bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of Calcium and Magnesium Lime Sources on Yield, Fruit Quality, and Elemental Uptake of Tomato
Authors: Mullins Charles A. , Wolt Jeffrey D.
Published: August 2022

Tomato (Lycopersicon esculentum Mill. cvs. Better Boy and Walter) were grown on an acid soil (pH 4.9) with initially low Ca and Mg levels which was limed with Ca(OH)2 and MgO in varied mole ratios. In 1980, marketable fruit yields were lower with the 100% Ca(OH)2 or 100% MgO lime ratio. In 1981, lime source had no effect on marketable fruit yields. Fruit blossom-end rot was most severe when no Ca was applied, while cracking appeared more severe with high levels of Ca application. Leaf Ca and fruit pH were higher for ‘Walter’ than for ‘Better Boy’. The Ca to Mg mole ratio of leaf tissue sampled at early fruiting was a good indicator of the Ca-Mg status of tomato in 1980, when highest fruit yields were obtained over a relatively narrow range of the leaf Ca to Mg mole ratio, with both Ca and Mg deficiency limiting yields. The leaf Ca to Mg mole ratio was well-correlated with the soil test Ca to Mg mole ratio during a given year, but the relationships were different between years. Yield and elemental uptake by tomato relative to levels of Ca and Mg application varied between years as a consequence of the differing climatic conditions in a hot, dry year (1980) versus a cooler, moister year (1981).
A Method for Studying the Three-dimensional Distribution of Roots Grown in an Artificial Medium
Authors: Saltveit Mikal E. , Young Eric
Published: August 2022

A method is described for studying the 3-dimensional distribution of roots grown in a medium consisting of small pieces of glass. After growing to a desired size, the plant is sacrificed by evaporating all water from the media with flowing air. To visualize the undisturbed root system, an immersion oil with the same refractive index as the glass is added to the glass container in which the plant was grown.
Growth and Composition of Radish under Various Regimes of Nitrogen Nutrition
Authors: Barker A.V. , Laplante Joan F. , Damon R.A.
Published: August 2022

In greenhouse studies with radish (Raphanus sativus L.), KNO3, (NH4)2SO4, urea, dried sewage sludge, and dried cow manure were applied at 200, 400, and 800 mgN/1,200 g soil with 0 or 10 ppm of nitrapyrin. Soil analysis for pH, and indicated that nitrification was inhibited throughout the growth (38 days) of the plants. Nitrogen deficiency limited plant growth at the 2 low rates of application of organic fertilizers. With the ammoniacal fertilizers, toxicity restricted root and shoot growth at the highest rate of N and especially in the presence of nitrapyrin relative to the KNO3 regimes. An interaction of nitrapyrin with the organic fertilizers limited root growth. This restriction was attributed partially to toxicity. Some indication of nitrapyrin toxicity was suggested by plant foliar appearance with the organic fertilizers but not with the inorganic sources. Ca and Mg concentrations varied with treatment, with increased rate of N and nitrapyrin addition sharply restricting their accumulation, especially with the ammoniacal and organic fertilizers. Percentage of K in the plants changed in a reciprocal manner to that of Ca or Mg. Compositional changes suggested that toxicity was a major factor causing a limitation of growth with the combination of nitrapyrin with ammoniacal or organic fertilizers.
Occurrence of Alternative Respiratory Pathway in Freshly Excised Apple Root Tissue
Authors: Wang S.Y. , Steffens G.L. , Faust M.
Published: August 2022

A cyanide-resistant alternative pathway was found to exist in root tissue of apple (Malus domestica Borkh.). In the absence of potassium cyanide (KCN), an inhibitor of cytochrome electron transport, the alternative pathway did not contribute to overall root respiration. However, in the presence of KCN or carbonyl cyanide m-chlorophenyl hydrazone (CCCP), an uncoupler, active participation of the alternative pathway was detected. Inhibition of O2 uptake by salicylhydroxamic acid (SHAM) was observed in the presence of antimycin A (AA) or sodium azide (NaN3), but to a lesser degree than when KCN was present. The degree of inhibition by SHAM was greatest in the presence of KCN, followed by AA and then NaN3. The antioxidant n-Propyl gallate (PG) was found to be an effective inhibitor of the alternative pathway. The site of inhibition in apple root tissue by PG is very similar to that of SHAM. Sodium benzoate, another antioxidant and free radical scavenger, and tetraethylthiuram disulfide (disulfiram), a copper chelator, did not inhibit the alternative pathway in apple root tissue.
Postharvest Quality and Storage Life of Grapes as Influenced by Adding Carbon Monoxide to Air or Controlled Atmospheres
Authors: Yahia E.M. , Nelson K.E. , Kader A.A.
Published: August 2022

The effects of 10% carbon monoxide (CO) added to air or controlled atmospheres (2% O2 with or without 5% CO2) on quality and storage life of grapes (Vitis vinifera L. cv. Thompson Seedless) were compared with those of the conventional SO2 fumigation treatments for decay control. CO in air reduced respiration and C2H4 production rates, and retarded berry browning and softening, but was only partially effective in retarding decay beyond 2 months at 0°C. SO2 treatments were very effective in controlling the spread of decay, but brown discoloration of the berries increased, especially after 2 months at 0° or 1°. When combined with 2% O2 with or without 5% CO2, CO inhibited C2H4 production and retarded decay development, but the presence of CO2 increased brown discoloration of the berries. A combination of 2% O2 + 10% CO was as effective as SO2 in controlling decay of grapes held at 0° for up to 4 months and caused less browning and bleaching than SO2.
Screening of Turfgrasses and Clovers for Use as Living Mulches in Sweet Corn and Cabbage
Authors: Nicholson A.G. , Wien H.C.
Published: August 2022

