bluuebunny/crossref_metadata_2025 huggingface dataset:
INITIAL GENETIC LINKAGE MAP AND EXPERIMENTS TOWARD TAGGING GENES WHICH CONTROL CHILLING REQUIREMENT IN BLUEBERRY (VACCINIUM SPP.)
Authors: Levi Amnon , Ogden Elizabeth , Rowland Lisa J.
Published: February 2019

Efforts are underway to develop genetic linkage maps for two interspecific blueberry populations (Vaccinium darrowi × V. elliottii and V. caesariense-derived populations). To date, 72 RAPD markers have been mapped, and another 200 markers have been identified as suitable for mapping in the V. darrowi × V. elliottii-derived population. Inheritance of 40 RAPD markers has been followed, and additional 40 RAPD markers have been identified as suitable for mapping in the V. darrowi × V. caesariense population. These two populations are comprised of individual plants that should have a wide range of chilling requirements. At a later date, plants will be classified according to their chilling requirements to identify RAPD markers that cosegregate with chilling requirements. Presently, a bulked-segregant analysis is being performed on a tetraploid breeding population (primarily V. corymbosum) to identify RAPD markers linked to chilling requirement genes.
Strawberry Nursery Soil Fumigation and Runner Plant Production
Authors: Larson Kirk D. , Shaw Douglas V.
Published: February 2019

Three preplant soil fumigation treatments were applied on 5 Apr. 1993 to a nursery site that had not been planted previously to strawberries (Fragaria ×ananassa Duch.): 1) a mixture of 67 methyl bromide: 33 chloropicrin (CP) (by weight, 392 kg·ha–1) (MBCP); 2) 140 kg CP/ha; and 3) nonfumigation (NF). On 26 Apr., cold-stored `Chandler' and `Selva' strawberry plants of registered stock were established in each treatment. Soil and root/crown disease symptoms were absent in all treatments during the course of the study. In October, runner plants were machine-harvested and graded to commercial standards. The cultivars produced a similar number of runners per mother plant. Fumigation with MBCP, CP, and NF resulted in 18.56, 15.75, and 7.89 runners per mother plant, respectively. For `Selva', runner root and crown dry weights were similar for the MBCP and CP treatments, but NF resulted in significant reductions compared to the other two treatments. For `Chandler', fumigation with CP resulted in reduced root dry weight, and NF resulted in reduced crown and root dry weights compared to fumigation with MBCP. The results demonstrate the marked decreases in strawberry runner production and runner size that can occur in the absence of preplant soil fumigation, even on new strawberry ground. Also, small, but significant, reductions in runner production and runner size may occur with CP applied at a rate of 140 kg·ha–1 compared to standard fumigation with MBCP. Chemical name used: trichloronitromethane (chloropicrin).
Rooting Cuttings in Cupric Hydroxide-treated Pots Affects Root Length and Number of Flowers after Transplanting
Authors: Svenson Sven E. , Johnston Diane L.
Published: February 2019

Stem tip cuttings of Evolvulus glomeratus Nees & Mart., E. tenuis Nees & Mart., Lantana camara L. `Dallas Red,' and L. montevidensis Briq. `Alba' were rooted for 6 weeks in 57-mm-diameter (150 ml) square pots. Before rooting, interior surfaces of half of the pots were treated with 100 g Cu(OH)2/liter, while remaining pots were left untreated. Elongation of adventitious roots stopped when root tips came in contact with a Cu(OH)2-treated surface. Cupric hydroxide treatment reduced total root length and the length of the longest root for all four species, but did not influence root, shoot, or total plant weight. One month after transplanting to 150-mm-diameter (1.2 liter) hanging baskets, plants moved from Cu(OH)2-treated pots had more flowers than those transplanted from nontreated pots. Applying Cu(OH)2 to interior surfaces of pots used for propagation prevented root deformation, reduced root length, and increased flowering following transplanting.
Suitability of Composted Bluegrass Residues as an Amendment in Container Media
Authors: Manning Leslie K. , Tripepi Robert R. , Campbell Alton G.
Published: February 2019

