bluuebunny/crossref_metadata_2025 huggingface dataset:
Sensor Effects on Leaf Temperature Measurements
Authors: Vrecenak Arthur J.
Published: September 2022

The steady-state porometer has been acknowledged as the state of the art in assessing leaf diffusive conductance in the field (3). This Note alerts users of the SSP to its limitations as a field sensor of leaf temperature, a use for which it is neither intended nor suited. The fact that some recent studies have reported leaf temperatures obtained with the SSP system as part of their results (1,2, 4) is cause for concern.
Effect of Trickle Irrigation and Black Mulch on Growth, Yield, and Mineral Composition of Watermelon
Authors: Bhella H. S.
Published: September 2022

Response of watermelon [Citrullus lanatus (Thunb.) Matsum. & Nakai cv. Charleston Gray] to factorial combinations of trickle irrigation or no irrigation and black polyethylene mulch or no mulch was evaluated during 2 successive years on a southwestern Indiana Lyles fine sandy loam. Both trickle irrigation and polyethylene mulch, alone and in various combinations, increased stem growth and early and total yields of watermelon compared to untreated watermelons. Greatest stem growth and early and total yields were obtained from plants grown on polyethylene mulch in combination with trickle irrigation. Mean fruit weight did not vary with treatment. Trickle-irrigated watermelon plants produced shallow rooting near trickle emitters; nonirrigated plants produced relatively extended, deep, and diffuse roots. Petiole Zn concentration was greater in plants grown on polyethylene mulch than no mulch. Trickle irrigation resulted in a decreased concentration of petiole Mn.
Staminate Floral Induction on Gynoecious Buffalo Gourd Following Application of AVG
Authors: Scheerens J. C. , Scheerens H. M. , Ralowicz A. E. , McGriff T. L. , Kopplin M. J. , Gathman A. C.
Published: September 2022

Application of AVG to the terminal meristematic region of gynoecious buffalo gourd (Cucurbita foetidissima HBK.) vines resulted consistently in the induction of staminate floral buds. Linear models adequately described the regressions of staminate floral induction frequency on AVG concentration and on frequency of AVG application. If AVG was applied repeatedly on gynoecious plants prior to the onset of female flowering, the transition to the potentially mixed floral phase was delayed. Chemcial name used: [S(E)]-2-amino-4-(2-aminoethoxy)-3-butyric acid (AVG).
Comparisons of ‘Honey Dew’ and Netted Muskmelon Fruit Tissues in Relation to Storage Life
Authors: Lester Gene
Published: September 2022

Changes in morphology of epidermal layers and in permeability of mesocarp membranes of ‘Honey Dew’ and netted muskmelon fruits (Cucumis melo L., var. inodorus and reticulatus, respectively) were compared for 10 through 60 days after anthesis to relate tissue changes to storage life. Twenty-day-old netted muskmelon fruit developed lenticular tissue (net) over the entire melon surface. The muskmelon net had become fissured by 50 days after anthesis (10 days postharvest). ‘Honey Dew’ fruit did not develop lenticular tissue nor did the epidermis become fissured. ‘Honey Dew’ and netted muskmelon fruits had similar membrane electrolyte leakage characteristics (60% ± 3%) when harvested ripe, but, after 10 days at 20°C, electrolyte leakage was 70% and 87%, respectively. Membrane electrolyte leakage for both cultivars had a high regression coefficient (R2 = 0.97) with fruit maturation and postharvest senescence. An intact epidermis indirectly affected mesocarp membrane permeability and perhaps contributed to differences in muskmelon cultivar storage life.
Translocation and Breakdown of 14C-labeled Paclobutrazol in ‘Nemaguard’ Peach Seedlings
Authors: Early J. D. , Martin G. C.
Published: September 2022

‘Nemaguard’ peach seedlings [Prunus persica (L.) Batsch] were grown in nutrient solution cultures containing 0.36 µM 14C-labeled paclobutrazol (0.59 MBq·liter–1) for 9 days. Microautoradiographs of transverse and longitudinal stem sections showed that 14C activity was localized in the xylem. Tissue extracts showed that the total 14C activity in the plants was distributed predominantly between the roots (40.9%) and leaves (49.1%). The majority of 14C activity in stems and leaves was located in the lowest stem and leaf fractions. The concentration of 14C activity was highest in leaves (478 dpm·mg–1 fresh weight), and essentially equal in the roots and stems (141 dpm·mg–1 fresh weight) indicating that transport of the compound was occurring via the xylem. Although 14C-labeled paclobutrazol was relatively stable in the nutrient solution, its degradation in the plant was rapid. By 9 days after treatment, the amount of 14C label remaining as 14C-labeled paclobutrazol was 71.5% in the roots, 41.5% to 68.1% in the stems, and 7.8% to 12.2% in the leaves. Chemical name used: β-(4-chlorophenyl)methyl]-α-(1,1-dimethylethyl)-1H-1,2,4-triazole-1-ethanol (paclobutrazol).
On Being Appointed Science Editor
Authors: Lipton Werner J.
Published: September 2022

I am delighted to have been appointed Science Editor of our Society and I will make every effort to help maintain “the quality and credibility of information published by the Society”, as required by the job description.
Ethylene Evolution by Tomato Plants under Nutrient Stress
Authors: Barker Allen V. , Corey Kenneth A.
Published: September 2022