The system of using a living sod intercropped with row crops is aimed at alleviating soil compaction, a major problem for commercial vegetable producers in the United States. Monoculture screening of 30 grasses and 52 legumes was conducted to select groundcovers suitable for use as living mulches with little or no crop suppression. Five turfgrasses and 3 dwarf white clover cultivars were selected from the trial and grown between rows of sweet corn (Zea mays L.) and cabbage (Brassica oleracea var. capitata L.) in the following year. Colonial bentgrass, creeping bentgrass, and a Kentucky bluegrass/white clover mixture significantly reduced sweet corn and cabbage yields. Red fescue adversely affected sweet corn, whereas 2 American white clover cultivars caused yield reductions in cabbage. Growth of Chewing’s fescue, Kentucky bluegrass, and the wild white clover cultivar ‘Kent’ had no effect on sweet corn or cabbage yields. Correlations of living mulch dry weight to vegetable yield parameters were negative and highly significant in both experiments.
Effect of Some Growth Regulators and Nutritional Compounds as Substitutes for Chilling of ‘Delicious’ Apple Leaf and Flower Buds
Authors: Shaltout Assem D. , Unrath C.R.
Published: August 2022

Rest of ‘Delicious’ apple (Malus domestica Borkh.) buds was satisfied partially by applications of 6-ben-zylamino purine + gibberellic acid (BA+GA4+7 = Promalin), BA alone, potassium nitrate, and thiourea; GA4+7 alone had no effect. The combination of thiourea and potassium nitrate was as effective as Promalin or BA in stimulating flower bud development. Potassium nitrate had a pronounced effect on forcing flower buds while thiourea had more effect on forcing vegetative buds. BA and Promalin affected both flower and vegetative buds. No treatment affected bloom date or growing degree hours (GDH) required for flower bud expansion under our conditions when applied after 450, 950, or 1200 hours of chilling. Promalin and BA were both effective at 300 and 500 ppm, while thiourea and potassium nitrate were effective at 2% and 3% (w/v), respectively.
Factors Altering Response of Plants to Triacontanol
Authors: Ries Stanley , Wert Violet , Biernbaum John A. , Gibson Thomas , Bradley W. Jack
Published: August 2022

Triacontanol (TRIA), a 30-carbon primary alcohol, was shown to be a more effective plant growth stimulator when formulated as a colloidal dispersion than as a suspension in chloroform and Tween 20 or acetone naphthaleneacetic acid (NAA), and CaCl2. TRIA applied at rates of 0.1 and 1.0 μg/liter consistently increased the dry weight of maize (Zea mays L.) shoots and rice (Oryza sativa L.) seedlings in short-term greenhouse and growth chamber experiments. This application rate is 1000-fold lower than optimum levels applied with other formulations. A 99.45% pure sample of TRIA stimulated maize growth 2 times more than a sample containing 96.40% TRIA at a concentration of 0.5 μg/liter. Neither dispersion pH nor water hardness altered activity of TRIA formulated as a colloidal dispersion. It may be practical to apply TRIA with a controlled-droplet applicator in volumes of water as low as 8–11 liters/ha. The most important environmental factors evaluated for their effect on crop response to TRIA were time of day and temperature prior to spraying. In growth chamber studies, foliar application of TRIA 3 to 7 hours into the photoperiod resulted in twice the growth increase as applications made 11 hours into the photoperiod. In the greenhouse, with supplemental high intensity lamps, sprays were about twice as effective applied 11 hours (5 pm) as 3 hours (9 am) into the photoperiod. There was a positive correlation between the temperature of the growth chamber environment one hour before spraying and the response to TRIA; however, temperature of the environment for one hour after spray application had no effect on TRIA activity.
Quantitative and Qualitative Characterization of Carrot Root Periderm during Development
Authors: Knowles Lisa O’Rear , Flore J.A.
Published: August 2022

Periderm from the roots of carrot (Daucus carota L.) was isolated enzymatically and analyzed anatomically and chemically during development. The outer transverse walls of the phellem layer formed a continuous, external membrane containing chloroform/methanol-soluble lipids. Separated by thin layer chromatography, these lipids contained at least 6 major chemical groups, the most abundant of which cochromatographed with fatty acids. Scanning electron microscopy revealed the absence of surface fine structure. The periderm membrane decreased in weight with development of the root, attributable to reductions in both chloroform/methanol-soluble and insoluble material per unit area.
Imbibitional Chilling Injury during Chickpea Germination
Authors: Chen Tony H.H. , Yamamoto S.D.K. , Gusta L.V. , Slinkard A.E.
Published: August 2022

Either imbibition at low temperatures or fast water uptake reduced germination of chickpea (Cicer arietinum L.) by 15%. The combination of imbibition at low temperatures and fast water uptake reduced germination by 65%. The most chilling-sensitive period for chickpea germination is the first 30 minutes of imbibition. Slow imbibition at 20°C for 24 hours prior to seeding of mechanically damaged chickpea seeds significantly improved percentage of germination, and uniform, vigorous seedlings resulted. Such prehydrated seeds also showed better emergence under field conditions, especially in early spring when the soil was still cold. The results suggest that mechanically damaged seeds sown in cold, wet soil undergo imbibitional chilling injury and fast water uptake, leading to poor field emergence. Prehydration of seeds by slow imbibition at warm temperature and/or fungicide application increased the germination and emergence of chickpeas sown into cold, wet soils.
Increased Geranium Growth Using Pretransplant Inoculation with a Mycorrhizal Fungus
Authors: Biermann Brenda J. , Linderman R.G.
Published: August 2022

