bluuebunny/crossref_metadata_2025 huggingface dataset:
Precocious PI 165561 and Precocious PI 165561R Pumpkin Breeding Lines
Authors: Paris Harry S. , Nerson Haim , Burger Yosef
Published: September 2022

Gene B of Cucurbita pepo L. conditions precocious yellow-fruit pigmentation and is incompletely dominant to its allele, B+ (3). This gene is found in representatives of several C. pepo cultivar groups, including ornamental gourd, zucchini, straightneck, pumpkin, and acorn. In addition to its primary effect, gene B can have a number of secondary effects, such as yellow spotting of leaves, decreased fruit size, reduced yields, bright orange flesh color, increased carotene content of the flesh, and improved flavor. The extent to which a particular secondary effect is manifested is dependent upon the genetic background.
‘Regal’ Sweet Potato
Authors: Jones Alfred , Dukes P. D. , Schalk J. M. , Hamilton M. G. , Mullen M. A. , Baumgardner R. A. , Paterson D. R. , Boswell T. E.
Published: September 2022

‘Regal’ sweet potato [Ipomoea batatas (L.) Lam.] was developed jointly by the USDA, the South Carolina Agricultural Experiment Station, and the Texas Agricultural Experiment Station. This cultivar has high yield and excellent baking flavor in combination with high levels of resistance to a wide array of diseases and insects.
Role of Plant Breeders in Dissemination of Virus Diseases
Authors: Stace-Smith Richard
Published: September 2022

There are relatively few references dealing with the role of man as a virus vector, and none that is so specific as to examine the role of plant breeders in the dissemination of virus diseases. Therefore, I have relied to a large extent on unpublished observations and what I hope is an unbiased interpretation of some selected papers on plant virus epidemiology. Some statements may appear outrageous initially. The following sentence is provocative: “Plant breeders usually possess only a superficial knowledge of plant viruses and the mechanisms by which they are transmitted.” This statement is not intended to belittle the training or competence of plant breeders. It is simply what I consider to be a statement of fact. Further, I suspect it will continue to be true for the foreseeable future. It would be equally true if the statement were reversed: “Plant virologists usually possess only a superficial knowledge of plant breeding and the mechanisms by which genetic factors are transmitted”.
In Vitro Propagation of a Rubber-producing Desert Shrub
Authors: Upadhyaya Abha , Sankhla Narendra , Davis Tim D. , Weber D. J. , Smith B. N.
Published: September 2022

Successful in vitro propagation of white rubber rabbitbrush [Chrysothamnus nauseosus (Pallas) Britt, ssp. albicaulis] was achieved using both stem segments and axillary shoot explants. Medium stem segments (2–3 mm diameter) were more successfully cultured than either small (0.8–1 mm diameter) or large (4–5 mm diameter) explants. Axillary shoot explants (10–15 mm long) began to form roots within 1 week after placement in media containing 5–10 μM (1–2 mg/liter) indolebutyric acid (IBA) or 5.3–10.6 μM (1–2 mg/liter) naphthalene-acetic acid (NAA). Root growth was accelerated in the presence of IBA. In the presence of 8.9 μM (2 mg/liter) benzyladenine (BA) and 0.53μM (0.1 mg/liter) NAA, both medium stem segments and axillary shoots rapidly produced numerous side shoots that were rooted easily on media containing IBA. In vitro culture appears to be a feasible means for the mass multiplication of this potentially important rubber-producing shrub.
Origin of Gynoecism in Squash
Authors: Shifriss Oved
Published: September 2022

Squash (Cucurbita pepo L.) cultivars are monoecious. A phenotypically sensitive gynoecious line, NJ34, was developed through crosses of 3 monoecious inbreds and selection for increasing number of pistillate flowers in plants of several filial generations. NJ34 consists of female and predominantly-female plants under conditions favoring strong male expression. Predominantly-female plants differentiate sporadically 1–3 staminate flowers. The proportion of females is estimated at over 50% with a potential increase of up to 100% under conditions favoring strong female expression. The data show: 1) that NJ34 is later in time of flowering than its monoecious parents, 2) that its females can be converted into monoecism by spraying with an aqueous solution of 250 ppm GA3, and 3) that this line carries gene B for precocious fruit pigmentation.
High Relative Humidity Promotes Blossom-end Rot on Growing Tomato Fruit
Authors: Banuelos G. S. , Offermann G. P. , Seim E. C.
Published: September 2022

Tomato (Lycopersicon esculentum L. ‘San Marzano’) was grown in the greenhouse under normal conditions. After pollination of flowers in the first truss, plants were transferred to growth chambers with either 95% or 55% RH, light and dark temperatures of 18° and 15°C, respectively, and a 16:8 hr, (light:dark) cycle. Blossom-end rot symptoms developed at the distal-end on the young green fruit within 15–16 days at 95% RH. Plant tissues from plants grown at high RH had lower Ca concentrations than comparative tissues of the low RH plants and exhibited increased growth compared to the low RH regime plants. The K content was affected indirectly by the high RH in most of the tested tissues.
Method for Quantifying the Cyanogenic Glucoside, Prunasin in Peach Trees
Authors: Reilly Charles C. , Okie W. R.
Published: September 2022

A method was developed to determine the concentration of prunasin, a cyanogenic glucoside, in bark and twigs of peach [Prunus persica (L.) Batsch] trees. The procedure allowed handling of large numbers of samples with concurrent estimations of reducing sugars and ninhydrin positive materials. Prunasin was extracted with 80% ethanol, concentrated, reacted with β-glucosidase, and the resulting benzaldehyde was detected by gas liquid chromatography (GLC). The technique was rapid and did not require specialty glassware or derivitization of prunasin prior to GLC.
Nitrogen Recovery by Seed Geranium as Influenced by Nitrogen Source
Authors: Cox Douglas A.
Published: September 2022

