bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of Cultivar, Postharvest Storage, Preprocessing Dip Treatments and Style of Pack on the Processing Quality of Strawberries
Authors: Morris J. R. , Sistrunk W. A. , Sims C. A. , Main G. L. , Wehunt E. J.
Published: August 2022

Two cultivars of strawberries originally harvested for fresh market were held under 5 postharvest storage treatments and then dipped in one of 4 chemical treatments. The berries were sliced or left whole, dipped, and then processed by freezing or thermal processing. The processed product from ‘Cardinal’ was superior to that from ‘Sunrise’ in this study, regardless of the holding or dip treatment. ‘Cardinal’ berries could be utilized for processing initially and after storage for 4 days at 4°C and after 2 days at 21°; however, ‘Sunrise’ was acceptable only initially and up to 4 days at 4°. Dipping berries for 1 min in a 0.5% calcium lactate solution or a 0.5% Ca lactate plus 1% citric acid solution improved berry firmness and character. The Ca dips were more effective in firming sliced berries than in firming whole berries. The Howard mold count of the berries became a major limiting factor for many of the postharvest storage treatments.
Dry Matter Partitioning and Assimilation in Fruiting and Deblossomed Strawberry
Authors: Forney Charles F. , Breen Patrick J.
Published: August 2022

Day-neutral strawberries (Fragaria × ananassa Duch. ‘Brighton’) were grown in a greenhouse and either continuously deblossomed or allowed to fruit over a 50 day period. Total plant dry weight was essentially the same in both treatments throughout this period. During a 25-day-period, the fruit truss was the predominant sink and, for about 9 days, fruit growth rate exceeded that of the whole plant, and the growth rates of other plant parts were reduced to zero. At the end of the study, fruiting plants had accumulated 16 g dry weight in fruit and had 62%, 53%, and 44% less dry matter in roots, crown, and leaf blades than deblossomed plants. The starch content of roots, crown, and leaf blades of deblossomed plants was about 18-, 7- and 4-times higher than plants with fruit. Fruiting reduced stolon, inflorescence, and branched crown emergence by 80% or more. Leaf area was not affected significantly by treatments, but specific leaf weight of deblossomed plants was as much as 44% higher than that of fruiting plants. Fruiting did not have a significant effect on unit leaf rate. Net photosynthetic rates of leaves which emerged with the 1st inflorescence were similar in both treatments before rapid fruit growth; thereafter, photosynthesis of comparable leaves was 60% to 80% higher in fruiting than deblossomed plants. The presence of fruit also increased stomatal and mesophyll conductance by 40%. The increase in root system in a finite soil volume may have affected assimilation by deblossomed plants adversely. These results show that strawberry fruit strongly inhibit starch accumulation and growth of vegetative parts, while maintaining or enhancing photosynthesis.
Yield and Quality of ‘Niagara’ Grapes as Affected by Pruning Severity, Nodes per Bearing Unit, Training System, and Shoot Positioning
Authors: Morris J. R. , Sims C. A. , Cawthon D. L.
Published: August 2022

A 4-year study was conducted on ‘Niagara’ grapes (Vitis labrusca L.) to examine the effects of 3 pruning severities (based on nodes retained), 3 levels of nodes/bearing unit (3, 6, and 9), 2 training systems [Geneva Double Curtain (GDC) and Bilateral Cordon (BC)], and 2 canopy management treatments (shoots positioned and shoots not positioned) on yield and fruit quality. Leaving heavy fruit loads suppressed yields in the 4th and final year of this study as a result of reduced node fruitfulness. The 3 node spurs were not as productive as the 6 and 9 node canes. GDC training produced higher yields than BC training in the 3 high yielding years of the study while maintaining vine vigor. Shoot positioning was more beneficial in increasing yields on the BC training system than on the GDC training system, because of the crowded conditions of the canes on the BC system. The effects of these variables on fruit quality were small, but the heavy fruit loads did result in fruit with a reduced percentage of soluble solids and pH, increased acidity and light color (increased CDM ‘L’ values). Shoot positioning reduced fruit pH, slightly in-creased acidity, and produced darker color (decreased CDM ‘L’ values). Under Arkansas growing conditions, if harvest is delayed beyond 14% soluble solids, it is possible that unacceptable fruit pH and acidity levels will exist.
Cuticular Permeability to Calcium Compounds in ‘Golden Delicious’ Apple Fruit
Authors: Glenn G. M. , Poovaiah B. W.
Published: August 2022

Isolated cuticles from ‘Golden Delicious’ apples (Malus domestica Borkh.) were mounted in a flow-through diffusion cell. Donor solutions containing 0.5m Ca chloride, Ca acetate, Ca nitrate, and two commercial formulations of Ca were allowed to flow over the outer surface of the cuticle. Calcium that permeated the cuticle was collected and analyzed by atomic absorption spectrophotometry. The effect of temperature and pH on Ca penetration also was investigated. Calcium chloride permeated the cuticle significantly faster than other organic or inorganic forms of Ca tested. The Ca penetration rate decreased with decreasing temperature as predicted by the temperature coefficient for diffusion of strong electrolytes. The decrease in the rate of diffusion at low temperatures seemed to be due to the increase in viscosity of the solution. Uptake of CaCl2 tended to be higher at pH 3 than at pH 11. The pCa was also higher at pH 3 than at pH 11. Solutions of CaCl2 dried significantly slower than other forms of Ca tested. Cuticular Ca movement and the potential advantages of the system for screening cuticular permeability of various forms of Ca were investigated.
Metabolism of Sulfur Dioxide in ‘Thompson Seedless’ Grape Berries
Authors: Peiser Galen D. , Yang Shang Fa
Published: August 2022