Inoculation of the various potting media with the mycorrhizal fungus Glomus fasciculatum (Thaxter) Gerd. & Trappe resulted in root colonization of geranium (Pelargonium × hortorum L.H. Bailey) by the endophyte that persisted after transplanting. By flowering time, mycorrhizal transplants grown at 11 or 43 ppm P were more uniform in growth than nonmycorrhizal transplants grown at the same nutrient regimes, had greater leaf areas and leaf weights, had increased root and shoot weights, and had lower foliar Mn concentrations. Mycorrhizae were sufficiently well-established on most seedlings at a minimum of 2 weeks after emergence to persist and continue to develop after transplanting. Pretransplant inoculation with G. fasciculatum increased subsequent geranium growth over that of nonmycorrhizal controls when both were transplanted into soil heavily infested with mycorrhizal fungus inoculum, even though size of mycorrhizal and nonmycorrhizal plants did not differ at the time of transplanting. Posttransplant inoculation with G. fasciculatum did not affect the growth of plants which were already mycorrhizal at transplant, but increased the growth of previously nonmycorrhizal transplants. Pretransplant inoculation in soil, peat, or vermiculite resulted in larger plants than posttransplant inoculation in these media.
Growth of Ten Species of Ornamental Tree Seedlings Exposed to Different Photoperiods
Authors: Broschat T.K. , Donselman H.M.
Published: August 2022

Ten species of tropical to temperate ornamental tree seedlings. [Bauhinia variegata L., Tabebuia heterophylla (DC.) Britton, T. caraiba (Mart.) Bur., Delonix regia (Bojer) Raf., Bursera simaruba (L.) Sarg., Pongamia pinnata (L.) Pierre, Jacaranda mimosifolia D. Don, Tamarindus indica L., Acer rubrum L., and Quercus virginiana Mill.] were grown outdoors under natural photoperiods or long day (LD) photoperiods during the autumn, winter, and early spring months. Growth response to photoperiod and temperature varied widely among both tropical and temperate species. Jacaranda mimosifolia, B. variegata, and T. indica were classified as quantitative LD plants since growth was enhanced by LD, but not prevented by short days. However, temperature appeared to be an overriding factor in the growth of T. indica. Delonix regia and A. rubrum grew continuously under LD, but ceased all growth when natural daylength (ND) became shorter than 10.8 h. Quercus virginiana, P. pinnata, B. simaruba, and T. heterophylla showed virtually no response to photoperiod, but temperatures below 15°C prevented growth in Q. virginiana. LD increased growth rate in T. caraiba during the autumn months, but low temperature prevented growth in either LD or ND in the winter. ND plants of this species grew more rapidly in the spring than those maintained under LD. This negative influence of LD on growth during the spring months also was noted in other species in this study.
Role of the Endocarp in ‘Manzanillo’ Olive Seed Germination
Authors: Crisosto Carlos , Sutter Ellen G.
Published: August 2022

The endocarp of ‘Manzanillo’ olive (Olea europaea L.) seeds was subjected to several treatments in order to determine its effect on germination of the olive seed. The endocarp inhibited germination in stratified as well as unstratified olive seeds. Removing the endocarp resulted in high percentages of germination, but only when it was completely removed or when the radicle end was removed. The endocarp did not inhibit germination by preventing imbibition, since water uptake occurred in the seed through the untreated endocarp and through the clipped cotyledon end. The endocarp also did not contain water soluble inhibitors that prevent germination. Rather, the endocarp seemed to inhibit germination through mechanical resistance. High percentages of germination can occur only when the structure of the endocarp is altered, reducing its resistance to embryo expansion.
Ground Color as a Peach Maturity Index
Authors: Delwiche Michael J. , Baumgardner Reginald A.
Published: August 2022

Changes in peach ground color were analysed over the periods of growth, maturation, and ripening for an early, mid-season, and late maturing cultivar. Color was measured with a tristimulus colorimeter in Hunter “L”, “a”, “b” coordinates. Ground color progressions over time were similar for the 3 cultivars. All color coordinates increased during the 3 weeks prior to harvest, with the “a” coordinate showing the largest rate of change with time. Ground color also was compared with a trial series of 6 uniformly spaced color references. High correlations between color reference selection and measured “a” value demonstrated the feasibility of a ground color reference maturity index even when color matches were not exact. Effects of packing house operations on ground color were investigated. Removal of fuzz by brushing had little effect on measured color, whereas wetting of the brushed surface caused a distinct decrease in lightness (“L” value) but little change in chromaticity (“a” and “b” value).
Growth Capacity of ‘Valencia’ Orange Buds on Different Rootstocks during Cold-hardening Temperatures
Authors: Yelenosky G. , Wutscher H. K.
Published: August 2022