Seed geranium (Pelargonium × hortorum, Bailey ‘Jackpot’) was grown in 10-cm pots in a peat-pine bark-perlite medium and fertilized with solutions of (NH4)2SO4 (AS), NH4NO3 (AN), Ca(NO3)2-4H2O (CN), CO(NH2)2 (UR), or Osmocote 14N–6.2P–11.6K (OS). Shoot and root growth and shoot N were greatest with AN and least with AS. Greatest N loss by leaching occurred with AS and CN; leaching loss was less with AN and OS and least with UR. In all treatments form of N in leachate reflected N source applied. Proportion of N not accounted for by analysis (lost as a gas) was greatest with AS and UR.
Influence of Lighting Systematics on the Interior Performance of Two Croton Cultivars
Authors: Bequette Barry L. , Blessington Thomas M. , Price James A.
Published: September 2022

Codiaeum variegatum (L.) Blume var. pictum (Lodd.) Mull, Agr. ‘Bravo’ and ‘Normal’ were produced for 8 months under light levels of 950, 650, or 350 μmol s-1m-2 before being held for 4 months indoors under 6, 12, or 24 hr light duration using either cool-white fluorescent (CWF) or incandescent (INC) lamps. After 8 months of growth in production, plant width and leaf length increased whereas leaf number, thickness, and variegation decreased as production light level decreased. The best quality plants with moderate variegation and adequate growth were those produced under 650 μmol s-1m-2. After 4 months indoors, ‘Bravo’ tolerated interior light conditions more successfully than ‘Norma’. Plants previously produced under 350 μmol s-lm-2 retained more leaves and maintained better plant quality than other production light treatments. Leaf retention was best with 12 hr of postproduction light duration. Adequate lighting to maintain the quality of properly acclimatized plants was provided by either CWF or INC lamps.
The Ontogeny of Somatic Embryos from Long-term Callus Cultures of Red Fescue
Authors: Torello W. A. , Rufner R. , Symington A. G.
Published: September 2022

Callus cultures initiated from mature caryopses of ‘Dawson’ red fescue (Festuca rubra L. var trichophylla Gaud.) and maintained on a Murashige and Skoog (MS) medium supplemented with 20 μm of 2,4-D for 18 months retained a high capacity for plant regeneration through somatic embryogenesis. Embryogenic (E) callus tissue was white and compact and usually developed in sectors between friable and translucent nonembryogenic (NE) callus tissue. Total E callus production was 64% after 12 weeks of culture, 32% after 20 weeks, which then stabilized between 18% and 26% for the next 50 weeks. Scanning electron microscopy of E calli after 6, 12, and 18 month culture periods revealed normal and aberrant somatic embryos at all stages of development. After 18 months of culture, all regenerated plants appeared typical of red fescue with the exception of 8% to 12% regeneration of albino plants. Chemical name used: (2,4-dichlorophenoxy)acetic acid (2, 4-D).
Germination Responses of Filbert Pollen to pH, Temperature, Glucose, Fructose, and Sucrose
Authors: Kim S. K. , Lagerstedt H. B. , Daley L. S.
Published: September 2022

Filbert (Corylus avellana L.) pollen germination on sucrose-agar media with B and/or Ca, Mg, and K, was affected adversely by increasing pH. Cultivar differences in germination of pollen were apparent: ‘Tombul’ and ‘Ennis’ germinated well; ‘Hall’s Giant’ intermediate; whereas ‘Barcelona’ and ‘Butler’ showed a poor germination percentage. Germination decreased as temperature increased from 15° to 30°C. Among concentration ranges of the sugars tested at 10% to 25%, sucrose was most effective, glucose permitted good germination at lower concentrations, and fructose inhibited germination.
Quality of ‘Bartlett’ Pears Thinned Chemically and by Hand
Authors: Meheriuk M. , Looney N. E.
Published: September 2022

In British Columbia, ‘Bartlett’ pears are thinned with naphthaleneacetamide (NAAm) applied by gun application at 10 μg-liter (w/v) or with air-blast sprayers at 44 g a.i.ha-1, between 13 and 21 days after full bloom. Concern has been expressed by packinghouse personnel about the storage quality of these pears. Higher incidences of breakdown have been suggested, and no controlled experiments have been reported to substantiate or refute such claims. Therefore, a study was conducted during 1980-1983 to assess several quality parameters of ‘Bartlett’ pears thinned by hand and with NAAm.
Effects of Tree Density on Mortality of Peaches on a Short Life Site
Authors: Horton B. D.
Published: September 2022

Peach tree short life (PTSL) is a serious problem in the southeastern United States. Time of pruning (1, 2, 6), low temperatures (5), rootstock (9), inadequate liming (7), cultural practice (8), fumigation (8), orchard site (2), and the ring nematode, Criconemella xenoplax (Raski) Luc & Raski (8, 4) have been associated with PTSL. An interaction of bacterial canker and time of pruning has been demonstrated (2) and other interactions have been suspected. Certain factors (e.g., over-cropping and drought) might stress the tree and reduce its vitality, thus increasing its susceptibility to bacterial canker or other diseases and/or freeze injury.
‘AUrora’ Muskmelon
Authors: Norton J. D. , Cosper R. D. , Smith D. A. , Rymal K. S.
Published: September 2022

‘AUrora’ is a multiple disease resistant muskmelon (Cucumis melo L.) cultivar developed by the Dept. of Horticulture, Alabama Agricultural Experiment Station, Auburn Univ., adapted to growing conditions in the Southeastern United States. ‘AUrora’ has resistance to downy mildew (Pseudoperonospora cubensis), powdery mildew, (Spherotheca fuliginea), and gummy stem blight (Didymella bryoniae). ‘AUrora’ is especially suited for home, local and commercial markets where “jumbo” size fruit is preferred.
‘NuMex R Naky’ Chile Pepper
Authors: Nakayama Roy M. , Matta Frank B.
Published: September 2022

