bluuebunny/crossref_metadata_2025 huggingface dataset:
Factors that Influence Biosynthesis of Volatile Flavor Compounds in Apple Fruits
Authors: Fellman John K.
Published: February 2019

Volatile ester molecules are important contributors to the perception of fruit taste. Biosynthesis of volatile compounds occurs via several biochemical pathways. Ongoing studies have concentrated on alcohol acetyl transferase, the terminal step in the acetate ester synthesis pathway. Our studies on volatile biosynthesis in apples have revealed several interesting phenomena. First, the nature and amount of volatile compounds are cultivarand strain-dependent. Studies with `Delicious' show a relationship between amount of peel coloration and flavor volatile content of tissue. Second, it is possible to manipulate the preharvest growing environment to influence the content of some volatiles in the fruit. Third, generation of volatiles is closely linked to the onset of climacteric ripening. Other experiments show the response of apples to different storage conditions with regard to volatile ester synthesis. In some cultivars softening apparently provides ester precursor molecules, leading us to speculate that there are glycosidically bound intermediates that are liberated by the action of cell-wall degradation.
The Use of Film-forming Antitranspirants to Control Rose Blackspot Disease
Authors: Roark R.S. , Behe B.K. , Bowen K.L.
Published: February 2019

Five antitranspirant materials, a horticultural oil, the fungicide chlorothalonil, and an untreated control were applied to rose plots using one of four application schedules. After 12 weeks, treatments were evaluated for their effectiveness in control of blackspot. Disease (P=0.0022) and defoliation (P=0.0008) showed significant treatment differences, while vigor and flowering were unchanged. Two antitranspirants, Stressguard 0.05% applied every 2 weeks and NuFilm17 1% alternated with chlorothalonil around rain events, gave similar disease control to weekly chlorothalonil applications. One antitranspirant, Vapor Gard, 1 % alternated with chlorothalonil around rain events, gave similar defoliation control to weekly chlorothalonil applications. These results indicate that blackspot disease can be effectively managed with fewer applications of chlorothalonil.
Computer Programs for Generating Weather-related Production Management Decisions
Authors: Powell Arlie A. , Harker Karl
Published: February 2019

It is always challenging to develop innovative Extension programs delivery methods. The development of a winter chilling model (Modified 45) for Alabama, the evaluation of a growth regulator (Dormex—hydrogen cyanamide) to replace lack of chilling in peaches and the establishment of a computerized weather program allowed us to create a superior expert program for grower application. Access through a personal computer is all that is required to monitor chilling accumulation and determine the most ideal time for application of Dormex (which is very critical). This information (formerly available from NWS) is now accessible through a private weather firm. The development of a chilling hour/heat unit (growing degree hour) for peaches is showing promise of providing growers still another useful product (via their PCs) in improving orchard management via better timing of practices.
Arbitrary Signatures From Amplification Profiles (ASAP) Distinguishes Somatic and Radiation Induced Mutations in the `Charm' Series of Chrysanthemum
Authors: Trigiano R.N. , Scott M.C. , Caetano-Anollés G.
Published: February 2019

Four chrysanthemum (Dendranthema grandiflora) spontaneous and radiation-induced sports from the cultivar `Charm' and phenotypically differing only in flower color were individually characterized using arbitrary signatures from amplification profiles (ASAP). ASAP analysis is based on a two-step arbitrary primer amplification procedure that produces “fingerprints of fingerprints.” In the first step, `Charm', `Dark Charm', `Dark Bronze Charm', `Salmon Charm', and `Coral Charm' were fingerprinted by DNA amplification fingerprinting (DAF) with standard octamer arbitrary primers. Diluted products from three monomorphic fingerprints for each cultivar were subsequently reamplified using four minihairpin decamer primers. Each of the 12 ASAP profiles revealed about 30% polymorphic loci and some were used to uniquely identify cultivars and estimate genetic relationships. The ASAP technique permits identification of previously genetically indistinguishable plant material and should facilitate marker assisted breeding and protection of ownership rights.
Cost Comparisons of Three Tree Species Using Three Alternative Production Methods
Authors: Adrian J.L. , Montgomery C.C. , Behe B.K. , Tilt K.M. , Duffy P.A.
Published: February 2019

In-field (IF) and above-ground (AG) container production of landscape ornamentals are both conventional methods which were compared to a newer production method, pot-in-pot (PIP). Our objective was to determine costs and economic feasibility for each method. Model nurseries were synthesized to represent a 4-ha nursery utilizing 2 ha of production area operating over a three-year period. Finished plant material were grown in 40-L containers for above-ground and pot-in-pot production, and 2 m ball and burlapped material for in-field production. One budget was constructed to reflect costs for Lagerstroemia indica, Cornusflorida, and × Cupressocyparis leylandii under each production method. Capital requirements and annual fixed costs for all three species were lowest for IF and highest for PIP production. Variable costs for all tree species were lowest for IF and highest for AG with PIP intermediate. With better utilization of a given production area, PIP had the lowest total cost of production, followed by AG and IF methods.
Are `Barton' and `Cloud 9' the Same Cultivar of Cornus florida?
Authors: Windham Mark T. , Trigiano Robert N.
Published: February 2019