‘Thompson Seedless’ grapes (Vitis vinifera L.) were fumigated with 0.5% SO2 at 0°C, and the amount of residual sulfite in the berries was followed over time. To prevent autooxidation during analysis, sulfite was stabilized using a solution of tetrachloromercurate-glycine, pH 10. After 72 hr, over 90% of the sulfite was oxidized to sulfate. Kinetics of sulfite loss indicate 2 different rates of loss, giving half-lives for sulfite of about 4 hr (70% of the total sulfite) and 20 hr (30% of the total sulfite). Presumably this reflects 2 forms, free and bound sulfite.
Effects of CO2 on Total Phenolics, Phenylalanine Ammonia Lyase, and Polyphenol Oxidase in Lettuce Tissue
Authors: Siriphanich Jingtair , Kader Adel A.
Published: August 2022

An atmosphere of air + 15% CO2 caused CO2 injury in lettuce (Lactuca sativa L.) in about 10 days at 0°C. However, subsequent removal of CO2 was necessary for the brown stain symptoms to develop. Under CO2 treatment, phenylalanine ammonia lyase (PAL) was induced and its activity correlated well with the development of the injury. Nevertheless, PAL activity did not seem responsible for the differences in susceptibility to CO2 injury among the 3 lettuce cultivars included in this study. Prevention of the development of brown stain symptoms by CO2 probably was due to its inhibition of phenolics production and the inhibition of polyphenol oxidase activity.
Genetic Components of Variance for Winter Injury, Fall Growth Cessation, and Off-season Flowering in Blueberry Progenies
Authors: Fear Carlos D. , Lauer F. I. , Luby J. J. , Stucker R. L. , Stushnoff Cecil
Published: August 2022

Genetic variance components, narrow sense heritability, and combining ability effects of parents were determined for several traits from analysis of a partial diallel cross involving 17 parents. Parents included several Vaccinium species and interspecific hybrids. For fall growth cessation, general combining ability (GCA) effects were variable from year to year, and heritability was low. Variance due to GCA was more important than specific combining ability (SCA) variance for winter injury in each of the years. The heritability estimate over years was low for winter injury, although individual year estimates were higher. Lowbush parents had high GCA effects for winter injury in years with snow cover but low estimates for years without snow cover. Off-season flowering was observed in some progenies in both years studied. Certain V. angustifolium Ait. parents had high GCA effects for the occurrence of off-season flowering. The heritability estimate for off-season flowering in combined years was 0.47. Variation due to years and to GCA × year interaction was significant for all characters studied.
Prezygotic Endogenous Barriers to Interspecific Hybridization in Prunus
Authors: Perez Salvador , Moore James N.
Published: August 2022

Eighteen species of Prunus and 4 interspecific hybrids from the 3 main subgenera were used to ascertain the prezygotic mechanisms that maintain reproductive isolation. The percentage of pollen germination of pure species was very high (82% to 97%), and ranged from 1% to 97% for interspecific hybrids. Pollen tube growth rates differed greatly among species and ranged from 3.8 to 8.7 mm/day in vitro, and from 3 to 12 mm/day in vivo. These values were highly correlated with pistil length (r = 0.90) and pollen volume (r = 0.91). Evidence was obtained suggesting the existence of additional incompatibility mechanisms, the 1st preventing interspecific fertilization in the subgenus Cerasus. In P. avium L., the pollen tubes of some species are inhibited and finally arrested before they reach the first half length of the style. In crosses involving P. cerasus L. and P. serotina Ehrh., the use of the latter as the seed parent showed a 10-fold increase in fruit set when compared to the reciprocal. Secondly, differences in pistil length and in pollen tube growth rate among species provide a sound basis for explaining the phenomenon of unilateral incompatibility in Prunus. The use of male-sterile genotypes of P. persica L., which had a prolonged period of receptivity, gave increased fruit set and showed increased potential for overcoming the prezygotic incompatibility barriers.
Production of Synthetic Seeds by Encapsulating Asexual Embryos of Carrot
Authors: Kitto S. L. , Janick Jules
Published: August 2022

Synthetic seed coats were applied to asexual embryos of carrot (Daucus carota L.) by mixing equal volumes of embryo suspension and a 5% (w/v) solution of polyethylene oxide (Polyox WSR-N 750) and dispensing 0.2 ml drops of this mixture onto teflon sheets. Drops dried to form detachable wafers consisting of embryo suspension embedded in Polyox. Embryo survival after drying was determined by redissolving wafers in embryogenic medium and culturing the rehydrated embryo suspension on filter paper supports in petri dishes for 2-3 weeks. When dried to constant weight (6.5 hr) 3% of asexual embryos coated with 2.5% Polyox survived encapsulation, whereas survival of uncoated embryos was nil. Pretreating the embryogenic suspension with 10−6 m abscisic acid (ABA) during the 14 day embryo induction phase increased coated embryo survival to 40% of the initial number of embryos.
Effect of Ethephon on IAA Transport, IAA Conjugation, and Antidotal Action of NAA in Relation to Leaf Abscission of Pecan
Authors: Wood Bruce W.
Published: August 2022

Ethephon at 3, 6, and 12 mm induced abscission of mature foliage on pecan [Carya illinoensis (Wangenh) K. Koch] seedlings. This effect was offset to varying degrees using NAA at 3, 6, or 12 mm in which NAA acted as an effective antidote to ethephon and presumably ethylene. Abscission varied with leaf age and with the relative timing of leaf treatment with ethephon and NAA. Leaves treated with NAA 6 days prior to ethephon treatment were much more sensitive to ethephon induced abscission than those treated one day prior to, at time of, or one day after ethephon sprays. There were no abscission response differences among the 3 latter NAA treatment times. Ethephon greatly reduced 14C-IAA transport in leaf midrib tissue and increased the amount of IAA conjugated in leaf tissue without changing free IAA levels. It is suggested that ethephon treatment reduces the amount of IAA transported from the leaf blade to the abscission zone by inhibiting auxin transport in vascular tissue. IAA inactivation by conjugation appears to have no influence on the IAA level reaching the cells of the abscission zone. Chemical names used: (2-chloroethyl)phosphonic acid (ethephon); 1-naphthaleneacetic acid (NAA).
Improvement of Germinated Seed Quality by Density Separation
Authors: Taylor A.G , Kenny T.J.
Published: August 2022

