bluuebunny/crossref_metadata_2025 huggingface dataset:
Introgression as a Source of Bitterness in Watermelon
Authors: Herrington M. E. , Brown P. J. , Carr A. R.
Published: September 2022

The sweet, juicy, red flesh of watermelon [Citrullus lanatus (Thunb.) Matsum. and Nakai] is a popular dessert in Australia, while the bland, white, firm-textured flesh of pie-melons, also Citrullus lanatus (Thunb.) Matsum. and Nakai, is used in jam making. Red flesh color of watermelon is a monogenic trait and recessive to white (7). Both bitter and sweet forms of C. lanatus occur and are naturalized in inland areas of tropical and subtropical Australia (3, 9). Bitter fruit of commercial watermelon occasionally have appeared in markets in Australia. A mutation within a commercial cultivar has been considered as the source of plants producing bitter fruit (1,3,6). The nonbitter characteristic of fruit in commerce is conferred by a single recessive gene (1, 7). However, in bitter fruit of C. lanatus, the concentration of Cucurbitacin E glycoside, the principal compound sensed as bitterness (2, 5), is influenced by a modifier gene or genes (1, 7). The concentration of the glycoside in bitter fruit of Accession 242 (a wild type), and of the bitter mutant of the commercial cultivar Hawkes-bury, are 240-590 mg°kg−1 and 1500-2100 mg°kg−1, respectively, and 910-1240 mg °kg−1 in the F1 (1, 2). The concentration of Cucurbitacin E glycoside in nonbitter fruit of C. lanatus is reported to be 0 mg°kg−1 (1) and 60-90 mg°kg−1 (8).
‘Northblue’, ‘Northsky’, and ‘Northcountry’ Blueberries
Authors: Luby J. J. , Wildung D. K. , Stushnoff C. , Munson S. T. , Read P. E. , Hoover E. E.
Published: September 2022

A blueberry (Vaccinium spp.) breeding program was initiated at the Univ. of Minnesota in 1967 using V. corymbosum L. and V. angustifolium Ait. and hybrids between the species. The objective was to develop low-saturated, high-quality, cold-hardy cultivars for commercial as well as home garden use (3). ‘Northblue’, ‘Northsky’, and ‘Northcountry’ are the first cultivars introduced from this program.
‘Migold’ Bell Pepper
Authors: Honma Shigemi , Price H. C.
Published: September 2022

‘Migold’ is a sweet, pointed bell pepper (Capsicum annuum L.) with yellow immature fruit that ripen to an orange-red color. It is a week earlier than ‘Romanian’ and is adapted to the northern United States. The fruit have been satisfactorily processed as a pickled product. Although initially developed for the pickling trade, ‘Migold’ is also well-suited for fresh market use, the garden, and as parents for breeding programs.
MI-2000, MI-100, and MI-08 Tomato Breeding Populations
Authors: Honma Shigemi , Murakishi H. H.
Published: September 2022

Tomato (Lycopersicon esculentum Mill.) populations MI-2000, MI-100, and MI-08 are germplasm released from the Michigan Agricultural Expt. Station. Each population is a bulk of seed from the more promising selections and may need further improvement for horticultural type. The principal value of each population should be as a source of genetic characters, disease resistance, parthenocarpy, and earliness.
Sophora microphylla Ait. ‘Earlygold’
Authors: Butcher S. M. , Bicknell R. A.
Published: September 2022

The genus Sophora belongs to the family Papilionaceae and contains about 20 species of temperate and subtropical trees and shrubs (1) of wide distribution. Three species are native to New Zealand: S. prostrata J. Buchan, S. tetraptera J.F. Mill, and S. microphylla Ait. The 2 tall species, S. tetraptera and S. microphylla, are widely planted as garden specimen trees because of their abundant golden yellow flowers produced in spring. 'Earlygold' is being released for its ornamental value and for its dwarf compact growth habit.
Retrospection, Reflection, and the Future of Horticultural Science Presidential Address1
Authors: Kelly John F.
Published: September 2022

During the past two years as Presidentelect and President of ASHS, I have heard from many of our Members relative to what some have labeled, “The Demise of Horticulture Departments”. Feature articles, editorials, and letters to editors have addressed the subject. Although we cannot deny that many changes have occurred in our applied science units—both private and public, academic and nonacademic—the vast majority of these changes represent progress.
A Realistic Inventory Control Project for Nursery Management Students
Authors: Smith M. A. L.
Published: September 2022

University horticulture students often do not experience the real challenges of the industry until after graduation due to the constraints of classroom schedules and the traditional lecture/laboratory format (3, 10). Practical management of a nursery inventory is a classic example. Complete inventory records are essential for making key management and planning decisions in any business, but the peculiar traits of a woody plant materials inventory demand exceptional ingenuity on the part of nurserymen. Nursery stock may remain in inventory for 7-10 years (from propagation to sale), and is continually changing (in terms of size and caliper) during this period. Individual plants are moved through multiple production stages with characteristic production losses at each stage, a complication that requires constant updates in inventory records. The long lag time between propagation and finished production also makes the target market and number of plants ultimately available for sale very difficult to predict accurately. Each unique requirement compounds the difficulty of maintaining a useful nursery stock inventory record.
Interactions of Soil-borne Organisms and Woody Perennial Root Systems
Authors: Perry Ronald L.
Published: September 2022

