bluuebunny/crossref_metadata_2025 huggingface dataset:
Embryo Development in ‘Tonda Gentile delle Langhe’ Hazelnut
Authors: Me Giovanni , Emanuel Enrica , Botta Roberto , Vailania Rosalina
Published: September 2022

‘Tonda gentile delle Langhe’ hazelnut bloomed from 22 Dec. to 19 Jan. Fertilization occurred about 5 months later, in the last 10 days of May. In the first days of June, the embryo was globular whereas the free nuclear endosperm had started to become cellular. Around the middle of June the embryo was heart-shaped and the endosperm was entirely cellular. In the following 2 weeks, the endosperm became vacuolated and then disintegrated. Cotyledons formed (torpedo stage) and grew quickly, filling the ovule by the end of June. The seed had its final shape and dimension by 20 July, but the embryonal axis continued elongating until nut maturity, 15 to 30 Aug. Mature embryos contained six to eight leaf primordia, the apical meristem, and the radicle.
Association of Sweet Cherry Epidermal Characters with Resistance to Monilinia fructicola
Authors: Biggs Alan R. , Northover John
Published: September 2022

Fruit from seven sweet cherry (Prunus avium L.) cultivars were harvested at full ripeness and inoculated under controlled conditions with conidia of the brown rot fungus Monilinia fructicola (Wint.). Cherries were assessed for incidence of brown rot, length of the incubation period, and number of conidia produced per fruit. Non-inoculated fruit were examined microscopically and the thicknesses of the cuticle and the external epidermal cell wall were determined. Percent infection and numbers of conidia produced per fruit were correlated negatively, and incubation period was correlated positively, with the thickness of the outer epidermal cell wall of the fruit.
An Expert System on a Microcomputer for Determining Apple Tree Spacing
Authors: Crassweller Robert M. , Heinemann Paul H. , Rajotte Edwin G.
Published: September 2022

Apple orchards are highly diversified and complex ecological and economic systems. Production is affected by a wide range of insect, disease, weed, and mammalian pests, and is subject to the same economic and social constraints as any business enterprise. A computer technology, expert systems (ES), is being used to assist fruit growers, county extension agents, and private consultants in making better decisions about the complex horticultural, entomological, and pathological orchard problems.
Pecans Show Little Response to Low Rates of Applied GA and BA
Authors: Worley Ray E.
Published: September 2022

Gibberellic acid (GA) and benzylamino purine (BA) induce many growth and fruiting responses in plants (Davies, 1986; Elkner and Coston, 1986; Forshey, 1982; Green, 1980; Jones, 1973; Unrath, 1974). This study was conducted to determine some vegetative, flowering, and yield responses of pecan trees to low rates of BA and GA.
E7-47, E7-54, E29-56, and E31-10 Apple Germplasm with Multiple Pest Resistance
Authors: Goonewardene Hilary F. , Howard Paul H.
Published: September 2022

E7-47, E7-54, E29-56, and E31-10 apples (Malus × domestica Borkh) were found resistant to apple scab, [Venturia inaequalis (Cke.) Wint.] in greenhouse tests and in the field. Field and laboratory resistance to red-banded leafroller [Argyrotaenia velutinana (Walker) in E7-47, European red mite [Panonychus ulmi (Koch)] in E7-54, apple maggot [Rhagoletis pomonella (Walsh)j in E29-56, and to codling moth (Laspyresia pomonella L.) in E31-10 were also found. E31-10 was also found to have resistance to European red mite in the field and greenhouse. E7-47, E7-54, E29-56, and E31-10 have been released as advanced pest- and disease-resistant germplasm lines by the ARS/USDA to interested apple breeders for use in breeding programs. The scientific names of diseases and insects mentioned in this release are as reported by the USDA (1960) and Sutherland (1978).
Horticulture in Morocco: North Africa’s California
Authors: Janick Jules
Published: September 2022

Morocco is an ancient kingdom and an emerging nation occupying a strategic bridge between northwest Africa and Europe. The most westerly nation of the Maghrib (the western Islamic world of North Africa that includes present-day Morocco, Tunisia, Algeria, and western Libya), Morocco borders both the Atlantic Ocean and the Mediterranean Sea, separated from Europe’s Iberian peninsula by the narrow straits of Gibraltar (Fig. 1). Geographically, Morocco is African, but there are close links to the Middle East and the Islamic world as well as to Europe via France and Spain.
Aesculus ‘Autumn Splendor’
Authors: Bergmann Ben A. , Pellett Harold M. , Hackett Wesley P.
Published: September 2022

The members of the genus Aesculus, known as buckeyes and horsechestnuts, includes trees commonly planted in parks, arboreta, college campuses, and home landscapes (2). Aesculus ‘Autumn Splendor’ is a selection that combines leaf scorch resistance, cold hardiness in USDA zone 4a, handsome flowers, and brilliant fall color to make it a particularly desirable medium-sized landscape tree.
Statistical Analysis of Experiments with Repeated Measurements
Authors: Littell Ramon C.
Published: September 2022

Experiments with data collected at several points in time on the same sampling unit are called experiments with repeated measurements or repeated measures experiments. The sampling unit is usually a plant in a greenhouse experiment or a plot in a field experiment. Objectives are usually to investigate response over time, often growth of a plant, to several treatments. These experiments have been called split-plot in time experiments (Steel and Torrie, 1960) because data are often analyzed in a split-plot fashion, taking time as the subplot factor. The term “split-plot” in reference to experiments with repeated measurements has fallen into disfavor (Damon and Harvey, 1987; Little and Hills, 1978; Snedecor and Cochran, 1980; Steel and Torrie, 1980; Yates, 1982). This change is in part due to the fact that experiments with repeated measurements are not true split-plot experiments because time is not an experimental factor whose levels are randomly assigned to subplot units. Therefore, mathematical conditions required for validity of the split-plot type of analysis of variance might not hold. Furthermore, objectives of repeated measures experiments are usually different from objectives of split-plot experiments. In the general statistical literature, the expression “univariate repeated measures analysis of variance” usually refers to the split-plot type of analysis of variance, and the term “subject” refers to a sampling unit. Mainplot and subplot portions of an analysis of variance in the split-plot vernacular are more generally referred to as the between- and within-subjects portions of the analysis, respectively. Computer programs, such as SAS GLM and ANOVA (SAS Institute, 1985) use the terminology of the general literature.
Statistical Analyses and the Personal Computer
Authors: George A , Milliken  , Remmenga M. D.
Published: September 2022