Initial growth and development of ‘Valencia’ orange [Citrus sinensis (L.) Osbeck] shoots from buds grafted on 7 different rootstocks were determined during cold-hardening and nonhardening temperature regimes for the 1st 4 months after budbreak. Cold hardening included 12 hr each of 15.6°/4.4°C day/night (D/N) in controlled-environment rooms, where 80% fluorescent and 20% incandescent light averaged 450 μmol m-2s-1. Nonhardening included 32.2°/21.1° D/N as well as greenhouse conditions with natural daylight. Rootstocks influenced growth of ‘Valencia’ during cold-hardening temperatures. Cold-hardening temperatures, however, did not stop ‘Valencia’ growth on any of the rootstocks. Total growth was less than 1/20 of the dry weight accumulated during the warm temperatures. During the cold-hardening treatment, ‘Valencia’ grew the most on the relatively cold-tender volkamer lemon [C. volkameriana (Ten. and Pasq.)] rootstock. The least growth was on the more cold-hardy Swingle citrumelo (C. paradisi Macf. × Poncirus trifoliata (L.) Raf.] rootstock. The amount of growth during cold-hardening temperatures generally coincided with the cold hardiness of the rootstocks, but statistical separation was poor. Trees grown at the warm temperatures started to freeze at higher temperatures than trees grown at cold-hardening temperatures. Rootstocks did not influence freeze avoidance, and no differences were apparent in freeze (ice) tolerance. Three layers of palisade cells were found in leaves that were grown at the cold temperatures.
Ethylene and Water Stress in the Senescence of cut Anthurium Flowers
Authors: Paull Robert E. , Goo Theodore T. C.
Published: August 2022

Anthurium flower (Anthurium andraeanum Andre) postharvest life was studied relative to water balance. Rate of water uptake declined to 20% of the harvest rate within 10 days. Silver nitrate pulsing reduced the water uptake rate decline and helped to maintain an increased rate 10 days after harvest. The spadix was the site of 50% to 60% of water loss while 20% to 40% of the loss occurred via the spathe and 10% to 20% via the stem. Water loss can be reduced by waxing with carnauba and other commerical fruit waxes, and this treatment can double postharvest life. The inhibitors Co2+ and amino-ethoxyvinylglycine significantly reduced the peak of ethylene produced, whereas inhibitors of ethylene response (Ag+, nitrogen and carbon dioxide bubbling) reduced autocatalytic ethylene production from cut anthurium flower stem sections. The cut stem ethylene production peaked 10 hr after cutting, then declined. Cytokinin also affected postharvest life, apparently via effects on water balance. Biocides (quaternary ammonium compound, streptomycin, nystatin, chloramphenicol, and a commercial flower preservative) had little effect on vase life. Wound ethylene-induced stem clogging and not microbial clogging of vascular tissue probably was the major factor limiting postharvest life, inducing water stress and senescence.
Pruning and Deblossoming Effects on Shoot Growth and Leaf Area of ‘McIntosh’ Apple Trees
Authors: Forshey C. G. , Marmo C. A.
Published: August 2022

Fourteen-year-old ‘McIntosh’/M 26 apple trees (Malus domestica Borkh.) were deblossomed, pruned, or deblossomed and pruned, and separated into different shoot and leaf types after harvest. Both deblossoming and pruning increased shoot growth; the former by increasing shoot numbers and the latter by increasing mean shoot length. In spite of differences in total shoot growth, there were no differences in the relative proportions of the 3 shoot types. Treatment did not affect total leaf area, but both deblossoming and pruning increased the proportion of shoot leaves with corresponding decreases in spur leaves.
Differential Tolerance of Tomato Strains to Maintained and Deficient Levels of Phosphorus
Authors: Coltman R. R. , Gerloff G. C. , Gabelman W. H.
Published: August 2022

Seven strains of tomato (Lycopersicon esculentum Mill.), with similar growth rates under adequate P availability, differed in dry matter accumulation by up to 73% when grown under P deficiency in a sand-alumina medium. The rate of P uptake per unit of root weight or length was a primary factor in strain capacity to acquire P under low-P stress. Variation in efficiency of internal P use also contributed to differential tolerance to P deficiency. The factors indicated to be responsible for tolerance to P-deficiency stress were present to different degrees in the different strains. Uptake rates per unit root were equally well correlated with total P absorption whether based on root length or root weight, suggesting that it may be most practical to screen for superior uptake capacities on the basis of root weight.
Modification of Ozone Sensitivity in Seedlings by Ethylenediurea: Soil Application vs. Stem Injection
Authors: Roberts B. R. , Jensen K. F. , Cathey H. M.
Published: August 2022

An anti-oxidant chemical, EDU, was applied in the greenhouse as a soil drench or by stem injection to 2-year-old containerized seedlings 7 days prior to fumigation with 0.35 or 0.95 ppm ozone (O3) for 3 hr. EDU treatment reduced the appearance of O3-induced symptoms (surface bleaching, bifacial necrosis, and chlorosis) on the foliage of red maple, Acer rubrum L.; honeylocust, Gleditsia triacanthos L.; sweetgum, Liquidambar styraciflua L.; and pin oak, Quercus palustris Muenchh. Stem injection of EDU was significantly more effective than soil drench at the same concentration, although both treatments afforded some protection at the low O3 level (0.35 ppm). About 50 times more EDU was required for comparable levels of O3 protection using soil application as opposed to stem injection. Honeylocust showed the greatest physiological response to EDU as evidenced by changes in root, stem, and leaf dry weight of stem-injected seedlings. All 4 species showed some sensitivity to O3 at 0.95 ppm in the absence of EDU. Chemical name used: N-[2-(2-oxo-1-imidazolidinyl)ethyl]-N’-phenylurea (EDU).
Extractable Mg, Fe, Mn, Zn, and Cu from a Peat-based Container Medium Amended with Various Micronutrient Fertilizers
Authors: Broschat Timothy K. , Donselman Henry M.
Published: August 2022

Extractability (in 1 n NH4OAc, pH 7.0) of Mg, Fe, Mn, Zn, and Cu from a Canadian peat, perlite, and sand medium amended with 6 commercial micronutrient fertilizer mixes was determined over an 80-week period with semi-weekly leaching. With the exception of Fe from FeDTPA, which dropped rapidly from very high levels to almost zero, and Fe from Esmigran, which was not extractable by NH4OAc, levels of all 5 elements from most fertilizer sources decreased slightly during the 1st month but then remained rather constant for the remainder of the 18 month experimental period. Extractable Mn, Zn, and Fe were reduced significantly by the superphosphate in Micromax Plus.
Pistillate Flower and Fruit Abortion in Pecan as a Function of Cultivar, Time, and Pollination
Authors: Sparks Darrell , Madden George D.
Published: August 2022