The root system of woody perennial crops exists in an extremely complex environment. We as horticulturists and problem solvers need to improve our understanding of the role of the interactions of soil microrganisms, soil media, and the root rhizosphere. It is for this purpose that several ASHS Working Groups—Rootstocks and Compound Genetics, Citrus Crops, Mycorrhiza, Pomology, Nursery Crops, and Viticulture and Small Fruits—have combined to help sponsor this symposium. Plant pathologists and soil microbiologists were invited to elucidate on the impact of pathogenic and beneficial soil bacteria, fungi, and nematodes. As brought out by authors in the following papers, practices employed in managing horticultural crops often discourage the development of plant growth-stimulating microorganisms. Such practices as fumigation and high application rates of fertilizers can alter the composition of the rhizosphere. Conversely, the bacteria, fungi, and nematodes can also alter the rhizospheres by producing substances such as antibodies and toxic metabolites. In citrus, mycorrhizae can alter the nutrient balances, which can indirectly suppress pathogenic fungi.
Root-colonizing Bacteria and Plant Health
Authors: Schroth M. N. , Weinhold A. R.
Published: September 2022

The purpose of this symposium paper is to give an overview and progress report of developments on root-colonizing bacteria to promote plant health. This topic includes such subjects as factors affecting the dynamics of root colonization, mechanisms of microbial antagonism, use of bacteria to control diseases, and commercial development of microbiological inoculants. Papers cited below and reviews (3, 5, 27–30, 34, 39) provide a more detailed account of specific investigations on root-colonizing bacteria and plant health and microbial interactions in the rhizosphere. The rhizosphere is defined as the sphere about roots that is influenced by root activities, such as the exudation of chemicals.
Identifying and Manipulating Metabolic Stress-resistance Traits
Authors: Hanson Andrew D. , Hoffman Neil E. , Samper Catalina
Published: September 2022

Overall plant resistance to environmental stresses is conferred by characters expressed at four levels of organization: developmental, structural, physiological, and metabolic or biochemical (Fig. 1). Characters expressed at the upper levels are usually controlled by many genes. The potential for using recombinant DNA (rDNA) technology to understand and alter stress resistance is presently limited to single-gene traits, especially those expressed at the biochemical level. Such traits may be rare, and the effects on overall crop performance of modifying them cannot be foretold (Fig. 1), but they remain invaluable for basic research. The ability to construct specific mutations in vitro with cloned genes, and then to reintroduce them into the plant via some mechanism of transformation, would provide the power of genetic analysis to test models of molecular function in stress (2, 22). The ability to suppress expression of individual genes by the use of anti-sense messages would serve similar ends (4, 25). Thus, there is much interest in identifying and isolating single genes related to stress resistance or susceptibility. We discuss and criticize three ways of going about this task and show how helpful an understanding of stress physiology and biochemistry can be.
Chilling Injury: A Review of Possible Causes
Authors: Markhart Albert H.
Published: September 2022

Chilling injury has been defined as injury at temperatures low enough to cause damage but not cause freezing of water (17). Common usage refers to temperatures between 0° and 15°C, which cause irreversible damage to tropical and subtropical species. Except for the obvious postharvest loss of quality in many fruits and poor stand establishment in some field crops, the economic importance of chilling injury is difficult to quantify. Chilling injury often results in plants being “set back” so that maturation is delayed and yield reduced. A better understanding of the physiological and biochemical causes of injury and mechanisms of resistance will enable the horticulturist to design better cultural practices and the breeder to develop more resistant cultivars.
Effects of Previous Tillage System and Nitrogen Rates on Yield and Nitrogen Concentration and Recovery by Turnip
Authors: Knavel Dean E.
Published: September 2022

Foliage dry weight for a fall turnip (Brassica rapa L. Rapifera group) crop grown in plowed no-till (NT) plots that previously contained a cover crop of hairy vetch (Vicia villosa Roth.) (NT + V) was greater for plants grown in plots that were previously treated with N at 0 and 56 kg·ha−1 than with 112 kg·ha−1. There were significant linear effects of N rates on fresh root and dry foliage weights of turnip plants in plots that had not contained vetch (NT − V), but not for plants in NT + V plots. About 64 and 48 kg·ha−1 of N were recovered by turnip plants grown in NT + V plots that were previously treated with N at 0 and 56 kg·ha−1, respectively. The previous tillage treatments had no effect on turnip root yield.
Effects of Planting and Harvest Date on Betalain Pigment Concentrations in Three Table Beet Genotypes
Authors: Wolyn D. J. , Gabelman W. H.
Published: September 2022

The effects of planting and harvest dates on violet betacyanin (BC) and yellow betaxanthine (BX) pigment concentrations and the BC : BX ratio were studied in three table beet (Beta vulgaris L.) genotypes. The R'R, Rt'r, and R'r genotypes, conditioning high (violet), medium (red), and low (orange) BC/BX ratios, were studied using two planting and three harvest dates. Total pigment (BC + BX) increased with both later planting and later harvest dates. BC : BX ratio increased with later planting date but decreased with later harvest dates. For any planting date-harvest date combination the three genotypes showed distinct pigment ratios. The Rt'r genotypes planted on 1 July and harvested at 50 days had a pigment ratio similar to the R'R genotype planted on 1 July and harvested at 100 days. Environment can affect betacyanin and betaxanthine production differently, altering pigment concentrations and ratios.
Interaction Between Rhizobial Inoculation and Fertilizer Nitrogen in Five Cowpea Cultivars
Authors: Fernandez George C.J. , Miller J. Creighton
Published: September 2022