Ethylene evolution was determined for tomato (Lycopersicon esculentum Mill.) plants grown under nutrient-deficient (N, P, K, Ca, Mg, S) conditions or under full nutrition with NH4+ or NO3 in sand culture. Ethylene evolution increased for plants deficient in K, Ca, or Mg relative to that of plants grown on nutritionally complete solutions with NO3. Deficiency of N, P, or S did not stimulate ethylene evolution relative to that detected from plants grown with complete nutrition with NO3. Physiological stress from NH4+ nutrition produced enhancements in ethylene evolution that exceeded those due to deficiencies of macronutrients.
Effect of pH and Temperature on Sorption of Auxin by Isolated Tomato Fruit Cuticles
Authors: Shafer Warren E. , Morse Ronald D. , Bukovac Martin J.
Published: September 2022

The effects of pH and temperature were determined on NAA sorption by enzymatically isolated tomato (Lycopersicon esculentum Mill. cv. Sprinter) fruit cuticles. Both cuticular membranes (CM) and dewaxed CM (DCM) sorbed more NAA at pH 2.2 than at pH 6.2. At each pH, increasing temperature (15° to 35°C) decreased NAA sorption by both CM and DCM. The same qualitative temperature (5° to 25°) response was observed with 2,4-D for CM at low (0.8) pH. Chemical names used: 2-(1-naphthyl)acetic acid (NAA); (2,4-dichlorophenoxy)acetic acid (2,4-D).
A Risk Management Model for Vegetable Crops
Authors: Rhodus W. Timothy , Precheur Robert
Published: September 2022

The use of micro-computer programs as a management teaching aid has enabled horticulture students to understand economic relationships involved in the production of apples (2, 3), strawberries (4), and selected greenhouse crops (7). By incorporating uncertainty about final crop yield and selling price, these models can be used to generate information about the relative “riskiness” of crop production, where risk is measured by the probability that total revenue will exceed total costs (1, 8). The objective of this research was to develop a micro-computer model that would assist students and/or producers in understanding the economic relationships between yield and price variability and overall risk.
‘Redlander’ Tomato
Authors: Herrington M. E. , Brown P. J. , O'Brien R. G. , Glass R. J.
Published: September 2022

Susceptible tomato (Lycopersicon esculentum Mill.) cultivars in coastal Queensland may suffer substantial losses from bacterial wilt [Pseudomonas solanacearum (Smith 1896) Smith 1914 biovar III] from late spring to autumn (3). Verticillium wilt (Verticillium dahliae Kleb. race 1) can be a major disease from autumn to early spring. A hybrid cultivar, Redlands Summertaste (1), recently was released and is resistant to bacterial wilt, verticillium wilt, and fusarium wilt [Fusarium oxysporum Schlecht, f.sp. lycopersici (Sacc.) Snyder & Hansen race 1 and 2]. However, although this cultivar has high yields (75 to 92 t·ha–1), the jointed fruit attachment and indeterminate growth habit limit returns to growers who have high labor costs. ‘Redlander’ was developed as an inbred cultivar to provide a locally adapted tomato in which resistances to bacterial, verticillium, and fusarium wilts are combined with good fruit quality, jointless pedicel, and determinate growth habit.
Factors Affecting Photosynthesis, Productivity, and Yield
Authors: Kennedy Robert A. , Fox Theodore C. , Loescher Wayne H.
Published: September 2022

The rate and efficiency of photosynthesis (PS) is unquestionably one of the primary determinants of crop yield. Yet, as this symposium illustrates, many other factors contribute to plant productivity. Indeed, the exact relationship between PS rate and yield remains undefined. For several years we have now been interested in factors that affect PS rate in both C3 and C4 plants, not only within the plant, but also external to it. Internal factors affecting PS that will be discussed include leaf age, leaf canopy, photorespiration, stage of plant development (including both vegetative and reproductive phases), and the occurrence of little-recognized metabolic pathways such as polyol synthesis and transport. External factors that affect PS, in addition to obvious environmental determinants such as temperature, light, and water, include the seasonal growth cycle. While we still do not understand how all of these factors interact to affect yield, we are beginning to understand their singular effects. Control of these factors, once thought to be within reach even before the advent of biotechnology, remains likely, but distant.
Yield and Environmental Stress
Authors: Boyer J. S.
Published: September 2022

Plant development is affected by physical stresses of all kinds. The most sensitive time is during anthesis and early fruit growth, when reproductive structures may fail to develop or embryos may abort. Water limitation can cause both effects, and explanatory theories are based on turgor, photosynthate availability, or hormonal relationships. Data will be presented for maize to show that failure of the female flower accounts for reproductive sensitivity to limited water. There is a correlation between sensitivity and the availability of reserve photosynthate that overrides the effects of turgor. The failure of the female flower is attributable partly to inhibited silk growth and partly to arrested development of the entire seed after fertilization takes place.
History and Evolution of Fruit Crops
Authors: Roach Frederick A.
Published: September 2022

The discovery in Anatolia (western Turkey) of carbonized remains of apples (Malus P.) and at Swiss prehistoric sites of apples, walnuts (Juglans regia L.), bullace (Prunus insititia L.), sweet cherry (Prunus avium L.), and European grapes (Vitis vinifera L.) dating back to 6500 bc shows that man had been collecting and using wild fruits as food for many thousands of years (ref. 1, p. 2 and 3). In Britain, the pollen, wood, and fruits of hazel nut (Corylus avellana L.) frequently have been identified in postglacial deposits (ref. 1, p. 227). Hazel nut is indigenous throughout Europe, western Asia, North Africa, and the Caucasus; it has been suggested that the nuts provided a source of food later replaced by cereals (ref. 1, p. 226).
Molecular Markers as Aids for Germplasm Management and Use in Lycopersicon
Authors: Rick Charles M.
Published: September 2022