Postharvest plant residues from Kentucky bluegrass (Poa pratensis L.) seed production may be useful as an organic amendment in container mixes. Postharvest residues of `South Dakota' bluegrass were composted with and without an N amendment, such as cattle manure (M) or alfalfa seed screenings (As). After composting, all residues were ground to 4- to 6-mm segments and mixed with sphagnum peat and perlite (2:1:1 by volume). Media that contained amended bluegrass residues had higher electrical conductivity (EC) values and lower C: N ratios (<19:1) than media made with other bluegrass residues. Tomato (Lycopersion esculentum Mill. `Laura') seedlings grown in residue composted with As had at least 3.5- and 4-fold more shoot dry weight and leaf area, respectively, than plants grown in any other composted medium. In addition, seedlings grown in composted bluegrass residues amended with As had 34% and 41% more shoot dry weight and leaf area than plants grown in a 75% peatmoss–25% perlite medium. Composted residue amended with alfalfa seed screenings appears to be suitable as a peatmoss extender in container media.
Layered Coatings to Control Weight Loss and Preserve Gloss of Citrus Fruit
Authors: Hagenmaier Robert D. , Baker Robert A.
Published: February 2019

Valencia oranges [Citrus sinensis (L.) Osbeck cv. Valencia] and Marsh grapefruit [Citrus paradisi Macf.] were treated with single or double layers of coating. In cases where two coatings were applied, the first coating was a moisture-barrier wax; the second was either polyethylene wax or a mixture of shellac and resin ester. The inner coating reduced weight loss, and the outer coating imparted gloss. Fruit gloss, as measured by reflectometer, decreased more rapidly during 1 week at 20C with a single glossy coating than with the same coating applied as a second layer over a wax-based first coating. For citrus fruit, using resin ester or shellac as a high-gloss second coating tended to overly restrict the exchange of O2 and CO2; however, two layers of wax did not.
Modified-humidity Packaging Reduces Decay of Harvested Red Bell Pepper Fruit
Authors: Rodov V. , Ben-Yehoshua S. , Fierman T. , Fang D.
Published: February 2019

Lowering the in-package relative humidity (RH) by adding hygroscopic material (e.g., NaCl) reduced decay of bell pepper (Capsicum annuum L.) fruit sealed in low-density polyethylene and stored 2 or 3 weeks at 8C. Without hygroscopic material, the in-package RH was close to saturation, and water droplets condensed on the fruit and inner film surfaces. Depending on the amount of NaCl, condensation was prevented or significantly reduced. Humidity level varied from ≈88% with 15 g NaCl to ≈97% with 5 g NaCl for a package containing 0.5 to 0.6 kg of fruit. Adding hygroscopic material increased the water vapor pressure deficit (VPD) in the packages and, accordingly, the weight loss of the fruit. However, peppers packaged with NaCl still had lower weight loss and better quality than the nonsealed fruit. The water regime formed in four-fruit packages in the presence of 10 g NaCl (92% to 95% RH, VPD 65 to 77Pa) enabled optimal balance between reduced fruit desiccation and inhibited pathogen development, thus extending the postharvest life of bell pepper.
Firmness and Aroma Composition of Strawberries following Short-term High Carbon Dioxide Treatments
Authors: Larsen Mette , Watkins Christopher B.
Published: February 2019

Firmness and aroma composition of strawberry fruit (Fragaria ×ananassa Duch. cv. Pajaro) stored in air or treated with 20% CO2 for up to 12 days at 0C were analyzed upon removal from storage. Fruit firmness increased after 2 days in CO2, while the composition of aroma compounds in the fruit was unaffected at this time. Ethanol and ethyl hexanoate accumulated after 3 days during high CO2 treatment, but these compounds usually decreased during subsequent cold storage in air. Ethyl butanoate and ethyl acetate also accumulated but continued to increase after 6 and 9 days of CO2 storage, respectively. This study suggests that treatment of strawberry fruit with CO2 after harvest, followed by air storage at 0C, can maintain firmness while minimizing off-flavor development.
Cold Hardiness within the Genus Actinidia
Authors: Chat Joëlle
Published: February 2019