Germinated seeds of ‘King Cole’ cabbage (Brassica oleracea L. ‘Capitata’) were separated on a float-sink basis from nongerminated seeds by density differences. Aqueous solutions of varying densities were prepared from Maltrin 250. Brief exposures (<2 min) of the germinated seeds to 1.10 g cc−1 solution did not affect the percentage of seedling growth. The percentage of recovery of germinated seeds increased, and the percentage of germinated seeds decreased as the solution density increased from 1.06 to 1.09 g cc−1. Sowing density-separated germinated seeds improved both the percentage of emergence and time to 50% emergence for nonaged and artificially aged seeds. The greatest improvement in emergence was observed from the aged seeds. Dry seeds were separated into density lots of 0.95 to 1.05 g cc−1 in 0.05 increments with solutions of hexane and chloroform. Each dry seed density lot then was germinated and separated. The dry seed density separation did not improve the percentage of germinated seeds or recovery. No correlation was found between the densities of dry and imbibed seeds.
Mineral Nutrient Status of Crabapple and Pear Shoots Cultured in Vitro on Varying Concentrations of Three Commercial Agars
Authors: Singha Suman , Townsend Edwin C. , Oberly Gene H.
Published: August 2022

Shoot tips of ‘Almey’ crabapple [Malus baccata (L.) Borkh. × M. pumila var. Niedzwetzkyana (Dieck) Schneid.] and ‘Seckel’ pear (Pyrus communis L.) were cultured on Murashige and Skoog (MS) medium containing 8.8 µm BA. Media were solidified with either Bacto-agar, Phytagar, or TC agar at concentrations varying from 0.3% to 1.2%. Explant nutrient levels were influenced both by agar brand and concentration. The trends in nutrient composition, although not identical, tended to be similar for both genera. Increasing agar concentrations resulted in increased P, Fe, Zn, and Al in the explant and reduced Ca, Mg, and Mn levels. Although striking variations in many elements occur both in agar brands and in explants cultured on media containing similar concentrations of different agar brands, variations in shoot proliferation and growth of explants cannot be explained on the basis of variations in individual elements. From the nutritional standpoint, the alterations in the elemental composition of the basal medium by the addition of specific agars best explain variations induced by different agar brands. Chemical names used: N-(phenylmethyl)-1H-purin-6-amine (BA).
Chill Unit and Growing Degree Hour Requirements for Vegetative Bud Break in Six Apple Rootstocks
Authors: Young Eric , Werner Dennis J.
Published: August 2022

Estimates were determined for chill unit (CU) and growing degree hour (GDH) requirements for vegetative bud break in 6 apple (Malus × domestica Brokh.) rootstocks: Antonovka 313, MM 111, MM 106, M.7a, M.26, and M.9. Rooted layers were lifted in the fall, potted, and kept in a cold room at 4°C for various lengths of time. plants then were moved to a greenhouse, and the percentage of bud break was determined for various GDH intervals. Prediction equations were determined for the percentage of bud break vs. chill unit accumulation and growing degree hour accumulation. M7a had the lowest chill unit and growing degree hour requirements for 50% bud break (590 CU and 4278 GDH). MM 106 required the most chilling (1220 CU), and M.26 the highest number of growing degree hours (6138 GDH) for 50% bud break.
Artificial Control of Polyembryogenesis in Fortunella by Continuous Gamma Irradiation
Authors: Watanabe Hiroshi
Published: August 2022

Continuous gamma irradiation during polyembryogenesis was tested to determine if the number of embryos could be reduced in ‘Marukinkan’ (Fortunella japonica Swingle), a polyembryonic Citrus relative, and effectively increase the number of F1 hybrids in crosses. The number of embryos in untreated plants was 10.9, and this number was reduced with increasing exposure rate to 2.4 at 500R/day. The percentage of monoembryonic seeds in untreated plants was 1.1, and this was raised with increasing exposure rate to 34.0% at 500R/day. Cytological and histological observations of polyembryogenesis showed that early adventive embryonic cell divisions were retarded severely by gamma-rays (500R/day), and most of them could not develop beyond the stage of small globular proembryos consisting of 1 to 4 cells. These proembryos finally disappeared, but the fertilized embryo generally survived, probably because of a division earlier than those of adventive embryos and a vigor afforded to fertilized cells.
Electrophoretic Variation and Enzyme Storage Stability in Cucumber
Authors: Staub Jack E. , Kupper Ricarda S. , Schuman Deborah , Wehner Todd C. , May Bernard
Published: August 2022

Forty-seven enzymes and general protein of fruit, seed, and cotyledons of Cucumis sativus L. var. sativus and var. hardwickii (Royle) Kitamura were examined by horizontal starch gel electrophoresis to provide information on enzyme activity, stability, resolution, and variability. Of the 5 extraction buffers tested, a Tris base/Tris HC1 buffer at pH 7.1 provided consistent, clear resolution of the enzymes tested. Further studies of several enzymes revealed: 1) 30% DMSO buffer extended the storage life of phosphogluconate dehydrogenase (PGD); 2) the appearance of additional bands to glucosephosphateisomerase (GPI) and disappearance of bands from PGD zymograms occurred when extracts were stored for 7–8 days at 10°C; 3) the zymogram patterns of glutathione reductase (GR), isocitrate dehydrogenase (IDH), malate dehydrogenase (MDH), and phosphoglucomutase (PGM) were not affected under this storage regime; and 4) zymograms of cotyledonary tissue of seedlings grown under flourescent light in either a 9 or 12 hr light photoperiod at 30°/26° and 22°/18° day/night temperatures for 14 days then stored for 120 days at –18° were similar to fresh extracts. Polymorphisms were observed in GPI, GR, IDH, peptidase, PGD, and PGM. No variety specific electromorphs were observed between hardwickii and sativus, thus supporting the conspecific hypothesis regarding these 2 varieties. Twenty-four of 46 plant introductions and 5 of 11 inbred lines were variable for 1 or more of the 6 polymorphic isozymes.
Branch Sampling for Estimating the Number of Fruit on a Tree
Authors: Kumar E. Vasantha , Srivenkataramana T. , Sundararaj N.
Published: August 2022