The following is a brief review of our investigations on problems of germplasm acquisition, analysis, maintenance, evaluation, and use in the Lycopersicon spp. It is based entirely on our published research; hence, only a synopsis will be presented and appropriate citations made to direct readers to full presentation of results and analysis.
Plant Germplasm Information Management System: Germplasm Resources Information Network
Authors: Perry Mark , Stoner Allan K. , Mowder Jimmie D.
Published: September 2022

A critically important aspect of the management of genetic resources is concurrent management of information pertinent to the preserved seeds or plant materials. An effective information system should: a) aid curators of collections by providing current information on inventories, exchange activities, etc.; b) perm it germplasm users to have rapid access to botanical and horticultural information about specific accessions and thereby encourage more effective use of plant germplasm; and c) allow personnel and organizations within and between countries to coordinate activities related to germplasm collection, exchange, and maintenance.
Genetic Considerations in Germplasm Collection and Maintenance: Introduction to the Symposium
Authors: Wehner Todd C.
Published: September 2022

Agricultural workers in many developed and developing countries are interested in collecting, evaluating, and maintaining germplasm of the crop species used in their particular agricultural production systems. However, opportunities to collect germplasm from centers of origin are being reduced as land is developed for agriculture, roads, housing, and other uses. Of the 240,000 angiosperm species thought to exist currently, it is estimated that 50,000 will become extinct by the year 2000 (2). The urgency to collect accessions of useful or potentially useful plant species is driving many germplasm institutions to expand. Thus, administrators of germplasm institutions are worried about their ability to maintain accessions unchanged for use in solving future problems (1). With such a large effort involved in the areas of germplasm collection and maintenance, it is important to use efficient collection methods, as well as proper means to preserve accessions.
Efficient Sampling from a Collection
Authors: Ryder Edward J.
Published: September 2022

The similar titles of Namkoong’s paper and this one invite comparison, not so much for their similarity as for the differences in sampling rationale. The main difference is in the nature of the populations that are being sampled. The population in the field is usually far away. Further, it is of unknown size and its genetic makeup and complexity can only be guessed.
Genetic Considerations in Germplasm Collection and Maintenance: A Summary
Authors: Wehner Todd C.
Published: September 2022

There are some 240,000 species of angiosperms in the world, of which 3000 or more have been used for food at one time or another. Of those, only 30 species are produced in quantities of at least 107 t/year, and 12 major crops supply the world's population with most of its plant- and animal-based calorie intake. Thus, humans are dependent for food on only a few species of the many thousands of flowering plants on the earth.
Methods of Screening Blueberry Seedling Populations for Drought Resistance
Authors: Erb W. A. , Draper A. D. , Swartz H. J.
Published: September 2022

Two methods of evaluating seedling drought resistance in Vaccinium (blueberry) spp. were examined. Twenty interspecific populations were greenhouse-grown and either matric-stressed in a dry 1 sand : 1 soil medium or osmotic-stressed in a nutrient solution containing polyethylene glycol (PEG). In both tests, population means were separated statistically by shoot damage ratings. The correlation (r = 0.46) between the two tests was positive and significant. Progenies of clones JU64 and JU62, which are sister seedlings (V. myrsinites Lamark × V. angustifolum Aiton), were the most drought-resistant. The soil screening test appeared more accurate because it grouped populations with common parentage. These tests indicated that the progenies differ in genetic capacity to resist drought.
Comparison of Two Nitrogen Fertilizer Sources for Highbush Blueberries
Authors: Brown Gerald R. , Wolfe Dwight , Rasnake Monroe
Published: September 2022

Highbush blueberries (Vaccinium corymbosum L.) were fertilized with equal amounts of nitrogen from ammonium sulfate (AMS) or sulfur-coated urea (SCU) for 6 years. The plots treated with SCU yielded significantly more than the AMS plots three out of the five harvest years. Except for plant size in 1984, treatments did not significantly affect berry size, plant survival, and other vegetative characteristics. Soil pH after 5 years was significantly lower on the AMS treatments than on the SCU-treated plots (5.4 vs. 5.7). The nutrient content of the leaf tissue did not differ significantly by fertilizer source. At the rate used in this study, SCU would be an acceptable nitrogen source for blueberries compared to AMS, but SCU is less effective in maintaining low soil pH.
Impact of Ten Spray Adjuvants on Leaf Gas Exchange of Pecan, Blueberry, Photinia, and Azalea
Authors: Andersen P. C. , Mizell R. F. , Knox G. W.
Published: September 2022

Three separate factorial experiments were designed to evaluate the effect of 10 adjuvants on net CO2 assimilation rate (A), leaf conductance to water vapor (g1), and transpiration rate (E) of pecan [Carya illinoensis (Wagenh.) C. Koch] ‘Elliott’, blueberry (Vaccinium ashei Reade) ‘Chaucer’, red top photinia (Photinia × Fraseri Dress), and azalea (Rhododendron × ‘Pink Ruffles’). Single applications of Bond, Leaf Act 80A, Nu-Film-17, Ortho X-77, Penetrator 3, Plyac, Sorba Spray ZNP, Sun Spray 7E, Triton CS-7, or Triton B-1956 at recommended rates did not affect A, g1, or E compared to a water spray. The main effect of plant species was highly significant in all three studies without adjuvant-species interactions. A significant adjuvant effect on A occurred with a second application of Nu-Film-17, Plyac, and Triton B-1956. The only significant effect, when treatments were analyzed separately by species, was that A of Plyac-treated blueberry was less than the control.
Effects of Soil Flooding on Leaf Gas Exchange of Seedling Pecan Trees
Authors: Smith Michael W. , Ager P. L.
Published: September 2022

