bluuebunny/crossref_metadata_2025 huggingface dataset:
Water Relations of Grapefruit Trees in Response to Drip, Microsprinkler, and Overhead Sprinkler Irrigation
Authors: Zekri Mongi , Parsons Lawrence R.
Published: August 2022

Water relations responses of 21-year-old grapefruit trees (Citrus paradisi Macf.) irrigated by three types of irrigation systems were compared. Drip, undertree microsprinkler, and overhead sprinkler with application levels of 150 and 450 mm of water per year were compared. Leaf water potential, stomatal conductance, and soil water status were measured under field conditions on a deep, well-drained sandy soil in central Florida. In the early part of a dry spring period, there were no differences in midday or early morning leaf water potential, but, by the end of this period, significant differences in leaf water potential were found among all three irrigation treatments. Highest leaf water potential and stomatal conductance values were maintained in the overhead sprinkler blocks. No midday stomatal closure was observed under the conditions of this study. Relationships among diurnal leaf water potentials, vapor pressure deficits, and stomatal conductance showed hysteresis; this affected the correlations among these factors. Greater water stress occurred in trees irrigated with drip than in trees irrigated with overhead sprinkler systems, but responses to microsprinklers were generally intermediate between the overhead sprinkler and the drip treatments. In an area with high rainfall and sandy soils, increased irrigation coverage can reduce leaf water stress.
Growth and Nutritional Status of Pecan in Response to Phosphorus
Authors: Sparks Darrell
Published: August 2022

Effects of applied P on pecan [Carya illinoensis (Wangenh.) C. Koch] were studied in the greenhouse and field. Objectives were to study P effects on vegetative and nut growth, leaf scorch and/or premature defoliation, and nutrition. Elements were analyzed for both total and extractable (2% acetic acid) fractions. In the greenhouse, deficiency symptoms occurred when leaf P (dry-weight basis) was 0.08%; vegetative growth was maximum when P was 0.19% to 0.22%. In the field, applied P increased nut growth and decreased leaf scorch and premature defoliation. Leaf P values for maximum nut growth and minimum leaf scorch and/or defoliation are greater than 0.14% and 0.16%, respectively. Except when P was within the visible deficiency range, applied P had little direct influence on the concentration of other essential elements under either greenhouse or field conditions. Generally, extractable P was a slightly better indicator of the P status of the tree than total P, but the differences are of doubtful physiological significance.
Anatomical Characterization and Possible Role of Calcium in “Pillowy”, a Fruit Disorder in Processing Cucumber
Authors: Staub Jack E. , Rousos Penny , Struckmeyer Burdean E.
Published: August 2022

The anatomical and nutritional aspects of a fruit disorder in processing cucumber (Cucumis sativus L.) termed pillowy were investigated in the field and greenhouse. Pillowy symptoms are areas of “styrofoam-like”, opaque- white, porous-textured tissue in the mesocarp of freshly harvested fruit. Parenchyma cells of pillowed fruit were hypertrophied and hyperplastic, with either numerous small or no intercellular spaces. While nonpillowy parenchyma cells plasmolyzed when placed in hypertonic solution, lack of plasmolysis in pillowy tissue indicated that cell membranes were not functioning normally. Some vascular tissue was collapsed and necrotic. Plants supplied 200 mg Ca/liter and grown at a relative humidity of 89% ± 8% created by clear plastic canopies had a significantly higher incidence (62% vs. 42%) of pillowed fruit than fruit matured in a greenhouse with 74% ± 7% RH. The Ca concentrations of exocarp or peel and mesocarp in nonpillowed fruit were significantly higher than that of pillowed fruit (0.59% vs. 0.49% and 0.37% vs. 0.24%, respectively). In pillowed fruit, the nonpillowed areas contained 0.25% Ca. Pillowing, measured as the percentage of pillowed tissue, increased linearly with decreasing Ca levels in the peel, pillowed, and nonpillowed tissue. Anatomical anomalies may be explained as Ca-related cell wall abnormalities associated with localized Ca deficiencies that are intensified by reduced transpiration at high relative humidity.
Ripening of Mature-green Tomato Fruit Slices
Authors: Mencarelli Fabio , Saltveit Mikal E.
Published: August 2022

In the article “Ripening of Mature-green Tomato Fruit Slices”, by Fabio Mencarelli and Mikal E. Saltveit, Jr. [J. Amer. Soc. Hort. Sci. 113(5):742−745, September 1988], Table 4 is called out in the next-to-last paragraph. There is no Table 4 in this article.
Nonchemical Methods for Postharvest Control of Botrytis cinerea on Cut Roses
Authors: Hammer Philip E. , Marois James J.
Published: August 2022

Cold storage of cut ‘Sonia’, ‘Royalty’, and ‘Gold Rush’ roses (Rosa hybrida L.) at reduced humidities (50% to 80% RH) significantly decreased the severity of Botrytis cinerea Pers. infections that developed from naturally occurring or experimentally applied inocula, compared to storage at saturated humidity. The disease reduction was attributed to the absence of free water on the petals. Wrapping the flowers in cellophane sleeves before reduced-humidity storage decreased water loss but also impaired disease control. No deleterious effects of reduced-humidity storage on poststorage fresh weight gain or visual quality were observed, whether the wrapped flowers are stored with or without vase solutions. Two biological control agents, the yeast Exophiala jeanselmei and a Coryneform-type bacterium, controlled B. cinerea infections during storage at 2.5°C when applied 0 to 48 hr after inoculation with the pathogen. The level of disease control achieved with the biological antagonists during storage was comparable to that achieved with the fungicide vinclozolin, but the biological antagonists did not control poststorage disease development as well.
Embryo Development and Germination of Cycas Seeds
Authors: Dehgan Bijan , Schutzman Bart
Published: August 2022