Abortion of pistillate flowers and fruit was determined in ‘Cherokee’, ‘Success’, ‘Stuart’, and ‘Desirable’ pecans [Carya illinoensis (Wang.) K. Koch]. Abortion occurred in 4 periods during the growth cycle of the fruit. The distinctness and magnitude of the drops varied greatly among cultivars. Total seasonal abortion was inversely related to the alternate bearing tendency of the cultivars. The 1st drop varied inversely with shoot length, the 2nd drop coincided with abortion of nonpollinated flowers and was increased by selling, and the 3rd drop coincided with abortion induced by self-pollination. The majority of fruit loss during the 4th drop followed fruit split or discoloration. This drop correlated with high soil moisture and humidity. However, a lesser drop, from embryo abortion, also is proposed to occur at this time.
Composition and Color of Fruit and Juice of Thornless Blackberry Cultivars
Authors: Sapers Gerald M. , Burgher Anita M. , Phillips John G. , Galletta Gene J.
Published: August 2022

Ripe fruit of 40 thornless blackberry cultivars and selections, and juice samples obtained therefrom, were compared to determine differences in color and composition after freezing, thawing, and heating. Color changes (reddening) during frozen storage were associated with within-sample variability in ripeness. Red subsamples of frozen blackberries were lower than black subsamples in soluble solids and total anthocyanin contents and higher in titratable acidity and anthocyanin recovery in the pressed juice. When juice samples were standardized to compensate for differences in pH and anthocyanin concentration, ripeness and cultivar effects on juice tristimulus parameters were small. Rapid thawing of frozen fruit resulted in less anthocyanin loss than did slow thawing. Heating darkened blackberry juice samples and increased values of A440/A513.
Quality Acceptance of Juices of Two Cultivars of Muscadine Grapes Mixed with Other Juices
Authors: Sistrunk W.A. , Morris J.R.
Published: August 2022

Juices from 2 cultivars of muscadine grapes (Vitis rotundifolio Michx.), ‘Noble’ (dark-skinned) and ‘Carlos’ (bronze-skinned), were mixed with juices of ‘Concord’ and ‘Niagara’ grapes, cranberry or apple. ‘Noble’ juice, combined with ‘Concord’ juice, resulted in the highest quality among the dark mixtures prepared. Also, the mixtures retained most color and flavor during a 12 month storage period. ‘Carlos’ juice rated higher in quality when blended with the light-colored juices of apple and ‘Niagara’ than with the dark colored juice. The light amber color was stable during a 12 month storage period, and the flavor and overall acceptance of the mixture were rated higher than for the others.
Effects of CO2 on Cinnamic Acid-4-Hydroxylase in Relation to Phenolic Metabolism in Lettuce Tissue
Authors: Siriphanich Jingtair , Kader Adel A.
Published: August 2022

An atmosphere of air + 15% CO2 prevented the development of cinnamic acid-4-hydroxylase in both lettuce (Lactuca sativa L.) and potato (Solanum tuberosum L.) tissues. Subsequent removal of CO2 did not allow the enzyme development to proceed, whereas total phenolic content increased and browning became visible. In addition, CO2 did not have an inhibitory effect on the enzyme, prepared from potato tissue, per se. Thus, the effects of CO2 on inhibition of lettuce tissue browning does not appear to involve this enzyme. No tyrosine ammonia lyase activity was found in lettuce tissue.
Development of a Screen for Resistance to Blueberry Shoestring Virus
Authors: Schulte Nancy L. , Hancock J.F. , Ramsdell D.C.
Published: August 2022

A screen to test for resistance to blueberry shoestring virus (BBSSV) was developed using rub inoculation and the ELISA technique. A high rate of infection can be obtained with a virus concentration of 0.25 mg/ml when it is applied to randomly selected leaves of container grown blueberries during any portion of the growing season. However, plants must be ELISA tested in the early spring or 5 times during the rest of the growing season to achieve >50% accuracy.
The Minitron System for Growth of Small Plants under Controlled Environment Conditions
Authors: Akers Carolyn P. , Akers Stuart W. , Mitchell Cary A.
Published: August 2022

The design and operation of a system is described in which small plants can be grown under controlled environment conditions. Important features of this “Minitron” system include precise control of temperature and CO2 concentration in a flowing atmosphere. Plants can be grown either hydroponically or in solid root support medium. For either culture method, nutrient solution or water is added from an external reservoir, altering neither atmospheric composition nor temperature equilibrium within a closed Minitron chamber.
Concentration of Anthocyanins Affecting Spathe Color in Anthuriums
Authors: Iwata R.Y. , Tang C.S. , Kamemoto H.
Published: August 2022

Spathe color is shown to be determined by relative concentrations of the anthocyanins cyanidin 3-rhamnosylglucoside and pelargonidin 3-rhamnosylglucoside in Anthurium andraeanum Linden ex Andre. A predominance of cyanidin 3-rhamnosylglucoside results in pink to dark red colors, whereas a predominance of pelargonidin 3-rhamnosylglucoside results in coral to orange. A flavone present in large and variable amounts was characterized but not demonstrated to have a modifying effect on cyanic shades.
Relationship between Chilling Injury of Grapefruit and Moisture Loss during Storage: Amelioration by Polyethylene Shrink Film
Authors: Purvis Albert C.
Published: August 2022