Rhizobial inoculation with commercial cowpea ‘EL’ mixed strain inoculant as compared to noninoculation, and effects of four levels (0, 14, 28, and 84 kg·ha−1) of fertilizer N (CaNO3–15.5% N) on yield and N2 fixation components in cowpea [Vigna unguiculata (L.) Walp.] were investigated in a field study. Plants were grown on a vertic albaqualf, fine, montmorillonitic, thermal soil with a pH of 6.7. Three high (H) and two low (L) N2-fixing, indeterminate cowpea cultivars, ‘H-California Blackeye No. 5’, ‘H-Brown Crowder’, ‘H-Tennessee White Crowder’, ‘L-Lady’, and ‘L-Mississippi Silver’, were used. In inoculated plants, N2 fixation was significantly reduced with increasing N levels. Although high-fixing cultivars produced more and larger nodules and expressed higher nitrogenase activity than the low fixers, no significant differences in top dry weight and total N/plant were observed between these groups at the time of flowering. Seed yield was greater in rhizobia-inoculated plants than in the noninoculated, fumigated controls. A significant linear increase in seed yield was observed with increasing N levels in the noninoculated, fumigated controls. The addition of fertilizer N to cowpeas inoculated at planting did not increase seed yield. In high-fixing cultivars, N2 fixation did not directly influence seed yield, but increased vegetative matter was produced. Seed and biomass yield were influenced by N2 fixation in low-fixing cultivars.
A Comparison of Five Irrigation Methods on Onions
Authors: Ellis J. E. , Kruse E. G. , McSay A. E. , Neale C. M. U. , Horn R. A.
Published: September 2022

Water use efficiencies of five irrigation methods on dry onions (Allium cepa L.) were compared in a two-year field study. The methods were: 1) graded furrows where water was measured into the upper end of the furrows and excess water was measured as it ran out the lower end; 2) level furrow where water was held in short, level furrows until infiltrated into the ground; 3) sprinkler; 4) trickle; and 5) trickle three times per week. Efficiency of water use (tonne per hectare per millimeter) was least with graded furrows and the same for the other four treatments in 1983, whereas there were no efficiency differences in 1984. Treatment differences in yield among onion grades occurred both years, but no differences in total yields among treatments for either year. The results do not justify the expense of conversion from existing furrow irrigation systems to pressurized systems for water savings on a uniform, heavy-textured soil where good-quality water is used.
Rooting of Interspecific Peach Hybrids by Semihardwood Cuttings
Authors: Mehlenbacher Shawn A.
Published: September 2022

Semihardwood cuttings of 82 genotypes of peach [Prunus persica (L.) Batsch] and complex hybrids of peach with almond (P. amygdalus Batsch), P. davidiana, P. kansuensis, and P. persica vulgaris siberica were rooted under mist. Average rooting percentages ranged from 7% to 100%. Peach selections generally rooted well with the exception of hardy rootstock selections. P. davidiana rooted poorly, but most of its hybrid progeny rooted well. P. kansuensis and its hybrid progeny rooted well. Peach x almond F1 hybrids generally rooted poorly; the rooting percentage was higher in backcrosses to peach.
Identification of Manganese Toxicity and Magnesium Deficiency on Melons Grown in Low-pH Soils
Authors: Simon James E. , Wilcox Gerald E. , Simini Michael , Elamin Osman M. , Decoteau Dennis R.
Published: September 2022

Field-grown muskmelons (Cucumis melo var. reticulatus Ser.) and watermelons [Citrullus lanatus (Thunb.) Matsum and Nakai] are sensitive to nutrient stress induced by low-pH soils. Severe foliar injury observed on melons grown in low-pH soils was caused by toxic levels of Mn and/or deficient levels of Mg in the leaf tissue. Manganese toxicity symptoms in muskmelons develop as chlorotic spotting on the adaxial surface of older leaves, with water-soaked rings around necrotic spots on the abaxial surface. In watermelons, Mn toxicity develops initially on older leaves as black-brown speckling on the abaxial leaf surface. Severe vein browning develops with age. Magnesium deficiency develops first on mature muskmelon and watermelon leaves as an interveinal bronzing, followed by a necrosis and browning of the interveinal tissue. Muskmelons are more sensitive to both Mn toxicity and Mg deficiency than are watermelons.
Influence of Light Treatments Before and After Induction Treatment on Flowering of Alstroemeria ‘Regina’
Authors: Healy William E. , Wilkins Harold F.
Published: September 2022

Early winter flowering of Alstroemeria ‘Regina’ plants was accomplished by a long-day, high-pressure sodium vapor lamp (HPS) treatment before the low 5°C temperature induction treatment. This HPS treatment predisposed the plants to respond to a subsequent long photoperiod treatment during winter. Winter generative shoot yield was increased by 35% through the use of HPS pretreatment. Stem length increased as the duration of the HPS treatment prior to cold induction increased.
Aryl Esters of IBA Increase Rooted Cutting Quality of Red Maple ‘Red Sunset’ Softwood Cuttings
Authors: Struve Daniel K. , Arnold Michael A.
Published: September 2022

Softwood cuttings of ‘Red Sunset’ red maple (Acer rubrum L.) were given 3-sec basal dips in five auxins at four concentrations. Auxins used were: IBA, K-IBA, NP-IBA, P-ITB, and P-IBA. All auxins were prepared in 10-, 20-, 30-, and 40-mm concentrations. Cuttings treated with 30 mm IBA had the highest percentage of rooting (70%). Other treatments exceeding 50% rooting were: 20 mm K-IBA and IBA and 30 mm P-IBA and P-ITB. Although the percentage of rooting was less in cuttings treated with aryl esters of IBA, rooted cutting quality was improved when compared with IBA-treated cuttings. Cuttings treated with 30 and 40 mm P-IBA had more roots per rooted cutting (two to three) and more total root length (20 cm) compared with 30 mm IBA-treated cuttings. Chemical names used: 1H-indole-3-butanoic acid (IBA); potassium salt of IBA (K-IBA); N phenyl-indole-3-butyramide (NP-IBA); phenyl indole-3-thiobutyrate (P-ITB); and phenyl indole-3-butyrate (P-IBA).
Economics of Changing from Matted Row to Annual Hill System Strawberry Production
Authors: Poling E. B. , Safley C. D.
Published: September 2022

