard error provided by the LSMEAN option is also incorrect. The new PROC MIXED procedure available in SAS 8.08 or above can be used to correct these problems in split-plot analysis. The analysis of split-plot experiments using the PROC MIXED is presented here.
Genotype x Temperature Interaction during Germination of Several Species of Prunus under Stratification
Authors: Pérez-González S.
Published: February 2019

Previous work has concluded that 7C is the optimum temperature for promoting peach and apricot seed germination. However, these results were based only on genotypes from septentrional regions. The objective of this study is to describe the behavior of a wider range of genotypes and species from temperate-subtropical regions, as a background to detect potential germplasm sources for adaptation to this environment. Seed samples from five species of Prunus were evaluated during stratification at several temperature regimes: Ambient fluctuating from 8 to 16C, 7C, 10C, and 14 ± 1.5C, from 1993 to 1995. Seed germination was monitored twice a week. Great differences were registered among species and genotypes for both speed and percent germination within each temperature treatment. With local species and genotypes germinating equally well and faster at warm temperatures than previously reported. These results will provide an important screening tool when selecting for adaptation to local climates, and also as a way to determine annual “winter quality,” in terms of chilling accumulation in the southern distribution range of temperate fruit crops in the north hemisphere.
Phylogenetic Studies on Prunus Species by DNA Fingerprints
Authors: Yoshida Masao , Shimada T. , Yanaguchi M.
Published: February 2019

Twenty-eight Prunus species were examined in order to survey their genetic diversity. Genomic DNA was extracted from 36 varieties and used for the template DNA of PCR. DNA fingerprints were generated by random primers or semi-random primers, some primers consensus to the repeated units as telomers, and three sets of sequence-tagged primers specific to domains of chloroplast DNA (psbA, rbcL-ORF106, atpB-rbcL). PCR products generated from these three domains were digested by 12 restriction enzymes. RFLPs were detected among varieties and subjected to the UPGMA. Thirty-six varieties were classified approximately into two groups: “Plum group” and “Cherry group.” It was inferred that these two groups were divided in old time. P. tomentosa, P. japonica, P. glandurosa, and P. besseyi, which are classified into the cherries, showed the same fingerprint patterns from chloroplast DNA of the plum group; plums and cherries have a large genetic diversity. It was supposed that the diversity of plums depended on nuclear DNA, besides the diversity of cherries on both nuclear and chloroplast DNA.
Aluminum Amendments Increase Retention of Triple Superphosphate-P in Soilless Container Media
Authors: Williams Kimberly A. , Nelson Paul V.
Published: February 2019

Soilless container medium components such as peatmoss and perlite have almost no capacity to retain PO4-P, and preplant amendments of triple superphosphate (TSP) are readily leached. Al amendments were tested to reduce P losses from these media. Al2(SO4)3 solutions at rates of 320 and 960 μg Al/cc were applied to a 70 peat: 30 perlite medium and dried at 70C. Adsorption isotherms were created at 25C for the Al2(SO4)3-amended media and an unamended control using solutions of Ca(H2PO4)2 at concentrations of P ranging from 0 to 500 μg·ml–1. Isotherms showed that P retention increased as Al concentration increased. In a greenhouse study, Dendranthema ×grandiflorum `Sunny Mandalay' was grown in these media with 100 g P/m3 from TSP incorporated into the mixes before planting. PO4-P, soluble Al, and pH were determined on unaltered medium solutions collected throughout the cropping cycle and foliar analyses were determined on tissue collected at mid- and end-crop. The highest rate of Al was excessive and resulted in low pH and soluble Al levels in the medium solution early and in the cropping cycle, which were detrimental to plant growth. When Al was applied at 320 μg/cc, soluble Al levels in medium solution were not significantly higher than in the unamended control, PO4-P leached from TSP was reduced, and sufficient PO4-P was released throughout the cropping cycle to result in optimal plant growth.
Improving Fruit Firmness and Reducing the Need for Hand-thinning in Peach by using Sprays of Release® LC
Authors: Southwick Stephen M. , Yeager James T. , Weis Kitren G.
Published: February 2019