The initial goal of this paper was to evaluate several PC-software packages as to their capabilities to carry out appropriate analysis of variance procedures and provide appropriate and necessary output. To date, most software reviews have concentrated on how well the computations for regression analysis are carried out. The reviews generally indicate the size of analysis of variance problems that can be handled, as to whether the program will do unbalanced and balanced analysis of variance computations, and as to the capability to provide multiple comparison procedures. But, such reviews do not indicate whether the claimed analyses are computed and presented correctly. Unfortunately, the grand goal of providing such comparisons for a large number of PC-based software packages is not achieved. There are at least two reasons for not completing the task.
Growth and Carbohydrate Distribution of Young Apple Trees in Response to Root Pruning and Tree Density
Authors: Ferree David C.
Published: September 2022

Root-pruning young greenhouse-grown MM.111 apple trees decreased leaves per tree, total leaf area, and dry weight of leaves, shoots, and roots. Root pruning had no influence on the carbohydrate fractions in the leaves or shoots, but caused an increase in soluble and insoluble fractions in the roots. No interaction occurred between root pruning and number of trees in the container. As number of trees per container increased, leaf, shoot, and total dry weight per plant decreased. Root pruning decreased shoot growth for 3 weeks after root pruning, with a return to the unpruned shoot growth rate in the 4th week. Photosynthesis and transpiration were reduced by root pruning, but not affected by tree density.
Evapotranspiration Rates of Turf Weeds and Groundcovers
Authors: Fry Jack D. , Butler Jack D.
Published: September 2022

Small weighing lysimeters were used to determine potential evapotranspiration (ET) (i.e., ET when soil water is not limiting) rates of turf weeds and ground-covers. When ET was monitored during two consecutive summers, white clover (Trifolium repens L.) had the highest mean water use rate (7.4 mm·day-1). Dichondra (Dichondra repens J.R. Forst. and G. Forst.), a low-growing C4 dicot, and barnyardgrass [Echinochloa crusgalli (L.) Beauv.], a C4 monocot, used the least water (3.9 and 4.1 mm·day-1, respectively). ‘Merion’ Kentucky bluegrass (Poa pratensis L.), a C3 species, and yellow foxtail [Setaria glauca (L.) Beauv.] and smooth crabgrass [Digitaria ischaemum (Schreb.) Muhl.], C4 species, exhibited intermediate ET rates. Water use rates of these ground-covers should be considered when using them in landscapes. Eradication of some weeds, such as white clover, in well-watered turf areas may be an effective means of reducing ET.
Drought Stress Induces Fruit Abortion in Pecan
Authors: Sparks Darrell
Published: September 2022

Fruit abortion in three cultivars of pecan [Carya illinoensis (Wangenh.) C. Koch] was compared during the 1986 drought. Fruit abortion in ‘Caddo’, ‘Western’, and ‘Cape Fear’ was, respectively, 36, 28, and 6 times greater from drought-stressed than from irrigated trees. These results may reflect cultivar differences in drought tolerance and/or differences in available soil moisture. The data also suggest that the third fruit drop in pecan is sensitive to water stress.
Fruit Germplasm Preservation
Authors: Hummer Kim
Published: September 2022

The cover photograph, by Joseph Postman, Plant Pathologist, USDA/ARS, demonstrates a portion of the unique diversity of Pyrus germplasm within the collection at the National Clonal Germplasm Repository (NCGR) in Coivallis, Ore. Each of the fruits in the photograph is a pear species, hybrid, or cultivar.
Scientific Poster Lettering and Display
Authors: Hershey David R.
Published: September 2022

ASHS specifies that minimum heights for poster lettering be 25 mm for the titles, authors, and institutions and 12.5 mm for everything else (ASHS, 1988). A survey of 167 posters in Poster Session 1 at the 1988 Annual Meeting indicated that these required minimum lettering sizes are usually not met (Table 1). One reason why these minimums are rarely met is that the minimum heights are unrealistic. The minimum heights were established for 2.4 × 1.2-m posters and not reduced when poster area was halved to 1.2 by 1.2 m. The 1:1 ratio between title and author/institution letter heights is not proportional because title lettering is nearly always taller than author/institution lettering. For example, HortScience titles are 5 mm tall with author/institution lettering 2.5 mm high. Thus, the smaller lettering for authors/institutions compared to titles on ASHS posters is understandable.
First-year Shoot Development and Carbohydrate Distribution in Fall-and Spring-planted Apple Trees
Authors: Young Eric
Published: September 2022

Fall- and spring-planted spur ‘Delicious’ trees were monitored for first-year spur and shoot development and major carbohydrate levels in 1986 and 1987. Fall planting resulted in significantly greater shoot extension growth and lower tendency to become spurbound than spring planting during both years for two strains of spur ‘Delicious’. Higher starch reserves were found following the growing season after fall planting than after spring planting. A root dip of 10,000 mg a.i. IBA/liter before spring planting in 1987 did not affect any of the characteristics measured. Chemical name used: lH-indole-3-butyric acid (IBA).
Growth and Development of Young ‘Loring’ Peach Trees after Foliar Sprays of Paclobutrazol and GA3
Authors: Casper Joyce A. , Taylor Bradley H.
Published: September 2022