The net present value (NPV) criterion was selected for comparing the monthly net cash flows over a 3-year period resulting from replacing matted row (MR) with annual hill (AH) strawberry (Fragaria × ananassa) production. In the base analysis, AH culture was found to be a profitable alternative to the MR system. The time pattern of the yield response to AH culture (annual cropping) vs. MR (harvesting limited to years 2 and 3 only) is the major economic advantage of the AH system. Discounting at the end of yearly planning periods instead of on a monthly basis overstated the NPV of the AH system.
Comparisons Between Bacterial Wilt Resistant and Susceptible Gynoecious Cucumber Lines and F1 Progeny
Authors: Staub J. E. , Peterson C. E.
Published: September 2022

Four sets of nearly isogenic bacterial wilt [Erwinia tracheiphila (E.F. Smith)] Holland resistant and susceptible gynoecious cucumber (Cucumis sativus L.) lines, along with their companion segregating generations were evaluated under replicated field conditions for flowering date, fruit quality, fruit number, and length : diameter ratio (L:D). In addition to flowering earlier, susceptible lines were higher-yielding and had longer fruits than their resistant counterparts. Although differences in fruit quality were not significant, susceptible lines were preferred by a panel of seven judges. Compared to susceptible lines, hybrid progeny were later-flowering and in some instances lower-yielding.
Identification of Two Linkage Groups in Cucurbita palmata Using Alien Additions Lines
Authors: Weeden N. F. , Graham J. D. , Robinson R. W.
Published: September 2022

Isozyme phenotypes were used to identify two (P2 and P3) of the six monosomic alien addition lines that have been isolated from a Cucurbita moschata × C. palmata hybrid. Phenotype P2 displayed the C. palmata fumarase isozyme, whereas P3 exhibited two glucose phosphate isomerases and an aspartate aminotransferase derived from C. palmata. P2 also possessed the hard rind trait characteristic of C. palmata. Both the biochemical and the morphological phenotypes were inherited in a non-Mendelian fashion, and no recombination was observed within either the P2 or P3 set of characters. It was concluded that the loci coding fumarase and hard rind were situated on the alien chromosome in P2 trisomics and that the other three loci were on a 2nd C. palmata chromosome possessed by the P3 line. The loci responsible for other C. palmata isozymes either were not expressed or were not located on any of the five C. palmata chromosomes represented in the alien addition lines.
Determining the Interspecific Origins of Clones Within the ‘Saba’ Cooking Banana Complex
Authors: Jarret Robert L. , Litz Richard E.
Published: September 2022

Leaf tissue extracts of Musa acuminata Colla diploid subspecies malaccensis, diploid M. balbisiana Colla, the triploid dessert banana cultivar ‘Valery’, the interspecific hybrid (acuminata × balbisiana) cooking banana cultivars ‘Chato’ and ‘Peli-pita’ and the triploid putative balbisiana-derived cultivars ‘Saba’, ‘Saba Puti’, and ‘Cardaba’ were subjected to isozyme analysis for four different enzymes. Isozyme banding patterns of the interspecific hybrids were generally additive and were a composite of the species-specific forms of each enzyme. Banding patterns for shikimate dehydrogenase, malate dehydrogenase, peroxidase, and phosphoglucomutase indicate that ‘Saba’, ‘Saba Puti’, and ‘Cardaba’ are acuminata × balbisiana hybrids.
Microcomputer-based Differential Thermal Analysis of Grapevine Dormant Buds
Authors: Wolf Tony K. , Pool Robert M.
Published: September 2022

Thermal and differential thermal analysis (DTA) are used to detect exotherms that result from the freezing of supercooled tissues (4). They provide a convenient and rapid means of assessing the hardiness of tissues that supercool, such as the floral primordia of Prunus spp. (3) and the compound buds of Vitis spp. (2). The inability to process a large number of tissue samples simultaneously, however, has been a major limitation of DTA. Ashworth et al. (3) described a computer-assisted data-logging system for recording thermal analysis data generated when Prunus flower buds were frozen. Multiple cooper-constantan thermocouples were used to increase the number of buds monitored on a given channel of a multichannel data-logger. Copper-constantan thermocouples, however, were not adequate with our instrumentation to discriminate exotherms generated by the freezing of individual shoot primordia of compound grapevine buds. Furthermore, anatomical barriers to ice propagation may be negated if thermocouples are inserted into buds to increase exotherm detection (5).
SELECT-A-BERRY, a Small Fruit Cultivar and Nursery Database Program
Authors: Poling E. B. , Kimsey H. R.
Published: September 2022

Diverse geographical and climatic zones in North Carolina permit the culture of a full range of small fruit crops, including rabbiteye and highbush blueberries, strawberries, blackberries, and muscadine and bunch grapes. However, information on specific cultivars is scattered throughout various horticultural publications and nursery catalogs and is not readily available. We have developed an extension software program, SELECT-A-BERRY, which facilitates retrieval of small fruit cultivar and nursery information. The menu-driven program has been formatted for the Tandy 1000 (Radio Shack, a Division of Tandy Corp., Fort Worth, Texas) microcomputers recently installed in all North Carolina county extension offices, but it will also run on the IBM-PC and other MS-DOS systems with 256 K bytes of computer memory. Although the program is designed primarily to assist North Carolina commercial and home garden extension clienteles, SELECT-A-BERRY can be modified by agreement with us and the N.C. Agricultural Extension Service for use in other regions as well.
Techniques for Water Emasculation and Cut Seedstalk Pollination in Celery
Authors: Ochoa Oswaldo , D’Antonio Vince , Quiros Carlos F.
Published: September 2022