`Loadel' cling peach [Prunus persica (L.) Batsch] trees were sprayed with Release® LC (Abbott Laboratories, North Chicago, Ill.) in 1993. Preharvest (harvested 16 July) sprays of 50, 75, 100, and 120 ppm applied on 15 June improved fruit firmness without altering fruit maturity (flesh color by commercial standards) in 1993. In the following 1994 season, flower number per centimeter of shoot length was reduced by sprays ranging from 50 to 120 ppm applied on 15 June and 9 July. No hand-thinning was required on trees treated on 15 June. Trees treated 9 July had 50% fewer fruit removed than on untreated trees, where more than 3000 fruit were removed by hand-thinning. Salable yield was higher than untreated control trees where Release® LC had been applied at 50 ppm on 15 June and 9 July. Fruit size equaled those of hand-thinned controls. As concentration increased on 15 June, salable yield decreased linearly. Fruit size (diameter and individual weight) increased with reductions in salable yield. Interestingly, fruit were evenly distributed along shoots after Release® LC treatment, similar to those found after hand-thinning. Release® LC will be available for commercial chemical thinning of stone fruit in California during 1995. Additional results from peach and other stone fruit will be presented.
Interaction of NAA with Accel and Promalin on Fruit Size in `Delicious' and `Empire' Apples
Authors: Bukovac Martin J. , Black Brent L. , Hull Jerome
Published: February 2019

NAA and Accel are used for fruit thinning of apples. However, when combined, many small (<65 mm) fruit were produced in `Delicious'. We extended our studies using Redchief `Delicious' and `Empire', and, since BA is common to both Accel and Promalin, to study the effect of NAA-thinning sprays on Promalin-treated Redchief trees. NAA (10–15 mg·liter–1) and Accel (25–100 mg·liter–1) were applied to Redchief and `Empire' at 100-mm king fruit diameter (KFD). NAA interaction with Promalin was studied using Redchief. Promalin (1.5 pt/A) was applied as a single spray (80% king bloom, KB) and as a split application (0.75 pt/A, 80% KB and repeated at 10-mm KFD) with NAA (15 mg·liter–1) at 10-mm KFD. In `Delicious', 2% to 9% of the fruit from Accel-treated trees was <65 mm in diameter, compared to 11% for NAA alone. However, when NAA was applied with Accel, 22% to 30% of the fruit was <65 mm and percentage of large fruit (75 mm+) was reduced by 24% to 36%. There was no strong interaction for fruit size in `Empire', but the combination decreased yield. NAA applied to Promalin-treated `Delicious' increased percentage of small fruit dramatically (14% to 25%). No increase in small fruit was observed with Accel of Sevin.
Pungency and Sugar Changes in lLong-day Onions Due to Different Storage Times and Temperatures
Authors: Patil Bhimanagouda S. , Dean Bill B.
Published: February 2019

Twenty-four genotypes of `Walla Walla' sweet onion (Allium cepa L.) grown in two locations were evaluated for several characteristics associated with bulb flavor and storage losses. The range of pyruvic acid content in bulbs stored (at 5C and 65–75% RH) for 0, 2, and 4 months were 3.4–7.54, 3.48–18.81, and 3.92–12.61 (μmol·g–1), respectively, among different genotypes. Bulb quality of several genotypes decreased during storage, as indicated by lower total sugar concentration (fructose, glucose, and sucrose) and greater pungency. At 5C after 4 months of storage, the range of marketable bulbs (percent by weight) was 31% to 89% among genotypes; however, at 15C, only two genotypes survived with 60% marketable bulbs. Pungency and sweetness changed independently during storage. Pyruvic acid was not correlated (r = 0.038) with the percentage of marketable bulbs remaining after 4 months of storage. In comparison with the short-day sweet onions (`Vidalia' and `Texas Grano 1015Y), `Walla Walla' sweet onions showed two-fold higher sugar: pungency ratio among genotypes.
Changes in Onion Bulb Quality during Storage of Short- and Long-day Cultivars
Authors: Kopsell David E. , Randle William M.
Published: February 2019