Two-year-old Actinidia vines, grown on their own roots, were subjected to artificial freezing tests in midwinter to determine their relative hardiness. Plant survival, growth recovery, and stem necrosis were used for estimating freezing injury. Actinidia deliciosa (A. Chev.) C.F. Liang & A.R. Ferguson var. deliciosa vines, which included `Abbott', `Bruno', `Greensill', `Hayward', and `Jones' kiwifruit, were all severely damaged by exposure to a temperature of –18C for 4 hours. Actinidia arguta (Sieb. et Zucc.) Planch. ex Miq., A. kolomikta (Maxim. et Rupr.) Maxim., and A. polygama (Sieb. et Zucc.) Maxim. appeared to be more tolerant to winter cold than A. deliciosa, indicating that potential germplasm exists for improvement of cold hardiness through interspecific hybridization.
Development of Plants from Single-node Cuttings Differs among Cultivars of Red Maple and Freeman Maple
Authors: Wilkins Lorna C. , Graves William R. , Townsend Alden M.
Published: February 2019

Six red maple (Acer rubrum L.) and four Freeman maple (A. ×freemanii E. Murray) cultivars were compared for rooting of single-node stem cuttings and subsequent development of rooted cuttings. Cuttings were taken in May 1990 and 1991 and treated with either 3 or 8 g IBA/kg. Rooting after 4 weeks differed among cultivars, ranging from 22% for `Karpick' to 100% for `Schlesinger' over both years. Rooting scores, based on root counts and lengths, were highest for `Schlesinger' and lowest for `Scarlet Sentinel' and `Karpick'. IBA at 8 g·kg–1 resulted in better rooting than at 3 g·kg–1. Mean length of shoots formed on potted rooted cuttings was 22.6 cm for `Franksred', which initiated shoots on 100% of the cuttings that rooted. In contrast, <50% of `Armstrong', `Jeffersred', `Karpick', `Northwood', and `Scarlet Sentinel' rooted cuttings initiated shoots, and mean length of new shoots was <4 cm for these cultivars. The amount of leaf desiccation that occurred after removing cuttings from the propagation bench varied among cultivars, and the percentage of viable leaf surface area correlated positively with final root or shoot dry mass for all cultivars. Chemical name used: indole-3-butyric acid (IBA).
A Budbreak-based Chilling and Heating Model for Predicting First Entry of Pecan Nut Casebearer
Authors: Sparks Darrell
Published: February 2019

A modification of the chilling and heating model for pecan budbreak was used to describe the interactive effects of chilling and heating on the date of first entry of the pecan nut casebearer (PNC; Acrobasis nuxvorella Neunzig) into the pecan [Carya illinoinensis (Wangenh.) K. Koch] fruit. Selected data from unpublished and published sources were used to construct the model. Base temperatures of 9.4 and 13.9C for chilling and heating, respectively, provided the best fit (r2 = 0.981) for the model used to predict PNC activity. An inverse relationship [1/Y = 0.0037259(1 – 0.1e–0.0028069x – 574.9638969)] was found between chilling (1 Dec. through February) and heating (beginning 1 Feb.) degree-days accumulated until entry of first-generation PNC into the pecan fruit. This model can be used to predict entry of first-generation PNC larvae into fruit over a range of geographic and climatic conditions and pecan genotypes. Model validation using 1994 data from two sites in Texas suggests precision is sufficient to use the model as a guide in managing nut casebearer control.
Relationship of U.S. Department of Agriculture Grades to the Value of Fraser Fir Christmas Trees
Authors: Arnold Roger J. , Jett J.B. , Huxster William T.
Published: February 2019

Wholesale values, retail values of five eastern United States lots, U.S. Dept. of Agriculture (USDA) Christmas-tree grades, and measurements of various growth and quality traits were obtained on ≥1400 Fraser fir [Abies fraseri (Pursh) Poir.] (8 years old) Christmas trees. Retail lot values were similar, but average retail value correlated poorly with wholesale value within merchandising height classes. For each of the current wholesale categories (defined by the combination of 30.5-cm interval height classes and USDA grades), average values ranged widely. Some cull-grade trees, which would be unmerchantable according to USDA standards, had moderate retail value. Also, the retail mean of any one wholesale category generally was not significantly different from that of adjacent categories. Some tree quality defects that have equal impact on USDA grade, and consequently wholesale value, differed widely in their effect on retail values. This study indicates that current USDA Christmas-tree grade standards do not adequately differentiate Fraser fir trees with respect to their retail value. We propose a new method of Christmas-tree quality certification that involves computed Christmas-tree quality index values that offer greater accuracy in describing quality with respect to retail value.
Vegetative Growth of Potato under High-pressure Sodium, High-pressure Sodium SON-Agro, and Metal Halide Lamps
Authors: Yorio N.C. , Mackowiak C.L. , Wheeler R.M. , Sager J.C.
Published: February 2019