Probability sampling schemes for selecting limbs of a tree form a basic tool for estimating characteristics of a tree or an orchard. Experimental investigations in fruit crops which have estimation of tree and/or orchard parameters as the objective often employ judgement sampling in selecting trees or their parts. Two varying probability sampling schemes for selecting branches from terminal fruit-bearing trees are proposed. The first has a new size measure—the number of feeder branches, and the other is a variation of Jessen's scheme. The schemes are compared for estimating fruit number by taking single-branch samples from an orange tree. They also are compared for applicability and adaptability to varied investigations with fruit trees.
Modeling High Temperature and Exposure Time Interactions on Pittosporum tobira Root Cell Membrane Thermostability
Authors: Ingram Dewayne L.
Published: August 2022

Excised roots of Pittosporum tobira Thunb. were exposed to temperatures of 25° to 60°C for 30 to 300 min before cell membrane thermostability was determined by electrolyte leakage procedures. Response to treatment temperature for each exposure duration was sigmoidal. The critical temperature causing injury to root cell membranes decreased linearily as exposure duration increased exponentially. A mathematical model to describe the interaction of treatment temperature and exposure duration on membrane thermostability is presented.
Leaf Cell Membrane Thermostabilities of Cucumis melo
Authors: Lester G.E.
Published: August 2022

Seedling leaf segments of 4 Cucumis melo L. cultivars were heated for 15 min at 50°C to observe the interaction of leaf age, temperature, and acclimation on membrane thermostability. Membrane injury was measured by the increase in solution conductivity due to electrolyte leakage from leaf segments. The threshold temperature for C. melo leaf membrane leakage was about 40°, and 50° was the approximate inflection temperature for 50% injury. Leaf age, growing temperature, and acclimation influenced membrane thermostabilities. Within 5-day-old leaves, heat tolerance was influenced significantly by the growing temperature during 24 hr prior to heat injury.
Influence of Presowing Seed Treatments of Table Beets on the Susceptibility to Damping-off Caused by Pythium
Authors: Taylor A.G. , Hadar Y. , Norton J.M. , Khan A.A. , Harman G.E.
Published: August 2022

Table beet (Beta vulgaris L.) ‘Ruby Queen’ seeds were either germinated in aerated water till radicle emergence or osmoconditioned (OC) in –1.2 MPa solutions of polyethylene glycol 6000 or MgSO4 for 7 days at 15°C. Seeds were sown in soil in growth chambers, infested with Pythium spp., and damping-off incidence was evaluated after 14 days. Disease incidence was reduced, compared to dry sown seeds, as a result of presowing treatments. High populations of bacteria (106–108 CFU/ml of solution) developed during the aerated soak, which protected seeds from Pythium damping-off. Seed leaching or osmoconditioning did not decrease susceptibility to damping-off in the absence of high seed bacterial populations. The fluid drilling gel was studied as a delivery system for chemical fungicides. Damping-off in dry-sown seed was reduced by incorporating thiram into a hydroxyethyl cellulose (Natrosol 250 HHW) gel. Gel alone had no effect on damping-off. In field studies, only slight improvements in stand were attributed to the incorporation of thiram in presowing treatments. Fungicide dressing of dry seed resulted in a large improvement in emergence. All presowing treatments had greater field emergence than dry-sown seeds in the absence of thiram, which was attributed to bacterial protection from damping-off.
Development of Ethylene Biosynthesis and Ethylene-induced Ripening in ‘d'Anjou’ Pears during the Cold Requirement for Ripening
Authors: Blankenship Sylvia M. , Richardson Daryl G.
Published: August 2022

Forty-six days at –1°C were required to stimulate ethylene synthesis in harvested ‘d'Anjou’ pears (Pyrus communis L.). The effect of exogenous ethylene on changes in quality parameters and organoleptic properties, and the effect of cold temperature on the development of ethylene production, were studied during the 46 days at –1°. Pears were held in 10 or 50 ppm exogenous ethylene at 20° after 30 or less days at –1°. Respiration increased from 8 to about 19 mg CO2·kg-1·hr-1 in fruit held in ethylene over a 12-day period, whereas fruit held in air showed only a slight increase. Firmness of fruit held in ethylene decreased from 66 to 12 N over 12 days at 20°. No significant change in firmness occurred in fruit held in air at 20°. The volume of extractable juice was unchanged in fruit held in air, but declined in fruit held in ethylene. The soluble solids content was not affected by ethylene treatment. Taste panel evaluation determined that fruit held 30 days at –1° then held 10 days in ethylene at 20° were ripe, sweet, and juicy, but fruit held in air were comparable to fruit never held at 20°. Pear flesh disks cut from fruit held 21 days at –1° did not convert exogenous 1-aminocyclopropane-1-carboxylic acid (ACC) to ethylene, but did so when cut from fruit held 41 or 50 days at –1°. Only with the onset of ethylene production was endogenous ACC detectable in pear flesh. During the 46 days at –1° required for initiation of ethylene production, the capacity to convert ACC to ethylene developed first, followed by production of ACC and ethylene.
Changes in Free and Conjugated Indole-3-Acetic Acid during Initiation and Early Development of Adventitious Roots in Mung Bean
Authors: Norcini J.G. , Heuser C.W. , Hamilton R.H.
Published: August 2022