Hybridization in celery is a difficult task faced by the breeder due to the complex floral biology. Celery flowers are hermaphroditic but protandrous and are arranged in compound inflorescences or umbels, formed by small groups of flowers or umbellets disposed in whorls (3). The different developmental stages of the flowers in the umbel makes it difficult to control pollinations effectively. Pollen from young flowers will pollinate old ones that have receptive stigmas in the same inflorescence or anywhere else on the plant. Honma (4) reported a useful technique for celery hybridization, which is the standard procedure used today by breeders. The accuracy of this method depends on the faithful drop of stamens before any of the stigmas become receptive; otherwise, accidental self-pollinations will occur.
An Approach to Parthenocarpy in Peppers
Authors: Shifriss Chen , Eidelman Eli
Published: September 2022

Environmental parthenocarpy leading to seedless fruits is a well-known phenomenon in pepper, particularly when the crop is exposed to low temperatures before and during anthesis. The resulting fruits show large variation in fruit deformation and are of low marketable value. Genetic parthenocarpy controlling even shape may be useful for fruits for both home use and industrial processing. However, parthenocarpic pepper cultivars are an attractive goal that is still far from realization. From greenhouse pot experiments (2) carried out over 3 years with ‘California Wonder’, fruit weights of up to 150 g were obtained with a high correlation between seed number and fruit weight. Linear regression from this study demonstrated that parthenocarpic fruit of ‘California Wonder’ weigh 60–70 g, about half that of the largest-seeded fruit. Fruit of greenhouse plants weigh about half that of field-grown fruit. It is expected that the parthenocarpic fruits in the field will weigh more than 60–70 g. Moreover, in cultivars with “giant” fruits, in which the realization of large fruit weight depends on the genetic potential for weight and seed number, the parthenocarpic fruits are expected to be heavier than in the parthenocarpic Belltype cultivars.
‘AU-Jubilant’ and ‘AU-Producer’ Watermelons
Authors: Norton J. D. , Cosper R. D. , Smith D. A. , Rymal K. S.
Published: September 2022

Prevalence of diseases, particularly anthracnose, fusarium wilt, and gummy stem blight, is a major factor limiting production of watermelons in the southern United States. Although satisfactory control of anthracnose and gummy stem blight may be accomplished with the proper application of organic fungicides during normal weather conditions, chemical control is not effective during periods of high humidity and rainfall. Furthermore, the 3 leading cultivars, Charleston Gray, Jubilee, and Crimson Sweet, are not resistant to either anthracnose or gummy stem blight (1,2, 7).
‘Minerva’ Rose of Sharon (Althea)
Authors: Egolf Donald R.
Published: September 2022

‘Minerva’ is the 3rd triploid Hibiscus syriacus L., commonly known as the ‘Rose of Sharon’, introduced by the U.S. National Arboretum. ‘Diana’(l), NA 32224, with pure white flowers and the first triploid introduction, and ‘Helene’(2), NA 41786, with white flowers and prominent dark-red eye spot, have become highly esteemed and are now the leading nursery cultivars. The introduction of ‘Minerva’ extends the color range to lavender and further elevates the ‘Rose of Sharon’ to an elite summer flowering shrub.
‘Winterset’ Lettuce
Authors: Ryder Edward J.
Published: September 2022

Major reliance for protection of lettuce plantings from lettuce mosaic virus (LMV) in the United States is placed on a seed indexing procedure developed in California (1). The only major crisphead lettuce (Lactuca sativa L.) cultivar in the United States with resistance to lettuce mosaic has been ‘Vanguard 75’, released by the U.S. Dept. of Agriculture, cooperatively with the California Agricultural Experiment Station, in 1975 (3). ‘Vanguard 75’ is one of the important cultivars in the mid-February to early March harvest period in the desert districts of California and Arizona. It is also a major early cultivar in the spring season of the San Joaquin Valley. ‘Winterset’ is a new lettuce mosaic-resistant crisphead lettuce. It is suitable for the same periods and districts as ‘Vanguard 75’ and, in addition, is adapted for production in late winter in the desert.
‘Autumn Amber’ Fragrant Sumac
Authors: Hooks R. F. , Oaks W. R.
Published: September 2022

‘Autumn Amber’ fragrant sumac, Rhus trilobata Nutt., should be adapted to areas where other plants of fragrant sumac are found. The species grows at elevations up to 2100 m, from Oregon to the Great Plains States and southward into Mexico. In the southwestern states, it is found on limestone outcrops in central and western Texas, and is common in New Mexico, Arizona, and California. In Mexico, it is native to the states of Nuevo Leon, Chihuahua, Cochuila, Tamaulipas, Durango, Puebla, Hidalgo, San Luis Potosi, and Colima. Without irrigation, best growth is obtained when planted in areas receiving 30-36 cm of precipitation. With irrigation, ‘Autumn Amber’ is adapted throughout the western states.
Growth Inhibitors: Correlations vs. Causes1
Authors: Dennis F. G.
Published: September 2022

Growth inhibitors have been implicated in the control of many physiological processes, including dormancy of seeds and buds (35, 36, 45), apical dominance (43), root initiation (12), flowering (13, 16, 44), abscission (5, 8, 25), fruit development (11), dwarfism (29, 40, 50) and senescence (26). Despite the abundance of correlative evidence obtained, no cases are known in which irrefutable proof exists for such control. The purpose of this paper is to discuss how correlations may be extended to proof of a causal relationship. For convenience, most of the illustrations will be drawn from studies of seed and bud dormancy.
Publication of Horticultural Research: Some Problems and Alternatives
Authors: Edgerton L. J. , Whitaker Thomas W.
Published: September 2022