Germination of Cycas revoluta seed is slow and erratic when planted immediately after collection, and most lose viability in a few months. In a 2 × 4 × 4 factorial experiment, seeds were stored at 5° and 22°C for 24 weeks and subsequently treated with H2SO4 (18 M) for 0, 1, 2, or 3 hr followed by GA3 (1000 ppm) for 0, 24, 48, or 72 hr. Morphophysiological complex dormancy contributes to the lengthy germination process. Removal of the fleshy, water-repellant sarcotesta (containing inhibitors), scarification of the thick water-impermeable sclerotesta, and maturation of the embryo, which is in very early stages of development at the time of seed abscission, all enhance germination. At 5°, 92% of the seeds survived, but only 42% of the seeds stored at 22° were viable after 24 weeks, the result of desiccation. Under all but 72 hr of GA3 exposure time, response surface shapes lead to the expectation that germination will be better without H2SO4 or with higher levels of H2SO4 than with intermediate levels. The response to GA3 at any given exposure to H2SO4 is similar in both cold- and warm-stored seeds: for a given GA, level, one optimum H2SO4 exposure gives the best germination percentage, peak value (PV), or germination value (GV). Optimal GV results when seeds are stored at 5° for 24 weeks to allow embryo maturation followed by removal of the sarcotesta, 1 hr of H2SO4 exposure, and 36 hr of GA3 exposure.
Allelopathic Substances in Asparagus Roots: Extraction, Characterization, and Biological Activity
Authors: Hazebroek Jan P. , Garrison Stephen A. , Gianfagna Thomas
Published: August 2022

Aqueous extracts of asparagus (Asparagus officinalis L.) roots inhibited seed germination in tomato and lettuce, but not in cucumber. The extracts reduced hypocotyl growth in lettuce, shoot growth in asparagus, and inhibited radicle elongation in barley, lettuce, and asparagus. Seedling growth in tomato and two cultivars of wheat were not affected. Inhibition was concentration-dependent. Radicle growth in ‘Grand Rapids’ lettuce was sensitive to an extract concentration as low as 0.05 g dry root tissue/100 ml H2O. Asparagus radicles were more sensitive than asparagus shoots. In one experiment, phytotoxicity of crude extract was not altered by autoclaving. Aqueous root extracts of A. racemosis Willd. also inhibited germination and radicle growth in ‘Grand Rapids’ lettuce. A crude extract was purified by solvent partitioning, and charcoal adsorption, cation exchange, and thin-layer chromatography (TLC). A band from the TLC was found to fluoresce under ultraviolet light, react with phenolic-sensitive localization reagents, and inhibit the growth of lettuce and asparagus radicles.
Temperature and Photosynthetic Photon Flux Influence Chrysanthemum Shoot Development and Flower Initiation under Short-day Conditions
Authors: Karlsson Meriam G. , Heins Royal D. , Erwin John E. , Berghage Robert D. , Carlson William H. , Biernbaum John A.
Published: August 2022

The effects of photosynthetic photon flux (PPF), day temperature (DT) and night temperature (NT) on leaf number, leaf unfolding rate and shoot length were determined for chrysanthemum (Dendranthema grandiflora Tzvelev. ‘Bright Golden Anne’) grown under short day (SD) conditions. A functional relationship was first developed to predict if flower bud appearance would occur within 100 SD under a given set of environmental conditions. All combinations of DT and NT in the range from 10° to 30°C were predicted to result in flower bud appearance at higher PPF than 10.8 mol·day−1·m−2. The number of leaves formed below the flower increased quadratically as DT and/or NT increased from 10° to 30°. As PPF increased from 1.8 to 21.6 mol·day−1·m−2, one to two fewer leaves were formed per shoot. Rate of leaf unfolding increased linearly with increasing average daily temperature from 0.2 leaves/day at 10° to 0.5 leaves/day at 30°. Internode length was highly correlated with the difference between DT and NT (DIF = DT – NT) such that increasing DIF from –12° to 12° resulted in progressively longer internodes.
Improved Stand Establishment of Direct-seeded Cabbage with Seed Covers
Authors: Perkins-Veazie Penelope M. , Cantliffe Daniel J. , White James M.
Published: August 2022

Seed treatments and soil covers were used to assess stand establishment and uniformity of direct-seeded cabbage (Brassica oleracea L. var capitata) under high and low soil temperatures. Generally, primed seeds did not result in increased or more uniform seedling emergence compared to untreated seeds. Germinated seeds sown with a magnesium silicate gel (Laponite) or a starch-acrylamide-acrylate polymer gel (Liquagel) resulted in incomplete stands under heat stress, and stands for all plantings were generally lower when cabbage seeds were sown in a gel than when sown without a gel. Peat-vermiculite (Plug-mix) and calcined clay (GrowSorb) seed covers improved stands regardless of seed treatment when average soil temperatures were ≥30°C. Under normal (25°) to cooler soil conditions stands were not improved by seed treatment or seed cover.
Primocane Removal Enhances Yield Components of Raspberries
Authors: Freeman Jack A. , Eaton George W. , Baumann Thomas E. , Daubeny Hugh A. , Dale Adam
Published: August 2022