Changes in the levels of putative free and conjugated indole-3-acetic acid (IAA) were examined by high performance liquid chromatography (HPLC) during the first 96 hr of adventitious root formation in mung bean [Vigna radiata (L.) R. Wilcz. ‘Berken’] stem cuttings. The putative IAA was characterized as biologically and chemically similar to IAA; ester- and amide-conjugated IAA also were found. Amide-conjugated IAA was an order of magnitude more abundant than either free or ester-conjugated IAA, both of which were present at low levels. In duplicate experiments, the relative levels of free and conjugated IAA in the rooting region fluctuated similarly during root formation, although some differences in timing and magnitude were observed.
Inbreeding and Coancestry of Freestone Peach Cultivars of the Eastern United States and Implications for Peach Germplasm Improvement
Authors: Scorza Ralph , Mehlenbacher Shawn A. , Lightner Gary W.
Published: August 2022

Analysis of the pedigrees of selected eastern United States freestone peach [Prunus persica (L.) Batsch] cultivars reveals high degrees of inbreeding and coancestry. Commonly used parents include ‘Admiral Dewey’, ‘Elberta’, ‘Halehaven’, ‘J.H. Hale’, ‘Rio Oso Gem’, and ‘St. John’. These cultivars and their progeny were used as parents primarily for superior fruit quality. Selection for fruit quality has led to the intensive use of relatively few cultivars and a restriction in freestone peach germplasm. Future progress in the development of high quality, cold hardy, disease- and insect-resistant cultivars will depend upon expansion of the germplasm base, and identification and interfusion of genes conferring desired tree and fruit characters into existing eastern United States peach germplasm.
Kentucky Bluegrass and Annual Bluegrass Response to Ethephon
Authors: Eggens J. L. , Wright C. P. M.
Published: August 2022

The effectiveness of ethephon for reducing the growth of annual bluegrass (Poa annua L.), when grown as single plants in pot culture in the greenhouse or outdoors, and within a Kentucky bluegrass (Poa pratensis L.) sod, was evaluated. Ethephon reduced the growth of annual bluegrass more than that of Kentucky bluegrass. Concentration was more important in reducing plant spread than the number of applications. Ethephon applied to field grown turf reduced the leaf area per tiller of annual bluegrass but not Kentucky bluegrass. Leaves per tiller and the shoot dry weight of field grown Kentucky bluegrass increased with increasing ethephon rates compared to nontreated plots. Although significant growth retardation occurred for both species in pot culture, only Kentucky bluegrass canopy height decreased in the field with increasing ethephon rates. Decreased Kentucky bluegrass canopy height resulted from reduced sheath length. Chemical names used: (2-chloroethyl) phosphonic acid (ethephon).
Light, Osmotic Stress, and Fungicides Affect Hulled Creosotebush Mericarp Germination
Authors: Tipton Jimmy L.
Published: August 2022

Light reduced final percentage of germination, maximum germination rate, and time to maximum germination rate of hulled creosotebush [Larrea tridentata (D.C.) Cov.] mericarps. The final percentage of germination declined at an osmotic stress greater than −0.4 MPa, but maximum germination rate increased at a stress greater than −0.6 MPa, and inflection time increased with increasing stress. Twice the recommended level of 3 fungicides tested had a negative impact on germination, and all fungicides delayed the time to maximum germination rate at all levels.
Aflatoxin Suppression by Modified Atmospheres Containing Carbon Monoxide
Authors: Buchanan Jack R. , Sommer Noel F. , Fortlage Robert J.
Published: August 2022

Aflatoxin production by Aspergillus flavus growing on potato-dextrose agar, cooked rice medium, and raw pistachio nuts, was suppressed in 2 ways. First, CO suppressed growth of the fungus if O2 was low. Second, CO suppressed aflatoxin production, evidently by interfering with aflatoxin metabolism, even if the atmosphere permitted nearly normal fungal growth. Fungal growth was equal or better in 2% O2 than in air (20.8% O2). Addition of 10% CO slowed growth materially only if O2 was low, but aflatoxin accumulation was suppressed by CO only slightly more in low O2 atmospheres. After growth for 32 days at 20°C in cooked rice medium or raw pistachios in an atmosphere containing 2% O2 + 10% CO, aflatoxin was <2% of the production in an atmosphere containing 2% O2 or air without CO.
Peach Flower Thinning and Possible Sites of Action of Desiccating Chemicals
Authors: Byers R. E. , Lyons C. G.
Published: August 2022

Airblast application of fertilizers, desiccating herbicides, or surfactants reduced fruit set and increased fruit size of ‘Redhaven’ peach [Prunus persica (L.) Batch]. The addition of the surfactant, aikylaryl polyoxyethylene glyco phosphate ester (Spray Aide), to ammonium thiosulfate (ATS) at rates from 0 ml/liter to 5 ml/liter did not increase thinning. When rates of ATS/ha remained constant, water volumes from 2338 Iiter/ha to 420 liter/ha did not affect thinning. Forty-six percent to 62% more flower buds developed on twigs from chemically thinned trees than on hand thinned trees. Most of this flower bud increase was on the 5 basipetal nodes of current season shoots. Treatment of the stigma, petals + anthers, peduncle, or calyx with ATS reduced fruit-set. Necrotic regions in the peduncle of some flowers could be seen under a microscope 48 hr after treatment. Flowers sprayed with DuPont WK or NH4NO3 + X-77, plus methylene blue (added as a tracer) had blue dye in the veins of the calyx, pedicle, and peduncle of some flowers after 24 hr.
Rootstock and Scion Effects on Carbon Partitioning in Apple Leaves
Authors: Brown Christopher S. , Young Eric , Pharr David M.
Published: August 2022