Ten cultivars of Cornus florida (Barton, Cherokee Princess, Cloud 9, First Lady, Fragrant Cloud, Plena, Purple Glory, Rubra, Springtime, and Welch's Jr. Miss) were evaluated for horticultural characters of canker incidence, susceptibility to spot anthracnose and freeze damage, bloom number, bract length, and phenology. Of the ten cultivars, only `Barton' and `Cloud 9' were similar for all characteristics studied. DNA amplification fingerprinting (12 standard primers) and Arbitrary Signatures from Amplification Profiles (four minihairpin primers) were used to test our hypothesis that `Barton' and `Cloud 9' were genetically distinct, but phenotypically similar. Polymorphisms were not observed; therefore, we could not reject the null hypothesis that `Barton' and `Cloud 9' are the same genotype.
Implications of Using Kenaf Stalk Core and Coconut Coir Pith as Nursery Container Media
Authors: Goyne Mitchell W. , Arnold Michael A.
Published: February 2019

Four underutilized small trees, Chilopsis linearis, Rhus lanceolata, Acacia wrightii, ×Chitalpa tashkentensis, and a commercial control Fraxinus velutina, were grown outdoors in 15-L containers. Four media combinations, 3 pine bark: 1 sand, 3 pine bark: 1 coconut coir pith, 3 kenaf stalk core: 1 sphagnum peat, and 3 kenaf stalk core: 1 coconut coir pith (v/v), were amended with Sierrablen 18N–2.6P–10K at three rates, 3.6, 7.1, and 10.7 kg·m-3. Fraxinus velutina and C. linearis seedlings were transplanted to the field to evaluate initial landscape establishment. Growth was typically reduced, in both the field and container, when kenaf media was used during production. EC was greatest early and with higher fertility rates. Leachate pH decreased over time, and was lower at high fertility rates. Soil particle size >6.0 mm decreased substantially in kenaf media over time. Water holding capacity increased, while air space and total root volume decreased in kenaf media. Physical characteristics and growth responses were similar with coconut coir and peat moss.
Growth of `October Glory' Red Maple in Multiple Locations in the Southeast
Authors: Sibley J.L. , Ruter J.M. , Eakes D.J.
Published: February 2019

Limited information exists for container production of red maple cultivars. The objective of this study was to evaluate first-year growth of container-grown `October Glory' at 3 locations with disparate climates in Georgia and Alabama (Tifton, Ga., Blairsville, Ga., and Auburn, Ala.). Rooted cuttings were planted in 9.2-L containers in one location in the same substrate in April 1995. Trees were transported to each location in mid-June and irrigated from overhead risers at 1.3 cm/day for 6 months until dormant, then transported to a single location for harvest. Despite weather differences among locations, final heights were not different (Blairsville 59.8 cm; Auburn 53.0 cm; and Tifton 60.2 cm). Shoot diameter increase and shoot dry weight was greatest at Tifton (8.4 mm, 17.5 g), least at Blairsville (6.3 mm, 9.2 g), with Auburn similar to both locations (6.8 mm, 12.2 g). Root dry weight and root: shoot ratio was greater in Tifton (17.2 g, 0.97) than Blairsville 14.9 g, 0.51) and Auburn (7.0 g, 0.64).
Effect on Blueberry Quality as Affected by Various Types of Padded Surfaces
Authors: Mullinix Benjamin , Krewer Gerard , Sumner Paul
Published: February 2019

'Climax' and 'Tifblue' blueberry cultivars were harvested, cooled, and later warmed to room temperature for use in individual berry dropping experiments. Surfaces used were concrete, “Softer NoBruze” and “Poron #7R70-Grey.” Berries in the check were not dropped. Three groups of 25 berries were dropped individually from various heights ranging from .5 ft to 7 ft. Initially, berries were cut to determine percent flesh showing bruising. Later, berries were rolled between fingers and assigned a firmness: firm, medium firm, or soft. The first two firmnesses are considered marketable. Fruit tended to bruise more when harvested later in season. More bruising occurred with higher drop heights. More marketable fruit resulted from thicker padding. Repeated dropping increased bruising. “NoBruze” was superior to “Poron” at any thickness. Many berries in the mechanical harvester have to drop over a foot onto a metal surface; padding these surfaces should increase percent of marketable (undamaged) berry yield.
Small Fruit Breeding in the Southern U.S.: Progress And Prospects
Authors: Clark John R. , Rom Curt R.
Published: February 2019

Small fruit production in the southern United States has been impacted greatly by fruit breeders this century. This workshop, co-sponsored by the American Pomological Society, includes presentations from individuals who have contributed collectively over 150 years to small fruit and grape breeding. James N. Moore has conducted breeding at the University of Arkansas, developing 30 cultivars. His presentation on brambles outlines achievements and future opportunities for improvement. Arlen Draper has been involved with the development of 61 small fruit cultivars while working with the USDA-ARS with an emphasis on blueberry. His presentation focuses on blueberry breeding and provides insights into the future of new blueberry cultivar developments. Gene Galletta has conducted small fruit breeding at North Carolina State University and USDA-ARS and has been involved with the development of 50 cultivars. His presentation reflects on the history of strawberry breeding in the South and the challenges that lie ahead. Ron Lane has served as a fruit breeder and horticulturist at the University of Georgia Experiment Station at Griffin and his work has emphasized the development of muscadine grape cultivars. The past and future of muscadine and bunch grape breeding is discussed in his paper. Articles from all authors in this workshop will be published in Fruit Varieties Journal in 1997.
Quantifying Loss of Firmness in Blackberries
Authors: Perkins-Veazie P. , Collins J.K. , Clark J.R
Published: February 2019