Potato (Solanum tuberosum L. cvs. Norland and Denali) plants were grown under high-pressure sodium (HPS), metal halide (MH), and blue-light-enhanced SON-Agro high-pressure sodium (HPS-S) lamps to study the effects of lamp spectral quality on vegetative growth. All plants were initiated from in vitro nodal cultures and grown hydroponically for 35 days at 300 μmol·m–2·s–1 photosynthetic photon flux (PPF) with a 12-hour light/12-hour dark photoperiod and matching 20C/16C thermoperiod. `Denali' main stems and internodes were significantly longer under HPS compared to MH, while under HPS-S, lengths were intermediate relative to those under other lamp types, but not significantly different. `Norland' plants showed no significant differences in stem and internode length among lamp types. Total dry weight of `Denali' plants was unaffected by lamp type, but `Norland' plants grown with HPS had significantly higher dry weight than those under either HPS-S or MH. Spectroradiometer measurements from the various lamps verified the manufacturer's claims of a 30% increase in ultraviolet-blue (350 to 450 nm) output from the HPS-S relative to standard HPS lamps. However, the data from `Denali' suggest that at 300 μmol·m–2·s–1 total PPF, the increased blue from HPS-S lamps is still insufficient to consistently maintain short stem growth typical of blue-rich irradiance environments.
INDIVIDUAL STUDIES IN WOODY PLANT PROPAGATION
Authors: Davidson Carlton C. , Sibley Jeff L. , Eakes D. Joseph
Published: February 2019

Traditional propagation courses seldom allow extensive evaluation of the variables required for successful propagation. A series of experiments were designed to give an individual student practical experience in woody plant propagation. Softwood terminal cuttings were taken on five shrub or tree species, dividing each species into separate experiments comparing talc vs. liquid auxin formulations. Selections evaluated included luster leaf holly with treatments of 3000, 8000, and 16,000 ppm K-IBA; hetz holly, crape myrtle, and anise tree with treatments of 1000, 3000, and 8000 ppm K-IBA; and sugar maple with 8000 and 16,000 ppm K-IBA. Budding and seed propagation also were evaluated in sugar maple. In each species, except sugar maple, liquid quick-dip at the highest K-IBA concentration produced the best rooting. The student gained many educational benefits in basic experimental design, evaluation of data collected, and drawing conclusions to findings significant by industry standards. The student also learned and how production cycles have an impact on various methods, development stages of cutting material, and wounding techniques. The practical propagation experience gained was of primary importance thereby further preparing the student for employment in the industry.
COMPARISONS OF USING ELECTRIC POLLINATOR OR BOMBUS IMPATIENS FOR POLLINATING HYDROPONICALLY GROWN TOMATOES
Authors: Snyder Richard G.
Published: February 2019

A successful greenhouse tomato crop depends on the optimization of several factors; among these factors are water, nutrition, and all facets of environmental control. Good pollination, however, is one of the most important requirements for the production of fruit of high yield and quality. Poor pollination causes fruit that are smaller, angular, or puffy, due to reduced seed numbers and poor gel fill in the locules. In Spring 1993, two 7.3 × 29.3 double plastic-covered greenhouses were used to compare the conventionally used electric pollinator to bumblebees for effective pollination; replicated variety trials were performed within each. In one greenhouse (12 replications, RCBD), `Trust' performed better than `Caruso' in yield and quality, although it was smaller in fruit size. In the other greenhouse (four replications, RCBD), `Match' and `Switch' were better than all others (`Belmondo', `Capello', `Laura', and `Rakata') for most yield and quality variables. Means across varieties were similar for the two pollination techniques, with marketable weights identical. For gutter-connected greenhouse ranges of 0.1 ha or larger, bumblebees are an economically viable option for pollinating hydroponically grown tomatoes.
CUCUMBER YIELD RESPONSES TO RAW AND PROCESSED POULTRY LITTER
Authors: Roberts Warren , Duthie Jim , Whitworth Julia
Published: February 2019