A trial of six raspberry (Rubus ideaus L.) cultivars was established to study the effects of primocane removal, using dinoseb, on yield and its components. In 1982 through 1984, sprays were applied using both single and multiple follow-up treatments with and without shielding the primocanes in the immediate stool area. The effects of cultivars and treatments on yield components were studied by two-dimensional partitioning of the variation in marketable yield. When primocanes were removed, the cultivars had fewer canes, larger fruit, and increased marketable yield. Cultivars differed in their requirements for treatment because some cultivars produced canes more readily than others. Higher-yielding cultivars generally had fewer canes and greater length of laterals. Chemical name used: 2-(1-methylpropyl)-4,6-dinitrophenoI (dinoseb).
Comparison of Fluid Drilling with Conventional Planting Methods for Stand Establishment and Yield of Spring and Fall Cauliflower Crops
Authors: Kahn Brian A. , Motes Janies E.
Published: August 2022

Fluid drilling was compared with dry seeding and transplanting for effects on stand establishment and crop yields in spring and fall crops of cauliflower [Brassica oleracea L. (Botrytis Group)]. Two cultivars, at least two seeding dates, and one transplanting date were used in each experiment. Fluid drilling and dry seeding produced the desired post-thinning stand with March seeding dates. Fluid drilling usually failed to produce the desired post-thinning stand when planting occurred during the hot, dry weather of August. Fluid drilling was not superior to dry seeding or transplanting for earliness, uniformity of harvest, or total marketable yields in spring and fall cauliflower crops, with the exception of one spring planting date. Therefore, fluid drilling did not show benefits sufficient to justify the specialized techniques and equipment required. Cuitivar and planting date effects often were more important than effects of stand establishment methods in these studies.
Crop-Water Production Functions for Sweet Corn
Authors: Braunworth William S. , Mack Harry J.
Published: August 2022

Sweet corn (Zea mays L.) was irrigated using randomized complete block and line source experimental designs in 1984 and 1985 on a mixed, mesic Cumulic Ultic Haploxeroll soil. Irrigations were scheduled when ≈50% of the available water was depleted in the root zone of the 100% treatment to refill the root zone to 0% to 100% of field capacity (five irrigation levels). Four yield parameters were measured for all plots: yield of all ears before husking, yield of good husked ears, kernel yield (fresh), and total dry matter production of plants and ears. Maximum relative total unhusked ear yield and near-maximum evapotranspiration (ET) were obtained at 85% of maximum water applied, indicating that high yields can be maintained with deficit irrigation. Without irrigation, only 44% of maximum yield was obtained. Maximum water use efficiency (WUE), defined as the total unhusked ear yield in kg·ha−1·mm−1ET, occurred between 407 and 418 mm of ET. The maximum WUE corresponded to ≈313 mm water applied (WA); maximum yield, however, occurred within the range of 449 to 518 mm WA. Irrigation treatments to achieve maximum WUE were predicted to result in a 10% yield reduction.
Ethephon and NAA Facilitate Early Harvesting of Pecans
Authors: Wood Bruce W.
Published: August 2022

In an attempt to solve the problems of nonuniform and delayed shuck dehiscense of pecan [Carya illinoensis (Wangenh.) C. Koch], ethephon and NAA were evaluated for their efficacy as harvest-aid treatments. A 3-year study under commercial-like orchard conditions using 75-year-old ‘Stuart’ trees resulted in a spray mixture of 9 mm ethephon and 1.5 or 3.0 mm NAA, or just 9 mm ethephon alone, accelerating shuck dehiscence by 1 to 2 weeks relative to that of the nontreated control. While all three treatments induced some degree of leaflet abscission, the two treatments employing the NAA and ethephon combination induced only about one-fourth (21% vs. 75%) as much leaflet abscission as when ethephon was used alone. However, this level of leaflet abscission (21%), plus an associated 50% drop in net photosynthesis for several days post-treatment, was sufficient to reduce in-shell nut yields in subsequent years. This appears to preclude commercial acceptability of such treatments for pecan. Chemical names used: (2-chloroethyl)phosphonic acid (ethephon), 1-napthaleneacetic acid (NAA).
Permeability of Polymer Film Wraps for Citrus Fruit Fumigated with Hydrogen Cyanide to Control California Red Scale
Authors: Houck Laurie G. , Jenner Joel F. , Moreno Daniel S. , Mackey Bruce E.
Published: August 2022

Permeability to the postharvest fumigant hydrogen cyanide (HCN) varied markedly among 13 plastic film-wrapping materials. Permeability was determined by comparing California red scale [Aonidiella aurantii (Maskell)] (CRS) surviving fumigation on film-wrapped and nonwrapped, insect-infested, fruit. HCN transmission rates for several films also were determined by a permeation cell technique. Some films partially restricted passage of the fumigant to the fruit and CRS survival was high, while permeability of other films differed little from unrestricted exposure on nonwrapped fruit and CRS survival was low. For films with low permeability to HCN, increasing the HCN concentration or the length of fumigation time are possible methods of increasing the amount of HCN that penetrates to the fruit for control of quarantined insects. The permeability of film wrapping materials to fumigants should be a prime consideration when selecting films for wrapping citrus fruit in quarantine situations.
Reduced Irradiance Affects Dry Weight Partitioning in Easter Lily
Authors: Miller William B. , Langhans Robert W.
Published: August 2022

