bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of Carbon Dioxide Enrichment During Stock Plant Cultivation
Authors: Molitor H. -D. , von Hentig W. -U.
Published: September 2022

Carbon dioxide enrichment has become an important factor in ornamental plant production during the past few years. Nurseries, especially those producing cuttings or young plants, increasingly use CO2 enrichment during stock plant cultivation and propagation. This development was brought about by new and inexpensive equipment for measuring and regulating greenhouse CO2 concentrations. Although the positive effect of CO2 enrichment on plant growth has been well established by previous investigations (3, 4, 6, 8, 9), optimum CO2 concentrations have not been clearly defined. Only a few previous investigations have dealt with the influence of CO2 enrichment on the growth and yield of stock plants and on successful propagation (1, 2, 5, 7, 10). Therefore, the aim of this study was to find optimum CO2 concentrations for stock plant cultivation and for the propagation of different plant species. Results with only five cultivars and species are presented, although 15 different species were tested.
Stock Plant Etiolation
Authors: Bassuk Nina , Maynard Brian
Published: September 2022

The discovery and use of auxins in rooting and the development of mist propagation are unequivocal milestones in the history of propagation due to their broad applicability and effectiveness. Stock plant etiolation may prove to be in a similar class with these techniques. The practical use of stock plant etiolation to improve rooting in cuttings has largely been spurred on in the past 10 years by the successes achieved by Howard and others at the East Mailing Research Station, United Kingdom (9). For all the renewed interest, however, the practice of withholding light to improve propagation is probably an ancient one, having been employed every time a stool bed or layer was made or even a cutting inserted into opaque media.
Treatment of the Stock Plant with Plant Growth Regulators to Improve Propagation Success
Authors: Preece John E.
Published: September 2022

Exogenously applied plant growth regulators (Table 1) may act by altering endogenous hormone systems, influencing interactions among these systems, or by disrupting portions of the plant (23). This activity generally occurs because the applied growth substance substitutes for a hormone, affecting its synthesis, catabolism, conjugation, transport, or receptor site(s).
Introduction to the Symposium
Authors: Blanpied G. D.
Published: September 2022

Shortly after the turn of the century, mechanical refrigeration was incorporated into the fresh produce marketing chain in industrialized countries to reduce losses that occurred when fresh fruits and vegetables glutted the market at harvest time. Forty years later, controlled atmosphere (CA) storage was put into commercial practice to lengthen further the marketing period for the expanding apple crops in Western Europe and North America. Later, CA technology was applied to other fruit and vegetable crops. Today, many producers of fresh produce again are faced with the problems associated with large crops. They turned to postharvest horticulturists for the technology needed to lengthen the marketing periods so that their products can be sold at a profit. Much research has been, and will continue to be, conducted to improve the condition of commodities held in CA storage for prolonged periods of time.
Individual Seal-packaging Enables the Use of Curing at High Temperatures to Reduce Decay and Heal Injury of Citrus Fruits
Authors: Ben-Yehoshu S. , Shapiro B. , Moran R.
Published: September 2022

The marked extension of life of citrus fruit by individual seal-packaging has attracted both basic and commercial interest (5). Delayed physiological deterioration by seal packaging was related to the alleviation of water stress of the harvested fruit (10). A risk from this technique is the possibility that decay might be enhanced by the water-saturated atmosphere of the sealed fruit (5). Although most reports do not describe any marked effect on decay, several noted that the percent decay of ‘Shamouti’ and ‘Valencia’ oranges was lightly increased by seal-packaging (5). This increase could be a function of time, since the storage life of sealed fruit is longer than that of nonsealed fruit (5, 20). Sealing of citrus fruit increased stem-end rot in general and Alternaria rot in particular (5). However, this type of decay usually requires 8 weeks for incubation, longer than fruit are usually kept in sealed packages. The major pathogen causing decay of citrus is still the green mold Penicillium digitatum Sacc. (20).
Introduction to the Symposium
Authors: Gray D. J.
Published: September 2022

The prospect of using plant somatic embryos produced in tissue culture as synthetic seeds has been a subject of increased interest, as evidenced by recent news articles (e.g., refs 7, 8, and 12). This interest is partly stimulated by the now more than 150 agriculturally important species for which somatic embryogenesis has been obtained (14). For example, somatic embryogenesis is now routine in soybean (1, 11) as well as many grasses and cereals (3, 15). In addition, recently reported methods for embryogenesis and plant regeneration from tissue cultures of European larch (10), Norway spruce (5, 6), and sugar pine (4) may represent long-awaited break-throughs for conifers.
Hormonal and Osmotic Effects on Developmental Potential of Maturing Rapeseed
Authors: Finkelstein Ruth R. , Crouch Martha L.
Published: September 2022

Seeds account for more than 70% of the world’s food supply, either directly or as potential plants. Unfortunately, not all plants are propagated efficiently through seed. Some crops must be propagated vegetatively, while others have poor seed set. Additionally, attempts to improve seeds by introducing desirable traits via interor intra-specific crosses often result in aborted seeds, yet successful rescue by excision and culture of hybrid embryos demonstrates that the hybrid genotype is viable (14). For these crops, somatic embryogenesis offers the possibility of producing genetically uniform synthetic seed.
Encapsulation of Somatic Embryos in Synthetic Seed Coats
Authors: Redenbaugh Keith , Slade David , Viss Peter , Fujii Jo Ann
Published: September 2022