Roots of 53-day-old pecan seedlings [Carya illinoensis (Wangenh.) C. Koch] were either not flooded or flooded by submerging pots to ≈2 cm above the soil line in containers of water. Leaf gas exchange measurements at 1000 µmol·s–1·m–2 photosynthetic photon flux, 340 µl·liter–1 CO2, and 27°C were made prior to flooding, after 1, 8, or 15 days of flooding, and 7, 14, or 21 days after flooding was terminated. Net CO2 assimilation rate (A) decreased 56% after 1 day of flooding. Flooding 9 or 15 days did not further depress A. Carbon assimilation of trees that had been flooded for 8 days and then returned to nonflooded soil for 7 days were similar to unflooded trees. In contrast, A of seedlings flooded 15 days did not regain the A of unflooded trees 14 days after flooding terminated. Transpiration rates (E) paralleled A in all treatments. Leaf conductance to CO2 (gL) was positively correlated with A (R2 = 0.94). However, leaf internal CO2 (Ci) concentration was not decreased by reduced gL. Water potential (ψl) and turgor potential (ψP) of leaves were higher when trees were flooded, but osmotic potential (ψs) was unaffected.
Verticillium Wilt Resistance in Eggplant, Related Solanum Species, and Interspecific Hybrids
Authors: Alconero R. , Robinson R. W. , Dicklow B. , Shail J.
Published: September 2022

No significant resistance to verticillium wilt (Verticillium dahliae Kleb) was found in 59 eggplant (Solanum melongena L.) accessions, in a sexual hybrid between S. melongena and S. integrifolium, or in eight somatic hybrid clones between S. melongena and S. sisymbriifolium. A relatively high degree of resistance was observed in accessions of S. aculeatissimum, S. scabrum, and S. sisymbriifolium. All 58 accessions of S. gilo tested were susceptible, as were all accessions of S. incanum, S. integrifolium, S. laciniatum, S. macrocarpum, S. mammosum, and S. nodiflorum.
Plantlet Regeneration from Protoplasts of Petunia alpicola
Authors: Ford-Logan Jane , Sink K. C.
Published: September 2022

The isolation, culture, and plant regeneration of protoplasts derived from callus or suspension cultures of Pentunia alpicola Smith and Downs was established. Protoplasts formed macrocalli, at 85% percent plating efficiency, in Murashige and Skoog (MS) liquid medium containing 2,4–D (1.0 mg·liter–1), NAA (0.5 mg·liter–1), BA (0.5 mg·liter–1), and 20% coconut water. Shoot regeneration from macrocalli occurred at 65% frequency on MS containing zeatin (1.0 mg·liter–1), and shoots were readily rooted on either MS containing NAA (0.01 mg·liter–1) or IBA (1.0 mg·liter–1). However, plantlets failed to grow in artificial planting medium. The results provide the basis for somatic cell genetic studies for a Petunia sp. that has distincitive morphology compared to cultivated petunias. Chemical names used: (2,4-dichlorophenoxy)acetic acid (2,4–D), 1-naphthaleneacetic acid (NAA), N-(phenylmethyl)-1H-purin-6-amine (BA), (E)-2-methyl-4-(1H-purin-6-ylamino)-2-buten-l-ol (zeatin), and 1H-indole-3-butyric acid (IBA).
Sugary (su) and sugary enhancer (se) Sweet Corn Inbreds with Resistance to Maize Dwarf Mosaic Virus
Authors: Juvik John A. , D'Arcy Cleora J.
Published: September 2022

Maize dwarf mosaic virus (MDMV), an economically serious viral disease of sweet corn (Zea mays L.) in the United States and other countries of the world, is transmitted primarily by aphid vectors. Early infection by the virus in sweet com can cause stunted growth, delayed maturity, reduced yield, and poor ear quality (11). To provide public and private breeders with germplasm to help alleviate this problem, the Illinois Agricultural Experiment Station announces the release of nine sugary (su) sweet corn inbreds with improved resistance to maize dwarf mosaic virus. These newly developed inbreds have been designated IL793a, IL794a, IL795a, IL796a, IL796b, IL797a, IL798a, IL799b, and IL800a.
Improving Horticulture Internship Programs
Authors: Haque Mary , Lewis Preston
Published: September 2022

In 1980, ASHS completed a survey of internship programs offered at institutions with 2- and 4-year horticulture programs and landscape architecture programs. The results indicated that 50% of 62 responding institutions had internship programs; however, the number of students taking advantage of existing programs was relatively small (1).
Economic Effects of Excessive Vegetative Growth in Deciduous Fruit Trees
Authors: Elfving D. C.
Published: September 2022

Excessive vegetative growth and its control remain significant and often costly problems facing deciduous fruit growers. The term “vegetative growth” is often understood to mean “shoot growth”, since the most visible manifestation of vegetative growth is the development of new shoots each year. Other forms of vegetative growth also occur in deciduous fruit trees, although their impact on productivity is less clearly understood. In this paper, “excessive vegetative growth” will refer to any condition that results in an undesirable amount of shoot growth.
Comprehensive Extension System—The Land-grant Example
Authors: Larsen R. Paul
Published: September 2022