The effects of reduced irradiance on dry weight partitioning in Easter lilies was examined by forcing vernalized bulbs of Lilium longiflorum Thumb. ‘Nellie White’ during two growing seasons. Forcing commenced in a glasshouse under standard growing conditions; immediately following flower bud initiation (FBI), plants were transferred to a range of irradiance reduction treatments (0%, 20%, 50%, or 85% reduction) in the greenhouse or to complete darkness in a growth chamber. Greenhouse irradiance reduction treatments resulted in alterations in whole-plant source-sink relationships. Total plant dry weight and overall plant quality were reduced in shaded plants. The depletion rate of mother bulb dry matter was not affected by reduced irradiance, whereas daughter bulb reserve loss was increased by irradiance reduction treatments. There was no daughter bulb reserve remobilization in plants grown in complete darkness after FBI. Flower bud and open flower dry weights were progressively reduced as irradiance was reduced. With an 85% irradiance reduction, plants forced from 17.5-cm bulbs had 63% bud abortion, whereas, with 20.0-cm bulbs, only 12% of the buds aborted. Plants grown in complete darkness after FBI became etiolated, and flowers failed to open. These results demonstrate differences in the ability of various morphological regions of the bulb to respond to reductions in greenhouse irradiance. Since the daughter bulb response to reduced irradiance was relatively slow, additional remobilization of dry matter from the daughter bulb is probably of minimal benefit during short periods of reduced irradiance in commercial greenhouses.
Differences in Mid-day Wilting and Yield among Sweet Potato Genotypes
Authors: Bouwkamp J. C.
Published: August 2022

Response to mid-day wilting (dehydration avoidance) among sweet potato [Ipomoea batatas L. (Lam)] genotypes is a consistent trait within and among years. This response is significantly related to storage root dry weight and net photosynthesis in most years. The relationship is more obvious among relatively high-yielding clones or when data are obtained over several years. Reduced mid-day wilting increases yield in high-yielding genotypes through increased net photosynthesis and increased partitioning of assimilates to storage roots. Increased storage root dry weight is also related to the percentage of water in the vines at near full-turgor through increased partitioning to roots and reduced mid-day wilting. Wilting response and vine moisture together account for nearly 25% of the variation in yield of high-yielding clones tested over 5 years with irrigation.
Whole-plant Response of Easter Lilies to Ancymidol and Uniconazole
Authors: Bailey Douglas A. , Miller William B.
Published: August 2022

All growth retardant treatments (ancymidol, 50 mg·liter−1, one or two sprays; uniconazole, 5, 10, or 15 mg·liter−1, one or two sprays; 20 mg·liter−1, one spray) reduced Easter lily (Lilium longiflorum Thunb.) plant heights when compared to controls. Plant heights decreased linearly with increasing concentration of uniconazole for both one- and two-spray treatments. High concentrations of uniconazole delayed anthesis; ancymidol treatments did not. Individual corolla length was not affected by treatments. Treatments did not affect daughter bulb depletion or new daughter bulb growth. Total leaf area and leaf dry weight decreased as uniconazole concentration increased; ancymidol treatments did not affect leaf area, but did reduce leaf dry weight. Leaf total soluble carbohydrate decreased with increasing concentration of uniconazole. Chemical names used: α-cyclopropyl-α-(4-methoxyphenyl)-5-pyrimidine-methanol (ancymidol); (E)-1-(p-chlorophenyI)-4,4-dimethyl-2-(1,2,4-triazol-1-yl)-1-penten-3-ol (uniconazole).
Sugar/Acid Composition and Development of Sweet and Tart Carambola Fruit
Authors: Campbell Craig A. , Koch Karen E.
Published: August 2022

The oxalic-acid-accumulating fruit of carambola (Averrhoa carambola L. Oxalidaceae) was examined during development to characterize changes in sugars and acids and to evaluate potential maturity indices. Commercial maturity (color break) occurred 65 and 60 days after fruit set of sweet ‘Arkin’ and tart ‘Golden Star’, respectively. Fruit size at this stage was highly variable (51 to 103 mm long) and not a reliable indicator of maturity. Total soluble sugar concentration, mainly glucose and fructose, was almost 25% greater in the sweet ‘Arkin’ fruit (≈27 mg·g−1 fresh weight) than in the tart ‘Golden Star’ carambolas (22 mg·g−1 fresh weight). At harvest, sucrose made up only 15% to 20% of the total soluble sugars. Oxalic acid was the predominant organic acid in young fruit of both cultivars, but levels differed dramatically between sweet ‘Arkin’ (≈1 mg·g−1 fresh weight) and tart ‘Golden Star’ (≈7 mg·g−1 fresh weight). Malic acid (<1.5 mg·g−1 fresh weight) was also present. Acidity in sweet ‘Arkin’ carambolas declined rapidly during early growth, but remained high during development of tart ‘Golden Star’. Sugar accumulation, acid reduction, and color development continued for at least 7 days after color break if fruit remained on trees, but such fruit were not firm enough for typical commercial handling.
Trichome Secretion Composition, Trichome Densities, and Spider Mite Resistance of Ten Accessions of Lycopersicon hirsutum
Authors: Weston P. A. , Johnson Deborah A. , Burton H. T. , Snyder John C.
Published: August 2022

Trichome secretion composition, glandular trichome densities, and spider mite resistance were measured for 10 accessions of Lycopersicon hirsutum Humb. & Bonpl., a wild, South American relative of tomato exhibiting high arthropod resistance. The sesquiterpene hydrocarbons zingiberene and γ-elemene were identified as major volatile components of Type VI trichome secretions from L. hirsutum f. typicum (hir) plant introduction (PI) 251303. These compounds predominated trichome secretions from five other hir accessions, whereas the methyl ketones 2-undecanone and 2-tridecanone predominated trichome secretions from five accessions of L. hirsutum f. glabratum (gla). Type IV trichome densities were greater on gla than on hir accessions, whereas Type VI trichome densities were greater on hir than on gla. Type VI trichome densities were greater on plants cultured under a 14- to 15-hr photoperiod (LD) than on plants cultured under an 8-hr photoperiod (SD) for gla, but not hir, accessions. Type IV trichome densities were greater under SD than under LD conditions for all accessions. In general, hir accessions were more resistant to mites (Tetranychus urticae Koch) than gla accessions. Spider mite resistance was correlated with Type IV trichome density on hir, but not on gla, accessions. Differences in Type IV trichome densities alone between hir and gla do not explain the greater mite resistance of hir accessions.
Analysis of Self-incompatibility Reaction in Easter Lily by Using Heat Treatments
Authors: Hiratsuka S. , Tezuka T. , Yamamoto Y.
Published: August 2022