Container-grown ‘Loring’/Lovell seedling peach trees [Prunus persica (L.) Batsch] trained to four current-season extension shoots (ES) were treated with 60, 240, or 960 mg of foliar-applied paclobutrazol (PBZ)/liter 8 weeks after shoot growth began, followed 2 weeks later by a 50-mg spray of gibberellic acid (GA3)/liter. PBZ reduced both the post-treatment increment in trunk cross-sectional area (𝚫TCA) and current-season shoot length (𝚫ES) by up to 26% and 43%, respectively, as compared to control. GA3 increased 𝚫TCA by 45% and stimulated an increase in 𝚫ES, especially on the trees treated with PBZ at 0 and 60 mg·liter-1. PBZ had reduced the total length of lateral shoots (LS) developing on the ES by up to 48% and 38% as compared to control by 2 and 14 weeks, respectively, after PBZ application. However, the GA3 application increased the total LS length by 38%. The ES positioned at the two most basal locations on the tree trunk produced a 31% increase in LS length per ES, but there was no interaction between ES location and PBZ or GA3 influence on the final growth parameters. Total plant dry weight and root: shoot ratio were not affected by PBZ, but GA3 increased plant dry weight 38% and decreased the root: shoot ratio. Chemical name used: β -[(4-chlorophenyl) methyl]- α-(1,1-dimethylethyl)-l-H-l,2,4-triazole-1-ethanol (paclobutrazol).
Relationship Between Densities of Pear Psylla and Twospotted Spider Mite and Pear Leaf Nutrient Levels
Authors: Sugar David , Righetti T. L. , Westigard P. H.
Published: September 2022

Differential population levels of pear psylla (Psylla pyricola Foerster) and of twospotted spider mite (Tetranychus urticae Koch) were established in ‘d’Anjou’, ‘Bartlett’, and ‘Bosc’ pear (Pyrus communis) trees by application of selective insecticides and acaricides. Numbers of psylla or mites counted were used to calculate psylla days and mite days by averaging numbers per leaf on successive sampling dates and multiplying this average by the number of days between samples. The N concentration of apparently uninjured shoot leaves of ‘d’Anjou’ and spur leaves of ‘Bartlett’ were negatively related to mite days. The reduction in N induced by mites on ‘d’Anjou’ shoot leaves was large enough to affect fertilizer recommendations based on foliar N. Phosphorus concentration was negatively related to mite days in both shoot and spur leaves of ‘d’Anjou’, but not in other cultivars. Other leaf nutrients were not consistently affected. Densities of the pear psylla were not correlated with foliar mineral nutrient concentrations, although high population levels were not established in this study.
Yield and Plant Nutrient Content of Vegetables Trickle-irrigated with Municipal Wastewater
Authors: Neilsen G. H. , Stevenson D. S. , Fitzpatrick J J. , Brownlee C. H.
Published: September 2022

Tomato (Lycopersicon esculentum L.), sweet pepper (Capsicum annuum L.), onion (Allium cepa L.), cucumber (Cucumis sativus L.), bush bean (Phaseolus vulgaris L.), and melon (Cucumis melo L.) were grown from 1983 through 1986 with trickle irrigation using either well water or secondary effluent. Yields with effluent irrigation were greater than or similar to yields obtained with well water. Effluent irrigation resulted in decreased Zn, increased P, and variable results for other nutrients in plant tissues. After 4 years of effluent irrigation, the exchangeable Na content of the 0.0 to 0.3-m depth increased, but soil chemical changes were of little practical significance. No major limitations were found for the production of high yields of vegetables irrigated with municipal wastewater on the loamy sand soil at the experimental site after 4 years.
Picea Graft Success: Effects of Environment, Rootstock Disbudding, Growth Regulators, and Antitranspirants
Authors: Beeson Richard C. , Proebsting William M.
Published: September 2022

Several techniques were tested to improve the development of Colorado blue spruce (Picea pungens Engelm. ‘Hoopsi’) grafts. In the Pacific Northwest, Picea grafts are normally made on active rootstocks in heated greenhouses between December and mid-March. Grafting on dormant rootstocks and holding these grafts in an unheated, polyethylene-covered lath house resulted in generally higher graft success. IBA, NAA, and BA applied to the base of the scion just before grafting increased graft success by 10% to 13%. Retarding the development of the rootstock by dikegulac applications or by bud removal stimulated scion growth. Polyethylene tents and a film-forming anti-transpirant had no effect on graft success. Chemical names used N-(phenylmethyl)-1H-purin-6-amine (BA); 2,3:4,6-bis-0-(l-methylethylidone)-a-l-xylo-2-hexulofuranosonic acid (dikegulac); 1H-indole-3-butyric acid (IBA); 1-naphthaleneacetic acid (NAA).
Growth, Nutrient Status, and Yield of Celery Seedlings in Response to Urea Fertilization
Authors: Tremblay Nicolas , Gosselin André
Published: September 2022

Celery seedlings (Apium graveolens L. cv. Florida 683) were seeded in multicell styrofoam trays containing a commercial peat mix. They were fertilized with nutrient solutions at two nitrogen fertilizations (150 or 350 mg N/liter), two NO3:NH4 ratios (2:1 or 3:1), and two urea-N levels (0% or 50%) in factorial combinations to determine main and interactive effects of urea on seedling growth, nutrient status, and crop yield. Urea used in combination with low N improved the percentage of shoot dry matter and increased leaf area, shoot and root dry weight, and root: shoot ratio of the seedlings. Urea proved beneficial in improving transplant yield potential under high-N fertilization.
Acetaldehyde Vapors Influence Postharvest Quality of Table Grapes
Authors: Pesis Edna , Frenkel Chaim
Published: September 2022