‘NuMex R Naky’ has been released as a high yielding, long, wide, smooth-fruited chile (Capsicum annuum L.). ‘NuMex R Naky’ is adapted to southern New Mexico; it sets fruit under high day temperatures and low relative humidity. ‘NuMex R Naky’ fruit have a high concentration of extractable red color and exhibit low pungency. ‘NuMex R Naky’ is recommended for home and commercial production of green and red chile in New Mexico.
Do Net Gas Exchange Rates of Green and Red Peach Leaves Differ?
Authors: Marini Richard P.
Published: September 2022

Net gas exchange properties of green and red peach (Prunus persica L. Batsch) leaves were studied. Net photosynthesis, transpiration, and stomatal conductance were similar for both leaf types. Young leaves (about 60% fully expanded) had greater dark respiration rates than fully expanded leaves. Chlorophyll content was greater for green leaves than for red leaves, but did not change consistently as leaves aged. Red leaves contained more anthocyanin than green leaves. Anthocyanin content was similar for green leaves of different ages, whereas anthocyanin declined in red leaves as they aged.
Rate of Water Loss from Detached Leaves of Drought Resistant and Susceptible Genotypes of Cowpea
Authors: Walker David W. , Miller J. Creighton
Published: September 2022

Cuticular resistance to water loss was estimated for drought resistant and susceptible cowpea [vigna unguiculata (L.) Walp.] genotypes in a series of field and greenhouse experiments. The procedure consisted of harvesting the youngest, fully-expanded middle trifoliate leaf of a well-watered plant. The detached leaf was weighed immediately and then allowed to dry in an air-conditioned laboratory (about 25°C). Leaves again were weighed 24 and 48 hr after detachment and then oven dried at 70° for 24 hr. Oven dry weight was used to determine leaf water content (LWC) at each sampling time. Specific drought resistant and susceptible genotypes consistently expressed increased or reduced LWC, respectively, 48 hr after detachment. Interestingly, named cultivars generally had even higher LWC values after drying than did the selected resistant genotypes. Intraspecific variability for the trait appears to exist and may be related to drought adaptation in cowpea.
Sensitivity of Potted Citrus Plants to Top Sprays and Soil Applications of Paclobutrazol
Authors: Bausher M. G. , Yelenosky G.
Published: September 2022

Different concentrations and methods of applying paclobutrazol on citrus plants [Citrus limon (L.) Burm. f.] under greenhouse conditions suggest 102 ppm (a.i.) foliar sprays or 20 mg per 2.5 liter pot are threshold concentrations for visible change in growth and development. Most apparent was reduced shoot extension, largely the result of shortened internodes. The leaves were smaller than those on untreated plants but little changed in length/width ratios. Loss of mass (weight) was mostly in the main stem and primary root. The most effective application method was as a soil drench which induced changes in the root as well as the tops of plants. As a stem-sprout inhibitor, paclobutrazol was less effective than “Tre-Hold.” Chemical names used: β-[(4-chlorophenyl)methyl-α-(l,l-dimethylethyl)-1H,2,4-triazole-l-ethanol (paclobutrazol); 1.15% ethyl 1-naphthalene acetate (“Tre-Hold”).
Micropropagation of Ficus carica L.
Authors: Pontikis C. A. , Melas P.
Published: September 2022

Many plant species now can be propagated successfully through tissue culture. In vitro work with figs has been restricted to attempts to enlongate single shoot tips to obtain plants free of fig mosaic virus (3). The present work was undertaken to develop a method for rapid propagation of Ficus carica L. ‘Kalamon’ to overcome supply problems for high density fig orchards.
‘A. Mackenzie’ Rose
Authors: Svejda Felicitas
Published: September 2022

‘A. Mackenzie’ is a complex hybrid (Rosa sp.) that combines winter-hardiness with free and recurrent flowering and high levels of resistance to blackspot (Diplocarpon rosae Wolf.) and mildew [Sphaerotheca pannosa (Wallr. ex. Fr.) Lév.]. It is the 3rd winter-hardy shrub rose derived from this breeding program; prior shrub rose introductions were ‘John Franklin’ (4) and ‘Champlain’ (5). Compared with ‘John Franklin’ and ‘Champlain’, ‘A. Mackenzie’ shows less winter mortality, is more resistant to blackspot, and has more attractively formed flowers, but it has a shorter flowering season and is less productive than ‘Champlain’.
Introduction to the Workshop on Wastewater Utilization in Horticulture
Authors: Sanderson Kenneth C.
Published: September 2022

Cool, clear water! More than two-thirds of Earth is covered with water, snowfields, glaciers, and ice caps. Water is so common that it has been treated with neglect, if not contempt.
Interspecific Hybridization of Prunus
Authors: Layne Richard E.C. , Sherman Wayne B.
Published: September 2022

Interspecific hybridization is a technique commonly used by plant breeders to transfer genes from one species to another. Interspecific hybrids are usually obtained with greater difficulty than intraspecific hybrids because genetic barriers to hybridization usually increase with an increase in genetic unrelatedness (6, 11, 18, 41). Breeders resort to interspecific hybridization only when the characters are absent or inadequately expressed at the intraspecific level. Stone-fruit breeders have made much use of interspecific hybridization in the improvement of Prunus cultivars and rootstocks (3, 5, 6, 8, 12, 14, 15, 18, 19, 28, 34, 36, 37, 41, 42, 43) particularly in the subgenus Prunophora (plums), because plum species tend to intercross more freely than do members of other subgenera (41, 42). This paper will review the problems that have been encountered in making interspecific Prunus hybrids and the techniques that have been used to overcome them. In addition, techniques are presented that have been employed successfully with other interspecific hybridizations which may have application for Prunus.
Effect of Transplanting Time on Growth and Development of Fraser Fir Seedlings
Authors: Hinesley L. Eric
Published: September 2022