Self-incompatibility of Easter lily (Lilium longiflorum Thunb.) was overcome by heating the styles. Immersing detached prepollinated styles in distilled water at 45C for 5 min promoted the growth of incompatible pollen tubes. When heat-treated styles were kept at 25C for various periods before pollination, the effect of overcoming selfincompatibility diminished as the period between the heat treatment and pollination was increased. Heat treatment of styles within 2 hr after incompatible pollination promoted the growth of pollen tubes to a distance comparable to compatible ones. When the styles were heated during the period from 3 to 8 hr after incompatible pollination, the growth of pollen tubes was retarded to some extent as compared to those treated within 2 hr after pollination. Treatment at 12 or more hours after pollination no longer promoted the growth of incompatible pollen tubes. These results suggest that overcoming self-incompatibility by heating is temporary and the incompatibility machinery is already induced at ≈3 hr after pollination.
Respiration and Ethylene Production in Harvested Watermelon Fruit: Evidence for Nonclimacteric Respiratory Behavior
Authors: Elkashif Mohamed E. , Huber Donald J. , Brecht Jeffrey K.
Published: August 2022

In the article “Respiration and Ethylene Production in Harvested Watermelon Fruit: Evidence for Nonclimacteric Respiratory Behavior,” by Mohamed E. Elkashif, Donald J. Huber, and Jeffrey K. Brecht [J. Amer. Soc. Hort. Sci. 114(1):81–85, January, 1989], the respiratory drifts in Fig. 1 were not clearly visible. An improved figure is printed below.
Organogenesis and Patterns of Floral Bud Development in Two Eastern Thornless Blackberry Cultivars
Authors: Takeda Fumiomi , Wisniewski Michael
Published: August 2022

Axillary buds on lateral branches of ‘Black Satin’ and ‘Hull Thornless’ thornless blackberries (Rubus sp.) were examined from September to May in 1984–1985 and 1986–1987, and in Spring 1988. Initial inflorescence development in ‘Black Satin’ was evident in October; however, most buds remained vegetative until January. Perianth primordia became distinct around the terminal floral apex in some buds in late February to early March. Buds sampled from lateral branches at the top portion of plants were more advanced than buds from the bottom portion at several sampling dates. Axillary buds of ‘Hull Thornless’, in contrast, remained vegetative in all floricane portions until late March. Subsequent developmental rates were rapid and uniform. Once the terminal flower appeared, the most basal floral apex in the primary (A1) axis was next to develop. Remaining floral apices along the axis developed sequentially in an acropetal direction. Neither uniformity and time of bud initiation nor subsequent rate of development appeared to affect the length of bloom period.
Lime and Nitrogen Influence Soil Acidity, Nutritional Status, Vegetative Growth, and Yield of Muskmelon
Authors: Bhella Harbans S. , Wilcox Gerald E.
Published: August 2022

A field study was conducted on an acidic loamy sand to evaluate muskmelon (Cucumis melo L. cv. Classic) response to calcitic limestone and 0, 67, and 100 kg N/ha. Lime application increased soil pH and Ca concentration and lowered soil NH4-N and Mn concentrations. Higher levels of N increased soil NH4-N, NO3-N, and K concentrations and decreased soil pH. Plants developed Mn toxicity symptoms in unlimed plots and the severity of foliar injury increased with increasing N levels. Lime application increased P, Ca, and Mg and reduced Mn and Zn concentrations in leaf tissue. Tissue concentrations of N, Mn, and Zn were higher and Ca, Mg, and B were lower as N level increased from 0 to 100 kg N/ha. Muskmelon fruit yields and soluble solids content were increased and culls reduced both by lime and N. Maximum vegetative growth and total fruit yield were obtained at 67 kg N/ha with lime application.
Analysis of Water Potential Isotherms in Two Ornamental Shade Tree Species Entering Winter Dormancy
Authors: Augé Robert M. , Stodola Ann J. W.
Published: August 2022

Osmotic adjustment in response to onset of winter dormancy was characterized in well-watered, potted sweetgum (Liquidambar styraciflua L.) and southern magnolia (Magnolia grandiflora L.) growing outdoors in Knoxville, Tenn. Analyses of water potential isotherms indicated that adjustment occurred in both species, with osmotic potential (ψπ) at full turgor decreasing 0.8 MPa in sweetgum (by the time of first color, 27 Oct.) and 1.0 MPa in magnolia (by 1 Dec.). Osmotic adjustment occurred despite the fact that plants did not suffer osmotic stress; morning and afternoon leaf relative water content (RWC) and leaf water potential (ψ) remained high throughout the fall. Leaf conductance was halved in sweetgum and doubled in magnolia as the autumn progressed. A correlation was found in magnolia between turgid : dry weight ratio and ψπ at full turgor. Tissue elasticity decreased somewhat, as the elastic modulus increased ≈2 to 3 MPa in each species through the autumn. Water potential isotherms changed most dramatically through the autumn in magnolia. Initially, ψ was −1 MPa at 82% RWC and, by December, leaves were able to withstand ψs of −3 MPa before RWC dropped to 82%. These changes are similar to those commonly reported as responses to drought or salinity.
Pollination and Pollen Tube Growth in Relation to Cranberry Fruit Development
Authors: Birrenkott Brian A. , Stang Elden J.
Published: August 2022