No one will deny that there are problems with the traditional methods of publishing the results of scientific research, and, in fact of all forms of printed communication. These concerns and problems cover a wide range of issues from the increasing cost of publishing a paper in many journals, including our own, to the sheer mass of accumulating journals, periodicals and reference books on our library shelves. The present membership fees have probably placed a burden on some individuals, and the page charges, whether paid by the individual member or through his department’s budget have been a matter of concern. It could be argued that the high page charges should induce or encourage authors to be more concise in their writing. Experience, however, indicates that this does not necessarily follow.
Susceptibility of Apple and Peach Stems to Attack by Pine Voles1,3
Authors: Byers R. E.
Published: September 2022

Stems of 3 peach, 3 apple, and 11 apple rootstock cultivars were compared to ‘Golden Delicious’ apple stems for differences in susceptibility to attack by pine voles, (Microtus pinetorum LeConte) in cage-trials. ‘Ambergem’, ‘Glohaven’ and ‘Elberta’ peach and ‘Halford’ peach seedling stems were significantly less damaged than ‘Golden Delicious’ apple. No differences in susceptibility were detected among the apple scion and rootstock cultivars. In an interplanted peach and apple orchard apple trees were more severly damaged by voles than peach trees.
Ethylene Production Increased by Bruising of Apples1
Authors: Lougheed E. C. , Franklin E. W.
Published: September 2022

Bruising increased ethylene production of freshly harvested ‘Red Snow’ and ‘Northern Spy’ apples.
Inhibition of Friction Discoloration on ‘d’Anjou’ Pears by 2-Mercaptobenzothiazole1
Authors: Wang C. Y. , Mellenthin W. M.
Published: September 2022

Treatment with 2-mercaptobenzothiazole (MBT) inhibited the friction discoloration of fruit of ‘d’Anjou’ pear (Pyrus communis L.). The inhibition was apparently due to inactivation of the pear polyphenoloxidase.
Effect of Duration of Acid Scarification on Endocarp Thickness and Seedling Emergence of Blackberries1
Authors: Moore J. N. , Brown G. R. , Lundergan Catherine
Published: September 2022

Blackbercy seed germination and earlier seedling emergence were increased by extending the duration of sulfuric acid scarification to 3 hours in an ice bath prior to after-ripening. Increased duration of acid treatment decreased endocarp thickness and seed weight A significant negative correlation was found between endocarp thickness and percent germination, but evaluations of different genetic clones indicate that other inherent factors are also involved in seed germinability.
Education for Foreign Students: A U.S. University Perspective
Authors: Rigney J. A.
Published: September 2022

I approach the subject of “Education for Foreign Students” with considerable misgivings, partially because this topic has been under discussion by groups like this for the past 15 years. The very process of re-examining programs that are appropriate for foreign students implies that we have had some second thoughts about what the professional goals of these students are or should be. Alternatively, perhaps this re-examination results from a feeling that our original views on student goals were accurate but that we adopted poor strategies in achieving such goals. In either case we leave ourselves open to the charge of being presumptious in imputing a set of goals to other people on the basis of our prejudices. If the experience of the past 15 years of technical assistance has taught us anything, it is that we simply cannot successfully impose our own judgement on what other people should do with their own lives and resources. Therefore, it is my hope that some of my colleagues on this panel will be able to shed more light on what the foreign students themselves really feel about the quality of the graduate programs they have encountered in the United States apart from the superficial frustrations they experienced. Let me leave this side of the question to them with only one caveat, namely: the opportunity to study in the United States is by far the most highly prized form of technical assistance in the eyes of the developing nations, and this opportunity will likely have a more lasting effect than anything else we have done.
Evaluation of Single and Double Roof Thermometer Shelters for Recording Minimum Temperatures during a Radiantly Cooled Night1
Authors: Wolnick D. J. , Martsolf J. D. , Dietrich D. L.
Published: September 2022

Temperatures in 4 simple thermometer shelters over a 3-1/2 hour period, under nighttime radiant cooling conditions were compared in early June, 1972. Temperatures within shelters having a single roof of wood or plastic were found to be significantly lower than air measured by an aspirated thermocouple. Temperatures in shelters having a double roof of wood did not differ significantly from air temperature. The temperature differences among single- and double-roof shelters were not considered sufficient to warrant the use of a double-roof shelter for orchard thermometer support.
Soil Moisture Stress and Sweet Corn Seedling Development1
Authors: Arnold Charles Y.
Published: September 2022

Pregerminated seeds of 2 cultivars of sweet coin (Zea mays L.) planted in soil that had been brought to various moisture levels were grown to the appearance of the 4th leaf. Successively lower moisture levels resulted in a reduction in the rate of leaf appearance and a progressive tendency for the leaves to unroll more slowly.
A New Technique for Evaluating Changes in Onion Firmness During Storage and a Comparison with Sensory Measurements1
Authors: Crete Rene , Voisey Peter W. , Bernier R. , Larmond Elizabeth
Published: September 2022

A rapid technique for measuring onion firmness is described. The bulbs were compressed at 15 cm/min, and the time taken for the force applied to change from 400 to 3200 g indicated automatically by electronic apparatus. Since the deformation rate was constant this time was a direct measure of bulb deformation and provided an objective comparison of bulb firmness under controlled test conditions that simulated sensory evaluations. Results showed that the differences between cultivars, the effect of chemical treatments, and storage time can be evaluated. The instrumental results are well related to human evaluations.
The Influence of Growing Temperatures and Leaf Trimming on Nutrient Content in Lettuce1
Authors: Knavel Dean E.
Published: September 2022