Three-year-old (3-0) Fraser fir seedlings were transplanted into an irrigated transplant bed at 2-week intervals between 1 Aug. and 15 Oct. and once the following spring prior to budbreak. Following one growing season in the transplant bed, seedlings established the previous August and early September had the greatest dry weight, stem diameter, and shoot elongation.
Wood Ash as Soil Liming Material
Authors: Lerner B. R. , Utzinger J. D.
Published: September 2022

Elemental content was determined for ash of Prunus serotina J.F. Ehrh. (black cherry), Celtis occidentalis L. (hackberry), Quercus rubra L. (red oak), and Q. alba L. (white oak), plus a mixture of species containing Pinus (pine), Picea (spruce), and Malus spp. (apple). Ash from the 4 species averaged 26% Ca, 7.0% K, 1% P and smaller amounts of Mg, Mn, Fe, B, Cu, Zn, Pb, Cd, Ni, Cr, Al, and Na. The species mixture was lower in Ca and K but higher in most of the other elements. The effective calcium carbonate equivalent (total neutralizing power or TNP) of the wood ash ranged from 83% (mixed species) to 116% (red oak). Increased rates of application of wood ash increased soil pH. No significant effects of wood ash applied to soil were found on germination, leaf area, leaf number, plant height, fresh weight, dry weight, yield, or leaf tissue elemental analysis of snapbean (Phaseolus vulgaris L.) at 2400-9700 kg/ha.
Yield and Composition of Muskmelon as Influenced by Preplant and Trickle Applied Nitrogen
Authors: Bhella H. S. , Wilcox G. E.
Published: September 2022

Field experiments were conducted to determine N-use-efficiency of muskmelon (Cucumis melo L.) grown in a loamy sand under trickle irrigation and black plastic mulch. Nitrogen rates of 0, 67, or 100 kg N/ha preplant plus 0, 50, or 100 ppm trickle applied N (fertigation) were compared. Significant increases in stem growth, soil NO3-N, petiole NO3-N, and early and total yields generally were attained with increasing preplant N fertilization rates. Muskmelon yield response to increasing N fertigation response was increased in regimes that received no preplant N. Fertigation response was reduced in regimes that received 67 or 100 kg preplant N/ha. A significant curvilinear relationship was established between soil saturation extract NO3-N and petiole NO3-N.
Undergraduate Education is Important, Too!
Authors: Warfield David , Coyne Dermot P.
Published: September 2022

Transplanting is an ancient horticultural practice, which is a good thing because our profession is in need of a transplant—an attitude transplant! I was both encouraged and discouraged as I read Dermot P. Coyne's Presidential Address in the Oct. 1985 issue of HortScience 20:805–808. Encouraged, because he raised points that we need to address; discouraged, because he missed the starting point. Allow me to paraphrase an old saying: “Big grad students from little undergrads grow“. Let me lay it out in the open: I was shocked that our President finds no role for undergraduate education in tackling world hunger. I disagree!
The Pour-through Nutrient Extraction Procedure
Authors: Wright Robert D.
Published: September 2022

Nutrient absorption and subsequent plant growth is related to an adequate supply of the nutrient in the soil solution. Thus, fertilizer practices in a nursery and greenhouse should attempt to maintain nutrient levels in the soil solution that promote optimal growth (2, 3). Maintenance of nutrients for greenhouse and nursery crops is usually via slow-release fertilizer or frequent additions through the irrigation water, where mass flow rather than diffusion is probably the predominant process by which nutrients move to plant root surfaces. In effect, the container medium serves primarily as mechanical support for the plant, and, in contrast to mineral soil systems, nutrients adsorbed to the medium are insignificant in relation to the rate of nutrient uptake and subsequent plant growth. This is particularly true for macronutrients, although the extent that it applies to micronutrients is still not clear.
Rate, Timing, and Slow-release Nitrogen Fertilizers on Bell Peppers and Muskmelon
Authors: Wiedenfeld R. P.
Published: September 2022

Slow-release methylene urea, sulfur-coated urea, and ammonium sulfate fertilizers were applied at different rates and times on muskmelon (Cucumis melo var. reticulatus Naud.) and peppers (Capsicum annuum L.). Increasing N application rate did not affect muskmelon yields, but, in some instances increasing rates up to 134 kg N·ha−1 improved pepper fruit yield and weight. With an increasing N rate, pepper petiole N increased. Timing of fertilizer application did not affect yield of either crop, but application at thinning increased muskmelon fruit weight over preplant application in one instance, whereas the opposite effect occurred in peppers. Split applications and application at thinning increased pepper petiole N content over preplant application in most instances. Early N availability seemed necessary to benefit fruit size and yield, whereas delayed split applications increased only plant N content. Fertilizer source had no effect on either crop in this study. Chemical names used: S-(O-O-diisopropyl phosphorodithionate ester of N-(a-mercaptoethyl)benzene-sulfonamide (bensulide) and N-N-diethyl-2-(1-naphthalenyloxy)propionamide (napropamide).
Tomato Yield as Influenced by Plant Protection Systems
Authors: Perry Katharine B. , Sanders Douglas C.
Published: September 2022