Short-day (SD) and long-day (LD) cultivars of onion (Allium cepa L.) representing various storage and flavor characteristics were greenhouse-grown to maturity. Bulbs were harvested and cured, then stored at 4C and evaluated monthly for pyruvic acid concentration (EPY), soluble solids content (SCC), and weight loss (WL). The EPY of `Dehydrator #3' (SD) decreased linearly with storage while EPY of `Granex 33' (SD) increased linearly. The EPY of `Zenith' (LD) had a quadratic response, decreasing then increasing during storage, while EPY of `Sweet Sandwich' (LD) increased then decreased quadratically during storage. Cultivar SSC generally decreased, while WL increased during storage.
Enhancing Ripening Characteristics of “Netted” and `Honeydew”-type Melons
Authors: Shellie Krista C. , Wolf David
Published: February 2019

“Netted” (Cucumis melo var. reticulatus Naud.) cantaloupes typically abscise when mature, and have a shorter postharvest life than “Honeydew” (Cucumis melo var. inodoris Naud.) -type melons. The amount of ethylene and carbon dioxide produced by two cantaloupe genotypes (slipping), one Honeydew genotype (non-slipping), and the F1 hybrids derived from the slipping x non-slipping genotypes were measured during ripening to understand the genetic control of ethylene and fruit abscission. Sterile, nondestructive gas sampling ports inserted into 20-day-old fruit were used to extract samples from the central cavity of the melons and monitor ethylene and carbon dioxide from day 30 until the fruit was horticulturally mature. Honeydew melons had a lower rate of respiration during maturation and ripening than Netted melons, and Netted melons produced 10-fold more ethylene during ripening than Honeydew types. F1 fruit produced ethylene at levels similar to the Netted parent, abscissed 2 to 4 days later than the Netted parent, yet respired during maturation and ripening like the Honeydew-type parent. Ethylene production, respiration, and abscission appear to be controlled by dominant gene action.
Techniques for Inoculation of Guayule Seedlings with Two Soil-borne Pathogens
Authors: Kuti J.O. , Latigo G.V. , Bradford J.O.
Published: February 2019

Soil-borne pathogens such as Macrophomina phaseolina (the causative agent of charcoal rot) and Phymatotrichum omnivorum (the causative agent of cotton root rot) contribute to mortality of transplanted guayule (Parthenium argentatum, Gray) seedlings in southern Texas. In order to select guayule genotypes for resistance to these pathogens, it would be useful to develop reliable greenhouse inoculation procedures for screening guayule seedlings. Twelve-week-old guayule seedlings (`11591', a USDA standard breeding line) were inoculated using two inoculation methods (soil-drenching and root-dipping) in two soil media (field soil and commercial soil mix). Plants were rated for disease severity 2 to 5 months after inoculation and pathogens were re-isolated from diseased plants to establish Koch postulates. The soil drenching technique, using field soil, caused rapid development of disease symptoms that were consistent with re-isolation frequencies of pathogens from the diseased plant tissues.
Bicarbonates and Botrytis: VI. Control of Gray Mold Enhances Geranium Growth
Authors: Palmer C.L. , Langhans R.W. , Horst R.K. , Israel H.W.
Published: February 2019

Botrytis cinerea Pers. causes gray mold on greenhouse-grown geraniums (Pelargonium ×hortorum L. H. Bailey), among many other crops. Bicarbonates effectively control rose powdery mildew (Plant Dis. 76:247–480) and inhibit B. cinerea in vitro colony growth and conidial germination (Phytopathology 84:546, 1065). To examine bicarbonate effects on gray mold incidence and geranium growth, we sprayed seedling geranium cultivars Red Elite and Scarlet Elite weekly with 0, 25, and 50 mM NH4HCO3 or KHCO3. Seedlings were transplanted in Metromix 360 and misted every 24 m for 5 s to enhance disease development. Data were collected biweekly on disease incidence, floral number, plant height, and dry weight. Both cultivars performed similarly. Disease incidence decreased with application of bicarbonates. KHCO3 at 25 mM slightly increased dry weight and height over 0 mM, whereas 25 and 50 mM NH4HCO3 greatly increased both features. Fifty mM KHCO3 decreased height slightly, but had no effect on dry weight. Floral number decreased slightly with all bicarbonate treatments. It is indicated that KHCO3 at low levels and NH4HCO3 enhance seedling geranium growth by controlling gray mold incidence and by providing additional nutrients. (Supported by H&I Agritech Inc., Ithaca, NY 14850.)
Tomato Little-leaf Syndrome—A Possible Explanation
Authors: Olson S.M. , Chellemi D.O. , Andersen P.C.
Published: February 2019