Pollination and pollen tube growth were evaluated in two years as potential factors suppressing cranberry (Vaccinium macrocarpon Ait.) fruit set. Supplementing insect pollination with hand pollination increased fruit set from ≈30% to ≈38% in both years. The number of flowers per unit area was an important contributor to fruit set variation in one year. Cranberry uprights exhibited a temporal decline in fruit set when flowers were pollinated sequentially; the first flowers to open had a higher probability of fruit development than flowers opening later. Examination of stigmas indicated flowers receiving low amounts of pollen (<10 tetrads), or pollen that fails to germinate, are more likely to abort. An inadequate number of pollen tubes and lack of subsequent fertilization provides a partial explanation of fruit abortion in cranberry. Cranberry fruit set under existing field conditions appears to be limited, in part by insufficient pollination and pollen tube growth, with the latter apparently the result of intraplant competition for resources. Providing supplemental hand pollination increased cranberry yields in both years, 48% over natural insect pollination when the number of flowering uprights per unit area was high (≈3000/m2). A significant amount of yield variation was explained by the number of flowering uprights per unit area in both years.
Fruit and Seed Development of Seven Jojoba Clones over Two Seasons
Authors: Simons Robert A. , Palzkill David A. , Younes Mohamed H.
Published: August 2022

Fruit and seed development of seven jojoba [Simmondsia chinensis (Link) C. Schneid.] clones were monitored over two seasons. Pollination occurred in late February and early March. However, most of the seed dry matter and wax accumulated after 15 June in both years. Fruit weight rapidly increased during May, followed by a leveling off in June and a 70% drop in weight in July as fruit matured and water was lost. While all seven clones exhibited similar fruit and seed developmental patterns, there were large differences between clones in the actual values observed over the two seasons. Differences in final seed weight between clones were due to differences in both rate and length of time of filling.
Yield and Production Efficiency of Four Apple Cultivars in Selected Orchard Management Systems
Authors: Ferree David C. , Funt Richard C. , Bishop Bert L.
Published: August 2022

Trees of ‘Golden Delicious’, ‘Topred Delicious’, ‘Millersturdeespur Delicious’, and ‘Sundale Golden Delicious’ apple (Malus domestica Borkh.) were grown in two or more of the following orchard management systems established in 1973: slender spindle (SS), 2151 trees/ha, ‘Golden Delicious’ and ‘Sundale Golden Delicious’; trellis (TR), 1121 trees/ha, all cultivars; interstem hedgerow (IH), 795 trees/ha, all cultivars; and pyramid hedgerow (PH), 425 trees/ha, ‘Golden Delicious’ and ‘Topred Delicious’. Yields of ‘Golden Delicious’ in the SS and TR were similar during the first 7 years and these systems generally produced higher yields than the less-intensive systems (IH and PH) during this period. Except for a drop in yield in the TR system in year 10, ‘Golden Delicious’ trees ≥8 years old in all systems produced >50 t·ha−1. ‘Topred’ in the TR system outyielded IH and PH every year, while IH had higher yields than PH in three out of the eight cropping years. The spur-type cultivars Sundale and Millersturdeespur had lower yields per hectare than the standard-habit cultivars because they were spaced too widely. Yields of the systems with ‘Sundale’ generally followed plant density, with the SS being highest, IH lowest, and TR in between and often not significantly different from the other two systems. Orchard management systems had no consistent effects on fruit size. The cumulative yield per hectare of ‘Golden Delicious’ over 11 years grown as SS outproduced the IH and PH systems, with the TR yields intermediate. ‘Sundale’ managed as SS outproduced both the TR and IH systems. ‘Topred’ in the TR had higher cumulative yields per hectare than the PH system. An economic comparison of the ‘Golden Delicious’ systems indicated that PH provided the highest rate of return and the SS the lowest, with the IH and TR systems intermediate.
Determination of Heat Unit Requirements for Collard Harvest in the Southeastern United States
Authors: Dufault Robert J. , Decoteau Dennis R. , Garrett J. Thomas , Nagata Russell T. , Batal K. Dean , McLaurin Wayne J. , Granberry Darbie M. , Perry Katharine B. , Sanders Douglas
Published: August 2022

‘Champion’, ‘Georgia’, ‘Heavicrop’, and ‘Vates’ collards (Brassica oleracea L. var acephala) were planted in Fletcher and Lewiston, N.C.; Charleston, Clemson, and Florence, S.C.; and Attapulgus and Plains, Ga. to determine the most reliable method to predict harvest maturity based on temperature. Although cultivar differences existed within some of the planting dates, when pooled over all planting dates, cultivars yielded similarly within locations. Eight methods of calculating heat units from planting to harvest were applied to daily maximum and minimum air temperatures supplied from local weather bureaus for the spring and fall growing seasons from 1985 through 1987 in the three-state area. Coefficients of variation were used to determine which method was most reliable in predicting day of first harvest. The method with the lowest cv was to sum, over days for planting to harvest, the difference between the daily maximum and a base temperature of 13.4C; however, if the maximum was >23.9C, the base temperature was subtracted from an adjusted maximum equal to 23.9C minus the difference between the maximum and 23.9C. This method produced a cv of 9.1% compared to 11.4% for the standard method of summing the mean temperature minus the base of 4.4C over the entire growing season, or compared to 13.4% for counting days to harvest from planting.
Derivation of DRIS Norms from a High-density Apple Orchard Established in the Quebec Appalachian Mountains
Authors: Parent L.E. , Granger R.L.
Published: August 2022