From colonial times to the present, America has prized education as the provider of individual opportunity, as well as our national progress. The value of practical education was delineated clearly with the passage of the Land-grant “Morrill Act” by the U.S. Congress, signed by Abraham Lincoln in 1862. The Land-grant Act provided grants of federal land to every state that agreed to establish at least one college to teach agriculture and the mechanic arts along with other scientific and classical subjects. This and subsequent legislation to support research and extension developed the “trilogy of American ingenuity”—the blended roles of teaching, research, and public service that form both the mission and strength of America's land-grant universities.
Cultural Practices for Using True Seed in Potato Production under Temperate Climates
Authors: Martin Mark W.
Published: September 2022

Potatoes (Solanum tuberosum L.) normally are propagated vegetatively by tubers and produce a uniform, productive, high-quality crop. However, tubers accumulate systemic diseases, which greatly reduce their productivity and quality. Many countries control these diseases with complex and expensive seed certification programs. Such control methods are not available in many other countries where potatoes are an important part of the diet.
Gene Expression in Embryogenesis
Authors: Sung Z. R. , Smith J. M. , Choi J. H. , Krauss M. , Borkird C. , Liu L. -S.
Published: September 2022

The objective of our research is to understand the genetic basis of embryogenesis. Somatic embryogenesis from carrot culture was chosen as the experimental system because of its simplicity and the ease with which it lends itself to obtaining a large number of embryos for genetic and biochemical experiments. Our general philosophy is to avoid media manipulation and to focus on gene expression during embryogenesis. One approach is to isolate genes preferentially expressed at specific stages of embryogenesis, and then to study the role of these genes in development.
Role of ABA in the Regulation of Somatic Embryogenesis
Authors: Ammirato Philip V.
Published: September 2022

Abscisic acid (ABA), a naturally occurring plant growth inhibitor, exerts a number of striking effects on the development of somatic embryos grown in suspension cultures. When added at moderate concentrations to populations of proembryos, ABA permits normal embryonic growth and maturation but inhibits diversions from this pathway. It prevents the initiation and growth of new embryonic centers and the malformation of cotyledons and shoots. In fully formed embryos, it inhibits their germination or conversion into plantlets. ABA also influences cellular differentiation, affecting both anatomy and biochemistry. Its role is to permit the normal progression of the embryonic programs. With ABA, somatic embryos closely resemble zygotic embryos in both structures and behavior. Practically, the manipulation of endogenous or exogenous ABA levels in populations of somatic embryos increases the frequency of embryos that reach maturity and facilitates their manipulation in large scale propagation and mechanized delivery.
Germplasm Determination of in Vitro Somatic Embryogenesis in Alfalfa
Authors: Brown Daniel C. W.
Published: September 2022

More than 1000 higher plant species have been reported to regenerate in vitro via either somatic embryo formation or shoot formation (1, 9, 11, 12, 16, 27, 40, 42, 45, 46). Although many reports of plant regeneration are not accompanied by the necessary developmental or histological evidence for verification, it is apparent that most successes follow an organogenic rather than an embryogenic route. However, regardless of which developmental pathway is followed or the complexity of the protocol that is used ultimately to recover a complete plant, much of the work on in vitro regeneration can be described as empirical in nature.
Introduction to the Symposium
Authors: Anderson George
Published: September 2022

Urban horticulture is an emerging area of interest to the researcher, teacher, landscape architect, city planner, forester, nurseryman, and the public. In today's society, demands are made on plants and man which are often above and beyond anything that could be considered normal for the species. The human animal is expected to work efficiently and effectively amidst austere surroundings of glass and concrete of major cities and to “relax” in busy, often sunless streets. In order to improve this working environment, planners and architects recommend a greater use of plants, the benefits of which have been provided for us by many of the early researchers in design and greenspace architecture. Trees and other woody plants improve the urban environment by screening unwanted views, by reducing noise and air pollution, and by generally improving the well-being of the individuals who come in contact with them. However, we often fall short of success in our search for suitable plants for use in the urban environment.
Ecophysiology of Urban Trees and Their Management—The North American Experience
Authors: Whitlow Thomas H. , Bassuk Nina L.
Published: September 2022

Only a few species are capable of colonizing extreme environments, whereas more moderate environments can support many more. The diversity of species in a habitat is thus controlled by the environment, whether by soil fertility, altitude or any other factor. This diversity reflects the number of species adapted to grow in a habitat, and the nature of this adaptation must be examined in light of the physiological effect of the environmental factors making up the habitat, and their variation in time and space (11).
Scale Propagation as a Method of Measuring Summer-sprouting Tendency in Easter Lily
Authors: Matsuo E. , Ohmachi K. , Arisumi K. , Sakata Y. , Kobayashi M.
Published: September 2022

Summer-sprouting in Easter lily (Lilium longiflorum) occurred more frequently in scale-propagated plantlets than in yearling planting stock. Cultivars without summer-sprouting in scale-propagated plantlets had no summer-sprouting in yearling planting stock. Cultivars having high percentages of summer-sprouting in scale-propagated plantlets also had high percentages of summer-sprouting in yearling planting stock.
‘Park’ Kentucky Bluegrass Response to Foliarly Applied Urea
Authors: Wesely R. W. , Shearman R. C. , Kinbacher E. J.
Published: September 2022

This study was conducted on ‘Park’ Kentucky bluegrass (Poa pratensis L.) established on a Sharpsburg silty clay loam (Typic Argiudoll). Urea was applied at 0, 0.8, 1.6, 2.4, and 3.2 g N/m2 in 35 ml·m–2 of distilled water. Treatments were applied at 3-week intervals beginning 29 Apr. 1980 and ending 2 Sept. 1980. Turfgrass color, quality, clipping yield, total N percentage in clippings, and tissue succulence were highest for 3.2 g N/m2. Maximum N-rate responses occurred during spring and fall and were highest 1 week after treatment. Acceptable turfgrass quality was maintained at 1.6 g N/m2 per application. Nitrogen recoveries based on clipping removal were 49%, 60%, 59%, and 59% for 0.8, 1.6, 2.4, and 3.2 g N/m2, respectively.
Enhancing Seed Germination of Sand Blackberry
Authors: Campbell Peta L. , Erasmus D. J. , Staden J. van
Published: September 2022