Leaf expansion, carbon exchange rate (CER), mass carbon transfer (MCT), and carbohydrate pools were measured in one-year-old apple trees throughout the growing season. Two rootstocks, M.9 (full dwarf) and MM111 (vigorous) and 2 scion cultivars, ‘Redchief and ‘Northern Spy’ were used in all 4 combinations to give a wide range in growth vigor. Leaves of trees on MMIII had slightly higher CER than those on M.9. MCT was higher in ‘Northern Spy’ than in ‘Redchief’. Leaves of trees on MMIII had higher daily accumulations of starch and sorbitol than those on M.9; however, when these accumulations were expressed as a percentage of CER, the differences were not significant. ‘Northern Spy’ leaves showed no net dry weight gain over 24 hr, whereas ‘Redchief leaves did. About 17% of the leaf dry weight was not accounted for by nonstructural carbohydrates or MCT in ‘Redchief’ leaves. The morning starch concentration for all the trees increased throughout the season. The specific leaf weight of ‘Redchief was higher than for ‘Northern Spy’ on all dates. Specific leaf weight also increased throughout the season. Sorbitol accumulation rate in the leaf decreased from a mid-season high, whereas sucrose accumulation rate increased from mid-season. Starch accumulation rate in the leaf also decreased from a midseason high. Accumulation rates of starch and transport carbohydrates remained parallel throughout the growing season.
Effects of Cultivar, Soil Moisture, and Hedge Height on Yield and Quality of Machine-harvested Erect Blackberries
Authors: Morris J. R. , Sims C. A.
Published: August 2022

The response of 4 erect blackberry cultivars to 2 levels of soil moisture and 2 hedge pruning heights was evaluated. Supplemental irrigation increased yield on all cultivars, but was most effective for the highest-yielding cultivar, ‘Cherokee,’ during the first harvest season (6.03 T/ha for irrigated plots compared to 4.22 T/ha for nonirrigated plots). Increased lateral branching and yield, with no effect on fruit quality, resulted when the new primocanes were pruned mechanically to a height of 90 cm compared to 120 cm. ‘Cherokee’ and ‘Comanche’ berries had superior color compared with that of other cultivars. Irrigation resulted in a slight reduction in percentage of soluble solids and pH.
Endogenous ABA Levels in Floral Bud Parts of the Evergreen Azalea during Floral Development
Authors: Pemberton H. B. , Brenner M. L. , Wilkins H. F.
Published: August 2022

Individual flowers from Rhododendron L. ‘Prize’ inflorescences were used at various stages of development for quantitative analysis of endogenous free abscisic acid (ABA) content by gas-liquid chromatography with electron capture detection. A decrease of endogenous ABA levels was observed in bud scale, petal, and gynoecium tissue during 6 weeks of cold treatment (9°C) given for release of floral bud dormancy. However, plants which received no cold treatment flowered as rapidly as plants exposed to 6 weeks of 9°. Therefore, a relationship between endogenous ABA levels and the capacity of azalea floral buds for continued development after a cold treatment could not be shown. Regression models of endogenous ABA content on respective morphological measurements of flower bud parts were computed to illustrate the relationship between destructive hormonal determinations and defined morphological changes over time.
Effects of Drying on Cut Douglas-fir
Authors: Montano Jose M. , Proebsting William M.
Published: August 2022

Cut coastal Douglas-fir trees (1.0 to 1.5 m) were allowed to dry to various water potentials in a greenhouse. About one-half of the tree population, dried to a water potential (ψ) of −3.5 MPa, lost significant quantities of needles but were otherwise comparable to undried trees. Drying to −4.0 MPa or below resulted in significantly reduced water uptake after rehydration and irreversible damage. Changes in percentage of moisture content and stomatal conductance generally paralleled ψ but were less useful indices of the damage threshold. Bark wrinkling and percentage of broken needles were useful morphological indices of the damage threshold. Subjective ratings of quality were less reliable indices of the damage threshold. Water potential was an appropriate single measurement of Christmas tree water status and a suitable index of the damage threshold.
Retention of Apple Quality in Low-oxygen Storage Followed by Standard Controlled Atmosphere Regimens
Authors: Lidster P. D. , McRae K. B. , Johnston E. M.
Published: August 2022

The initial storage of ‘McIntosh’ apples in a low-oxygen atmosphere (LO) of 1.5% CO2 plus 1.0% O2 at 3°C for as little as 1.25 months reduced the rate of titratable acids loss and the rate of apple softening in subsequent storage in the standard controlled atmosphere of 5.0% CO2 plus 3.0% O2 at 3°. With total storage time of 7.5 months, the initial LO storage effect on titratable acid loss was observed in 2 of the 3 years studied, whereas the effects on firmness loss were consistent over 3 crop years. ‘Spartan’ apples stored initially in LO at 0° were determined by a trained panel to retain crispness and hardness in subsequent standard controlled atmospheres of 3.0% CO2 plus 2.5% O2 at 0°, with the highest ratings obtained for durations of 3.0 months in LO and 4.5 months in standard atmospheres, whereas ‘Golden Delicious’ apples stored for 4.5 months in LO plus 3.0 months in 3.0% CO2 plus 2.5% O2 at 0° were determined to be the crispest and hardest. Extended storage of ‘McIntosh’ in LO increased the incidence of flesh browning in the 1981 crop year but decreased the incidence of senile brown core in the 1983 crop year. Storage of ‘McIntosh’ apples initially in LO for 2 to 5 months followed by the standard atmosphere reduced the risk of flesh browning resulting from low-oxygen injury and retained up to 90% of the firmness retention imparted by continuous LO storage.
Muskmelon Growth, Yield, and Nutrition as Influenced by Planting Method and Trickle Irrigation
Authors: Bhella H. S.
Published: August 2022