Measurement of firmness of blackberries is challenging because of their nonspherical shape, large pyrenes, and mixture of receptacle and epidermal tissues. Firmness at harvest is important to minimize damage from finger compression and after harvest, as fruit that soften during storage often have more decay and leakiness than firmer fruit. We have done subjective ratings over the last 4 years using a scale of 1 (firm) to 5 (mush) and find that discerning between ratings of 2 and 3 is the most difficult subjective decision. We have used a hand-held penetrometer adapted with an insect pin to measure epidermal thickness and receptacle firmness after storage, but correlation with subjective ratings has been unsatisfactory. We have also measured whole fruit compression using a Texture Technologies ® TA2 texture analyzer that collects 500 data points per second. While this works well with fruit subjectively rated 1 to 3, it cannot measure soft fruit rated 4 and 5. However, both puncture and compression tests have successfully quantified firmness loss with ripening.
Thrips Resistance Studies of Onions (Allium cepa L.) in South Texas
Authors: Hamilton Brian K. , Pike Leonard M. , Sparks Alton N. , Bender David A. , Jones Richard W.
Published: February 2019

Thrips are the major insect pest of onions grown in South Texas. Four cultivars, `IPA-3', `TG1015Y', `1664' (glossy control), and `1900B' (waxy control), were grown in a split-plot design with insecticide sprayed or nonsprayed treatments as the main plots and cultivar as the subplots. The experiment was conducted at the Texas Agricultural Experiment Station, Weslaco, Texas, in the 1995-96 season. The objectives of the study were to compare `IPA-3' and `TG1015Y' for thrips resistance and evaluate possible resistance mechanisms that may be present in `IPA-3'. The average number of thrips per plant and leaf damage rating were significantly higher for `TG1015Y', indicating that some resistance is present in `IPA-3'. However, there were no significant differences in yield between the two cultivars. A comparison of leaf wax characteristics indicated no significant difference between `TG1015Y' and `IPA-3' using gravimetric or gas chromatography techniques. However, scanning electron micrographs of `TG1015Y' leaves appeared more similar to `1900B' and `IPA-3' appeared more similar to `1664'. The insecticide spray treatment had significantly fewer thrips, less damage, and higher yield than the nonsprayed treatment.
Growth Differences in Hydroponic and Container-grown Geraniums
Authors: Williams Eddie B. , Hayslett William F. , Shaw Sabrina L.
Published: February 2019

Seeds of Dynamo white geraniums were started in a soilless media in the germination chamber. After germination, one-third of the plants were placed under an intermittent mist system, and two-thirds were placed in rockwool cubes (7.62 cm × 7.62 cm × 6.35 cm) and placed into the hydroponics system. Plants that were placed under the mist system were transplanted into 16 cm × 16 cm (width × depth) plastic pots containing a soilless media of 1 peat moss: 1 perlite (v/v). After 45 days, half of the hydroponically grown plants were transplanted into 16 cm × 16 cm plastic pots containing peat moss and perlite. Observations included final plant height, top fresh weight, and top dry weight. The hydroponically-grown geraniums were significantly taller than the pot-grown geraniums and the hydroponic/pot-grown geraniums, 58.17 cm, 36.42 cm, and the 41.75 cm, respectively. The hydroponically grown plants were also significantly higher in top fresh weight and top dry weight.
Breedlove Dehydrated Foods Feeding Hungry People Worldwide in Partnership with Fruit and Vegetable Growers
Authors: Roberts Roland E. , Gray Kenneth , Bryant Joseph J.
Published: February 2019

Breedlove Dehydrated Foods (BDF), the largest charitable dehydration plant in the world, is capable of dehydrating 6,000 lb. raw product/hr. BDF dehydrates and distributes nutritious fruits, vegetables, and legumes to charitable organizations which feed hungry people. At least 35,617 people die from hunger in our world every day! Thousands of tons of nutritious but slightly imperfect horticultural products are wasted yearly in the United States. Donations totaling $7.8 million funded construction of BDF. Texas A&M and Texas Tech Universities provided expertise to plan and operate BDF. BDF dehydrated over 30 million lb. of fruits and vegetables in the initial two years of operation. BDF is a model of people focused on an unusually high goal and working together.
Components of Resistance to Colletotrichum acutatum in Strawberry (Fragaria ×ananassa Duch.)
Authors: Gimenez Gustavo , Ballington James R. , Milholland Robert D.
Published: February 2019

Two experiments were designed to study components of resistance to Colletotrichum acutatum on runners of three strawberry cultivars: incubation period, latent period, length of the lesion and spore production, and infection frequency with three levels of inoculum density (104, 105, 106 spores/cc) were considered. Rate of disease development was also determined. There were significant differences in all the components among the resistant and susceptible cultivars. Both 'Chandler' and 'Sweet Charlie' expressed susceptible reactions. The length of the lesion, number of spores/cm of the lesion, incubation period, latent period, and rate of anthracnose development were statistically similar in 'Chandler' and 'Sweet Charlie'. The only significant difference among them was found in infection frequency. 'Chandler' had a greater number of infection sites with all three concentrations of spores included. The cultivar Pelican showed a high level of partial resistance associated with longer incubation and latent periods, lower number of spores/cm of lesion, shorter lesion, smaller number of infection sites, and lower rate of disease development.
Development of a Pinkeye-type Southernpea Cultivar with Green Cotyledons: A Progress Report
Authors: Fery R.L.
Published: February 2019