Germination was greater for seeds scarified manually or with 15% NaOCl than for those scarified with concentrated H2SO4. Fifteen percent NaOCl for 18 hr scarified the seed endocarp and negated the need for stratification. Germination of 85% was attained after 8 weeks incubation in the light at alternating 15°/30°C. This percentage compared favourably with 82% germination resulting from manual scarification techniques. Electron microscopy revealed that endocarp degradation was much more extensive after 18 hr in 15% NaOCl than after 4 days in a 1% solution.
Effect of Shoot Vigor on Pistillate Flower Production and Abortion in ‘Stuart’ Pecan
Authors: Sparks Darrell
Published: September 2022

In pecan [Carya illinoensis (Wangenh.) C. Koch)], pistillate flower production is positively and abortion is inversely correlated with growth of the supporting shoot. Shoot growth from 1-year-old branches of 4- and 8-cm lengths was increased by pruning all other branches from the supporting limb. Pistillate flower production increased and subsequent abortion decreased with increasing shoot vigor. The results demonstrate a cause-and-effect relationship between shoot vigor and pistillate development and abortion.
Effect of High Temperature on Fruit Set in Tomato Cultivars and Selected Germplasm
Authors: Berry S. Z. , Uddin M. Rafique
Published: September 2022

Selected F3 and F4 lines of different origin were evaluated at high temperature (26° night and 35°C day) in the greenhouse along with several known heat-sensitive and heat-tolerant tomato (Lycopersicon esculentum Mill.) cultivars. A number of the selected lines had fruit set comparable to the tolerant cultivars Saladette, Ohio 7663, BL 6807, and Chico III. The expected greater fruit set of the tolerant cultivars vs. that of the sensitive cultivars was observed. High fruit set in this study was not associated with high seed number in the majority of tolerant cultivars evaluated.
Identification of Mineral Deficiencies Associated with Mango Decline by DRIS
Authors: Schaffer Bruce , Larson Kirk D. , Snyder George H. , Sanchez Charles A.
Published: September 2022

The Diagnostic Recommendation and Integrated System (DRIS) approach was used to identify mineral deficiencies associated with mango decline (a disorder of unknown etiology) of ‘Tommy Atkins’ mango (Mangifera indica L.) trees in the field. Nutrient deficiencies associated with decline were related to the nutrition of entire orchards and not to the nutrient status of individual trees within an orchard. The nutrient imbalance index (NII) was higher for trees in the orchards with the largest percentage of declined trees compared with the healthy orchard. The most deficient elements in orchards with declining trees according to DRIS were Mn, Fe, or a combination of both elements. The concentration of these elements was below the critical value in two of the three declined orchards sampled. Magnesium concentration was generally higher in declined orchards than in healthy orchards. Phosphorus had the most negative DRIS index, but the concentration was still above the critical value in an orchard that contained no declined trees. DRIS determinations from potted trees showing no mineral deficiency symptoms in a previous study also showed P to have the most negative DRIS index. DRIS, when used along with sufficiency ranges, appears to be a useful approach for identifying nutritional deficiencies involved in a mango decline.
An Inexpensive, Microcomputer-based Bulletin Board System for Extension Programs
Authors: Autio Wesley R. , Carroll Kathleen M. , Coli William M. , Leahy Kathleen P. , Cooley Daniel R.
Published: September 2022

A microcomputer-based bulletin board using the FIDO software package was established at the Univ. of Massachusetts for the distribution of information in the cooperative extension programs of home horticulture, fruits, vegetables, cranberries, and integrated pest management. System establishment costs were under $3000, and costs for the first year were about $200 for the maintenance of a telephone line. The system logged 4595 calls from university personnel, county extension staff, state agencies, and farmers during the first year of operation (July 1986 to June 1987). A total of 307 individual information files were uploaded to the system by both university and county extension staff, while 387 downloads occurred from the system.
‘Texas Grano 1105Y’: A Late Maturing, Medium Length Storage Shortday Onion
Authors: Pike L. M. , Horn R. S. , Andersen C. R. , Leeper P. W. , Miller M. E.
Published: September 2022

The development of a late maturing, high yielding, disease resistant shortday onion (Allium cepa L.) with improved shipping quality and medium length storage characteristics was the objective leading to selection and increase of this cultivar.
‘Puget Gold’ Apricot
Authors: Norton R. A. , King J. , Moulton G. A.
Published: September 2022

‘Puget Gold’ is a partially self-fruitful apricot (Prunus armeniaca L.) that has been more prolific and reliable in bearing than other cultivars tested at Northwestern Washington Research and Extension Center, Mount Vernon. Since planting in 1979, it has produced a moderate to heavy crop every year, compared to ‘Skaha’ which did not crop at all in two seasons and set only a few fruits in most years. Because weather conditions at bloom time in early spring can inhibit pollination activity by insects, resulting in poor fruit set, the climate of the cool, moist Puget Sound region is not well suited to apricot production. Moisture-borne fungus diseases also can destroy blossoms and maturing fruit. Seven years' evaluation have shown ‘Puget Gold’ trees to be much better adapted to these adverse conditions than existing cultivars. ‘Puget Gold’ can fill a useful place in home orchards and gardens of western Washington, or other cool maritime climates.
‘Milo’ Cucumber
Authors: Sekioka T. T. , Takeda K. , Tanaka J. S. , Gilbert J. C.
Published: September 2022