The importance of tissue culture for clonal propagation in agriculture continues to increase each year. In general, commercial use of tissue culture propagation has been limited to crops that have a high per-unit value, such as ornamentals and fruit and nut trees. A lowcost, high-volume propagation system is not available, but could be of significant value to medium per-unit value crops such as lettuce, celery, and many others (Table 1). For these crops, highvolume propagation potential of somatic embryogenesis combined with formation of synthetic seeds for low-cost delivery would open a new field for clonal propagation. Candidate crops for synthetic seed production can be classified into two categories: 1) those that have a strong technological basis, such that high quality somatic embryos can currently be produced, and 2) those with a strong commercial basis. The latter category of crops are those in which seed costs are high because of fertility problems, gamete instability, labor-intensive hybrid seed formation, or a number of other reasons. Currently, there are few crops (Table 1) that meet both requirements and are suitable for synthetic seed technology.
Concluding Remarks
Authors: Gray D. J.
Published: September 2022

Potential applications of synthetic seed technology to agriculture are numerous, but certain milestones are ahead. The driving force behind commercialization must be the added benefit conferred by use of synthetic seed-derived plants, and this benefit will vary greatly in magnitude depending on specific applications. Increased crop value must be great enough to justify new research and development costs that are not encountered in traditional seed production. Anticipated profit for a few high-value applications will fuel basic advances in technology that will be adaptable to many other crops and applications.
Mechanisms of Rest and Dormancy: Introduction
Authors: Kobayashi Kent D.
Published: September 2022

The objective of this symposium was to present current information on the physiological and hormonal mechanisms of dormancy and rest in buds and seeds of temperate plants. Papers in the symposium provide current information on new terminology on dormancy; rest-breaking effects of chilling on seeds and buds; hypotheses of apical dominance, auxin transport, and apical dominance; effect of environmental factors on dormancy development; mechanisms of dormancy breaking agents; and role of abscisic acid in bud dormancy.
Apical Dominance
Authors: Martin George C.
Published: September 2022

None of the physiological events in plant growth and development is truly independent. Photosynthesis, flowering, and mineral transport are sharply focused areas of research; yet these phenomena are not separable from other metabolic events in the plant. This feature of interdependence may be called correlations (26) or growth correlations (49, 50). The control exerted by the growth zone emanates from a meristem; these meristems include the root or shoot apex, cambium, flowers, fruit, pollen on stigma, and the ovule or seed in a fruit.
Analysis of Apical Dominance in Relation to IAA Transport
Authors: Brenner M. L. , Wolley D. J. , Sjut V. , Salerno D.
Published: September 2022

Correlative inhibition of axillary shoot growth is one aspect of apical dominance that has been extensively investigated, but we still have a limited understanding of how this interesting process is controlled (2). Substantial evidence indicates that auxin, especially IAA synthesized in the apical portion of the plant, can inhibit axillary shoot growth (see refs. 2, 14, and 15) and that the inhibitory effect of IAA is most likely exerted indirectly (see ref. 10). In general, when apical dominance is released by surgical removal of the apical portion of a young plant, release of suppressed growth of axillary buds is detectable within 6 to 12 hr. There are three phases of growth, an initial slow phase, a second accelerated growth phase (see ref. 2) and a subsequent slow phase. There is also considerable information indicating that factors from roots, especially cytokinins, may be important for promotion of axillary shoot growth (12).
Postharvest Senescence of Horticultural Crops: Organizer’s Comments
Authors: Sherman Mark
Published: September 2022

Most people have experienced occasions when senescence in a horticultural commodity has disappointed them as consumers. This may have been when a dozen roses, ordered for someone special, failed to open and deliver the visual and fragrant pleasure that was expected. Perhaps it was when the bushel of apples stored in the cellar was found to be shrivelled and too soft to consume. Our personal experiences take on economic significance when one considers the cumulative effect of the losses that occur during the harvesting, handling, storage, and distribution of fresh fruits, vegetables, and flowers. Estimates have placed the losses during marketing at anywhere from 5% to 50%, depending on the commodity. Directly or indirectly, all of these losses are related to processes of senescence.
Senescence of Cut Flowers
Authors: Mayak Shimon
Published: September 2022

Typically, wilting symptoms are associated with termination of vase life of most cut flowers (8), suggesting that water relations are of importance, especially when it concerns an advanced phase of vase life.
Suppression of Growth and Plant Moisture Stress of Forsythia with Flurprimidol and XE-1019
Authors: Vaigro-Wolff A. L. , Warmund M. R.
Published: September 2022

Flurprimidol and XE-1019, applied at 15.0 and 2.5 mg/plant respectively, suppressed shoot dry weight and increased xylem pressure potential of Forsythia spectabilis Spaeth when drought was induced but did not affect leaf size or root dry weight. XE-1019 did not suppress growth when applied on 28 Aug. 1985. Plants treated with flurprimidol in late August had less shoot growth and higher xylem pressure potential than untreated controls or plants treated with XE-1019. Mefluidide applied as a foliar spray at 5000 mg·liter-1 on 25 June 1985 did not suppress growth or affect plant moisture status of forsythia. None of the growth regulators reduced the transpiration rate of forsythia plants. Chemical names used: N-[2,4-dimethyl-5-[[(trifluoromethyl) sulfonyl]amino]phenyl]acetamide (mefluidide); α-(1-methylethyl)- α-[4-trifluoromethoxy)phenyl]-5-pyrimidinemethanol (flurprimidol); (E)-(p-chlorophenyl)-4,4-dimethyl-2-(1,2,4-triazol-1-yl)-1-penten-3-ol (XE-1019).
Growth of Dieffenbachia maculata ‘Perfection’ as Affected by Air and Soil Temperatures and Fertilization
Authors: Conover C. A. , Poole R. T.
Published: September 2022