Responses of muskmelon (Cucumis melo L. ‘Classic’), with respect to root development, stem and leaf growth, petiole mineral concentration and yield, to trickle irrigation and planting method (direct-seeded vs. transplanted) were evaluted. Field studies were conducted on a southwestern Indiana Lyles silt loam or fine sandy loam soil during 2 successive years using black plastic mulch. Trickle irrigation decreased depth of penetration of muskmelon roots as compared with no irrigation. Trickle irrigation significantly increased the stem length and diameter, leaf area, mean fruit weight and yield, but decreased soluble solids in fruit. Direct-seeded muskmelon plants produced deep, taproots exhibiting positive geotropism, whereas transplants produced more extensive lateral, plagiotropic or geotropically insensitive roots. Direct-seeded muskmelons had significantly larger stem length and diameter, leaf area, soluble solids, and petiole Mn concentration, and lower petiole Fe and Na concentration than transplants. Significant correlations were established between various components of muskmelon growth and development.
Thinning of Peaches by Temporary Inhibition of Photosynthesis with Terbacil
Authors: DelValle T. B.G. , Barden J. A. , Byers R. E.
Published: August 2022

Greenhouse studies were conducted to identify a chemical that would temporarily suppress net photosynthesis (Pn) of peach leaves. Antitranspirants and photosynthetic inhibitors were tested on leaves of greenhouse-grown peach trees [Prunus persica (L.) Batsch]. Leaf dips of 8% Vapor Gard (poly-1-p-methen-8-9 diyl), 10−3 m ABA, 10−3 m diuron, and 10−3 m terbacil reduced Pn by more than 50% within 1 day after treatment, without causing excessive visual phytotoxicity. Since terbacil strongly reduced Pn with minimal phytotoxicity, it was applied as limb treatments to bearing ‘Madison’ peach trees in the field. Treatments were single applications at 1000 or 2000 ppm, double applications a week apart at 1000 ppm, or 2000 ppm at week 1 followed by 1000 ppm at week 2. Fruit drop was 73% to 90% on terbacil-treated limbs compared to 20% natural drop on nonthinned controls. All terbacil treatments increased the size of remaining fruit over that of the nonthinned checks. The 1000 ppm treatment resulted in fruit size similar to the hand-thinned check, but higher concentrations caused smaller fruit than the hand-thinned control.

Chemical names used: abscisic acid (ABA); N’-(3,4-dichlorophenyl)-N,N-dimethylurea (diuron); 5-chloro-3-(1,1-dimethylethyl)-6-methyl-2,4(1H,3H)-pyrimidinedione (terbacil).
Nitrogen Source and Application Timing for Trickle Irrigated Strawberries
Authors: Locascio S. J. , Martin F. G.
Published: August 2022

Strawberries (Fragaria × ananassa Dutch.) were grown during 2 seasons to evaluate 5 N sources and 2 times of N and K application using trickle irrigation with N and K rates of 134 and 149 kg ha−1, respectively. Fruit yields were influenced by significant interactions between N-source and time of N and K application during both seasons. With 100% of the N and K applied preplant, marketable fruit number and weight were significantly greater with sulfur coated urea (SCU) or isobutylidene diurea (IBDU) than with urea, NH4NO3 or KNO3 + Ca(NO3)2 as the N sources. With 40% of the N from the above 5 sources applied preplant and 60% of the N and K supplied with the trickle irrigation from NH4NO3 + K2SO4 or KNO3 + Ca(NO3)2, production was similar with all N sources. Leaf tissue N and K concentrations were not influenced consistently by N source. During both seasons, leaf N concentrations were higher with the split than with the 100% preplant treatments.
Net CO2 Assimilation Rate and Nitrogen Content of Grape Leaves Subsequent to Fruit Harvest
Authors: Williams L. E. , Smith R. J.
Published: August 2022

The relationship between net CO2 assimilation rate (A) and nitrogen (N) content during leaf senescence was determined on field grown Vitis vinifera L. ‘Thompson Seedless’ leaves. Measurements commenced subsequent to fruit harvest and were made at weekly intervals until leaf fall. Maximum A was greater than 2.0 nmoles CO2 cm-2s-1 when leaf N content was greater than 3.0%. There was a linear relationship between A and percent N content regardless of whether A was expressed on an area or dry weight basis. However, the correlation between A on a dry weight basis and percent leaf N was greater than that between A on an area basis and percent leaf N. The percent N content and net CO2 assimilation rate decreased as weight per unit leaf area (W) increased. There was no effect on leaf N content on stomatal conductance (gs) when N content was greater than 2%. The results suggest that leaf N content could be used an as indicator of a grapevine's leaf photosynthetic capacity subsequent to fruit harvest.
Hydraulic Conductivity of Roots, Mineral Nutrition, and Leaf Gas Exchange of Citrus Rootstocks
Authors: Syvertsen J. P. , Graham J. H.
Published: August 2022

Whole plant transpiration and maximum rates of net gas exchange of CO2 and H2O vapor from single leaves were positively correlated with the hydraulic conductivity of roots of seedlings of 5 citrus rootstock species, [Poncirus trifoliata (L.) Raf. × Citrus sinensis (L.) Osbeck, P. trifoliata, C. autantium L., C. paradisi Macf. × P. trifoliata, and C. reticulata Blanco]. Leaf N and P content and shoot:root ratio also were positively correlated with root conductivity. Differences in soil water depletion and plant water relations of 2 of the rootstocks during drought and recovery cycles apparently were related to their root conductivity. The ranking of root conductivities of these seedlings generally reflects the vigor that these rootstocks impart to trees in the field. Thus, the capability of root systems to conduct water and mineral elements is an important factor in plant growth and physiological activity.
Hormonal Regulation of Growth and Development of Tomato Embryos in Vitro
Authors: Neal Catherine A. , Topoleski Leonard D.
Published: August 2022