‘Milo’, a monoecious slicing cucumber (Cucumis sativus L.) F1 hybrid (Fig. 1), was released by the College of Tropical Agriculture and Human Resources (CTAHR). It was developed for the local market preference for crisp ovary wall. ‘Milo’ is resistant to cucumber mosaic virus (CMV) and watermelon mosaic virus 2 (WMV-2) and tolerant to powdery mildew [Sphaerotheca fuliginea (Schlecht. ex Fr) Poll.].
‘Sovereign Opal’ Grape
Authors: Reynolds Andrew G. , Denby Lyall G. , Strachan Gary E. , Bouthillier Michael
Published: September 2022

‘Sovereign Opal’ grape (Vitis sp.) was developed at the Agriculture Canada Research Station, Summerland, B.C. It is a late-midseason wine cultivar suitable for varietally labelled or generic white wines.
Seed After-ripening and Temperature Influence Butia capitata Germination
Authors: Carpenter William J.
Published: September 2022

Butia fruit coloration at removal from the infructescence indicates the ability of the seeds to germinate. Seeds from yellow-green fruits had significantly lower germination percentages than seeds from bright to dark yellow fruits. Soaking cleaned seeds in deionized water or aqueous GA3 solutions at 1000 ppm for 24 hr following mechanical or acid scarification failed to promote germination. Butia seeds required 90 to 150 days after-ripening at 5° to 25°C before sowing. After-ripened seed sown at 40° and held there for 2 to 3 weeks and at 30° thereafter had 70% to 80% germination and superior vigor. Constant 40° temperature during germination reduced seedling growth. After-ripening and germination at 40° substantially increased total germination and reduced germination time. Time required for germination declined as after-ripening increased from 30 to 150 days.
Salinity Effects on Three Turf Bermudagrasses
Authors: Francois L. E.
Published: September 2022

Bermudagrass (Cynodon spp.), a salt tolerant species, is frequently grown on saline soil. However, new cultivars or accessions used in breeding programs may further increase salt tolerance. Therefore, salt tolerance of the cultivar Tifway II and the accessions Tifton 10 (obtained from China) and Tifton 86 (obtained from Israel) was tested. Plants were grown in the greenhouse in 0.05 m3 pots filled with Pachappa fine sandy loam (mixed, thermic, Mollic Haploxeralf). Four salinity treatments were imposed by irrigating with waters salinized with NaCl and CaCl2 (1:1, by weight). Electrical conductivities of the irrigation waters were 0.9, 6.2, 11.7, and 17.2 dS·m–1. Top growth was measured at nine consecutive harvests. Relative top growth of Tifton 10, ‘Tifway II’, and Tifton 86 was unaffected by soil salinity until the electrical conductivity of the saturated-soil extract (κe) exceeded 2.7, 8.4, and 10.3 dS·m–1, respectively. Each unit increase above these thresholds reduced yield of Tifton 10 by 2.3%, ‘Tifway II’ by 2.8%, and Tifton 86 by 2.5%. These results place Tifton 10 in the moderately tolerant, and ‘Tifway II’ and Tifton 86 in the tolerant salt-tolerance categories.
Influence of Light, Medium, and Fertilization on Growth and Acclimatization of Ponytail Palm
Authors: Wang Yin-Tung , Sauls Julian W.
Published: September 2022

Ponytail palms (Beaucarnea recurvata L.) were grown in three media having similar water holding capacities but different porosities, under 70%, 50%, or 27% full sunlight and fertilized with each irrigation or once every three irrigations. Plants grown in media with lower porosities grew more than plants in a peat-lite medium but required more frequent irrigation. Plants grew less under 27% full sun than at the two higher light levels. Frequent fertilization did not increase plant size but decreased pH and increased electrical conductivity of the growth medium leachate substantially. Plant acclimatization increased with decreasing production light intensity and noncapillary porosity of the medium.
Relationship Between Leaf Area and Dry Matter in Southernpeas
Authors: Rhoden E. G. , Croy L. I.
Published: September 2022

Rapid, nondestructive, and precise methods for measuring leaf area are required to model plant growth, transpiration, and photosynthesis. Five southernpea [Vigna unguiculata (L.) Walp.] cultivars were grown in a controlled environment using a Kirkland silt loam (Udertic Paleustoll) to determine if consistent relationships exist between leaf area, leaf dry matter, and total dry matter. Leaf area and leaf dry matter were closely correlated for the five southernpea cultivars (R2 = 0.90). Furthermore, leaf area and plant dry matter were also highly correlated (R2 = 0.89). The leaf area:leaf dry matter ratios were also consistent for all cultivars throughout the vegetative growth period. Therefore, in studies where leaf area is required, leaf dry matter or plant aerial dry matter may be used to estimate leaf area of southernpeas during the vegetative stage.
Chilling Injury, Peroxidase, and Cellulase Activities in the Peel of Mango Fruit at Low Temperature
Authors: Zauberman Giora , Fuchs Yoram , Rot llana , Wexler Asya
Published: September 2022