The development of southernpea (Vigna unguiculata) cultivars with a persistent green seed color has been the subject of much interest for more than two decades because seeds of such cultivars can potentially be harvested at the near-dry seed stage of maturity without loss of their fresh green color. The success of the cream-type cultivar Bettergreen, which is homozygous for the gc gene conditioning green cotyledons, demonstrated that the development of cultivars with persistent green seed color is feasible. In 1990, an effort was initiated to develop a pinkeye-type southern pea cultivar homozygous for the gc gene. The pinkeye is the major cultivar class of southernpea utilized for processing in the United States. Seeds containing embryos homozygous for the gc gene are easily identified, and this ability to select in the seed stage greatly facilitated the rapid development of advanced breeding lines. More than two dozen advanced generation pinkeye lines with green cotyledons were ready for preliminary field testing in 1995, and seven were selected for detailed evaluation in 1996. Results of the 1996 tests indicate that the gc gene has been successfully incorporated into elite pinkeye germplasm.
Influence of Root Pruning and Rootstock on Growth and Performance of `Golden Delicious' Apple
Authors: Ferree D.C. , Knee M.
Published: February 2019

`Smoothee Golden Delicious' apple trees on nine rootstocks or interstems were mechanically root pruned annually for 9 years beginning the year after planting. Root pruning reduced trunk cross-sectional area (TCA) by 14% over the first 5 years and 22% in the last 4 years of the trial. Yield and fruit size were reduced by root pruning in most years with the fruit size effect obvious in June at the end of cell division. Interstem trees of MAC.9/MM.106 were larger than trees on M.9 and the following interstems: M.9/MM.106, M.9/MM.111, M.27/MM.111. Trees on seedling (SDL) rootstock were the largest and had the lowest yield per unit TCA and lower cumulative yield/tree than trees on M.7, MM.106, and MM.1ll. There was no interaction for any measure of growth or yield between root pruning and rootstock or interstem.
Disease Resistance in Twenty Dieffenbachia Cultivars
Authors: Norman D.J. , Henny R.J. , Yuen J.M.F.
Published: February 2019

Twenty commonly grown Dieffenbachia cultivars were tested for their resistance to diseases affecting production caused by the following bacterial and fungal pathogens: Xanthomonas campestris pv. dieffenbachiae (McCulloch and Pirone) Dye, Erwinia chrysanthemi Burk, Fusarium solani Sacc, and Myrothecium roridum Tode ex Fr. Two isolates of each pathogen were used to compare heterogenic pathogen populations to the relatively homogenetic asexually produced cultivars. Cultivars having horizontal resistance toward tested pathogens could then easily be identified. The cultivars Camille, Compacta, and Parachute showed the broadest horizontal resistance, with resistance toward three of the four pathogen groups tested. Disease resistance identified in this research permits the selection of plants to be used in breeding, and also creates a baseline to compare resistance of newly developed cultivars.
Embryogenic Callus Induction in Fraser Fir
Authors: Rajbhandari Nirmala , Stomp Anne-Marie
Published: February 2019

Mass propagation of Fraser fir [Abies fraseri (Pursh) Poir], a valuable Christmas tree species in the United States, is problematic because methods currently used are inadequate. According to our results with somatic embryogenesis, the culturing methods used with other Abies species are applicable to Fraser fir. Stage 1 somatic embryogenic callus, characterized by suspensor cells and embryo heads, was obtained at low frequency using Schenk and Hildebrandt medium supplemented with 5 mm glutamine, 0.05% casein hydrolysate, 0.01% myoinositol, 2% sucrose, 5 μM benzyladenine, and 0.6% agar. The developmental stage of the embryo was important; embryogenic callus was obtained only with immature, precotyledonary embryos, not with fully formed embryos. Cold storage of cones containing immature embryos inhibited callus proliferation. Genotype was significant in that 35 of 44 families tested proliferated callus; however, only one embryo within one family continued proliferation to produce stage 1 embryogenic callus. Fully formed somatic embryos were not produced because the callus did not continue to proliferate. Although these experiments met with only limited success, they demonstrate the potential for somatic embryogenesis in Fraser fir and the general applicability of methods used with other Abies species.
Changes in Chlorophyll Fluorescence of Apple Fruit during Maturation, Ripening, and Senescence
Authors: Song Jun , Deng Weimin , Beaudry Randolph M. , Armstrong Paul R.
Published: February 2019

Trends in chlorophyll fluorescence for `Starking Delicious', `Golden Delicious' and `Law Rome' apple (Malus ×domestica Borkh.) fruit were examined during the harvest season, during refrigerated-air (RA) storage at 0 °C, following RA and controlled-atmosphere (CA) storage, and during a poststorage holding period at 22 °C. Fluorescence parameters of minimal fluorescence (Fo), maximal fluorescence (Fm), and quantum yield [(Fm-Fo)/Fm, otherwise denoted as Fv/Fm] were measured. During `Starking Delicious' fruit maturation and ripening, Fv/Fm declined with time, with the rate of decline increasing after the ethylene climacteric. During RA storage, all fluorescence parameters remained constant for approximately 2 weeks, then steadily declined with time for `Starking Delicious' fruit. Superficial scald was detected after Fv/Fm had declined from an initial value of 0.78 to ≈0.7. Fv/Fm was consistently higher for CA-stored fruits than for RA-stored fruits. We were able to resegregate combined populations of “high-quality” (CA) and “low-quality” (RA) `Law Rome' fruit with 75% accuracy using a threshold Fv/Fm value of 0.685, with only 5% RA-stored fruit incorrectly identified as being of high quality. During a poststorage holding period, Fo, Fm, and Fv/Fm correlated well with firmness for `Starking Delicious', but not for `Golden Delicious' fruit, which were already soft. Fo and Fm were linearly correlated with hue angle for 'Golden Delicious' fruit, decreasing as yellowness increased. The accuracy, speed of assessment, and light-based nature of fluorescence suggests that it may have some practical use as a criterion to assist in sorting apple or other chlorophyll-containing fruit or vegetables on commercial packing lines.
Fusarium Yellows and Turnip Mosaic Virus Resistance in Brassica rapa and B. juncea
Authors: Fjellstrom Robert G. , Williams Paul H.
Published: February 2019