Indoleacetic acid (IAA), gibberellic acid (GA3), and kinetin were incorporated into tissue culture media to determine the effective concentrations for sustaining growth of excised immature tomato (Lycopersicon esculentum Mill.) embryos. GA3 (10-7 to 10-5 M) stimulated growth of 13- and 15-day-old embryos but resulted in morphological abnormalities. Kinetin (10-8 or 10-7 M) promoted embryonic development and expansion of cotyledons but inhibited subsequent growth. Combinations of kinetin and GA3 or kinetin and IAA were most beneficial for embryos excised 12 days after pollination, when embryonic development was at a globular to early heart-shaped stage.
Crossability of a Diverse Group of Polyploid Blueberry Interspecific Hybrids
Authors: Chandler Craig K. , Draper Arlen D. , Galletta Gene J.
Published: August 2022

Five blueberry interspecific hybrids (3 tetraploids, 1 pentaploid, and 1 hexaploid) and 2 highbush (Vaccinium corymbosum L., 2n = 4x = 48) blueberry clones were crossed in all combinations. Seeds per pollination and seed germination were the criteria used to measure the success of these crosses. The tetraploid interspecific hybrids were fully cross-fertile with the highbush clones and with each other. The pentaploid and hexaploid interspecific hybrids were only partially cross-fertile with the highbush clones and with the tetraploid interspecific hybrids; nonetheless, they still produced an adequate amount of viable seed in most combinations. Significant reciprocal differences in crossability were detected for 4 of the 5 species hybrids.
Self- and Cross-compatibility Relationships among Genotypes and between Ploidy of the Rose
Authors: Cole Patricia , Melton Bill
Published: August 2022

The breeding of hybrid rose cultivars is part of the ornamental rose industry, but there have been few studies concerned with the factors limiting reproduction in the genus Rosa L. In this study, 28 species of Rosa were examined under field conditions for self- and cross-compatibility relationships. Twenty-five specimens of 25 species were tested for self-compatibility. All of the 23 diploid plants tested exhibited more than 96%. Twelve of the 16 polyploid plants preserved the 96% self-incompatibility reaction. A distinct separation existed between self-compatible and self-incompatible polyploid plants. Four of the 5 diploid cross-fertilizations produced unexpected reciprocal differences. Significant reciprocal differences were not obtained from the polyploid level cross-fertilizations. Some parthenocarpy occurred in the R. stellata species. Pollen viability and abundance, daily maximum and minimum temperature, and maximum and minimum relative humidity were not correlated with the compatibility reactions.
Influence of Genotype and Cytokinins on in Vitro Shoot Proliferation of Grapes
Authors: Reisch B. I.
Published: August 2022

The in vitro shoot proliferation responses of 4 Vitis genotypes in the presence of 3 cytokinins was examined. All genotypes grew best in media containing 6-benzyladenine (BA), but the concentration response was variable. Kinetin had no effect upon the 2 interspecific hybrid cultivars but evoked a slight response with 2 genotypes of V. labrusca and V. labruscana. Adenine sulfate had no effect alone; however, when combined with BA, it decreased the rate of shoot proliferation. Addition of the auxin picloram (PIC; 0.1–2.5 μm) to BA-containing (5.0–10.0 μm) medium reduced the rate of shoot proliferation. Using low concentrations of PIC combined with 0.0 or 1.0 μm BA, there was a small increase in shoot tip multiplication. Callus growth was rapid in the presence of 5–10 μm BA and 1–2.5 μm PIC. In summation, the rate of shoot proliferation in grape shoot tip cultures is governed to a large extent by the interaction of cytokinins and genotypes.
Role of Vase Solution Microorganisms in the Life of Cut Flowers
Authors: Zagory D. , Reid M. S.
Published: August 2022

Out of the 25 microorganisms commonly occuring in carnation (Dianthus caryophyllus L. ‘Improved White Sim’) vase solutions, 3 greatly reduced carnation vase life when added individually to vase solutions. Some of these microorganisms also reduced the vase life of roses (Rose hybrida ‘Cara Mia’), chrysanthemums (Chrysanthemum × morifloium Ramat. ‘May Shoesmith’) and other cultivars of carnation (‘Improved Red Sim’ and ‘Improved Pink Sim’). The microorganisms that reduced flower vase life were tentatively identified as a yeast, a fluorescent pseudomonad and a nonfluorescent pseudomonad. A 10-fold reduction in the initial inoculum level affected neither the final microbial concentrations nor the vase life of the test flowers. The effects of the different microbes were not correlated with their effects on solution pH.
Effect of Night Interruption on Cold Acclimation of Potted ‘Concord’ Grapevines
Authors: Wolpert James A. , Howell Gorden S.
Published: August 2022

Two photoperiod regimes, natural daylength (ND) and night interruption (NI) of ND with a white light source, were used to test the importance of photoperiod on growth parameters, cold acclimation, and root conductance of potted ‘Concord’ grapevines (Vitis labruscana Bailey). By 3 Sept., NI-treated plants had a greater percentage of shoots with actively growing apices and a greater number of nodes per shoot than those untreated. No differences were seen in effect of light treatment on the extent of shoot maturation, as evidenced by shoot color change from green to brown. No consistent differences in hardiness of primary buds or canes of the first 12 nodes could be attributed to light regime. Apical tissues were less hardy than basal tissues for all regimes early in the acclimation period (10 Sept.). Root conductance, measured as suction-induced water flow, decreased throughout the acclimation period but did not differ between light treatments. Results are discussed in light of current hypotheses and of evidence of interrelationships among photoperiod, shoot growth cessation, shoot maturation, and cold acclimation.