‘Sultanina’ and ‘Perlette’ grapes (Vitis vinifera L.), with initially low sugar concentrations (13% to 14% total soluble solids content; TSS) and high acidity received postharvest application of 0.2% to 0.9% acetaldehyde vapors for 24 hr. This treatment increased TSS, decreased acidity of the juice, and enhanced the sensory preference by judges in a test panel. However, the response was limited to early picked fruit with low TSS and high acidity and the treatment damaged the berries of ‘Sultanina’ grapes and left some off-flavor. The levels of acetaldehyde and ethanol in the juice were positively correlated with the amount of applied acetaldehyde, the level of ethanol being 20 times higher than that of acetaldehyde. After 4 days of shelf life, the levels of both acetaldehyde and ethanol declined in the juice.
Production Temperature Affects Leatherleaf Fern Postharvest Desiccation
Authors: Stamps R. H. , Nell T. A. , Cantliffe D. J.
Published: September 2022

Leatherleaf fern [Rumohra adiantiformis (Forst.) Ching] was grown in controlled environment chambers set for day/night temperatures of 35/24C (high temperature regime, HTR) or 24/13C (low temperature regime, LTR). Fronds were harvested for vase life studies at 1100 and 1800 HR and held in holding rooms in deionized water. Plants were then moved to a greenhouse environment (16–25C) and, after 1 week, an additional set of fronds were harvested. Water uptake of harvested fronds declined exponentially and was generally lower for HTR fronds. HTR fronds had, for the most part, reduced vase life compared to LTR fronds. Most (81%) of the HTR fronds exhibited desiccation symptoms, whereas none of the LTR fronds did. These differences did not appear to be related to preharvest diffusive resistance or water potential differences.
Element Concentration in Layers of Table Beet Roots and in Various Beet Cultivars
Authors: Van Buren Jerome P. , Peck Nathan H. , MacDonald George E. , Cary Earle E.
Published: September 2022

The concentration of mineral elements from the outer peel to the core of five table beet (Beta vulgaris L.) cultivars was determined by separating roots into five fractions. Soil contamination was important only in affecting the concentration of Fe in the outer peel. Mineral element concentration was highest in the outer peel, decreasing by about one-half in the inner peel. Some mineral element differences are noted among cultivars.
Deep Supercooling in Stem and Bud Tissues of Pecan
Authors: Rajashekar C. B. , Reid William
Published: September 2022

Seasonal changes in deep supercooling and cold-hardiness of stem tissue and apical buds of pecan [Carya illinoensis (Wang enh.) C. Koch] cultivars were studied. All the pecan cultivars showed supercooling in stem and apical buds. Supercooling in stem and apical buds was maximal in early January and least in early spring. A good correlation between killing temperatures and freezing of supercooled water was found in apical buds. Similar results were observed for stem samples collected during early spring. Apical buds appeared to be more prone to injury during spring than stem tissue in all the pecan cultivars. In early April, stem samples of pecan cultivars were killed at or below –20.1C, whereas apical buds were killed at –16C or above. Apical buds of ‘Posey’ showed greater cold-hardiness than those of other pecan cultivars in midwinter and early spring.
Explant Orientation Affects Axillary Shoot Proliferation of Apple Cultivars in Vitro
Authors: Zimmerman Richard H. , Fordham Ingrid
Published: September 2022

More axillary shoots developed from subcultured shoots of apple (Malus domestica Borkh.) that were placed inverted in the medium. This effect was particularly noticeable for ‘Delicious’ and strains of it, which normally proliferate poorly and begin to senesce 3 weeks after the beginning of the subculture period. Inverting the subcultured shoots reduced or eliminated the tendency to senesce early. Axillary shoots from inverted shoots rooted as easily as those from ones oriented either vertically or horizontally. Chemical names used: N–(phenylmethyl)-1H-purin-6-amine (BA), 1H-indole-3-butanoic acid (IBA), and gibberellic acid (Ga3).
Evaluation of Asparagus Species for resistance to Fusarium oxysporum f. sp. asparagi and F. moniliforme
Authors: Stephens Christine T. , De Vries Renee M. , Sink Kenneth C.
Published: September 2022

“Asparagus decline” decreases production and kills Asparagus officinalis L. The principal pathogens involved in the decline are considered to be Fusarium oxysporum f. sp. asparagi Cohen and Heald (FOA) and F. moniliforme (Sheld.) emend. Synder and Hans. (FM). Three- to four-month-old plants of A. officinalis and three other asparagus species were inoculated in the greenhouse and evaluated for resistance to these Fusarium spp. Of the 90 A. officinalis accessions evaluated, two all-male cultivars, Lucullus 234 and 328, received the lowest disease ratings to FOA and FM. Asparagus densiflorus ‘Sprengeri’ and ‘Myersii’ received the lowest disease ratings of the other asparagus species tested. Of the total 95 germplasm entries evaluated, 39% were more resistant than the susceptible control ‘UC 157’, 44% were rated similiar in susceptibility, and 17% were more susceptible. Accessions responded similiarly to both Fusarium spp.
Nitrogen Source and Calcium Supplement Affect Stem Strength of Poinsettia
Authors: Lawton Kay A. , McDaniel Gary L. , Graham Effin T.
Published: September 2022

The effects of nitrate and NH4NO3 used alone or in combination with CaCl2 sprays were examined on self-branching poinsettia (Euphorbia pulcherrima Willd.) cul-tivars Annette Hegg Dark Red (AHDR) and Gutbier V-14 Glory (Glory) and the standard cultivar Eckespoint C-1 Red (C-1). Stem retention was increased in the AHDR and C-1 that received Ca(NO3)2 liquid fertilization. Calcium chloride sprays enhanced stem strength of C-1 when used in combination with ammonium fertilizer, but not when used with Ca(NO3)2. Calcium chloride foliar sprays did not improve stem strength of the self-branching cultivars with either of the N fertilizer formulations tested.
Adjuvants Affect the Efficacy of Glyphosate on Selected Perennial Weeds
Authors: Swietlik Dariusz
Published: September 2022