Dieffenbachia [Dieffenbachia maculata (Lodd) G. Don ‘Perfection’] were grown at 13° or 18.5°C minimum air temperature (AT) with constant soil temperature (ST) of 13.0°, 18.5°, 24.0°, or 29.5° and fertilized (FR) with 1.4, 2.8, or 4.2 g N/m2 per week from a 3N-1P-2K ratio stock solution. Data from experiments conducted during Winter 1981-82 and 1982-83 showed that air and soil temperatures had greater effects on plant growth than fertilizer rate. Interactions of AT and ST were highly significant for plant height, grade, number of basal breaks, and fresh top and root weights with plants produced at 18.5° AT better than 13° plants at low ST, but not at 29.5° ST. Quadratic responses of plants grown at 18.5° AT to increasing ST were similar to data obtained for tissue Ca and Mg, with lowest tissue levels occurring at the extremes of ST.
Response of Cut Gerbera Flowers to Fluoridated Water and a Floral Preservative
Authors: Tjia B. , Marousky F. J. , Stamps R. H.
Published: September 2022

Twenty gerbera (Gerbera jamesonii H. Bolus, ex Hook f.) cultivars were evaluated for longevity in deionized water (DI), deionized water containing 1 mg fluoride (F)/liter, and deionized water containing 200 mg 8-hydroxyquinoline citrate (8-HQC) + 20 g sucrose (S)/liter. Flowers of different cultivars differed in fluoride sensitivity. Sensitive cultivars developed necrosis on the tips of ray florets within 12 to 24 hr of exposure to fluoridated water, whereas the least-sensitive cultivars were injured within 4 to 6 days. Petal necrosis was the prim ary factor reducing longevity in fluoridetreated flowers. Petal necrosis did not occur on flowers held in DI or 8-HQC + S. The mean postharvest lives of the 20 cultivars held in fluoridated water, DI, and 8-HQC + S were 2.6, 5.3, and 8.3 days, respectively.
Apparent Effect of Zinc Treatment on the Growth Rate of Pecan Production and Yield
Authors: Sparks Darrell
Published: September 2022

Rosette was the major pecan [Carya illinoensis (Wangenh.) C. Koch] production problem prior to the discovery, in 1932, that the disorder was a symptom of Zn deficiency. A comparison of pecan production during the 10-year period prior to 1933 and the 10-year period following 1933 was made to determine the apparent effect of the use of Zn on the growth rate of pecan production from orchards in native and non-native pecan areas. Following the discovery of the cause of rosette, the rate of pecan production increased in non-native but not in native areas. The differential response is proposed to have been due primarily to less severe Zn deficiency in orchards in native than non-native areas. Alternatively, correction of Zn deficiency would have been less likely in native area orchards because of the general ineffectiveness of soil applications of Zn on calcareous soils.
Growth Responses of Seedlings to Varying Rates of Fresh and Aged Spent Mushroom Compost
Authors: Lohr Virginia I. , Coffey David L.
Published: September 2022

Seedlings of broccoli (Brassica oleracea L. Group italica), lettuce (Lactuca sativa L.), marigold (Tagetes patula L.), and tomato (Lycopersicon esculentum Mill.) were grown in 50% (by volume) vermiculite and 0%, 12.5%, 25%, 37.5%, or 50% fresh or aged spent mushroom compost, with Canadian peat comprising the remaining portion. Percent dry weight of the plants decreased linearly, whereas dry weight, height, and quality ratings showed quadratic responses as the rate of compost in the growing mix increased. Plants were smaller in fresh than in aged spent mushroom compost. Lettuce, marigold, and tomato (moderately salt-sensitive crops) grew best with 25% aged spent mushroom compost, and broccoli (moderately salt-tolerant) grew best with 37.5% aged compost.
Cultivar Identification of Japanese Persimmon by Leaf Isozymes
Authors: Tao Ryutaro , Sugiura Akira
Published: September 2022

Leaf extracts of 163 Japanese persimmon cultivars (Diospyros kaki L.) and six other Diospyros species were analyzed for isozyme variation of glucose phosphate isomerase (GPI, E C 5.3.1.9) and malate dehydrogenase (MDH, E C 1.1.1.37). With both systems, the bands were sharp and well-resolved, and intracultivar polymorphism was absent. Isozyme phenotypes were more varied with GPI than with MDH. With Japanese persimmons, GPI yielded 24 different banding patterns, and six cultivars were uniquely discriminated by this enzyme alone. MDH produced only three different banding patterns, with none of the cultivars discriminated. When both enzyme systems were taken together, 18 cultivars were uniquely discriminated and the rest could be classified into 22 groups of 2 to 18 cultivars each.
Variation in Desert Willow Flower and Leaf Size
Authors: Tipton Jimmy L.
Published: September 2022

Apparent differences in flower and leaf size among Chilopsis linearis (Cav.) Sweet accessions were investigated. Corolla area ranged from 6.4 to 15.9 cm2, with significant differences among plants. Leaf width ranged from 5 to 17 mm, length from 80 to 206mm, and area from 1.7 to 12.7 cm2, with significant differences among plants for all three measurements. Leaf width accounted for 62.3% of the variability in area, length accounted for 17.7%, and width and length combined accounted for 89.7%. Width and length were not related.
Genotype and Plastic Mulch Effects on Earliness, Fruit Characteristics, and Yield in Muskmelon
Authors: Maiero Marisa , Schales Franklin D. , Ng Timothy J
Published: September 2022