Large amounts of poultry litter are produced in eastern Oklahoma. Nitrate leaching from stockpiled litter can contaminate water supplies. Poultry producers need additional land for disposal of litter. Poultry litter can be a good fertilizer because it usually contains 2% to 3% N, P2O5, and K2O. The ratio of N: P: K is about 1:1:1. Soils in the area often need fertilizer with about a 1:1:2 ratio for cucumber production. This study was established to determine if poultry litter alone could be used to supply all of the nutrients needed for cucumber production, and if excess nutrients would be detrimental to crop growth. Treatments consisted of two rates of raw poultry litter, two rates of composted litter, and synthetic fertilizer applied in either a single or a split application. Treatments ranged from 112, 112, and 224 kg·ha–1. The greatest yield came from the highest rate of poultry litter. Composted litter did not yield more than raw litter. Splitting the application of synthetic fertilizer did not improve yields over that of a single application of the same material.
INFLUENCE OF FLOWER REMOVAL ON TWO VARIETIES OF WHITE POTATOES AND THREE CULTIVARS OF SWEET POTATOES IN MISSOURI
Authors: Wilson Mack , Khan Victor , Stevens Clauzell
Published: February 2019

A randomized design was conducted in 1994 to determine the effect of flower removal on yield of two potato and three sweetpotato cultivars. The results showed a three-way interaction with mean height of `Atlantic' and `Snowden' potatoes evaluated in this study. Total root numbers of the two potato cultivars were significantly greater when rowcovers were used. The yield of grade A sweetpotato cultivars was greater when flowers were removed. The yield and marketable yield of U.S. no. 1 sweet potatoes was significant when flowers were removed.
INFLUENCE OF ROOT ZONE TEMPERATURE ON GROWTH, YIELD, AND PHENOLOGY OF SWEETPOTATOES GROWN IN NFT
Authors: Loretan Philip A. , Avicki Fred A. , Mortley Desmond G. , Horton Wiletha
Published: February 2019

A cooling system using the principles of heat transfer was designed to provide a temperature difference of 6C between root and shoot zones and to study the effect of this difference on growth, yield, and phenology of `TI-155' sweetpotato [Ipomoea batatas (L.) Lam.] grown using the nutrient film technique in a greenhouse. Treatments were temperature control (20C) and variable temperature (26C) in a randomized complete-block design with two replications. A modified half Hoagland's nutrient solution with a 1 N: 2.4 K ratio was used and was changed every 2 weeks. Nutrient solution pH was maintained between 5.5 and 6, and electrical conductivity, salinity, and solution temperature were monitored at regular intervals. Storage root fresh and dry weights (except for fibrous root dry weight) and foliage fresh and dry weights were not significantly influenced by root zone temperature. Leaf expansion rate and vine length were lower for root zone temperature control plants; stomatal conductance, transpiration, and leaf unfolding rates were similar for both treatments.
CHEMICAL THINNING OF `SURECROP' PEACH WITH LATRON AG-98 SURFACTANT
Authors: Caylor A.W. , Dozier W.A. , Pitts J.
Published: February 2019

Latron AG-98 (formerly named Triton AG-98) was applied to 8-year-old `Surecrop' peach trees on Lovell rootstock at 0%, 2%, 4%, and 6% (v/v) on 13 Mar. 1990 and 1992 and 28 Mar. 1991. Our objective was to determine the effect Latron AG-98 had on percentage of blossoms removed, fruit set, total fruit count and yield, and marketable fruit weight. The percentage of blossoms removed increased with increasing rates of Latron AG-98. The 4% and 6% rates removed the greatest percentage of blooms in all 3 years. The number of fruit per 50 cm of shoot length, number of fruit removed by hand-thinning, percent fruit set, total fruit number, and total fruit yield decreased with increasing rates of Latron AG-98 in 1990 and 1992 but not in 1991. The marketable fruit weight increased with increasing rates of Latron AG-98 in 1990 and 1992 but not in 1991. Latron AG-98 was not effective in 1991 because of a 2-day delay in application. Latron AG-98 was effective in removing blossoms from `Surecrop' peach at all three rates. However, the 4% and 6% rates reduced the yields below a commercially acceptable level. The 2% rate of Latron AG-98 could be useful as a tool to reduce the labor required to hand-thin peaches.
GIBBERELLIC ACID ENHANCES FRUIT SET OF PHYSICALLY DAMAGED BLUEBERRY FLOWERS
Authors: Krewer Gerard , NeSmith Scott , Rieger Mark , Mullinix Ben
Published: February 2019