‘Jackpot’ tomatoes (Lycopersicon esculentum Mill.) were grown in 6 plant protection systems with or without black polyethylene mulch. Mulching increased early and total yield of large and marketable fruit and increased total yield of cull fruit. Row covers reduced early yield of large fruit and average large fruit weight. Use of large transplants from 7.5-cm square peat pots tended to increase early marketable yield but decreased early and total average large fruit weight as compared to performance without a plant protection system.
Nitrogen and Plant Spacing Effects on Growth and Fruiting of Potted Highbush Blueberry
Authors: Eck Paul , Stretch A. W.
Published: September 2022

Increasing the rate of N application and the spacing distance between potted 3-year-old highbush blueberry (Vaccinium corymbosum L.) plants ‘Earliblue’ increased fruit production and promoted early ripening. The increased N rate was associated with increased vegetative growth and berry size, whereas the increased plant spacing was associated with an increase in flower bud formation and flower number.
Influence of Summer Pruning on the Growth Pattern of Vigorous ‘Delicious’ Apple Limbs
Authors: Myers Stephen C. , Ferree D. C.
Published: September 2022

‘Delicious’/M9 planted in 1974 were unpruned or pruned on 3 July, 3 Aug., or 3 Sept. 1979, and at a comparable time in 1980. In the distal section, total length and dry weight of lateral shoots were greater on vertical than on horizontal limbs. Lateral shoot length and dry weight were decreased in the distal but not affected in the middle and proximal sections by pruning. Pruning and limb orientation had no effect on the distribution of dry weight in the limb sections. Time of pruning had no influence on the distribution of growth in the limb sections.
Year-round Production of Greenhouse-grown French Tarragon
Authors: Bassuk N.
Published: September 2022

Potted tarragon (Artemesia dracunculus L.) plants were grown in a greenhouse under short days (8 hr) or long days (16 hr), combined with a pretreatment of gibberellic acid (GA3) spray, or several weeks of 4°C cold. Long days promoted shoot growth whereas plants grown under short days grew in a basal rosette form most of the time. Cold pretreatment was not necessary to break dormancy; however, it did significantly increase total production. GA3 pretreatment was not as successful as cold in promoting regrowth. Regular harvest of the foliage stimulated growth under long days.
Electrophoretic Characterization of Lettuce Cultivars
Authors: Mejia Luis , McDaniel Robert G.
Published: September 2022

Seed proteins were extracted from an array of lettuce (Lactuca sativa L.) cultivars. Polyacrylamide gel electrophoresis was employed in a comparative analysis of the soluble proteins and isozymes characteristic of seed from each cultivar. Some fall desert, winter desert, and coastal cultivars were distinguishable based upon variation in soluble proteins or esterase isozymes.
6-BA Applied after Shoot and/or Root Chilling and Its Effect on Growth Resumption in Apple and Peach
Authors: Young Eric , Werner Dennis J.
Published: September 2022

Cytokinin (6-BA) was applied to the dormant shoots of young apple (Malus domestica Borkh.) and peach [Prunus persica (L.) Batsch.] trees after applying all combinations of shoot and root chilling during rest. After greenhouse forcing, bud-break, new shoot dry weight, and new root growth were greatest in apple trees with both shoot and root chilling. In contrast, only shoot chilling was necessary for maximum response in peach. Applied 6-BA substituted for root chilling in apple trees that had only the shoot chilled, resulting in budbreak equal to trees that had both the shoot and root chilled. Applied 6-BA had no significant effect on peach budbreak or new shoot and root growth. Chemical name used: 6-benzyladenine (6-BA).
In Vitro Propagation of Citrus Rootstocks
Authors: Moore G. A.
Published: September 2022

Internodal seedling stem sections of 3 Citrus rootstocks—sour orange (C. aurantium L.), ‘Carrizo’ citrange [C. sinensis (L.) Osb. × Poncirus trifoliata (L.) Raf.], and ‘Cleopatra’ mandarin (C. reshni Hort. ex Tanaka)—were cultured on media containing varying concentrations of BA and NAA. A medium containing 22 μM BA with or without 5.4 μM NAA was optimum for shoot initiation in all 3 rootstock types, but the 3 genotypes varied greatly in numbers of shoots produced. NAA in the medium was inhibitory to shoot production in long-term cultures. Chemical names used: N- (phenylmethyl)-1H-purin-6-amine (BA) and 1-naphthaleneacetic acid (NAA).
A Labor-saving, Nutrient-screening Procedure Using Large-batch Solution Culture
Authors: Rousos Penelope A. , Harrison Helen C.
Published: September 2022

The identification of exceptional genotypes in a breeding program can involve evaluating the responses of large numbers of plants to environmental stress (2). Major hydroponic systems include aerated standing or flowing-nutrient solution, mist, and nutrient film cultures. Flowing solution culture currently provides the most consistent environment for roots, but it is costly and difficult to maintain (1, 3).
A Bachelors Degree: The Right Weapon in the Battle Against World Hunger?
Authors: Warfield David L.
Published: September 2022

What can be done to alleviate hunger and malnutrition in the world? That is a large, complex question! The answers are political, social, religious, and horticultural. It is axiomatic that one of the best approaches to answering a big question is to break it down into a series of smaller questions that can be worked on. One smaller question is: How can we as horticulturalists and as a horticultural society make our most-effective contribution to solving the problem? The answer I propose is to increase our emphasis on undergraduate education.
Integrating International Agricultural Development Activities in Land-grant Universities and Colleges
Authors: Oyer Edwin B.
Published: September 2022

A recent World Bank report (8) classed over half (73 of 125) of the countries listed in its World Development Indicators as low-income or lower middle-income economies. Their per capita gross national products (GNP) are less than $1700, with a range of $80 to $1630. Agriculture contributes from 24% to 75% of their national gross domestic products, and a majority of their citizens live in rural areas although they may not be directly involved in farming. The adult literacy rate for these countries ranges from 5% to 95%. The authors state that “Agricultural production is a key factor in the development of most countries. In the poorest countries, it is critical.”
A Horticulturist's View of International Agricultural Strategies
Authors: Eisa Hamdy M.
Published: September 2022