Four open-pollinated cultivars of muskmelon (Cucumis melo L. var. reticulatus Naud.) and five hybrids among them were grown with clear plastic mulch, black plastic mulch, and on bare soil to study genotype × mulch interactions for days to hermaphroditic flowering, days to fruit maturity, fruit soluble solids, fruit weight, and yield. Interactions were not significant for any trait measured, indicating that all genotypes responded similarly to mulch treatments. Diallel analysis showed that general combining ability (GCA) was greater than specific combining ability (SCA) for all traits measured, suggesting that additive variance was more important than nonadditive variance. Plastic mulches increased fruit maturity and total yields but reduced soluble solids content.
In Vitro Adventitious Shoot Formation from Anthers of Pomegranate
Authors: Moriguchi T. , Omura M. , Matsuta N. , Kozaki I.
Published: September 2022

Anthers of pomegranate (Punica granatum L.) were cultured in vitro on nutrient media containing BA and NAA. Callus from anther walls were produced after 30 days of culture. Subsequently, adventitious shoots were formed by transferring callus to a medium containing 2.0 μm of BA and 0.5 μm of NAA. Regenerated shoots had a diploid chromosome number of 18. Chemical names used: N-(phenylmethyl)-1H/purin-6-amine (BA); 1-naphthaleneacetic acid (NAA).
Outdoor Sand-Nutrient Culture System
Authors: Peck Nathan H. , MacDonald George E.
Published: September 2022

Many different hydroponic systems and methods have been used for growing plants. This report describes an outdoor sand-nutrient culture system that has been used for more than 10 years to study the response of vegetables to inorganic nutrition under natural outdoor conditions and with controlled rooting conditions. The system is simple, dependable, and provides abundant aeration for plant roots.
Chilling Sensitivity of Roselle
Authors: Wolfson D. , Marani A. , Steinitz B.
Published: September 2022

Roselle (Hibiscus sabdariffa L.) is an annual herbaceous subshrub believed to be indigenous from India to Malaysia (2). It is a short-day plant (1), and when grown at the latitude of Israel (32°N), the earliest possible date of flower initiation is 5 Aug. Preliminary studies have indicated that vegetative and reproductive growth ceases in autumn (5), which may be due to exposure to low night temperatures. The objective of this study was to determine the sensitivity of roselle to chilling at different growth stages.
A System to Control Root-zone Temperature
Authors: Graves William R. , Dana Michael N.
Published: September 2022

Most systems used for controlling rootzone temperature (RZT) involve grouping plants in each treatment together in one temperature-controlling apparatus (3, 5). The power of experiments using systems with grouped plants is limited because the groups constitute single experimental units during data analysis. Some systems have overcome this problem, but reports may lack fabrication details (2) or indicate a limited RZT range was used (1, 4). We designed a precise, inexpensive system capable of achieving a wide range of RZT in which individual plants are discrete experimental units.
Influence of Ancymidol on Growth and Interior Quality of Syngonium podophyllum ‘White Butterfly’
Authors: Wang Yin-Tung
Published: September 2022

Compared to floriculture crops, relatively little research has evaluated the effects of growth retardants on production and interior quality of foliage plant species. Ancymidol decreased intemode length in several foliage plant species (1–3), but not china green or dieffenbachia (3). Ancymidol improved interior performance of Epipremnum aureum and Pilea depressa (2). This experiment was conducted to determine the effect of ancymidol on growth of Syngonium podophyllum ‘White Butterfly’ in production and simulated interior conditions.
‘Summercrisp’ Pear
Authors: Luby J. J. , Bedford D. S. , Hoover E. E. , Munson S. T. , Gray W. H. , Wildung D. K. , Stushnoff C.
Published: September 2022

‘Summercrisp’ is a cold-hardy, early-season pear (Pyrus spp. L.) cultivar introduced by the Univ. of Minnesota for use in cold climates where most pear cultivars grow poorly and do not fruit consistently. The name ‘Summercrisp’ connotes the early harvest season and that the fruit is best consumed without ripening, while the flesh is firm and crisp.
‘Victory’ Dieffenbachia
Authors: Henny R. J. , Conover C. A. , Poole R. T.
Published: September 2022

Dieffenbachia species and cultivars have been important ornamental tropical foliage plants for many years. Their attractive foliar variegation, ease of production, and adaptability to interior environments are major reasons for their importance as commercial foliage plants. About 20 cultivars have been produced commercially in Florida. Most new cultivars were obtained from private plant collections or as mutations of established cultivars. Because dieffenbachias occur naturally in a diversity of sizes, growth habits, and variegation patterns, they were included as part of the foliage plant breeding program at the Central Florida Research and Education Center—Apopka. The hybrid Dieffenbachia × ‘Victory’, herein described, was developed and selected as a part of the program.
Horticulture in Michigan and at Michigan State University
Authors: Iezzoni Amy F. , Kelly John F.
Published: September 2022

Michigan State Univ. (MSU) has a long history of rendering outstanding service to the citizens of Michigan, the nation, and the world. Founded in 1855 as the Agricultural College of the State of Michigan, the teaching institution soon began its tripartite mission of instruction, research, and public service. In 1862, the college became a prototype for the 68 land-grant colleges established under the Morrill Act. Now, 132 years later, MSU has 11 baccalaureate-granting colleges that offer more than 125 programs, many of these offering multiple fields of concentration, and an enrollment of ≈42,000 students.
“Hiring Horticulture Graduates“ or “Where Are the Horticulture Graduates”
Authors: Smeal Paul L.
Published: September 2022