Diagnosis and Recommendations Integrated System (DRIS) norms for trees on dwarfing rootstocks were derived from a 7-year fertilization trial on a Blanford loam (coarse loamy, mixed, frigid Typic Fragiorthod) in southern Quebec. ‘Morspur McIntosh’ (Malus domestica Borkh.) scions budded on M.7, M.26, Ott.3, or M.9 dwarfing rootstocks received 12 fertilization regimes involving N-, P-, K-, Ca-, and Mg-based materials applied at three rates each. Top yielding trees on Ott.3 had lower Mg concentration in their leaves than those on other rootstocks. Year-to-year variation of DRIS norms led to yearly defined DRIS norms. Annual yields can be used instead of cumulative yields to generate DRIS norms, especially from the 6th year after planting. If tissue samples are collected at the appropriate sampling period, incorporating the dry matter index into the nutrient balance equation (M-DRIS) of orchard trees helps to separate limiting from nonlimiting nutrients and also integrates numerical information on nutrient concentrations and nutrient ratios. These concentrations and ratios are commonly diagnosed independently or concomitantly with the sufficiency range approach and with DRIS, respectively. M-DRIS may be particularly useful when available critical values are not fully satisfactory, as was the case in this investigation.
Effects of Shading on Structural Characteristics of the Leaf and Yield of Fruit in Capsicum annuum L1,2
Authors: Schoch Paul G.
Published: August 2022

Two groups of peppers, cv. Yolo Wonder, were cultivated and examined during their vegetative growth period, 1 group in full sun, the other in shade. An analysis of early foliation was initiated following appearance of 3 leaves characteristic of the juvenile growth stage. Observation of the epiderm is indicated that shading increases leaf surface, increases cell division, and cell expansion. Shade decreases the number of stomata per mm2 and the percentage of stomata in relation to other cells. Shade also increases by more than 40% the overall wt of dry materials. After flowering, the 2 lots were transplanted under identical conditions to open fields. Analysis of their fruit yield confirms recommendation of shading during the vegetative growth period in tropical regions.
Leaf, Pod, and Systemic Chlorosis Reactions in Phaseolus vulgaris to Halo Blight Controlled by Different Genes1
Authors: Kenneth Hill , Coyne D. P. , Schuster M. L.
Published: August 2022

‘Great Northern (GN) Nebraska #1, sel. 27’ and PI 150414 dry bean lines were highly tolerant to races 1 and 2 of halo blight bacterium (Pseudomonas phaseolicola) when inoculated with 5 × 106 and 2 × 108 cells per ml. The tolerant reactions to both races was completely dominant in the F1 ‘Gallatin 50’ (susceptible) crossed with both tolerant parents when inoculated with the low cell concn. However, tolerant and susceptible plants occurred in F1’s when inoculated with the high cell concn. In the F2 generation derived from the above crosses, the tolerant inoculated leaf, pod, and plant non-systemic chlorosis reactions to race 1, were each controlled by a different major dominant gene designated by the symbols LHB-1, PD HB-1, SC HB-1, respectively. Coupling linkage was detected between the genes controlling the leaf and systemic chlorosis reactions. This is the first report of 3 different genes, each separately controlling the expression of the halo blight reaction in different plant parts, namely, susceptible water-soaked reaction in inoculated pods and leaves, and systemic chlorosis reaction of leaves.

The leaf tolerant reaction to race 1 in ‘GN Nebraska #1, sel. 27’ and PI 150414 was controlled by the same allele. The same dominant allele in PI 150414 controlled the tolerant reactions to races 1 and 2.
Influence of the Tree on the Response of Citrus Fruits to Preharvest Applications of (2-Chloroethyl)phosphonic Acid1
Authors: Jahn Otto L. , Young Roger
Published: August 2022

Preharvest applications of (2-chloroethyl)phosphonic acid (ethephon) on ‘Bearss’ lemons were relatively ineffective for inducing degreening or abscission. This was not due to lack of absorption or ethylene production. Similar rates of application as a postharvest dip induced degreening, suggesting that a factor from the tree inhibited the response to ethylene. This possibility was supported by data from further tests on ‘Bearss’ lemons and on ‘Robinson’, ‘Lee’, and ‘Dancy’ tangerines and ‘Hamlin’ oranges. Degreening and abscission responses to ethephon in detached fruit or fruit on which the stem was girdled were greater than in fruit on the tree. Applications of gibberellic acid retarded these responses. The results varied among cultivars and between the degreening and abscission responses. However, the general response pattern suggests that the tree provides a factor (or factors) which, on translocation to the fruit, inhibits degreening and abscission. This inhibitory factor may be a growth promoter such as auxin, gibberellin, or cytokinin.
Levels of Endogenous Growth Regulators in Abscising and Persisting Peach Fruits1
Authors: Martin George C. , Nishijima Chikara
Published: August 2022

At “June drop”, the abscission zone occurs predominantly between the fruit and the receptacle. The abscising fruits had low levels of a growth promoter and high levels of a growth inhibitor, tentatively identified as ABA. Persisting fruits had higher levels of the growth promoter and lower levels of the growth inhibitor than did abscising fruit. Treatment of immature fruits with the chemical thinners 3-CPA or ethephon induced levels of growth regulators in the abscising fruits equivalent to those in abscising non-treated fruits.
A Morphological and Histochemical Study of (2-Chloroethyl)Phosphonic Acid-Enhanced Abscission of Sour and Sweet Cherry Fruit1
Authors: Wittenbach V. A. , Bukovac M. J.
Published: August 2022