Each country has its own agricultural strategy, based on many interrelated factors—e.g., its own natural and human resources, system of government policies, contribution of agriculture to the economy, and trade relations with other countries. No country can afford to claim complete self-sufficiency in its agricultural production. Furthermore, agricultural strategies are related to strategies in other sectors—e.g., population, education, industry, energy, transport, etc. Because of the complexity of the subject, this paper will concentrate on the factors to be considered in determining an agricultural strategy. It will also examine some of those factors as they relate to horticultural development strategies for some of the Middle East countries. Prior to addressing the main topics of this paper, however, a brief description of the World Bank and its role in agricultural development for member countries is in order.
Agriculture and Rural Development Strategy
Authors: Steen Dwight , Kretchmer Paul
Published: September 2022

In the 13 countries and Caribbean islands where the U.S. Agency for International Development (AID) has programs in Latin America, the agricultural sector is still the dominant economic force. Over half the population of these countries lives in rural areas, in spite of high migration rates to the cities. Agriculture is the primary economic activity: Agriculture generates 68% of the foreign exchange necessary to buy imported products; it contributes 20% of the gross domestic product of these economies; agriculture is the single most important source of employment (employing from 40% in Peru to 70% in Haiti) of the entire labor force; and agriculture contributes about 50% of the value added to these economies.
Introduction to the Symposium: An Extension Worker's View
Authors: William Ray D.
Published: September 2022

Extension workers often identify production, marketing, managerial, or educational constraints that reduce agricultural efficiencies. In Oregon, problems expressed by growers of several horticultural crops appeared to have a common soil management component. Some Christmas tree growers, for example, complained about poor vigor and growth of 2nd- or 3rd-cycle trees that were planted immediately after harvest of the previous crop. Growers reasoned that poor growth (and reduced marketability) might be caused by increasing concentrations of herbicide residues that resulted from yearly applications of atrazine or hexazinone, rather than soil erosion and related soil management problems. Grape producers and lily bulb growers were concerned about soil erosion, since crops were planted parallel to the slope. Frequent mechanical harvesting of brambles led to growers’ fears of soil compaction, while fruit growers noted slower rates of water infiltration in orchards where natural vegetation is managed with a flail compared to areas interplanted with a sod.
Grass Interplanting in Horticulture Cropping Systems
Authors: Butler Jack D.
Published: September 2022

Of the 5000 grass species identified worldwide, more than 1400 may be found in the United States (17). The potential benefits of interplantings in horticultural crops justifies the effort to identify the most appropriate grasses for this practice. Grass interplantings are used to reduce erosion, increase water infiltration into the soil, improve traffic-carrying ability, improve soil structure, limit weed invasion, moderate soil temperatures, and reduce soil contamination of crops. Disadvantages in using grasses for interplantings include increased competition for water and nutrients, harborage of pests, and expense of establishment and maintenance.
Weeds and Integrated Pest Management Systems
Authors: Norris Robert F.
Published: September 2022

Growing a single crop species (monoculture) has dominated agricultural systems in the United States in the last 50 to 75 years. Monoculture has been favored primarily because of mechanization with concomitant reductions in production costs. Some pest management specialists have thought that monoculture of crops may lead to increased insect, nematode, and disease problems. Weed management is probably more easily accomplished in large fields with monocultured crops than in small-scale farming employing polycropping techniques.
Predicting Effects of Modified Cropping Systems: Forestry Examples
Authors: Radosevich Steven R. , Wagner Robert G. , Orcutt Deborah R.
Published: September 2022

Small conifers often must coexist with the components of early plant succession for prolonged periods of time in forest regeneration. Forest regeneration and the management of perennial horticultural crops are similar in this respect, since individual “crop” plants in both instances usually occur in close proximity to each other or associated species. Association of the crop with its neighbors may be detrimental in both situations (10, 15), but other interactions also are possible (8). Thus it is necessary for forest managers and horticulturists to recognize the physical, physiological, and environmental components that influence the outcome of plant-to-plant associations. It also is necessary for land managers (foresters, horticulturists, etc), to understand the consequences of their actions, since short-term impacts on vegetation can have long-term influences on environmental resource availability, subsequent vegetation, and the populations of other organisms. Long-term impacts of management are not exclusive to forest regeneration, but the need for prediction may be most obvious there because of the relative longevity of forest communities in comparison to most of those in agriculture.
Growth and Fruiting of ‘Heritage’ Primocane Fruiting Red Raspberry in Response to Paclobutrazol
Authors: Braun Joseph W. , Garth Jeannie K. L.
Published: September 2022

Paclobutrazol (PP333) was applied to dormant ‘Heritage’ primocane fruiting red raspberry (Rubus idaeus L.) plants at dosages of 0, 6, 12, 24, 48, and 96 mg a.i.·0.37 m−2 ·hill−1. After 29 days of fruit production, the average cumulative fruit yield of primocanes treated with 24, 48, or 96 mg of paclobutrazol was 92% greater than for control primocanes. The cumulative fruit yield of primocanes receiving the 24-mg dosage remained significantly greater through 50 days of production compared to that of control primocanes. Cumulative fruit yield was not adversely affected at any time during the production season by any of the dosages applied. The 24-mg dosage suppressed final primocane height by 19% but did not significantly decrease primocane diameter or the number of nodes formed. The vegetative responses to 48- and 96-mg dosages were similar, with an average reduction in primocane height, diameter, and total number of nodes formed of 36%, 25%, and 14%, respectively. Early onset of anthesis was positively correlated (r = 0.72) with suppression of vegetative growth. Production midpoint occurred 60 ± 3.7 days after initial anthesis and varied (r = 0.85) with the date of first anthesis. Chemical name used: β-[(4-chlorophenyl)methyl]-α-(1,1-dimethylethyl)-1H-1,2,4-triazole-1-ethanol (paclobutrazol).
Kentucky Bluegrass Cultivar Evapotranspiration Rates
Authors: Shearman R. C.
Published: September 2022