The ornamental horticulture industry, including nursery production, landscaping, grounds management, and garden center and retail sales is experiencing the greatest growth and sales in its history. The demand for nursery stock, goods, and services has exceeded all expectations, and it will continue. One result of this growth has been an increasing demand for trained horticulturists, but there are not enough to satisfy that demand. Student enrollment in ornamental horticulture is declining at a time when demand for BS graduates exceeds the supply. At present, there are five to 10 job openings for every graduate. Why is this happening? There are several reasons, but the one of primary importance is low income potential, especially low starting salaries. It is difficult to attract students to a profession that offers a marginal income.
Permanent Labels for Identifying Plant Materials
Authors: Wolfe Dwight , Brown Gerald
Published: September 2022

In the article “Permanent Labels for Identifying Plant Materials”, by Dwight Wolfe and Gerald Brown (HortScience 22:662, August 1987), the second and third lines of the third paragraph appear at the bottom of the center column of text.
Preharvest Growing Conditions and Postharvest Behavior of Subtropical and Temperate-zone Fruits
Authors: Monselise Shaul P. , Goren Raphael
Published: September 2022

The science and practice of growing plants and the study of their usable parts and products are traditionally two separate fields of horticulture. The former is the domain of production physiologists, the latter of postharvest physiologists. Nevertheless, it is common knowledge now that preharvest conditions are of the outmost consequence to the quality of postharvest products. Indeed, in the past 25 years, reports on studies linking preharvest factors and postharvest behavior have become more frequent (3, 5, 20, 28), but we know of a few attempts to survey their interaction in a general way.
Effects of Thidiazuron and CPPU on Meristem Formation and Shoot Proliferation
Authors: Fellman Cynthia D. , Read Paul E. , Hosier Mary A.
Published: September 2022

N-phenyl-N′1,2,3-thiadiazol-5-ylurea (thidiazuron) and several substituted pyridyl phenylurea compounds have been demonstrated to stimulate in vitro meristem and shoot formation at unusually low concentrations. These compounds appear to have strong cytokinin-like effects on a wide range of species and on species that respond little to conventional cytokinins. Thidiazuron has been reported to stimulate shoot proliferation in several woody species (e.g., Acer and Malus). The addition of 0.5μm N-(2-chloro-4-pyridyl)-N′-phenylurea (CPPU) to the culture medium caused dramatic shoot number increases in hardy dedicuous azaleas (Rhododendron sp.) cultured in vitro. In petunia (Petunia ×hybrida Hort. Vilm.-Andr.) leaf test systems both thidiazuron and CPPU caused greater proliferation when used as explant dips or in the medium than similar treatments with N-(phenylmethyl)-1H-purin-6-amine (BA). Further possible applications and roles for these compounds are discussed.
Cultivar Testing, a Seed Industry Perspective
Authors: Thomas Paul
Published: September 2022

Cultivar testing is an essential part of cultivar development programs. The main purpose is to determine the regional environmental adaptability and market fit of the new cultivars or hybrids. It is essential to know whether the items to be tested have the required disease resistance for the areas, whether they meet the needs of the industry as far as type or quality is concerned, and whether they will perform well under the environment of the region. Private research stations may not be in the immediate vicinity of the area of intended use, but adequate testing in these untested areas is still essential prior to release of new cultivars.
Vegetable Cultivar Testing in the Tropics
Authors: Harjadi Sri Setyati , Wien H. C.
Published: September 2022

Vegetable cultivar testing in the tropics is faced with fundamental problems that occur less frequently in the temperate areas. First, it must be decided what species of vegetables should be tested. Second, availability of planting materials, not only for the trial but also for the producer, can be a major limiting factor. Third, the methodology of testing is frequently different than in the temperate world, both in the cultural practices used and in the characteristics evaluated. Each of these points will be elaborated in the following paper, placing particular emphasis on the situation in Southeast Asia.
Chemical Control of Budbreak
Authors: Erez Amnon
Published: September 2022

Interest in artificial control of budbreak of deciduous fruit trees species is closely connected with commercial attempts to grow these species in warm locations, where the chilling requirements are not fulfilled naturally. This interest developed following attempts to grow such species in warm countries that did not want to or could not import these fruits from cooler regions. In subtropical regions like the Cape zone in South Africa, eastern Australia, and Israel, the problem was more acute in the 1950s and 1960s. Adoption of low-chilling cultivars, or a shift of production to cooler, better-adapted areas, improved tree performance considerably. Nevertheless, sporadic problems after exceptionally warm winters still pose a commercial problem. In other areas, such as southeastern United States, the risk of spring frost is such that low-chilling cultivars with their early budbreak cannot be grown in northern locations, and, in such regions, chemical treatments are needed occasionally.
Is Growing Temperate-zone Fruits Profitable in the Tropics and Subtropics?
Authors: Stino George Ramzy
Published: September 2022

Fruit trees normally thrive in zones with ecological conditions similar to their original habitats. The majority of temperate fruit trees require climates with sufficient winter chilling to break internal bud dormancy. This condition generally can not be fulfilled in tropical or subtropical climates. Temperate-zone cultivars have not been commercially productive in these areas; however, some poor-quality fruits have been obtained from seedy plants and some local selections.
Relationships Between Leaf Area per Fruit and Fruit Quality in ‘Bing’ Sweet Cherry
Authors: Roper Teryl R. , Loescher Wayne H.
Published: September 2022