The efficacy of glyphosate in controlling bermudagrass (BG) (Cynodon dactylon L.), guineagrass (GG) (Panicum maximum Jacq.), and purple nutsedge (PN) (Cyperus rotundus L.) was determined when the herbicide was used alone or in combination with adjuvants: Frigate, LI-700, or VPG in a volume of 378 liters of water/ha. No loss of BG control was noted as the glyphosate level was lowered from 4.5 to 2.25 kg·ha-1 with Frigate added, but control decreased with VPG or no adjuvant addition (LI-700 not used). No reduction in control of PN was observed when glyphosate amount was lowered from 3.4 to 1.7 kg·ha-1, provided LI-700 was present in the spray solution. With Frigate, VPG, or no adjuvant, however, the degree of PN control was less at 1.7 than 3.4 kg·ha-1. Frigate, LI-700, and VPG were equally effective in improving glyphosate efficacy on GG when the herbicide was used at 3.4 kg·ha-1, but the adjuvants had no effect at the herbicide level of 1.7 kg·ha-1. Chemical names used: α-(p-alkyl phenyl) Ω-hydroxypoly (ethylenoxy) phosphate ester, propylene glycol (VPG); fatty amine ethoxylate (Frigate); isopropylamine salt of N-(phosphonomethyl) glycine (glyphosate); phosphatidylcholine methylacetic acid (LI-700).
Postharvest Changes in Sugars, Acids, and Color of Carambola Fruit at Various Temperatures
Authors: Campbell Craig A. , Huber Donald J. , Koch Karen E.
Published: September 2022

Postharvest changes in color and compositional characteristics were monitored in ‘Arkin’ and ‘Golden Star’ carambolas (Averrhoa carambola L.) before, immediately following, and 6 days after they were stored for 44 days at 5, 10, or 15C. General commercial practice has been to store this tropical fruit at 10C or higher to avoid possible chilling injury. Results from the present work demonstrated that fruit stored at 5C maintained better appearance, lost less weight, and exhibited less change in soluble sugar (glucose, fructose, and sucrose) or organic acid (oxalic and malic) concentrations than fruit stored at 10C. Rewarming experiments (6 days at 23C) indicated that these fruit had not lost the capacity to ripen normally and did not develop symptoms of chilling injury. Carambolas therefore can be stored most effectively at 5C.
Pectinesterase and D-Galacturonase Activities in Eight Snap Bean Cultivars
Authors: Summers W. L.
Published: September 2022

Moisture content and levels of pectin pectylhydrolase (PE) and poly (1,4-α-D-galacturonide) glycanohydrolase (PG) were evaluated for eight commercial cultivars of snap bean (Phaseolus vulgaris L.) over four harvest periods. Moisture content varied from 80.8% to 91.7%. Cultivar and harvest period moisture contents differed significantly. PE activity ranged from 208 to 896 units/g dry pod tissue, and PG ranged from 7.1 to 16.6 units/g dry pod tissue. Lines chosen to represent firm-podded, canned snap bean types exhibited higher enzyme activity levels than soft-podded types.
Identification of Raspberry Cultivars in Vivo and in Vitro Using Isoenzyme Analysis
Authors: Cousineau J. C. , Donnelly D. J.
Published: September 2022

Isoenzyme analysis of leaf tissue was used to characterize and separate 18 greenhouse-grown red raspberry (Rubus idaeus L.) cultivars and two purple raspberry (R. ×neglectus Peck) cultivars. Five enzymes were found to be useful: Phosphoglu-coisomerase (PGI), phosphoglucomutase (PGM), malate dehydrogenase (MDH), triose phosphate isomerase (TPI), and isocitrate dehydrogenase (IDH). Fourteen of the 20 cultivars were uniquely separated using these enzymes. The remaining six were assigned to three different groups. Staining for additional isoenzymes may lead to the separation of cultivars within these groups. The effect of tissue type on isoenzyme banding patterns was determined by comparing different tissues from three cultivars. No differences were noted, except in the case of the enzyme PGM, for which differences in the relative densities of the bands were seen. For PGM, the best patterns were obtained from mature tissues (leaves, stems, or petioles). Three cultivars were micro-propagated from shoot tips in vitro and were subsequently analyzed by isoenzyme staining. The culture environment was not found to have any effect on isoenzyme phenotype. This result suggests that isoenzyme analysis can be used to identify raspberry cultivars grown in vitro.
Reduction of Plant Height by Head Smut Infection in Sweet Corn Cultivars
Authors: Baggett J. R. , Kean D.
Published: September 2022

Height reduction of sweet corn (Zea mays L.) plants by head smut [Sphacelotheca reiliana (Kuhn) Clinton] was measured in four field studies using seed furrow inoculation. Infected plants were consistently stunted whether sori occurred on the ears only or on ears and tassels. There was a significant relationship between plant height and infection of individual plants. Difference in mean height between plants later determined to be infected or non-infected was measurable 5 weeks after planting and increased steadily until growth ceased. This suggested the possibility of elimination of weaker plants in segregating populations before maturity. Mean height reduction of individual hybrids and inbred lines ranged from 7% to 65% of the height of non-infected plants, with an average of ≍30% reduction for all cultivars. Correlations between mean percent height reduction and disease incidence of cultivars were variable and generally low, ranging from r = −0.34 to 0.17. This suggested that degree of height reduction would be a poor indicator of the susceptibility of a cultivar to infection.
Effect of Seed Weight on Emergence and Seedling Vigor of Chinese Chestnut
Authors: Shepard Emily , Miller Diane Doud , Miller Gregory
Published: September 2022