Twenty well-watered Kentucky bluegrass (Poa pratensis L.) cultivars were evaluated for evapotranspiration (ET) under controlled environment, using the water-balance method. ET ranged from a low of 3.86 mm·day−1 for ‘Enoble’ to a high of 6.43 mm·day−1 for ‘Merton’, ‘Birka’, and ‘Sydsport’. Cultivars differed in shoot density, verdure, root density, stomatal density, and stomatal index. Only verdure was significantly correlated (r = 0.60) to ET for the 20 cultivars. Five cultivars were selected using cluster analysis to represent categories of high, medium, and low ET rates. ET for these cultivars increased from 1.1- to 1.7-fold when temperature was increased from 25° to 35°C, depending on cultivar. ET at 35° was positively correlated to vertical elongation rate (r = 0.96), and negatively correlated to shoot density (r = − 0.87) and verdure (r = − 0.83) under well-watered conditions.
A Systems Analysis of Postharvest Handling of Fresh Snap Beans
Authors: Shewfelt R. L. , Prussia S. E. , Jordan J. L. , Hurst W. C. , Resurreccion A. V. A.
Published: September 2022

The postharvest handling system of fresh market snap beans (Phaseolus vulgaris L. cv. Sprite) was analyzed to determine steps of greatest quality deterioration. A decrease in ascorbic acid concentration was the only consistent quality change noted between the arrival at the packinghouse and departure from the wholesale warehouse. Quality differences in percentage of fiber, percentage of seeds, color, hue angle, moisture, ascorbic acid, and sensory texture attributes observed in beans from different packinghouses suggest that cultural and harvesting factors are most critical. Short market shelf-life is a major limitation in marketing.
Development of Forecasting Equations for Apple Storage Disorders: The Tobit Model Versus Linear Regression
Authors: Autio Wesley R. , Weis Sarah A. , Bramlage William J.
Published: September 2022

Forecasting equations for predicting poststorage senescent breakdown from prestorage fruit Ca concentrations were developed for ‘McIntosh’ and ‘Cox's Orange Pippin’ apples using classical linear regression and the Tobit model. A comparison of the 2 regression methods was also made using 2 hypothetical data sets. Where the dependent variable was limited and a significant portion of the data was at the limit, as with ‘McIntosh’ apples, the Tobit model provided a superior forecasting equation. However, in cases where the dependent variable was not limited or it was limited and a significant portion of the data was not at the limit, as with ‘Cox's Orange Pippin’ apples, classical linear regression and the Tobit model produced similar forecasting equations.
Farming Systems Research Applied to Direct Market Vegetable Production in Texas
Authors: Steinberg S. L. , Novak J. R. , Vamosy M. L. , McCraw B. D.
Published: September 2022

A market-based farming systems research approach was used to analyze the vegetable production system for direct-to-consumer retail and wholesale marketing at the Dallas Farmers’ Market. The majority of farms produced 3–10 different vegetables for a harvest and marketing season of 4 months or more per year, irrespective of their size of operation or status as a full or part-time farmer. Watermelon, cantaloupe, sweet potato, squash, tomato, and southern pea were most commonly produced. Extensive use of leased land supported the production system by allowing land rotation or specific soil type selection. From this survey, a profile of the typical production unit was developed for use in research and extension.
Factors Affecting Intumescence Development on Potato Leaves
Authors: Petitte J. M. , Ormrod D. P.
Published: September 2022

Potato plants (Solanum tuberosum L.) were propagated in controlled environments from tubers or stem cuttings and exposed to SO2 and/or NO2. Cultivar, propagation method, and air quality affected intumescence formation on leaves. Tuber-propagated ‘Kennebec’ and ‘Russet Burbank’ plants developed intumescences in clean air, SO2, or NO2, but not in a SO2-NO2 mixture, whereas tuber-propagated ‘Superior’ and ‘Norchip’ had little or no intumescence formation. Cutting-propagated ‘Kennebec’, ‘Russet Burbank’, and ‘Norchip’ plants had no intumescence development. Intumescence development may be related to carbohydrate status of plants and maturity classification of cultivars.
Reduction of Chlorophyll in Cabbage Leaf Disks Following Cu2+ Exposure
Authors: Rousos Penelope A. , Harrison Helen C. , Palta Jiwan P.
Published: September 2022

Cabbage leaf disks (Brassica oleracea L., Capitata group) were floated (adaxial side up) in Cu2+ solutions (0, 0.16, and 0.40 mm Cu2+) for 1–4 days. The experiments were conducted in both light and dark environments. In light, total chlorophyll, chlorophyll a, chlorophyll b, and chlorophyll a/b ratios declined linearly with increasing exposure duration and Cu2+ concentrations. The rate and magnitude of these declines were unaffected by the addition of 0.5 mm CaCl2. Between the 2 cultivars tested, the relative chlorophyll contents in ‘Market Prize’ declined faster and reached lower levels than ‘Resistant Danish’, suggesting that ‘Market Prize’ is more susceptible to Cu2+stress. In the absence of light, there was little difference between the chlorophyll loss in the controls and Cu2+-treated tissue. For light and dark experiments, loss of chlorophyll a was primarily responsible for reductions in total chlorophyll content and in chlorophyll a/b ratios.
Thidiazuron Stimulation of Apple Shoot Proliferation in Vitro
Authors: Nieuwkerk J. P. van , Zimmerman Richard H. , Fordham Ingrid
Published: September 2022