Thirty-seven Brassica rapa L. and B. juncea L. lines from nine subspecies were tested for their reaction to two pathotypes of Fusarium yellows (Fusarium oxysporum Schlecht. f. sp. conglutinans (Wr.) Snyd. & Hans. race 1 and F.o. f. sp. raphani Kend. & Snyd. A subset of 16 lines from these same vegetable types were tested for their reaction to four strains of turnip mosaic virus (TuMV-C1, C2, C3, and C4). Resistance to both Fusarium pathotypes was widespread in these Brassica subspecies, whereas resistance to any strain of TuMV was uncommon. The broad availability of resistance to Fusarium yellows and scarcity of resistance to TuMV necessitate different approaches to obtain disease-resistant cultivars.
Heliconia wagneriana Petersen is a Short-day Plant
Authors: Criley Richard A. , Sakai William S.
Published: February 2019

Seasonal flowering behavior of Heliconia wagneriana Petersen was found to be caused by short daylengths (SD) using artificial short days (8 to 9 hours) and long days as daylength extension or night break lighting with incandescent lamps. The natural time for flower initiation was estimated to be mid- to late October (11 hours 40 minutes to 11 hours 20 minutes) in Hawaii, and 120 to 150 days were required from the onset of inductive SD to inflorescence emergence. The results may be used to manipulate flower availability for flower markets.
Compatibility Relationships in `Manzanillo' Olive
Authors: Cuevas Julián , Polito Vito S.
Published: February 2019

We investigated pollination and fruit set parameters in `Manzanillo' olive (Olea europaea L.) following self-pollination and pollination with `Sevillano', `Ascolano', and `Mission' pollen. Results of analyses and experiments conducted over 2 years in central California indicated that `Manzanillo' behaves as a self-incompatible cultivar (index of self-incompatibility = 0.22 to 0.24). Pollination with `Sevillano' resulted in a more than 4-fold increase in fruit set over self-pollination. When `Mission' or `Ascolano' pollen was used, there was no increase over self-pollinated samples. Analyses of pollen tube growth, fertilization, initial fruit set, and final fruit set were consistent with `Manzanillo' being considered as a self-incompatible cultivar cross-incompatible with `Mission' and `Ascolano'. Our results indicate that `Manzanillo' is likely to be more productive when interplanted with `Sevillano' rather than when planted without a pollinizer or with `Mission' or `Ascolano'.
Changes in Condition and Color during the Late Development of Selected `Delicious' Apple Strains
Authors: Ingle Morris , Townsend Edwin C.
Published: February 2019

Firmness, total soluble solids (TSS), starch concentration (starch index, SINDEX), and surface color (L*, a*, and b*) were measured for 18 `Delicious' apple strains (Malus ×domestica Borkh.) produced in a replicated, randomized planting at the West Virginia Univ. Experiment Farm, Kearneysville. There was a significant difference between 1991 and 1993 for firmness, L* on the blush or outer side (BL*), Bb*, BChroma, a* (nonblush side), hue angle, and Chroma. There were significant differences between strains in firmness and chromaticities and their derivatives, but not TSS or SINDEX. All measurements changed linearly with days after full bloom (DAFB). There were large chromaticity differences between the two sides of the fruit 130 DAFB, but the nonblush side changed more than the blush side, resulting in little difference at 158 DAFB. BL*(Ba*/Bb*) and L*(a*/b*) produced better separation of strains and sides than did Chroma, although the products were significantly correlated with hue angle and Chroma. The nonblush side of `Delicious' fruits should be monitored to obtain the highest percentage of fruit in the highest grades.
Characteristics of the California Persian Walnut Industry
Authors: Olson William H. , Ramos David
Published: February 2019

The Persian or English walnut (Juglans regia) is widely cultivated, with commercial production in France, Italy, Turkey, China, and the United States. Practically all of the U.S. production of Persian walnuts is in the central valley of California, which now has about 169,000 bearing acres with an average yield of around one and one-third short tons per acre. Many orchards produce over two tons, and three tons per acre are common in many modern plantings. Walnuts have two major outlets: the exported in-shell market (about 35% of production) and the domestic shelled market (about 68% of production). A cooperative handles about half the crop, while several independent handlers sell the remainder. Walnuts are sensitive to both low and high temperatures. Temperatures in excess of 90 °F will begin to sunburn nuts. Freezing temperatures will damage tender growth in the spring and fall. Dormant trees can tolerate 15 °F without injury if soils are moist. Dry winter soils and cold temperatures cause winter kill. A minimum of 800 hours of winter chilling are required to avoid delayed bud break and poor crops. Walnuts do best on deep, medium textured, well drained soil. Under these conditions, both rootstocks, the Northern California Black Walnut (J. hindsii) and Paradox (J. regia x J. hindsii), do well. Under less favorable soil conditions, Paradox is the preferred rootstock. A mature walnut orchard requires 4 to 4.5 acre-feet of water per acre per year if the trees are to produce the maximum number of high quality nuts possible. Hartley, preferred for its in-shell quality, is the leading cultivar, with about 30% of the acreage. In recent years, the Chandler variety has accounted for most new plantings. It is known for high kernel quality and yields. Yield factors include: bearing habit, bearing area, flower differentiation, fruit set, nut size, kernel percentage, and kernel quality. Major insect pests of walnut include codling moth, navel orangeworm, and walnut husk fly. The major diseases are walnut blight, deep bark canker, Phytophthora, and blackline. Major research efforts include the walnut breeding program, which includes blackline and Phytophthora susceptibility of new cultivars and root-stocks, codling moth and walnut husk fly control, epidemiology and control of walnut blight, pruning and planting strategies, and clonal propagation.
Fertilization and Harvest Technique Affect Yield of Aloe barbadensis Miller
Authors: Wang Yin-Tung
Published: February 2019