Chinese chestnut (Castanea mollissima Bl.) has much potential as a nut-producing orchard or landscape tree, being resistant to chestnut blight [Endothia parasitica (Murr.) P.J. & H.W. Anderson] and high-yielding. Chestnut is monoecious and largely self-sterile, requiring cross-pollination to produce nuts (Sanders, 1974). There is considerable variation in nut traits, such as size and sugar content, even among nuts from the same tree (Miller, 1987), due to, in part, xenia effects. The nut is composed mostly of cotyledonary tissue with a small embryo and no endosperm (Sanders, 1974). Propagation by seed is generally successful; however, no criteria exist for selection of nuts that will produce superior seedlings. The objectives of this study were to examine the relationships between seed weight, seedling emergence, and seedling growth of half-sib Chinese chestnut seeds.
Uniconazole Effects on Forcing of Florists’ Hydrangeas
Authors: Bailey Douglas A.
Published: September 2022

Florists’ hydrangea is a woody perennial that has been adapted to potted plant production. A major factor in a hydrangea forcing program is height control. Currently, daminozide is used for reducing internode elongation in hydrangeas, but high concentrations (5000 to 7500 mg-liter-1) are sometimes needed to control vigorous cultivars such as ‘Rose Supreme’ (Jung, 1964; Ulery, 1978). Uniconazole has been shown to be an effective height-controlling agent at low concentrations for woody perennials, including Forsythia, Ligustrum, Pyracantha, and Rhododendron spp. (Knox and Norcini, 1987; Vaigro-Wolff and Warmund, 1987). Therefore, uniconazole was examined as a potential height-controlling chemical for florists’ hydrangea. Dormant plants of H. macrophylla ‘Rose Supreme’ were defoliated and placed into 4C dark storage for 6 weeks beginning 2 Dec. 1987. On 13 Jan. 1988, the plants were removed from the cooler, potted one per 1.3-liter plastic container, and placed into a 26/15C (venting/night) greenhouse. The growth medium consisted of a 1 soil : 2 sphagnum peat : 2 perlite (by volume) mixture amended with 890 g treble superphosphate, 593 g KNO3, 593 g MgS04, 4.75 kg ground dolomitic limestone, and 74 g Frit Industries Trace Elements No. 555 (Peters Fertilizer Products, W.R. Grace & Co., Fo-gelsville, Pa.) per cubic meter. The plants were fertilized at each watering with Ν and K, each at 200 mg-liter-1, supplied from 367 mg NH4NO3/liter and 517 mg KNO3/liter, respectively. Fertilizer solution was maintained at 6.0 pH by injecting 75% (w/w) technical grade H3PO4 into the system, supplying 37 mg P/liter at every watering. Each plant was pruned at potting, allowing only two shoots per plant to develop, and pots were spaced at 40 × 40 cm during forcing.
AT-1310, AT-1487, and AT-3365: Clonal Jojoba Germplasm Selected for Horticultural Use
Authors: Palzkill David A. , Younes Mohamed H. , Hogan LeMoyne
Published: September 2022

Cultivars or germplasm with published performance records are presently unavailable for jojoba. Only one cultivar, Mirov, is widely recognized in the industry, and it is not widely planted. Unfortunately, published performance records do not exist for this cultivar. Most existing commercial acreage has been planted with seed or seedlings collected from many different locations, or with cuttings collected from selected female plants growing in seedling plantings. There is a need for cultivars of known performance to both increase seed production of commercial plantings and to provide standards with which to compare other clones. The purpose of this report is to briefly describe three jojoba clones that have been studied for 8 years and have performed well in a field planting and to announce their release.
Fraud, Sloppiness, and Mistakes in Horticultural Science
Authors: Hershey David R.
Published: September 2022

It is hoped that Science Editor Lipton’s opinion [ASHS Newsletter 5(2):1–2] that horticultural research publications are free of fraud is correct, as fraud is typically very difficult to prove and there are considerable pressures to “publish or perish”, even in horticulture. Unfortunately, a type of fraud seems widespread in commercial horticulture in the form of “miraculous” claims for horticultural products, such as fertilizers and biocatalysts. This type of fraud reflects badly on horticultural science; therefore, horticultural scientists have a duty to conduct research that tests such claims.
Variation in Nutrient Requirements of Blueberries and Other Calcifuges
Authors: Korcak Ronald F.
Published: September 2022

Calcifuges, represented by the blueberry and cranberry (Vaccinium spp.) and rhododendrons and azaleas (Rhododendron spp.), are an economically important segment of the horticultural industry. They share the common requirement of an acid soil, about pH 5.5 or below, and minimal nutrition. Indeed, overfertilization, particularly when plants are young, can cause foliar injury. Much nutritional research has been performed on these acid-loving plants from the aspects of fertilizer recommendations and soil management practices. It is not the purpose of this paper to review the nutritional requirements or recommendations of blueberries and other calcifuges. Such information can be found elsewhere (Eck, 1966; Joiner et al., 1983; Kenworthy, 1973; Kofranek and Lunt, 1975; Korcak, 1988; Trevett, 1962). Instead, the two-fold purpose of this paper is to first examine the role of selected elements (Mn, Al, Fe, Ca, and N) on blueberry growth in atypical soil/site environments and, second, to explore the potential variation within Vaccinium that may be beneficial in genetic selection for growth under these new situations.
Genetic Aspects of Mineral Nutrition: Future Challenges and Directions
Authors: Sussman Michael R. , Gabelman Warren H.
Published: September 2022