Plants of bibb lettuce (Lactuca sativa var. capitata L.) were grown in greenhouses from January 6 to March 20 at 2 temperature regimes, one involving a –1°C minimum and the other a 10° minimum. On a whole head basis, only N was influenced by temperature; plants grown at the lower temperature contained more N. Youngest leaves contained most of the N and P, while the oldest contained most of the absorbed K, Ca and Mg. Plants grown at the lower temperature contained more N in the youngest leaves and more K in the oldest leaves. Ca levels were highest in oldest leaves of plants grown at the higher temperature. Trimming off the oldest, cold-injured leaves removed approximately 84% of the total Ca present in the plants.
Induction of Parthenocarpic Fruit Development in Cucumber by Growth Regulators1
Authors: Elassar G. , Rudich J. , Palevitch D. , Kedar N.
Published: September 2022

The effect of growth regulators indoleacetic acid (IAA), parachlorophenoxy-acetic acid (4-CPA), β-napthoxyacetic acid (β-NOA), gibberellin (GA3 and GA4+7) and benzyladenine (BA) applied directly to flowers at anthesis, caused parthenocarpy in cucumbers (Cucumis sativus L.), while (2 chloroethyl)phosphonic acid (ethephon) and abscisic acid (ABA) were ineffective. Only synthetic auxins and BA effectively induced parthenocarpy in treated whole plants. 4-CPA was the most effective treatment for induction of parthenocarpic fruits, as determined by number and shape. Application of GA to the entire plant caused increase in vegetative growth, but fruit development was inhibited even under conditions of natural pollination.
Control of Seed-borne Botrytis cinerea (Pers ex Fr.) on Gerbera jamesonii Bolus1
Authors: Orlikowski L. , Hetman J. , Tjia B.
Published: September 2022

Botrytis cinerea was shown to be seed-borne on gerbera seeds. Inoculation of seeds increased damping-off of seedlings from 5 to 90%. Benlate or Thiram at a concentration of 0.1% applied as a dip for 1, 5 or 10 minutes eliminated or reduced the post-germination mortality of seedlings.
A Nutritional Disorder of Red Oak Seedlings1
Authors: Fenn P. , Durbin R. D.
Published: September 2022

Seedlings of red oak (Quercus rubra L.) grown in various planting media without nutritional supplements developed marginal necrosis and puckering on their first whorl of leaves. These symptoms were prevented by supplying Ca++ to seedlings growing in a vermiculite-peatmoss mixture. An exogenous supply of Ca++ was also required for initial growth in silica sand.
Changes in Scientific Names for Certain Crop Plants1
Authors: Terrell Edward E. , Winters Harold F.
Published: September 2022

Nomenclatural and taxonomic changes in scientific names are discussed for the following crops: Prunus dulcis (Mill.) D. A. Webb (almond); Fagopyrum esculentum Moench (buckwheat); Erythroxylum coca Lam. (coca); Lens culinaris Medic, (lentil); Abelmoschus esculentus (L.) Moench (okra); Carya illinoensis (Wangenh.) K. Koch (pecan); Vigna unguiculata (L.) Walp. subsp. unguiculata (southern pea or cowpea); Prunus avium (L.) L. (sweet cherry); and Citrullus lanatus (Thunb.) Matsum. & Nakai (watermelon).
A Chemosystematic Study of Musa Cultivars1
Authors: Bonner J. W. , Warner R. M. , Brewbaker J. L.
Published: September 2022

Peroxidases from certain Musa spp. isolated using horizontal Polyacrylamide gel electrophoresis revealed 4 major zones of activity and 15 separate peroxidase bands. Good agreement was obtained among cultivars of different ploidy groups when composite zymograms were constructed from gel data and compared to a current taxonomic classification. Three clones of unknown origin were genotypically classified as ‘Hapai’ (AA); ‘Tuu Gia’ (AA); and ‘Eslesno’ (AAB).
Genetic Relationship among Potato Cultivars Grown in the United States1
Authors: Mendoza H. A. , Haynes F. L.
Published: September 2022

A coancestry analysis carried out among a group of commercial potato cultivars and breeding lines indicates that the genetic relationship among the presently cultivated cultivars is closer than has been postulated. The lack of genetic variability for yield in variety trails replicated in time and space also indicates the genetic similarity which characterizes current U.S. cultivars. With the recurring use of related parents in breeding programs during the past 20 years, the stability of performance over a wide range of environments has been reduced. The genetic uniformity of the present cultivars may present a potential danger of epidemics, especially in the eventual case of introduction of parasites still not present in the U.S. It is hoped that the input of new sources of genetic variability would permit a greater genetic advance.
Fire Blight Resistance in Pear Cultivars1
Authors: van der Zwet T. , Oitto W. A. , Blake R. C.
Published: September 2022

Of 20 cultivars of pear (Pyrus spp.) evaluated for their degree of resistance to fire blight, caused by Erwinia amylovora (Burr.) Windslow et al., following 6 years of epiphytotic conditions, 9 were rated as resistant: (in descending order) ‘Magness’, ‘Moonglow’, ‘El Dorado’, ‘Cornice’, ‘Maxine’, ‘Mac’, ‘Dawn’, ‘Duchess d’Angouleme’, and ‘Kieffer’. Small plots of trees, sufficient to determine very susceptible cultivars, are not adequate to evaluate resistant cultivars.
Rooting Mugo Pine Cuttings1
Authors: Kiang Y. T. , Rogers O. M. , Pike R. B.
Published: September 2022