Aloe barbadensis (Aloe vera) plants remain in production fields for several years, with their lower leaves harvested periodically. A long-term experiment was initiated in November 1993 to determine the effects of fertilization and severeness of harvest on leaf yield. Plants were grown in large pots with or without monthly applications of a 20N–8.6P–16.6K soluble fertilizer from March to October. Beginning in June 1994, the lower leaves were harvested quarterly to have 18, 15, or 12 leaves remaining. Fertilization doubled the number of leaves harvested and tripled the total yield over a 2-year period. The lower leaves on the nonfertilized plants, particularly on plants with 18 leaves remaining, sometimes became dry or partially dry at harvest. The initial quarterly yield and cumulated yield were higher in plants with 12 leaves remaining; however, this trend disappeared over time. The fertilized plants produced an average of 10 kg per plant, while the nonfertilized plants produced only 3.2 kg per plant annually. At several harvests, plants with 18 leaves remaining had higher % dry mass in the inner semi-translucent tissue than those having 12 leaves. Leaves of nonfertilized plants had high % dry mass in the inner leaf tissue when harvested in June and September 1995. Plants with 12 leaves remaining can become unstable and the tops break off in gusty wind.
Effect of Confined Fertilization on Salinity of Root Media
Authors: Albahou M.S. , Green J.L.
Published: February 2019

When using the closed, insulated pallet system (CIPS), it is desired to apply the fertilizers once at the beginning of planting and last through harvest. When doing so, the electrical conductivity (EC) of the root environment needs to be at a reasonable level. Therefore, the objective of this experiment was to determine the effect of fertilizer conserver placement and increasing rate on the EC of the growth media. When delivering nutrients in such a manner, the fertilizer ions have limited surface area in contact with the root growth media that limits ion diffusion rate. Five fertilization rates, 15, 45, 60, 75, and 105 g per 1.5-L media pouch, were tested in a completely randomized arrangement. In each pouch, two fertilizer conservers were placed in the center of the lower half of media, each containing a different source of fertilizer. Tomato cv. `Pik Red' was used to test the growth response to treatment. At day 100, the ECs of the middle 5 cm stratum of the growth media for the 15–75 g treatments were not significantly different from each other. Their ECs ranged from 2.52 to 4.51 dS/m. However, middle layer in the 105g treatment was 12.97 dS/m, while EC for the layer immediately below it was 1.18 dS/m. Because there were no differences in shoot and fruit weights among all fertilization treatments, compensation nutrient uptake and water uptake specialization may have occurred in the high salinity and lower salinity, respectively. The data illustrate that delivery of nutrients in small conservers is a feasible approach for the CIPS. Only small amounts of fertilizer are required for a 100-day tomato crop grown in CIPS.
Seed Hydration Using the Drum Priming System
Authors: Warren Jabe E. , Bennett Mark A.
Published: February 2019

Drum priming enhances seed performance without the waste and additional materials associated with conventional osmotic or matric priming techniques. Sweet corn (Zea mays L.) se (`White D' Lite') and sh2 (`WSS-4948') endosperm seeds were hydrated using drum priming at 25 °C for 6 hours. During each cycle, 125-g seed samples were exposed to 1.6, 3.2, 4.8, or 6.0 mL of distilled water and then rotated in a drum for 1 hour to ensure uniform uptake. At the end of this period, samples of 100 seeds (each) were removed and moisture content was determined. Drum priming hydrated all seedlots gradually, with increasing time required at reduced water levels for individual seedlots to achieve the desired moisture content (25% to 30%). Drum priming may provide a better alternative to conventional systems of priming.
Seed Treatments Improve the Germination and Seedling Emergence of Switchgrass (Panicum virgatum L.)
Authors: Haynes Janine G. , Pill Wallace G. , Evans Thomas A.
Published: February 2019

Switchgrass (Panicum virgatum L.) is one of the perennial, native, warm-season grasses recommended as a component of wildflower meadows. Seed treatments to alleviate low seed vigor and seed dormancy of switchgrass would enhance establishment of either plug transplants or seedlings after direct sowing into the meadow. “Heavy” seeds (45.5 mg/50 seeds) of open-pollinated switchgrass stored under cool and dry conditions (average 13 °C, 30% relative humidity) for 24 months had higher germination percentage than “light” seeds (26.0 mg per 50 seeds). In factorial combination, the heavy seeds were subjected to acid scarification (8 M H2SO4 for 5 min), sodium hypochlorite treatment (5.25% NaOCl for 15 min), and moist chilling (prechilling in 0.2% KNO3, for 14 days). Acid scarification followed by NaOCl treatment additively increased germination, a response that was associated with marked corrosion of the lemma margin in the distal region of the caryopsis, as observed by scanning electron microscopy. Prechilling the seeds following acid scarification and NaOCl further increased germination. All three treatments combined (acid scarification, NaOCl, and prechilling) almost doubled the final emergence and greatly increased seedling shoot dry mass in both a warm and cool postsowing environment. However, the effectiveness of these seed treatments was lost after 32 months of dry storage.
Reduction of Chilling Injury in Stored `Hass' Avocado Fruit by 38 °C Water Treatments
Authors: Woolf Allan B.
Published: February 2019