(2-Chloroethyl)phosphonic acid (ethephon) significantly reduced the fruit removal force (FRF) at the lower abscission zone of ‘Montmorency’ sour (Prunus cerasus L.) and ‘Windsor’ sweet (Prunus avium L.) cherry fruit near maturity. No qualitative differences were detected in abscission layer development as a result of ethephon treatment. The primary effect was an acceleration of fruit separation following a pattern similar to that observed in the control. Separation in both treated and control sour cherry fruit was preceded by a loss of pectin and polysaccharides and a loss of cellulose orientation in the walls of cells comprising the abscission layer. Although separation in treated sweet cherry fruit was more extensive than in the control at maturity, it was still localized as in nontreated fruit and was not preceded or accompanied by a change in pectin, cellulose, or polysaccharides in the abscission layer. No effect of ethephon was observed on the upper abscission zone for either species through fruit maturity. Ethephon caused a dramatic increase in ethylene evolution from cherry fruit.
Citrate and Malate Concentrations in Tomato Fruits: Genetic Control and Maturational Effects1
Authors: Stevens M. Allen
Published: August 2022

There is continual change in the acidity of tomato fruits during development and maturation. The concn increases during development and reaches a maximum near incipient color, then decreases until well beyond maturity. The inheritance of citrate and malate concn in ‘Tondo Liscio’ (TL) and PI 263713 (PI) is controlled by a single gene for each compound. The dominant alleles, which were linked in the coupling phase in PI, condition a high concn of citrate and a low concn of malate. Recombination was about 18%. Study of divergent tomato accessions indicated that there are factors which condition higher and lower concn of citrate than the range delimited by TL and PI. There appears to be more than one malate factor controlling higher concn, but many tomato accessions are similar to the dominant low parent (PI). Current evidence indicates that there is no practical reason to breed for a specific citrate/malate ratio.
Multivariate Studies of Variations in Yams (Dioscorea alata L.)1,2
Authors: Rhodes A. M. , Martin F. W.
Published: August 2022

Two multivariate techniques, cluster analysis and principal components with varimax rotation, were applied to a model consisting of 100 characters and 30 cultivars of yams. Cluster analysis indicated 3 major groups of cultivars. Varimax solution indicated that the first component was highly loaded with anthocyanin characters; the second component with spiny vines and small tubers with long necks; and the third component, with tuber quality. Components 1 and 2 helped confirm the results of cluster analysis by delineating 3 overlapping groups of cultivars, Component 3 indicated cultivars of the 3 groups which were thought to be the most primitive because of their low quality culinary characteristics. The 2 techniques are, thus, complementary and each technique provides information not evident from the other.
Peach Fruit Abscission as Influenced by Applied Gibberellin and Seed Development1
Authors: Stembridge G. E. , Gambrell C. E.
Published: August 2022

Postbloom application of gibberellin A3 (GA3) to open pollinated peach trees prevented seed development in some fruit, and also resulted in the persistence and maturation of both seeded and seedless fruit on the same trees. GA3 temporarily promoted fruit growth and delayed abscission of both seeded and seedless fruit, but the final crop load was not altered. Both seeded and seedless fruit abscised from treated trees during physiological drop. The persisting seedless fruit, therefore, competed successfully with seeded fruit. Seedlessness was associated with smaller fruit size at maturity.
Accumulation and Usability of Tomato Fruit from a Single Harvest1
Authors: Nelson Philip E. , Wilcox Gerald E. , Bennett Ronald F.
Published: August 2022

Tomato fruit were found to accumulate at optimum harvest in proportions of 52-55% all red, 15-20% orange, 7-10% pink, and 15-26% green or overripe. A harvest ratio of 8 parts all red, 3 parts orange, and 1 part pink fruit gave a USDA tomato color index reading ranging from 66.1 to 67.4. In comparison, the all red fruit portion produced a 68.9 to 73.0 color index. Quality changes of the 8:3:1 blend processed juice were found in color, flavor, and ascorbic acid content, but the blends from all cultivars appeared to be commercially acceptable. Taste panel tests indicated no significant preference for all red over blended juice samples. The pH, titratable acidity, and refractive index were not significantly altered by the use of less than red ripe fruit. Utilizing the single harvest ratio of all red, orange, and pink fruits increased per acre yields 20-30%.
Biochemical Components of Highbush Blueberry Fruit as Influenced by Nitrogen Nutrition1
Authors: Hammett Larry K. , Ballinger Walter E.
Published: August 2022

The amino acid, organic acid, and free sugar contents as determined by gas-liquid chromatography, of ‘Wolcott’ fruit were not influenced quantitatively or qualitatively by different ratios of NH4-N and NO3-N applied in nutrient solution via a constant-flow gravity drip system to blueberries planted in sand. The amino acids detected in order of decreasing concn in the ‘Wolcott’ fruit were: tyrosine, glutamine, lysine, glutamic acid, tryptophane, gamma-aminobutyric acid, histidine, arginine, aspartic acid, alanine, serine, leucine, cysteine, threonine, isoleucine, valine, proline, and glycine. Citric acid was the predominant organic acid accompanied by lesser concn of shikimic and quinic acids. Fructose was the free sugar present in greatest concn in the fruit followed by beta-glucose and alpha-glucose. Sucrose was present at extremely low concn. The sugar/acid ratio of the ‘Wolcott’ fruit was not influenced by the N nutrient treatment.
Inheritance and Morphology of Two Dwarf Mutants in Watermelon1
Authors: Liu Peter B. W. , Loy J. B.
Published: August 2022

An inheritance study of 2 dwarf mutants in watermelon showed that dwarfness in each form is due to single, non-allelic, recessive genes designated dw-1 and dw-2. Dwarfness in dw-1 and dw-2 plants was primarily attributed to reduced length of internodes, but there was also some reduction in the number of internodes in the dwarfs compared to the normal plants. The shorter internodes in dw-1 dwarfs were due to both fewer and shorter cells than in the internodes of vine forms. In the dw-2 dwarf most of the reduction in internode length was due to fewer cells.