There are several avenues the modern plant scientist can use to study the genetic basis of mineral nutrition. The one that has been most widely followed to date could be termed the classical genetic or breeding approach, which involves collecting and screening germplasm for a particular phenotypic trait. For mineral nutritionists, this might involve looking for plants resistant to stressfully low levels of minerals (Gabelman and Gerloff, 1983) or for plants resistant to high levels of a toxic ion or salt (Rush and Epstein, 1981). A second approach, made possible in part by recent advances in recombinant DNA techniques, could be termed a molecular genetic approach. In this case, the researcher first identifies and isolates a specific gene or gene product that is suspected to play a role in mineral nutrition. Each of these approaches has advantages and disadvantages, as described below.
Guttation as a Technique to Evaluate the Water Status of Strawberry
Authors: Glenn D. M. , Takeda F.
Published: September 2022

The water status of strawberry (Fragaria х ananassa Duchesne) was indicated by the occurrence of guttation. Guttation was present when pre-dawn leaf water potential (PLWP) was greater than -0.07 MPa and absent when PLWP was below – 0.11 MPa. Plants exhibiting guttation had greater stomatal conductivity and lower leaf – air temperature at midday, indicating a greater transpiration rate. Hydathodes on older leaves did not consistently express guttation; thus, the occurrence of guttation must be evaluated on young leaves.
Row Cover Effects on Air and Soil Temperatures and Yield of Muskmelon
Authors: Motsenbocker C. E. , Bonanno A. R.
Published: September 2022

Three row covers (spunbonded polyester, double-slitted, and perforated polyethylene) used in combination with clear polyethylene mulch and trickle irrigation for muskmelon (Cucumis melo L.) production in 1985 and 1986, increased soil (5-cm depth) minimum and maximum temperatures and air (15-cm height) maximum temperatures compared to clear mulch alone. Increased minimum air temperatures resulted from the use of all row covers in 1985. All row covers enhanced earliness in both years. However, in 1985, there were no total marketable yield differences; in 1986, total marketable yield was greater with the spunbonded and double-slitted row covers than with the no row cover treatment. Within row cover treatment, the use of the perforated row cover in 1986 resulted in lower total marketable yields than with the spunbonded row cover. Excessive air temperatures with the perforated row cover may have resulted in reduced marketable yield. Lower minimum air temperatures in 1986 may have resulted in lower yields than in 1985.
Sweet Corn Seedling Responses to Band-applied Sources and Rates of Nitrogen Fertilizers
Authors: Peck Nathan H. , MacDonald George E. , Barnard John
Published: September 2022

Sweet corn seedlings (Zea mays L. var. rugosa cv. Jubilee) were grown with urea, (NH4)2SO4, NH4NO3, and Ca(NO3)2 at linearly increasing increments from 0 to 18 g of N/m of row. The N fertilizers, with 5 g of P from concentrated superphosphate and 5 g of K from KCl per meter of row, were placed in a band 5 cm below seed depth to the side of the seed at planting time in a Honeoye fine sandy loam soil with pH 7.0. Seedlings were sampled ≈30 days after planting for fresh and dry weight and for nitrate N, total N, P, K, Na, Ca, Mg, Zn, Mn, Fe, and Cu. Sweet corn seedlings grown with (NH4)2SO4 or NH4NO3 grew more rapidly than seedlings grown with urea, especially at the high rates of N fertilizers, and much more rapidly than seedlings grown with Ca(NO3)2 at all rates and for two planting dates. Seedlings grown with ≈3 g of N/m of row had the highest fresh and dry weights per seedling. Seedlings grown with (NH4)2SO4 or NH4NO3 had a higher concentration of P than seedlings grown with urea or Ca(NO3)2. Seedlings grown with (NH4)2SO4 had lower concentrations of nitrate N and Ca than seedlings grown with the other sources of N fertilizers. Seedlings grown with Ca(NO3)2 had higher concentrations of Ca and Mg, but lower concentrations of Zn and Mn than seedlings grown with the other sources of N fertilizer.
A Comparison Between Bags and Boxes for Shipping Texas Short-day Onions
Authors: Pike Leonard M. , Yoo Kil Sun , Camp Thomas H.
Published: September 2022

Quality was compared for short-day onions (Allium cepa L.) packed in corrugated paper boxes or conventional mesh bags when stored at 1, 15, or 24C for 3 weeks and an additional 2 weeks after transfer to a 24C holding room. It took 18 to 24 hr to equalize the air and bulb temperatures to 24C room temperature after transfer. Air temperatures in bags increased slightly faster than in boxes, but the bulb temperatures increased at the same rate. Weight loss was 2% to 4% after 5 weeks and was only slightly higher in bags. Incidence of black mold (Aspergillus niger Teigh.) was greatest at 24C continuously and was not affected by kind of container. Incidence of “slippery skin” (Pseudomonas spp.) was higher at 24C than at lower temperatures after 3 and 4 weeks, but was not affected by containers. Decay incited by Botrytis spp. occurred randomly and no sprouting was found during storage.
Responses of ‘Fuyu’ Persimmon to γ-Irradiation
Authors: Wheeler Denise R. , Packer John E. , MacRae Elspeth A.
Published: September 2022

Mature ‘Fuyu’ persimmons (Diospyros kaki L.) were exposed to 300 and 1000 Gy of γ-irradiation in combination with modified atmospheres generated by polymeric film bags. Only fruit treated with 1000 Gy when in such bags developed scald-like skin damage during a shelf-life period after cool storage. These fruit also produced elevated quantities of ethane immediately after irradiation. These results have implications relating to the handling of persimmons and for potential insect disinfestation by irradiation.
Postharvest Handling of Alstroemeria
Authors: Healy Will , Lang David
Published: September 2022