Polyethylene shrink film reduced pitting type chilling injury in ‘Marsh’ grapefruit (Citrus paradisi Macf.) stored at low temperatures. The film did not restrict heat exchange between the fruit and air in the storage room. Chilling injury occurred most rapidly in fruit stored at 5° and 7.5°C, but after 5 weeks the severity of injury was greatest in fruit stored at 2.5°. The pattern of response to temperature was the same for unsealed fruit and sealed fruit. Prestorage conditioning of the fruit for 8 days at 21° prior to storage at 5° reduced chilling injury. Restricting moisture loss with shrink film during the prestorage conditioning treatment did not negate the beneficial effects of conditioning. Restricting moisture loss following chilling had no effect on chilling injury. Thus, although moisture loss is a contributing factor, it does not appear to be the primary factor in chilling injury of grapefruit. In order to minimize chilling injury, moisture loss should be prevented during fruit exposure to chilling temperatures.
Effects of Fall Boron Sprays and Environmental Factors on Fruit Set and Boron Accumulation in ‘Italian’ Prune Flowers
Authors: Hanson Eric J. , Breen P.J.
Published: August 2022

Foliar B sprays (500 ppm) applied in the fall to ‘Italian’ prune (Prunus domestica L.) trees had no effect on fruit set in a warm spring when set was high (average, 12.2%), but increased fruit set by 32% in a cool spring when set was low (3.2%). Fall B sprays increased flower B levels and decreased pistil length, but had no effect on the rate of pollen tube growth through styles in the cool spring. Calcium sprays (0.5 m) applied in the fall prior to the cool spring did not affect fruit set, pistil length, pollen tube growth or flower Ca or B levels. Flowers on cut branches forced indoors accumulated as much B as those on intact trees, indicating that flowers are supplied B from reserves in nearby branches. Simulated rain did not leach B from flower buds readily. Flowers blooming on excised branches in high relative humidity (86%) contained 13% less B per flower than flowers in low humidity (29%). The amount of set and B concentrations in flowers in a given year may influence the response to fall applied B.
Potential for Production of Arrowroot in the Southern United States
Authors: Erdman M.D. , Phatak S.C. , Hall H.S.
Published: August 2022

Arrowroot (Maranta arundinacea L.) was cultivated in Tifton, Ga., under various fertilization regimes (0, 220, 449, 668, and 897 kg·ha−1 of a 10N–4.4P–8.3 mixture), plant densities (3450, 6900, 13800, 20700, and 27600 plants ha−1), in solutions of half-strength Hoagland's solution, unfermented dairy waste solution, and anaerobically fermented dairy waste solution, or in solution-supplemented soil studies. Optimum starch yield ha−1 occurred at 220 kg·ha−1 fertilizer treatment. Calculated starch yield of 2770 kg·ha−1 could be obtained at a planting density of 20700 plants ha−1. Growth of aerial biomass was demonstrated in solution culture; however, rhizomes were not produced. Biomass and starch yields of arrowroot cultivated in solution-supplemented soil were comparable when Hoagland unfermented or fermented solutions were used.
Effect of Gynoecious Expression on Yield and Earliness of a Fresh-market Cucumber Hybrid
Authors: Wehner Todd C. , Miller Conrad H.
Published: August 2022

Three versions of the hybrid ‘Meridian 76’ (‘Marketmore 76’ × ‘Tablegreen 72’) differing in sex expression were used to evaluate the effect of gynoecious expression on fruit yield and earliness. The versions tested were gynoecious × gynoecious (G×G), gynoecious × monoecious (G×M), and monoecious × monoecious (M×M). In 2 years of testing, the gynoecious (G×G and G×M) hybrids had 99% to 100% pistillate flowers on the first 10 nodes of the main stem of the plant, whereas the monoecious (M×M) hybrid had 3% to 5% pistillate flowers. The monoecious hybrid had a higher percentage of U.S. Fancy and No. 1 fruits and a lower percentage of culls than the gynoecious hybrids. There were few significant differences in yield among the 3 hybrids. The gynoecious hybrids were earlier than the monoecious hybrid, but there were no important differences in the yield of marketable fruit after the first harvest in either year. The G×M hybrid had a significantly higher yield than the M×M hybrid in the first harvest for both years. The G×M hybrid tended to outyield the G×G hybrid as well, but the differences were not always significant. The gynoecious hybrids (especially the G×M hybrid) of ‘Meridian 76’ provided an advantage in early yield but not in yield summed over all harvests (6 to 8 depending on year), compared to the monoecious hybrid.
Leaching of Container Media
Authors: Kerr Gregory P. , Hanan Joe J.
Published: August 2022

Leaching of salt from container media was investigated by means of the miscible displacement theory for 6 peat-perlite-glass bead combinations plus 4 other mixes. Columns were salinized with 15 meq 1−1 each CaCl2 and NaCl, then allowed to equilibrate. Electrical conductivity of the effluent was recorded as columns were leached, using 1 cm constant water head, with solutions of 1, 4, or 7 meq 1−1 each of CaCl2 and NaCl. The replacement efficiency of the soil solution by the leaching solution increased as glass bead content increased. Replacement efficiency of the soil solution had high correlation with mixture physical properties. No relationship to particle size distribution could be ascertained. Leaching solution concentration did not influence replacement efficiency and, generally, after 1 to 1.5 container capacities of effluent, removal of the original soil solution decreased substantially.
Rock Phosphate as a Source of Phosphorus for Vesicular-arbuscular Mycorrhizal Development and Growth of Citrus in a Soilless Medium
Authors: Graham J.H. , Timmer L.W.
Published: August 2022