`Hass' avocado (Persea americana Mill.) fruit were heat treated in water at 38 °C for 0 to 120 minutes, and stored at 0.5 °C for up to 28 days. After storage, fruit were ripened at 20 °C and their quality evaluated. External chilling injury (CI) developed during storage in nonheated fruit. Skin (exocarp) sectioning showed that browning developed from the base of the exocarp, and with longer storage, this browning moved outwards toward the epidermis. Longer durations of hot water treatment (HWT) progressively reduced CI; 60 minutes was the optimal duration that eliminated external CI, while best maintaining fruit quality. Concomitantly, electrolyte leakage of heated skin tissue increased ≈70% during storage, whereas electrolyte leakage of nonheated skin tissue increased ≈480% over the same period. Thus, significant protection was conferred by HWTs against low temperature damage to avocados and these effects are reflected in the morphology and physiology of the skin tissue.
Establishment in Treeshelters II: Effect of Shelter Color on Gas Exchange and Hardiness
Authors: Kjelgren Roger , Montague David T. , Rupp Larry A.
Published: February 2019

We investigated the microclimate, gas exchange, and growth of field-grown Norway maple (Acer platanoides L.) and green ash (Fraxinus pennsylvanica Marsh) trees nonsheltered, and in brown and white shelters. Shelter microclimate—air temperature (Ta), vapor pressure deficit (VPD), and radiation—and tree leaf area, growth in diameter, stomatal conductance (gs), and photosynthesis were measured during the first growing season after bare-root transplanting. Bark temperatures in midwinter were also measured. Treeshelter microclimate was greenhouse-like compared to ambient conditions, as shortwave radiation was lower, and midday Ta and relative humidity were higher. Although trees in shelters had greater shoot elongation and higher gs than trees grown without shelters, photosynthesis was not different. White shelters allowed 25% more shortwave radiation penetration and increased Ta by 2 to 4 °C and VPD by 0.5-1 kPa over brown shelters. However, tree growth and gas exchange generally were not affected by shelter color. Winter injury was increased for trees in shelters and varied with species and shelter color. Both species exhibited shoot dieback in shelters the spring following a winter where bark temperatures varied 40 to 50 °C diurnally. More new growth died on maple, particularly in white shelters where several trees were killed. These data suggest that supraoptimal summer and winter temperatures may reduce vigor and interfere with cold tolerance of some species grown in shelters.
A Revolution in New England: New Hampshire Develops an Annual Strawberry Production System
Authors: Bornt Charles D. , Loy J. Brent , Lord William G. , Wells Otho S.
Published: February 2019

Research was conducted in New Hampshire during Fall 1995 and Spring 1996 to determine a planting schedule, rowcover type, application time, and plastic mulch type to be used in adapting the annual hill strawberry production system to New England. Treatments in Fall 1995 included two planting dates, three mulch types, and four rowcover modifications. Yields did not differ statistically between a 18 Aug. and 1 Sept. planting date or among plastic mulches. Typar 518 floating rowcovers significantly increased branch crowns, and early and total fruit yield compared to hay mulch applied for winter protection. Research was initiated in Fall 1996 to determine the effect of runner production on yield. Plug plants (50 vs. 24 tray) were treated with different day lengths and temperatures and planted in the field on 26 Aug. or 9 Sept. All plants were covered with Typar 518 on 4 Oct. 1996. Larger, late-planted plugs treated with cool, short days produced no runners in Fall 1996 and increased branch crowns and total yield in Spring 1997. Plants set out in Fall 1995 were evaluated for 2nd year production with or without runner pruning and four rowcover treatments in Fall 1996. Runner pruning did not significantly increase total yields, but resulted in earlier fruit harvesting in Spring 1997. Typar 518 applied 4 Oct. resulted in the greatest yield of any rowcover treatment.
Effect of Leaf Age and Shading on the Phenolic Composition of Apple Foliage
Authors: Garcia M. Elena , Rom C.R. , Murphy J.B.
Published: February 2019

Two experiments were conducted to determine the effects of leaf age and shading on the phenolic content and composition of apple foliage. In the first study, it was determined that the phenolic content of `Liberty', at increasing leaf developmental stages, was leaf age—dependent. Early during leaf development, there was an increase in the phloridzin (the primary glycoside identified) and in total phenolics, reaching a maximum when the leaf is 6 days from 20-mm blade length. After this stage, the phenolic content decreased with increasing leaf age. In the second study, the leaves of two cultivars, `Liberty' and `Starkspur Law Rome', were tagged weekly when the leaf was two-thirds unfolded. Three weeks after budbreak, the trees were placed under three shade cloth treatments (0%, 60%, and 90% shade). After 4 weeks under the shade treatments, the tagged leaves were collected to determine their phenolic content. Shade significantly affected the foliar phenolic content. Leaves in 0% shade had the highest phenolic content, whereas the lowest content was found in leaves exposed to 90% shade. There was a significant leaf age × shade interaction. The phenolic content decreased with increasing leaf age except for those leaves whose development occurred before the experiment was started. The results indicate that light and leaf developmental stage are important factors in determining the phenolic content of apple leaves, but shading appears to have a stronger influence than leaf developmental stage. E-mail mgarcia@zoo.uvm.edu; phone (802) 656-2824.
Shoot Proliferation and Rooting in Vitro of Pulmonaria
Authors: Stimart Dennis P. , Mather John C. , Schroeder Kenneth R.
Published: February 2019