Relationships between leaf area per fruit and fruit weight, color, and soluble solids were modeled on spurs isolated following pit hardening on 2-year-old wood of ‘Bing’ sweet cherry (Prunus avium L.). Leaf area per fruit was found to be the largest measured source of variability in the three fruit quality parameters examined. Leaf area per fruit accounted for 66%, 36%, and 53% of the variability in fruit weight, fruit color, and soluble solids, respectively, at Pullman, Wash. Leaf area per spur accounted for 54%, 27%, and 28% of these same fruit quality parameters at Prosser, Wash. In all instances, there was a positive correlation between fruit quality and leaf area per fruit. Soluble solids content was most sensitive to increases in leaf area, followed by fruit weight and color. Leaf area per fruit is important because it represents photosynthetic potential. Ample productive leaf area is essential to producing high-quality sweet cherries.
Influence of Fall Planting Dates on the Survival and Growth of Taxus, Thuja, and Viburnum Species
Authors: Ball John
Published: September 2022

The influence of soil temperature on the survival and growth of fall transplanted Tauntonii yew (Taxus × media Rehd., ‘Tauintoni’) Techny arborvitae (Thuja occidentalis L. ‘Techny’) and American cranberrybush viburnum (Viburnum trilobum Marsh.) was investigated. Soil temperature appears to be a critical factor in the success of yew plantings, but less so for arborvitae and viburnum. Planting should be made ≈ 4 weeks before soil temperatures in the root zone reach 7°C.
Effect of Temperature, Duration, and Light During Simulated Shipping on Quality and Rooting of Croton Cuttings
Authors: Wang Yin-Tung
Published: September 2022

Croton (Codiaeum variegatum Blume cv. Craigii) cuttings, enclosed in polyethylene bags, were placed in light (20 μmol·s−1·m−2) or darkness at 15°, 20°, or 30°C for 5, 10 or 15 days (simulated shipping) and then placed in a mist bed to root for 4 weeks. Final leaf loss in most of the treatments was <7%. Cuttings in simulated shipping for 15 days at 30° in darkness and light had 31% and 56% final leaf drop, respectively. These cuttings also produced fewer roots than controls. Root length increased with increased shipping duration and shipping temperature from 15° to 20°, without further increase at 30°. Regardless of temperature and duration in simulated shipping, cuttings shipped in darkness had roots 2.5 to 5 cm longer than those shipped in the light.
Adventitious Shoot Regeneration from in Vitro Subcultured Callus of Rhododendron Exbury Hybrids
Authors: Harbage James F. , Stimart Dennis P.
Published: September 2022

Callus culture establishment and adventitious shoot development from callus of Rhododendron × ‘Gibraltar’ (G) and R. × ‘Old Gold’ (OG) after serial subculture were determined. Callus grew on Anderson's Rhododendron medium containing 2,4- D at 0.0045, 0.009, or 0.018 mm, but was optimum at 0.018 mm, since shoot organogenesis was suppressed at that level. After two callus subcultures, adventitious shoot development from callus on media containing 0, 0.017, 0.034, 0.068, or 0.136 mm zeatin (mixed isomers) was optimum at 0.034 and 0.068 mm zeatin for G and OG, respectively. After 17 weeks (five subcultures), 70- to 75-mg pieces of G and OG callus regenerated ≈20 shoots each. Adventitious shoot regeneration from callus declined with prolonged callus subculture. Regenerated plants are currently being evaluated for somaclonal variation. Chemical names used: (2,4-dichlorophenoxy)acetic acid (2,4-D); (E)-2-methyl-4-(1H-purin-6-ylamino)-2-buren-1-ol (zeatin).
Comparison of Methodologies for in Ovulo Embryo Rescue of Seedless Grapes
Authors: Gray D. J. , Fisher L. C. , Mortensen J. A.
Published: September 2022

In ovulo embryo rescue provides an attractive alternative to conventional methods of breeding for seedless grape (Vitis) by allowing recovery of progeny from abortive ovules of seedless × seedless crosses. This technique theoretically increases the proportion of seedless progeny that can be obtained in one breeding cycle (1). Proper inheritance studies can be accomplished by heretofore impossible direct combinations of seedless cultivars.
Fusarium Root Rot-resistant Snap Bean Breeding Line FR-266
Authors: Silbernagel M. J.
Published: September 2022

The ARS/USDA and the Agricultural Experiment Station of Washington State Univ. announce the release of germplasm line, FR (Fusarium Resistant)-266, a bush snap bean (Phaseolus vulgaris L.) line, which is resistant to Fusarium root rot caused by Fusarium solani (Mart.) Appel & Wr. f. sp phaseoli Burkh. Snyd. & Hans. FR-266 also is resistant to bean common mosaic virus (dominant I gene)(l), curly top virus, and is tolerant to white mold caused by Sclerotinia sclerotiorurn (Lib.) deBary. FR-266 is the only known green-podded, white-seeded, bush snap bean line that has this unique combination of multiple disease resistance factors.
‘Chilliwack’ and ‘Comox’ Red Raspberries
Authors: Daubeny Hugh A.
Published: September 2022

‘Chilliwack’ and ‘Comox’ are new red raspberry (Rubus idaeus L.) cultivars released from the breeding program at the Agriculture Canada Research Station, Vancouver, B.C. ‘Chilliwack’ has been noted for its large, firm fruit with exceptionally high quality (Fig. 1). The fruit appear equally well-suited to fresh and to processing markets and have considerable resistance to both pre- and postharvest fruit rots, the former caused by Botrytis cinerea Pers. ex Fr. and the latter caused mostly by B. cinerea and Rhizopus spp. [probably R. stolonifer (Ehr. ex. Fr.) Vuill]. ‘Comox’ has been noted for its exceptionally high yields and, similar to ‘Chilliwack’, the fruit are large and firm and suited to fresh and processing markets (Fig. 2). Plants of both cultivars are highly resistant to Ampho-rophora agathonica Hottes, the aphid vector of the raspberry mosaic virus complex (RMV). In addition, ‘Chilliwack’ plants have some resistance to root rot, most likely caused by Phytophthora erythroseptica Pethyb.
E11-24, E14-32, and E36-7 Apple Germplasm with Multiple Pest Resistance
Authors: Goonewardene Hilary F.
Published: September 2022