Vesicular-arbuscular mycorrhizal (VAM) development of Glomus intraradices Schenck & Smith and growth response of Carrizo citrange [Poncirus trifoliata (L.) Raf. × Citrus sinensis (L.) Osbeck] and sour orange (C. aurantium L.) seedlings were examined in peat-perlite medium fertilized with 4 levels of superphosphate (SP) and rock phosphate (RP). Loss of P from SP-amended medium was exponential, whereas release of P was linear from RP-amended medium. With SP, root colonization by G. intraradices and growth response of both citrus rootstocks were reduced compared to RP-amended medium. VAM colonization and growth response were less with SP-amended medium than RP, probably because of the initially high available P from SP which inhibited VAM development, and because P later declined to levels insufficient to support maximum growth. When RP was used as a controlled-release source of P, VAM colonization was comparable to that observed in mineral soils. Growth of VAM plants exceeded that of uninoculated plants fertilized with increased levels of soluble P because of P-induced Cu deficiency in absence of VAM. An additional advantage of RP was long-term availability of P, compared to SP which leached within weeks after application to peat-perlite. No further P fertilization may be necessary if RP and VAM inoculum are incorporated into soilless media before planting, whereas repeated application of soluble P would be required for slow-growing woody plants like citrus.
Fruit Moisture Status Effects on the Texture and Mechanical Properties of Sweet Cherries
Authors: Patten K.D. , Patterson M.E.
Published: August 2022

When the water content of cherries (Prunus avium L.) was increased by more than 5% of the initial weight following immersion in distilled water, the force to bioyield (FBY) and the maximum slope of a compression curve (slope 2) decreased, and impact-induced surface pitting increased. When water content of cherries was decreased by more than 2% of the initial weight following dehydration, FBY increased and the minimum slope of a compression curve (slope 1) and impact-induced surface pitting decreased. Force to bioyield and slope 1 and 2 increased with an increase in fruit turgor potential (ψp) and a decrease in fruit osmotic potential (ψπ). There was a slight positive correlation between fruit water potential (ψ) and FBY and slope 1. Fruit texture changed diurnally, corresponding to changes in fruit ψ. This diurnal texture change, however, was largely a response to diurnal differences in fruit temperature.
Relationships between Stem Length, Leaf Area, Stem Weight, and Accumulated Growing Degree-days in Apple Shoots
Authors: Johnson R.S. , Lakso A.N.
Published: August 2022

The relationship of leaf area and stem weight, with stem length at different times during the year, was studied on 5 apple (Malus domestica Borkh.) cultivars. Leaf area was related linearly to stem length, but the slope differed by up to 2-times between cultivars. Stem dry weight increased curvilinearly with respect to stem length and showed less variation among cultivars than did leaf area. These 2 relationships combined indicated that the stem constitutes an increasing proportion of the total shoot weight with increasing stem length. Dormant stems had a greater weight per unit length than stems of growing shoots. Both stem length and leaf area showed strong fitting linear relationships with accumulated growing degree-days, but the stem length relationship showed less variability among cultivars than did leaf area.
Sample Size Estimates for Peach Tree Growth and Yield Experiments
Authors: Marini Richard P.
Published: August 2022

Trunk cross sectional area (TCA), TCA enlargement, yield, yield efficiency, and terminal shoot length were recorded for each of 10 peach [Prunus persica (L.) Batsch] trees in plantings ranging in age from 4-15 years. Sample variances were used to estimate the number of trees per treatment needed to detect differences of a desired magnitude in experiments comparing 2 treatments. In general, 30 trees per treatment were required to detect a 15% difference in TCA and yield, while more than 40 trees per treatment were needed to detect a similar difference for TCA enlargement and yield efficiency. Twelve trees per treatment and 6 to 22 shoots per tree, depending on cultivar, could be expected to detect a 15% difference in terminal shoot length.
Relationships between Parental, Seed, and Seedling Chilling Requirement in Peach and Nectarine
Authors: Rodriguez-A. Jorge , Sherman Wayne B.
Published: August 2022

Attempts to select for flower bud chilling requirement (CR) at the seed stage were made in 58 families obtained from crosses and open-pollination of low chill selections and cultivars of peach and nectarine [Prunus persica (L.) Batsch] from the Florida breeding program. A nonsignificant correlation (r = 0.08) between midparent bud CR and family seed CR was obtained. A low significant correlation (r = 0.21**) was obtained between individual seed CR and the CR of the resultant seedling. Seed coat removal had no effect on these correlations. Narrow sense heritability for bud CR as determined by parent-offspring regression was 0.50 ± 0.06. The small range in CR of the seed and pollen parents, 300 to 450 and 200 to 400 chill units, respectively, may explain the low correlation values obtained. The data suggest that it is impractical to screen for seedling CR based on seed CR where the CR for climatic adaptability must be held within a range of less than 300 chill units.
Glucosinolates in Radish Cultivars
Authors: Carlson Diana G. , Daxenbichler M. E. , VanEtten C. H. , Hill C. B. , Williams P. H.
Published: August 2022

Intact roots of 109 radish (Raphanus sativus L.) cultivars were analyzed for glucosinolates (GS’s) and found to contain primarily 4-methylthio-3-butenyl-GS with small amounts of 4-methylsulfinylbutyl-, 4-methylsulfinyl-3-butenyl-, and 3-indolylmethyl-GS’s. Cultivars included oil radishes (ssp. oleifera) and food radishes (ssp. radicola) available in European, European-American, Japanese, and Korean markets. Regarding total GS’s, 80% or more of the red European-American radishes had 100-199 pmole/100 g, the Korean 100-299, and the Japanese 200-399. No correlation was found between root size and 4-methylthio-3-butenyl-, 3-indolylmethyl-, or total GS’s. Japanese radish peelings contained significantly greater concentrations of these 3 constituents than did the peeled root.
Effects of Growth Regulators on Abscission of Young Macadamia Fruit
Authors: Nagao Mike A. , Sakai William S.
Published: August 2022