Expanding shoot tips of Pulmonaria `Roy Davidson' and Pulmonaria saccharata `Margery Fish' were cultured in vitro on a modified Murashige and Skoog medium containing BA to establish proliferating cultures for use in comparing BA concentrations on shoot proliferation and rooting. The optimum level for shoot proliferation was 8.8 μm BA. Greatest rooting was on medium without BA. Genotype and time in culture influenced shoot and root counts. Chemical names used: N6-benzyladenine (BA)
Variability for Starch Digestibility in Dry Bean (Phaseolus vulgaris L.)
Authors: Hosfield G.L. , Bennink M.R. , Beninger C.W. , Engleright R.M. , Ospina M.T.
Published: February 2019

Undigested starch is a major contributor to gastrointestinal discomfort experienced from eating cooked dry beans (Phaseolus vulgaris L.). Plant breeders are interested in identifying genetic stocks of beans with highly digestible starch to use in food quality improvement programs. Before a selection program for starch digestibility can be initiated, genetic variability must be ascertained. Breeding lines and cultivars from several dry bean market classes were evaluated for their starch digestibility using a laboratory procedure involving the determination of total dietary fiber with 3-enzymes. Grinding raw and cooked beans using a mill with the same-size screen (either 40 or 60 mesh) resulted in larger particles in the raw than in the cooked bean sample and inflated the amount of indigestible starch in the raw bean samples. In an experiment in which cooked and raw beans were ground with different size sieves, we found that in order to obtain cooked and raw beans with comparable particle sizes (thus providing accuracy and reliability to indigestible starch determinations), the cooked beans should be ground and sieved through a 40-mesh screen, and raw beans through a 60-mesh screen. Navy bean was the market class with the most digestible starch (≈10%). Black beans and kidney bean had the least digestible—starch >15%. Manteca, a Latin American market class with a pale yellow seed coat, was similar in digestibility to navy beans. Although the evidence is anecdotal, Manteca beans are favored for their qualities of taste, texture, and good digestibility. The current research on indigestible starch appears to confirm the high digestibility, low-flatulence attributes of Manteca bean.
Segregation for Double Spine Trait in Hybrids of Microcitrus inodora
Authors: Bowman Kim D.
Published: February 2019

Several Microcitrus species are valuable as parents in breeding citrus rootstocks and scions because of useful characteristics, such as monoembryony, very short juvenility, short fruit maturation time, and resistance to Phytophthora and nematodes. The large-leaf Australian wild lime, Microcitrus inodora (F. M. Bail.) Swing., also possesses a trait that is generally undesireable in new hybrids, double axillary spines. Most F1 hybrids between M. inodora and single-spine Microcitrus and Citrus species were observed to possess the double spine trait. In crosses of M. australasica (F. Muell.) Swing. × M. inodora, M. papuana H. F. Winters × M. inodora, and M. warburgiana (F. M. Bail.) Tan. × M. inodora, double spines were present in 80%, 81%, and 87% of the progeny, respectively. In hybrids of Citrus species with M. inodora, percentage of double spines varied from 43% in progeny from M. inodora × Citrus aurantium L., to 100% in progeny from M. inodora × Citrus ichangensis Swing. When double-spined hybrids of M. inodora were used as parents in crosses with other single-spined Citrus species or hybrids, progenies varied from 0 to 86% with double spines. The patterns of inheritance suggest that the double spine trait is controlled by an allele of a nuclear gene that is dominant and homozygous in M. inodora, but that one or more other independently segregating alleles are necessary for expression of the double spine trait in advanced generation hybrids.
Genetic Diversity of Basil (Ocimum spp. - Lamiaceae) Based on RAPD Markers and Volatile Oil Constituents
Authors: Vieira Roberto F. , Simon James E. , Goldsbrough Peter , Figueira Antonio
Published: February 2019

Essential oils extracted from basil (Ocimum spp.) by steam distillation are used to flavor foods, oral products, in fragrances, and in traditional medicines. The genus Ocimum contains around 30 species native to the tropics and subtropics, with some species naturalized and/or cultivated in temperate areas. Interand intraspecific hybridization have created significant confusion in the botanical systematics of this genus. Taxonomy of basil (O. basilicum) is also complicated by the existence of numerous varieties, cultivars, and chemotypes within the species that do not differ significantly in morphology. In this study we are using RAPD markers and volatile oil composition to characterize the genetic diversity among the most economically important Ocimum species. We hypothesize that the genetic similarity revealed by molecular markers will more accurately reflect the morphological and chemical differences in Ocimum than essential oil composition per se. Preliminary research using five Ocimum species, four undetermined species, and eight varieties of O. basilicum (a total of 19 accessions) generated 107 polymorphic fragments amplified with 19 primers. RAPDs are able to discriminate between Ocimum species, but show a high degree of similarity between O. basilicum varieties. The genetic distance between nine species and among 55 accessions within the species O. americanum, O. basilicum, O. campechianum, O. × citriodorum, O. gratissimum, O. kilimandscharium, O. minimum, O. selloi, and O. tenuiflorum will be analyzed by matrix of similarity and compared to the volatile oil profile. This research will for the first time apply molecular markers to characterize the genetic diversity of Ocimum associate with volatile oil constituent.