E11-24, E14-32, and E36-7 apple (Malus domestica Borkh) were found to be resistant in greenhouse test to apple scab, [Venturia inaequalis (Cke.) Wint.j and to have field immunity to this disease. Field and laboratory resistance to codling moth (Laspyresia pomonella L.) also was found in E11-24 and E14-32, whereas E36-7 was found to have field, laboratory, or greenhouse resistance to plum curculio [Conotrachelus nenuphar (Herbst)] and European red mite [Panony-chus ulmi (Koch)], E11-24, E14-32, and E36-7 are being released as advanced lines of germplasm by the ARS/USDA to interested apple fruit breeders. The scientific disease and insect names mentioned in this release are as reported in refs. 3 and 4.
Rootstock Evaluation Through the NC-140 Project
Authors: Ferree David C. , Perry Ronald L.
Published: September 2022

The widely varying soil and climatic conditions of the apple and peach growing areas of the United States and Canada have resulted in serious problems with the adaptability of the rootstocks currently available to the fruit industry. Growers in each area are searching for the most efficient rootstocks adaptable to their region. In the past, it has taken 20 to 30 years to test rootstocks adequately and to develop the database on which to make sound recommendations to growers. In the interim, many costly mistakes were made; current economic conditions make these mistakes no longer tolerable.
Progress in Breeding Rootstocks in Romania
Authors: Parnia P. , Mladin Gh. , Duţu I. , Stanchi N.
Published: September 2022

For the past 10 years, new attention has been given in Romania to the development of improved fruit tree rootstocks by hybridization and mutation breeding. Prior to 1976, rootstock improvement was focused primarily on selection in seedling populations derived from both wild and cultivated forms, with emphasis on adaptation to local soil and climatic conditions. The rootstocks now in commercial use in Romania come from these sources.
Breeding and Evaluating Apple Rootstocks for Northern Europe
Authors: Zagaja S. W. , Czynczyk A. , Jakubowski T. , Omiecinska B.
Published: September 2022

The Research Institute of Pomology, Skiemiewice, Poland started its apple rootstock improvement program in the 1950s (9). As a result of that work, the “ P” series rootstocks have been released, of which P2 and P22 appear the most promising (4). The rootstock breeding program is continuing (10), and heritabilities of some horticulturally valuable traits are being studied.
Peach Rootstock Characterization by Protein Analysis
Authors: Mazzola M. , Carter G. E.
Published: September 2022

Protein extracts from woody tissue of five peach [Prunus persica (L.) Batsch] rootstocks (‘Nemaguard’, ‘Lovell’, ‘Tennessee Natural’, ‘Siberian C’, and ‘Boone County’) were analyzed by isoelectric focusing on Polyacrylamide gels. All detected proteins focused within the pH range 3.2 to 4.3 and were analyzed by densitometry. Each rootstock could be identified in the early spring by the presence of characteristic protein bands found at either end of the protein banding region.
Effect of Training System on Performance of Hand-harvested Summer-bearing Raspberries
Authors: Nehrbas Stanley R. , Pritts Marvin P.
Published: September 2022

Longitudinally mowing rows to half their width and the V-trellis system were used to separate fruiting canes from primocanes in a raspberry (Rubus idaeus and R. neglectus) planting. The effects of these two systems on yield and its components were determined in 1985 and 1986 for the red raspberry ‘Titan’ and the purple raspberry ‘Royalty’. Both systems were compared to a standard I-trellis configuration, in which primocanes and floricanes grow together. Yields for both cultivars were significantly higher with the V-trellis than with the I-trellis system. Longitudinal mowing reduced yields in the V-trellis, but plots that were mowed outperformed the standard I-trellis. ‘Titan’ was more responsive to cane manipulation than ‘Royalty.’
Seasonal Variation in Leaf Zinc Concentration of Apples Receiving Dormant Zinc
Authors: Neilsen G. H.
Published: September 2022

‘Delicious’, ‘Golden Delicious’, ‘Spartan’, and ‘Mcintosh’ (Macspur) apple (Malus domestica Borkh.) orchards with low leaf Zn concentration, typical of many orchards in British Columbia, but with otherwise adequate nutrition were monitored for leaf Zn concentration throughout the 1983–85 growing season. Mid-terminal leaf Zn concentration consistently declined from a high of 40 µg·g–1 in early May to values approaching or below the 14 µg·g–1 deficiency concentration, despite annual sprays of dormant Zn.
Cover Crop Suppression of Weeds and Influence on Strawberry Yields
Authors: Smeda R. J. , Putnam A. R.
Published: September 2022

Various fall-planted cover crops were evaluated for their influence on weeds and yield of ‘Midway’ and ‘Guardian’ strawberries (Fragaria x ananassa Duch). Rye (Secale cereale L. ‘Wheeler’) and wheat (Triticum aestivum L. ‘Yorkstar’) provided greater early season weed suppression than barley (Hordeum vulgare L. ‘Barsoy’). A high cover crop seeding rate increased weed suppression. Fruit yields were not reduced significantly by any of the cover crops.
Response of Strawberries and Annual Weeds to Fluazifop-butyl and Chloroxuron
Authors: Smeda R. J. , Putnam A. R.
Published: September 2022