Chilling injury (CI) developed on the peel of ‘Keitt’ mango (Mangifera indica L.) fruit that were stored at 5°C and consequently transferred to 20° for ripening. Peroxidase and cellulase activities in the peel of such fruit rose during the development of CI to much higher levels than in nonchilled fruit. The activity of these two enzymes started to increase before any changes in total soluble solids and acid contents of the pulp could be observed. We suggest that the increase in activity of the two enzymes is part of the CI syndrome that develops during storage of mango fruit at chilling temperatures.
Control of Weight Loss and Sprouting of Ginger Rhizome in Storage
Authors: Pauli Robert E. , Chen Nancy Jung , Goo Theodore T. C.
Published: September 2022

Methods were investigated to control weight loss and sprouting of stored ginger rhizome (Zingiber officinale Rosc), including waxing, sprout inhibitors, and gamma irradiation. Rhizomes stored for 3 months at 22°C and 70% RH lost about 20% weight. Waxing of the rhizome did not reduce water loss. Some wax treatments increased the number and length of sprouts. Preharvest application of maleic hydrazide significantly increased the number and reduced the length of sprouts. Postharvest CIPC application significantly reduced the length of sprouts. Vacuum infiltration increased the effectiveness of CIPC in reducing sprout length. Gamma and X-ray irradiation also reduced sprout number and length. Minimum doses of gamma radiation for sprout control was 25 Gy and 120 to 150 Gy for X-ray irradiation if the rhizome was stored for more than 3 months at 22°. A higher dose of irradiation (500 Gy) was required if complete sprout growth control was needed for storage periods <3 months at 22°. Suberization occurred during curing at 22°, but the suberin layer did not completely protect the cut surface. Chemical name used: isopropyl n-(3 chlorophenyl)-carbamate (CIPC).
Correlated Responses to Selection for Low Temperature Germination in Cucumber
Authors: Staub Jack E. , Lower Richard L. , Nienhuis James
Published: September 2022

Seed of four heterogeneous cucumber [Cucumis sativus (L.)] populations (C0-C3) that had undergone recurrent half-sib selection for improved germinability at 15°C were evaluated for seedling emergence and other horticultural characteristics under field conditions. Correlated responses to selection were observed for percent emergence 7 days after sowing and mean number of days to emergence. No correlated response to selection was observed for changes in sex expression, seedling vigor, or yield. These results suggest that selection for low temperature germinability at 15° did not result in any change in the horticulturally important characteristics monitored.
Inheritance of Three Enzyme Loci in Cucumber
Authors: Staub Jack E. , Fredrick Linda
Published: September 2022

The inheritance and linkage relationships among isocitrate dehydrogenase, phosphogluconate dehydrogenase, and peptidase with phenyl-alanyl-proline were determined. Progeny segregations fit a model for a dimeric enzyme encoded by one disomic locus with two alleles. Linkage associations among the three loci were not detectable with recombination fractions ranging between 0.353 to 0.481 among these loci.
Growth of Five Vegetable Crops Treated with the Herbicide Fluazifop in a Greenhouse
Authors: Boucounis Thomas G. , Whitwell Ted , Ogle Wayne L.
Published: September 2022

Weed control is essential for production of high quality vegetables with maximum yields. (±)-2-[4-[5-(trifluoromethyl)-2-pyridinyl]oxy]phenoxy]propanoic acid (fluazifop) is a systemic postemergence herbicide that selectively controls annual and perennial grasses in dicotylendonous crops. In the United States, fluazifop is registered for control of emerged grasses in soybeans, cotton, nonbearing trees, vines, and strawberries, dicotyledonous ornamentals, and fallow land (Imperial Chemical Industries, Inc. 1985; Fusilade-2000 product label I.C.I. Americas, Inc., Agr. Chem. Div., Wilmington, DE 19897). Research has dealt with the safe use of fluazifop in field-grown vegetables at various growth stages (4), but there are no data in the literature describing the effect of fluazifop on greenhouse grown transplants. Therefore, we determined the effect of two rates of fluazifop on the growth and development of five vegetables grown in a greenhouse for transplants.
Using Greenhouse Plant Beds for Demonstrating Plastic Mulch, Trickle Irrigation, and Row Covers
Authors: Decoteau Dennis R.
Published: September 2022

Demonstrations and evaluations of plastic mulch, trickle irrigation, and row cover effects on vegetable crops are primarily conducted in the field (1, 2). However, field evaluations of these procedures during the summer months are often not available for observation by grower groups that traditionally meet during the winter and spring months, or by students in plant production courses taught during the spring or fall semester. This report describes a plant bed system in a greenhouse that could be used for demonstrating plastic mulch, trickle irrigation, and row cover effects on selected vegetable crops regardless of season.
‘LaJewel’ Peach
Authors: Johnson C. E. , Young W. A.
Published: September 2022

‘LaJewel’ is a late season peach for fresh and pick-your-own marketing, maturing about 15 days after ‘Elberta’. Fruits are freestone with yellow flesh. Resistance to bacterial spot [Xanthomonas campestris pruni (Smith) Young et al.] is high.
To Be or Not to Be Dormant: Some Comments on the New Dormancy Nomenclature
Authors: Junttila Olavi
Published: September 2022

I have read the paper of Lang et al. (8) with great interest. The authors propose a new terminology and classification of dormancy based on three main terms: eco–, para–, and endodormancy. I agree with the authors that the present nomenclature, which developed over time, is complex, confusing, and difficult to understand. A wide variety of terms have been used, often even for the same phenomenon, and some terms have several definitions. Lang and coworkers hope to bring clarity to this situation by introducing the terms eco–, para–, and endodormancy. However, I find it difficult to adapt this terminology to a physiological description of dormancy. In my opinion, the new terms Lang et al. contribute to confusion rather than to clarity.