Rooting of cuttings of 4 clones of Mugo pine (Pinus mugo var. mughus Zeneri) averaged 75% when collected in June and dipped in a solution of 0.6% indolebutyric acid (IBA) plus 0.5% benomyl in 95% ethyl alcohol. Cuttings collected in March and June rooted better than those of September or December. Clones varied in rootability.
Market Structure Characteristics among Midwestern Wholesale Producers of Floriculture Crops1
Authors: Robertson J. L. , Sullivan G. H.
Published: September 2022

A survey conducted among all wholesale producers of florist crops in Chicago, Cleveland, Detroit and St. Louis revealed annual gross sales for 126 firms averaged $183,000 per firm. Retail florists comprised the principal customer type, followed by commission and merchant wholesalers. The number of firms selling entirely to terminal wholesale flower markets has declined appreciably in recent years with a trend toward expansion of sales to mass market outlets. A trend toward increased economic concentration among midwestern wholesale producers was evident Wholesale producers selling direct to retailers had an improved potential market position relative to wholesale producers selling primarily to terminal market wholesalers. Trade practices reflected these differences in market position.
Introduction to the Workshop
Authors: Sherman W. B.
Published: September 2022

Scion cultivars have been the basis of fruit industries and the main concern of most fruit research. Stock cultivars have often been taken for granted and rootstock breeding neglected because it has not been immediately rewarding to the breeder. Rootstock breeding, like many long term research programs, has not been strongly supported by various granting agencies, which often seek quick solutions to industry problems.
Levels of Hydroxyproline in Citrus Leaves1
Authors: Yelenosky George , Gilbert William
Published: September 2022

Colorimetric determination of hydroxyproline in acid hydrolysates of ‘Valencia’ orange (Citrus sinensis [L.] Osbeck), ‘Carrizo’ citrange (C. sinensis × Poncirus trifoliata [L.] Raf.), ‘Cleopatra’ mandarin (C. reticulata Blanco), and rough lemon (C limon [L.] Burm. f.) indicated 14 to 71 μg of hydroxyproline per g of oven-dried leaf tissue. Cold-hardening and growth regulator treatments of different citrus cultivars changed the concentration of hydroxyproline in the leaves. Cultivars with greater concentrations of hydroxyproline before cold-hardening were also more tolerant of freeze conditions after cold-hardening.
Temperature and Duration of Storage on Ethanol Content of Citrus Fruits1
Authors: Davis Paul L. , Hofmann Russell C. , Hatton T. T.
Published: September 2022

Ethanol content of juice of citrus fruits showed greater changes during storage and subsequent holding than did acetaldehyde, total soluble solids, titratable acid, or pH. In general, total soluble solids remained unchanged, titratable acid tended to decrease, and pH to increase slightly during storage but showed no effect due to storage temp. Acetaldehyde increased moderately during storage and more extensively during a 1-week holding period at 21.0°C. All fruits increased in ethanol during storage. Ethanol increased in grapefruit more at 1.0° than at 4.5° or 10.0°, while ethanol increased in oranges more at 10.0° than at 4.5° or 1.0°. This behavior may afford a new criterion for a rational basis for establishing optimum storage conditions.
Response of Chrysanthemum in Four Soilless Media1
Authors: Criley R. A. , Watanabe R. T.
Published: September 2022

Chrysanthemum morifolium Ramat cv. White Spider CF2275 plants were grown in soilless media comprised of an andesitic cinder and pumice inorganic component mixed in 4 ratios with 4 organic components, namely, sphagnum peat, aged wood shavings, aged pineapple waste, and ground tree fern trunks (hapuu). The plant responses in the different media showed little difference from those in the control medium of equal parts of soil, peat, and perlite. Mixtures containing from 33 to 50% organic matter were satisfactory for plant growth. The physical and chemical characteristics of the media were within the ranges defined as satisfactory by previous researchers.
Yields of Successive Cropping of Tomato in Sawdust and Bark Media1
Authors: Cotter Donald J.
Published: September 2022

Yields of greenhouse tomato (Lycopersicon esculentum Mill.) increased in bark or sawdust when the media had been prior cropped. Bark produced more marketable fruit than sawdust No unusual plant diseases were noted and root-knot nematode symptoms (a chronic problem in soil) were not observed on roots in either sawdust or bark.
Precipitation and the Economic Feasibility of Harvest Mechanization for Processing Tomatoes1
Authors: Sullivan G. H. , Wilcox G. E. , Uyeshiro R. Y. , Robertson J. L.
Published: September 2022

Simulation modeling techniques were used to determine the influence of precipitation during the harvest season on the economic feasibility of harvest mechanization for tomatoes on 3 soil types. Harvest mechanization was impeded on clay loam and silt loam soils at average precipitation levels during the harvest season due to wet soils and less than potential economic returns were realized. Only sandy loam soils consistently permitted full realization of the economic benefits that accrue from harvest mechanization.
Induction of Parthenocarpy by N-1-naphthylphthalamic Acid in Cucumbers1
Authors: Quebedeaux Bruno , Beyer E. M.
Published: September 2022

Parthenocarpy was induced in unfertilized pistillate flowers of cucumbers (Cucumis sativus L.) by the foliar application of N-1-naphthylphthalamic acid (Naptalam). These results substantiate the previous proposed hypothesis that potent auxin transport inhibitors in general are parthenocarpic agents for cucumber.
‘Priam’ Apple1
Authors: Decourtye L. M. , Williams E. B. , Janick Jules , Emerson F. H. , Dayton D. F. , Mowry J. B. , Hough L. F. , Bailey Catherine
Published: September 2022

‘Priam’ is a new fall red apple with resistance to apple scab caused by Venturia inaequalis (Cke.) Wint. ripening close to ‘Jonathan’ and about one week before ‘Delicious’ (Fig. 1).