Vase life of Alstroemeria hybrida ‘Regina’ was longest in inflorescences with secondary and tertiary florets. The presence of additional florets on a cyme decreased the vase life of the primary floret. Maximum flower opening and normal coloration occurred when the primary florets were harvested at the “rolled petal stage”. Cutting Alstroemeria stems above the blanched portion of the stem before placement in water increased water uptake and vase life. When secondary florets were present, leaf removal did not decrease vase life.
ABA and Polyox-encapsulation or High Humidity Increases Survival of Desiccated Somatic Embryos of Celery
Authors: Kim Yong-Hwan , Janick Jules
Published: September 2022

Survival of desiccated somatic embryos of celery (Apium graveolens L. cv. Utah Improved #15) was increased by pretreatment with 10-6 M ABA during the embryo production phase and encapsulation with Polyox, a water-soluble ethylene oxide polymer. Nonencapsulated embryos survived 48 or 72 hr of desiccation at 70% or 90% RH; no embryos survived desiccation at 30% or 50% RH. Embryos encapsulated with Polyox survived 7 to 9 days of desiccation at 70% RH. Embryo survival was generally highest at 3% sucrose with or without embryo encapsulation. Chemical names used: abscisic acid (ABA); ethylene oxide polymer WSR-N-750 (Polyox); 6-(4-hydroxy-3-methylbut-2-enylamino)purine (zeatin); 1H-indole-3-acetic acid (IAA); 2,4-dichlorophenoxyacetic acid (2,4-D).
Densitometry, Image Analysis, and Interpretation of Aerial Color Infrared Photographs of Citrus
Authors: Blazquez C. H.
Published: September 2022

Spectral densitometry measurements of aerial color infrared (ACIR) photographs of citrus trees made from outer crown and tree center correlated well with visual grading of the photographs. Measurements made from 400 to 700 nm identified two intensity peaks at 480 to 490 nm (I1) and another between 610 to 620 nm (I2). Spectral ratios (SR) (I1/I2) <0.69 were associated with healthy trees visual grade 0 (VG 0, 0% stress), ratios >0.86 were associated with moderate and severely stressed trees (VG 1, 2, 3; 25%, 50%, and 75% stress, respectively), and ratios >1.28 were found only in dead trees (VG 4, 100% stress). A formula whereby the absolute difference between wavelengths of the two peaks (DSR) was divided by the SR improved the accuracy of analysis of the densitometric measurements, making the separation of stressed trees more distinct. Image analysis of color infrared transparencies of groves indicated positive correlations between: 1) transmitted light brightness and dark class 1, 2) dark classes 1 and 2, and 3) gray levels 2 and 3. These results suggest that densitometric measurements were equal or better than visual grading and could be used in an automated system to count and separate stressed from healthy trees.
CALEX/Peaches, an Expert System for the Diagnosis of Peach and Nectarine Disorders
Authors: Plant R. E. , Zalom F. G. , Young J. A. , Rice R. E.
Published: September 2022

An expert decision support system for agricultural management called CALEX is currently being developed. The program runs on any IBM compatible personal computer with 256K or more of memory and either two floppy disk drives or a hard disk and one floppy disk drive.
A Forcing Unit for Belgian Endive
Authors: Sterrett S. B. , Savage C. P.
Published: September 2022

Belgian endive (Cichorium intybus L.) is an important salad vegetable in Europe (Ryder, 1979; Yamaguchi, 1983). The increasing per-capita consumption of Belgian endive in Europe and in urban areas of the United States, and its high market value (Corey and Whitney, 1987), indicates increasing potential marketing opportunities for this crop. Markets in the United States prefer firm, well-closed (tight), white chicons (blanched, edible head) that, on average, are 10 to 20 cm long and weigh 60 to 110 g (Hill, 1987; Ryder, 1979). Production of the chicons involves growing and harvesting the roots, storing the roots at –1 to 3C for vernalization, and then forcing them (Corey and Whitney, 1987), Blanched chicons are obtained by forcing vernalized roots in soil or hydroponically in the dark.
Microspray Applicator and Enclosure for Administering Chemicals to Plants
Authors: Bauer Edmund O. , Michler Charles H.
Published: September 2022

In our research on producing herbicide-tolerant hybrid poplars through somaclonal variation in microculture (Michler and Bauer, 1987; Michler and Bauer, 1988; Michler and Haissig, 1988), we had to test herbicide-tolerant plants in the greenhouse by spraying small volumes of herbicide on them. To do this, we needed an accurate, small-volume spray applicator. It was necessary to apply volumes of 10-5 liters to single immature trees at concentrations equal to field dosages. Other available small-volume spray applicators did not allow for application of single-tree dosages (McWhorter et al., 1988). The maximum plant size for efficient application with minimal drift was 15 to 18 cm or less crown diameter, sprayed from a maximum distance of 76 cm.
Three Brachytic Dwarf Peach Cultivars: Valley Gem, Valley Red, and Valley Sun
Authors: Hansche Paul E.
Published: September 2022

These are the first three cultivars to be released from a breeding program, initiated in 1976 at the Univ. of California, Davis (UCD), directed toward the elimination of ladder operations in the commercial production of shipping peaches and nectarines. The recessive dw allele of the Dw/dw gene is being employed to control tree size (4, 5). The recessive allele of this gene reduces internode length from the 1.8 + 0.31 cm found in standard trees to 0.77 ± 0.2 cm, thus compressing the canopy to about one-fifth that of standard cultivars. In addition to controlling tree size, this gene appears to facilitate precocious production and, at maturity, a near doubling of productivity over that of standard cultivars as they are normally grown in California; i.e., at a density of about 264 trees/ha (3). This high productivity appears to be due to these brachytic dwarfs generating about the same number of flowers, fruit, and leaves as standard trees, but on far less wood (3, 4). In our experience, the ripening of fruit on trees dwarfed by this gene is considerably more uniform than that borne on standard trees. We have not studied the basis of this phenomenon.