Tank mixes of chloroxuron, fluazifop-butyl, and a crop oil concentrate were compared to single applications for annual weed control and safety on strawberries (Fragaria × ananassa Duch.). No noticeable synergistic or antagonistic effect on weed control was observed for mixtures of 4.48 kg·ha–1 chloroxuron and up to 0.14 kg·ha–1 fluazifop-butyl; injury to ‘Guardian’ strawberries was minimal. Early season daughter plant production and percentage of daughter plants rooted of ‘Honeoye’ strawberries was reduced by tank-mixing chloroxuron, fluazifop-butyl, and crop oil, and to a similar extent, from a mixture of chloroxuron and crop oil concentrate only. Chemical names used: N’-[4-(4-chlorophenoxy)phenyl]-N,N-dimethylurea (chloroxuron); (±)-butyl 2-[4-[[5-(trifluoromethyl)-2-pyridinyl]oxy]phenoxy]propanoic acid (fluazifop-butyl).
Effects of Maturity and Harvest Methods on Storage and Quality of Onions
Authors: Smittle Doyle A. , Maw Bryan W.
Published: September 2022

‘Granex 33’ and ‘Sweet Georgia’ onions (Allium cepa L.) at various stages of maturity were harvested by hand and with a prototype mechanical harvester in 1985 and 1986. Bulbs were evaluated for storage losses and bulb quality. Storage losses of both hand-harvested and machine-harvested bulbs were generally similar and increased with increased maturity. Bulb pungency was not affected by harvesting methods and was least for bulbs harvested when 6% of the tops were down. Total sugar concentration of hand-harvested onions, cured with intact tops, was greater than that of machine-harvested onions, when harvested before any of the tops were down, but sugar concentrations at later maturities were similar. Onions that were harvested when < 13% of the tops were down showed greater dry weight in hand-harvested than machine-harvested bulbs.
Influence of Different Types of Mulches on Eggplant Production
Authors: Carter Johnny , Johnson Clarence
Published: September 2022

Field studies conducted during the summers of 1983 and 1984 evaluated the influence of different types of mulching materials on growth and development of ‘Black Beauty’ eggplant (Solanum melongena L.). Treatments consisted of a) pine needles, b) newspaper, c) black plastic, and d) no mulch. The effects of mulching on earliness, growth index, soil moisture, temperature, pH, leaf nutrient content, weed control, and yield were measured. In 1983, a year of limited rainfall, all of the mulching treatments caused a significant increase in growth when compared to the unmulched treatment. Growth was unaffected by mulching in 1984, a year of abundant rainfall. Earliness, measured by the number of fruit per plant prior to the first harvest, was significantly increased by black plastic in 1983 but was not affected in 1984, which suggests the effectiveness of mulching under limited rainfall. In both years, mulching did not affect soil pH, leaf nutrient content, or soil temperature. Black plastic or pine needles were significantly more effective than newspaper in conserving moisture and controlling weeds. Black plastic increased yields significantly compared to the unmulched control in 1983, whereas black plastic or pine needles increased yields in 1984.
Woody Seedling Response to Growth Retardants in Hydroponics
Authors: Hurtt Woodland , Sterrett John P.
Published: September 2022

Two- to 3-month-old seedlings (10 to 12 cm tall) were grown in solution culture to which varying levels of ancymidol or dikegulac were added. Height growth of green ash (Fraxinus pennsylvanica Marsh.) at 11 days after treatment was inhibited ≈50% by 12.5 mg·liter–1 dikegulac. Growth of green ash and silver maple (Acer saccharinum L.) at 7 days was inhibited 75% to 80% by 0.125 mg·liter–1 ancymidol. Growth responses of these seedlings were linearly related to the logarithm of dikegulac and ancymidol concentrations. Chemical names used: 2,3:4,6-bis-O-(1-methylethylidene)-α-L-xylo-2-hexulofuranosonic acid) (dikegulac); α-cyclopropyl-α-(4-methoxy-phenyl)-5-pyrimidinemethanol (ancymidol).
Potential for Juvenile Sod Production
Authors: Wu Lin
Published: September 2022

“Juvenile sod” refers to an immature sod produced in pans in a greenhouse, with only 5 to 6 weeks from seeding to harvest. Seeds were planted in peatmoss after adjusting pH to 7 and were watered with nutrient solution. Tensile strength produced in plastic pans having molded ribbed bottoms and drainage holes vs. flat-bottomed pans was compared. Covering the pans with thin plastic sheets vs. leaving them uncovered during the first 4 days of germination was examined for effect on tensile strength. Tall fescue (Festuca arundinacea Schreb), perennial ryegrass (Lolium perenne L.), and Kentucky bluegrass (Poa pratensis L.), seeded at 60 vs. 30, 60 vs. 30, and 30 vs. 15 g·m–2, respectively, were evaluated. Ribbed-bottom, covered pans, and increased seeding rates resulted in greater tensile strength, which was sufficient for marketable handling.
Availability of Urea, Ammonium, and Nitrate Applied to Pine Bark
Authors: Ogden Richard , Mills Harry
Published: September 2022

Initial availability of NO3, NH4, and urea applied to limed or unlimed pine bark as well as the form of N available over a period of 21 days was determined. Nitrate was not present in significant amounts when N was supplied as either urea or NH4, and the extractable amounts of both urea and NH4 declined significantly over the course of the experiment. Urea was the least effective of the N forms in supplying N in an extractable form. With NO3 as the N source, addition of lime to pine bark resulted in significant reductions in extractable NO3. Applications of NH4 gave relatively equal amounts of extractable N as NH4 from limed and unlimed pine bark after 21 days. It was concluded that N interaction and N transformations with these N forms in pine bark would influence total available N as well as the form of N available for plant growth.