The abscission of young Macadamia integrifolia Maiden & Betche fruit was investigated in vitro with explants consisting of a single fruit attached at the distal end of a segment of the peduncle. A 30% reduction in fruit removal force (FRF) of explants incubated in distilled water was evident within 48 hr after excision and was correlated with increased ethylene production. Pretreatment of explants with 5 and 10 mm ethephon accelerated FRF reduction. Pretreatment with increasing concentrations of silver nitrate (AgNO3) to 1.47 mm or AOA to 0.05 mm, inhibited the reduction in FRF. FRF reduction also was inhibited by 1000 μm NAA and 100 pM 2,4-D. GA3 and BA had no effect. Chemical names used: (2-chloroethyl)phosphonic acid (ethephon); 1-naphthaleneacetic acid (NAA); (2,4-dichloro- phenoxy)acetic acid (2,4-D); gibberellic acid (GA3); N-(phenylmethyl)-H-purin-6-amine (BA); (aminooxy)acetic acid (AOA).
Sorbitol Metabolism, the Climacteric, and Watercore in Apples
Authors: Marlow Gary C. , Loescher Wayne H.
Published: August 2022

Extraction and assay of sorbitol dehydrogenase (SDH) throughout fruit maturation of 3 apple (Malus domestica Borkh.) cultivars, watercore-resistant ‘Golden Delicious,’ occasionally susceptible ‘McIntosh’, and normally susceptible ‘Starkrimson,’ showed no relationship between susceptibility to watercore and extractable enzyme activity. There was, however, a relationship between increased SDH activity and onset of the climacteric as measured by ethylene and CO2 evolution, suggesting that SDH, like certain other enzymes, increases during maturation.
Relationship between Clone Age and Selection Trait Expression in Mature Walnuts
Authors: McGranahan Gale , Forde Harold I.
Published: August 2022

Data on 15 traits collected from 30 walnut selections were analyzed for changes in relation to both clone and rootstock age. Data collection began at first flowering (age 3 or 4) and continued annually for up to 28 years on each clone. Significant correlations were found between seasonal timing of the expression of phenological traits and clone age. The general trend was towards earlier leafing, bloom, and time of nut maturity as the clone aged. Correlations with rootstock age were lower than with clone age for phenological traits. Shell and kernel trait expression was more highly correlated with rootstock age than clone age, suggesting that changes may be due to vigor and other effects of grafting rather than aging per se. Estimates of the age of stabilization for phenological traits ranged between 9 and 18 years from germination. It is suggested that changes in leafing, bloom, and nut maturity dates be considered prior to commercial release of walnut cultivars.
Comparison of Four Sampling Methods for Predicting Poststorage Senescent Breakdown of ‘McIntosh’ Apple Fruit from Preharvest Mineral Composition
Authors: Weis Sarah A. , Bramlage William J. , Drake Mack
Published: August 2022

A 4-year study compared 4 methods of subsampling ‘McIntosh’ apples for mineral analyses intended for use in predicting postharvest senescent breakdown. Concentrations of Ca, Mg, K, P, and N were determined in outer cortex, whole fruit, and juice in 1979 and 1980, and in outer cortex and cortical plugs in 1981 and 1982. Multiple linear regression equations were developed for each sampling in 1979 and 1981 relating the natural logarithms (In) of Ca and P concentrations and Mg:Ca, K:Ca, and N:Ca ratios to In (breakdown percentage +1). Effectiveness of each equation as a predictor of breakdown during and following storage was tested using data collected the following year. Paired t tests comparing predicted breakdown, using 1979 equations and 1980 mineral analyses, to breakdown observed after storage in 1980-1981 showed that outer cortex- and whole fruit-based predictions were not significantly different from observed breakdown, but juice equations predicted significantly more breakdown than was observed. Correlation coefficients relating actual to predicted breakdown were positive and significant for all 3 methods. In 1981, separate equations were developed to predict fruit breakdown after air and after controlled atmosphere (CA) storage. Paired t tests showed the predicted incidence of breakdown following CA storage was not significantly different from actual breakdown incidences for either outer cortex or cortical plug equations. Breakdown incidence following air storage was less than predicted. In all instances, correlation between actual and predicted breakdown incidence was positive and significant. Outer cortex, whole fruit, and cortical plug analyses showed promise as breakdown predictors, but juice analyses were ineffective.
Bermudagrass Turf Responses to Nitrogen Sources
Authors: Horst G. L. , Fenn L. B. , Dunning N. B.
Published: August 2022

Turfgrass quality usually is related to fertilization management practices. Nitrogen fertilizer formulations are undergoing change in order to produce acceptable turfgrass response and reduce management costs. Field experiments conducted during 1979–81 evaluated the influence of Ca on urea and nitrate N sources on bermudagrass (Cynodon dactylon L.) turfgrass color, quality, verdure, and root-rhizome dry matter production. Color, quality, and verdure were significantly improved and persisted longer with the addition of Ca to urea N sources. Early season root and rhizome production also was increased with the urea + calcium application. Verdure was not significantly affected among the N sources. There was not a significant increase in tissue N content. Addition of Ca to the fertilizer formulation apparently enhanced N utilization.