Since the fall of 1986, tomato growers in northwestern Florida and southwestern Georgia production areas have encountered plants in their fields with unusual growth characteristics. Early symptoms consist of interveinal chlorosis of the young leaves. Subsequent top growth becomes severely distorted with leaflets along the midrib failing to expand properly, resulting in a “little-leaf” appearance. Additional symptoms included cessation of terminal growth, leaves with twisted and brittle midribs, and axillary buds failing to develop properly. Fruit that set on mildly affected plants are distorted, with radial cracks extending from the calyx to the blossom scar. In severely affected plants, fruit failed to set. The problem usually occurs at very low levels, but in 2 years since 1986, the problem has caused some economic damage. To determine a possible cause, samples were taken for virus detection. None were detected in affected plants. Samples were also taken of tissue and soil from affected areas for nutrient and pesticide analysis. No explanation could be developed from any of the tissue or soil samples. The problem usually occurs in wet areas and after very warm temperatures. The problem appears to be very similar to a nonparasitic disease that occurs in tobacco, called “frenching.” In tobacco, frenching occurs in wet, poorly aerated soils with a soil pH >6.3 and during warm temperatures. There seems to be an organism or organisms present under certain conditions that live on the root surface and exude chemicals that cause this distorted growth.
Morphological Variation in Western Trailing Blackberry (Rubus ursinus) in the Pacific Northwest
Authors: Anderson Angela K. , Finn Chad E.
Published: February 2019

Trailing blackberry cultivars, such as `Marion', can be traced to relatively few chance selections of Rubus ursinus Cham. & Schlecht. Wild R. ursinus offer a range of horticulturally desirable traits to breeders, from high fruit quality to improved cold hardiness. Cuttings from 460 plants, representing 20 populations in southern British Columbia, Washington, and Oregon, collected in 1993. Rooted clones were planted in 1994 in a replicated field trial to assess morphological variation. A greenhouse study was also undertaken, with 10 clones represented from each site, in two replications. Preliminary data from the greenhouse and field studies show variability in the following morphological characters: Glandular hairs; cane and prickle color; cane diameter; prickle density; internode length; leaf color, size, shape and density; and senescent leaf drop and color change. Floricane morphology will be assessed in 1995. Analysis of these data will determine relative genetic distances among the populations and enhance the understanding of the diversity available in R. ursinus.
Actinidia spp. Seedling Evaluation
Authors: Kempler Chaim , Kabaluk Todd
Published: February 2019

Kiwifruit (A. chinensis, A. deliciosa) seedlings were propagated from seeds collected from their native habitat in China. They were planted at the Pacific Agri. Res. Center in 1988 for the purpose of selecting superior fruit. Out of 2212 Actinidia seedlings, 1425 flowered by 1994, with 794 being male and 631 female. Some selections flowered 1 month earlier and matured 3 weeks earlier than `Hayward' kiwifruit. One accession had fruit of comparable size to `Hayward' while maturing about 2 to 3 weeks earlier. Some hairless selections had an average fruit weight of 90 g, °Brix index of 18%, light flesh color, 207 mg/100 g of vitamin C, and early maturation. Most of the seedlings were hardy under a coastal British Columbia climate.
Foliar-applied Boron and Root-applied Potassium Affect Growth, Yield, Quality, and Nutrient Content of Tomato
Authors: Sperry W.J. , Davis J.M. , Sanders D.C. , Nelson P.V.
Published: February 2019

Fresh-market tomato (Lycopersicon esculentum Mill.) was grown in a growth chamber, hydroponically, and in a field to evaluate the effect of foliar-applied boron (B) and root-applied K on growth, yield, quality, and tissue nutrient levels. Plant and root dry weight, plant height, fruit set, total yields, marketable yields, fruit shelf life, fruit firmness, and fruit crack were positively influenced by B treatments. Boron-treated plants contained more K than plants not treated with B. Plants not treated with B contained less calcium (Ca) than plants treated with B. Leaflets from plants treated with B maintained higher K levels during fruit development than leaflets from plants not treated with B. Roots from plants treated with foliar B had significantly more B than roots from plants not treated with B. Fruit from B-treated plants had significantly more B than fruit from plants not treated with B. This indicates B was translocated from leaves to root and fruit tissues.