Thidiazuron stimulated shoot proliferation on shoot tip explants of ‘Gala’ apple (Malus domestica Borkh.) when incorporated in Linsmaier-Skoog medium at concentrations of 10, 1, and 0.1 μm. Shoot numbers with thidiazuron were equivalent to, or greater than, the number produced when using 4.4 μm BA in the medium, but the shoots were shorter than with BA. At 10 and 1 μm thidiazuron, shoot leaves were narrow, had pointed laminae, and were somewhat distorted. Shoot proliferation continued when explants from the 2 highest thidiazuron concentrations were transferred to cytokinin-free medium. Shoots from cultures grown at all 3 concentrations of thidiazuron rooted after 1 to 2 subcultures on cytokinin-free medium. Chemical names used: N-(phenylmethyl)-lH-purin-6-amine (BA) and N-phenyl-N′-l,2,3-thiadiazol-5-ylurea (thidiazuron).
‘Silver Sheen’, an Imposter Clone of Waukegan Juniper
Authors: Hatch Laurence C. , Fantz Paul R.
Published: September 2022

‘Silver Sheen’ is a densely procumbent cultivar of Juniperus horizontalis Moench with steel-blue foliage that turns uniformly silvery-grey in winter. The cultivar is suitable for use as a ground cover or large container plant. ‘Silver Sheen’ is an improved selection of ‘Douglasii’, the widely marketed Waukegan juniper.
Paclobutrazol and Night Interruption Lighting Affect Episcia Growth and Flowering
Authors: Stamps Robert H. , Henny R. J.
Published: September 2022

Episcia cupreata (Hook.) Hanst. ‘Pink Panther’ plants were drenched with 0, 0.07, or 0.21 mg a.i. paclobutrazol and given night interruption lighting (NIL) of 4 hr (2200-0200 hr) at 2.6 μmol·s−1·m−2 or no light interruption. Paclobutrazol and NIL did not affect days to first flowering, while flower numbers per plant increased exponentially over time on paclobutrazol-treated and control plants. NIL increased flowers per plant from day 47 on. Flower longevity was greater on paclobutrazol-treated plants than controls. Plant size (canopy radius) was reduced by paclobutrazol, which caused a greater flower density per canopy area. Chemical name used: (R*, R*)-(±) β-[(4-chlorophenyl)methyl]-α-(l,l-dimethylethyl)-1H-l,2,4-triazole-1-ethanol (paclobutrazol).
Effect of Storage Temperature on Sugar and Organic Acid Contents of Watermelon
Authors: Chisholm Duane N. , Picha David H.
Published: September 2022

Sugars and organic acids in ripe ‘Charleston Gray’ and ‘Jubilee’ watermelons [Citrullus lanatus (Thunb.) Matsum & Nakai] were measured at harvest and after 14 or 19 days of storage at 0°, 7°, 16°, 23°, or 27°C. Soluble solids content (SSC), sucrose, fructose, and glucose concentrations mostly did not change during storage at 0°, but all generally were reduced at the higher temperatures. ‘Charleston Gray’ contained about 3% to 4% sucrose, 2% to 3% fructose, and 1.0% to 1.5% glucose. Fructose was the major sugar in ‘Jubilee’, followed by sucrose and glucose. Malic acid was the major organic acid in both cultivars. Temperature of storage had little effect on malic acid concentration. The concentration of citric acid decreased during storage at 23° or 27°, but not consistently at low temperatures.
Effects of Gene B in Cucurbita moschata
Authors: Paris Harry S. , Nerson Haim , Zass Nurit
Published: September 2022

The effects of gene B in Cucurbita moschata Poir. were studied by comparing 2 near-isogenic lines, PI 165561 (B+B+) and Precocious PI 165561 (BB) at 2 locations in Israel. B significantly increased femaleness and number of fruits, but decreased fruit size and yield and numerically decreased seed yield at one or both locations. Fruits of B+B heterozygotes were distinctly bicolor. There was a deficiency in the number of bicolor-fruited plants in BC6 progeny, the deviation from the expected 1:1 ratio of green-fruited to bicolor-fruited being significant. Overall, the effects of B in C. moschata were no different from its effects in C. pepo L.
Variability in Rubber and Resin Content Within and Among Eight Guayule Cultivars
Authors: Naqvi Himayat H.
Published: September 2022

Mean rubber concentration of 3-year-old guayule (Parthenium argentatum Gray) ranged from 7.37% to 9.72% among 8 cultivars. Resin concentration ranged from 4.48% to 6.69%. All cultivars were homogeneous for rubber and resin concentration, except N565. Rubber concentration was highly correlated with resin concentration.
Rapid Multiplication of Heuchera sanguinea Engelm. ‘Rosamundi’ Propagated in Vitro
Authors: Stapfer R. E. , Heuser C. W.
Published: September 2022

Shoots tips from in vitro cultures of Heuchera sanguinea Engelm. ‘Rosamundi’ were cultured on a modified woody plant medium containing one of 3 cytokinins (BA, 2iP, kinetin) or cytokinin plus NAA. BA and kinetin were the most effective stimulators of axillary shoot growth. Maximum shoot production (≥1 mm) occurred with 2, 4, 8, and 16 μm BA, or 16, 32, and 64 μm kinetin. The addition of NAA had no effect or reduced the number of shoots produced. Because of the rosette growth pattern, rooting of the resultant shoots was best accomplished by placing whole cultures in a soilless medium under high humidity and later dividing the rooted shoot masses. Chemical names used: N-(phenylmethyl)-1H-purin-6-amine (BA); N-(3-methyl-2-butenyl)-1H-purin-6-amine (2iP); N-(2-furanylmethyl)-1H-purin-6-amine (kinetin); and 1-naphthaleneacetic acid (NAA).