Rabbiteye blueberry (Vaccinium ashei R.) flowers often suffer slight freeze damage that prevents fertilization and fruit development. To determine if gibberellic acid (GA3) might be useful in rescuing freeze-damaged flowers the following treatments were applied before anthesis to two cultivars at different locations: 1) undamaged control, 2) approximately two-thirds of the corolla and most of the style removed, 3) approximately half of the style removed, and 4) ovules lanced with an insect pin by driving it through the equator of the undeveloped berry until the point came out the other side. Half the bushes were not sprayed, and half were sprayed with GA3 (312 ppm, v/v) the night following treatment. `Climax' at Chula, Ga., had good fruit set for treatment 1 with and without GA3 (70% to 85%). Good fruit set also occurred for treatment 2, 3, and 4 where GA3 was applied (47% to 54%), but poor fruit set without GA3 (4% to 16%). `Tifblue' at Chula had significantly better fruit set for treatment 1 with GA3 (54% vs. 27%). Excellent fruit set occurred for treatment 2, 3, and 4 where GA3 was applied (81% to 96%), and poor fruit set without GA3 (6% to 7%). `Tifblue' fruit set by GA3 sized better than `Climax' fruit set by GA3. The experiments provide corroborative evidence that flowers that have suffered freeze damage to the stigma, style, corolla, and perhaps ovules can be set with GA3.
THE EFFECT OF FIVE PREPLANT TREATMENTS ON THE EARLY PERFORMANCE OF PEACH ON A REPLANT SITE
Authors: Rom Curt R. , Blackburn B. , Bourne R.
Published: February 2019

The growth and productivity of `Redhaven'/Lovell peach during the first 3 years in a replant site was evaluated after planting in one of five preplant treatments. Treatments (trt) were 1) nontreated control (CK), 2) killed fescue (F), 3) soybean rotation (L), 4) summer solarization (SOL), and 5) methyl bromide fumigation (FUM). An orchard was removed from the experimental site in Spring 1991 before establishments of treatments. In June 1991, a tall fescue (K-31), soybeans, or mustard, and cabbage were sown in trt plots 2, 3, and 4, respectively. In July, trt 4 was covered with clear, 4-mil plastic sheeting for 90 days. In October, trt 5 was fumigated with methyl bromide under a 4-mil plastic sheet. Trees were planted in Spring 1992. Soil characteristics, weed populations, and tree growth and productivity were measured in the first three seasons after planting. FUM significantly reduced weed density into the third season. SOL plots had the highest weed density in years 2 and 3. TCSA, yield, and yield efficiency of FUM trees were significantly larger than CK. Trees in F or SOL had significantly lower yields.
THE INFLUENCE OF YIELD ON FATTY ACID COMPOSITION OF PECAN NUTS
Authors: Storey J.B. , Grauke L.J. , Sistrunk Laurence , Thompson Tommy E.
Published: February 2019

Four cultivars of pecan [Carya illinoinensis (Wangenh.) K. Koch] were studied for 3 years to determine if variations in yield influence fatty acid composition of kernels. Trees used in the study are part of the U.S. Dept. of Agriculture, Agricultural Research Service Historical Block, a test orchard planted in randomized block design with four blocks, having one single-tree replication per block and containing 36 cultivars. Four trees of each of four cultivars (`Cheyenne', `Mohawk', `Pawnee', and `Osage') were used in this test. Trees were in their 5th to 7th leaf from grafting and showed patterns of increasing yield over time for each cultivar. `Osage' was earliest to mature nuts each year and produced nuts with the lowest linoleic acid content. `Cheyenne' was latest to mature nuts and had nuts with the highest linoleic acid content. Oleic acid composition varied with yield in `Osage' and `Pawnee': as yield (kilogram/square decimeter trunk area) increased, oleic acid content decreased. Kernel color, as determined by a Hunter LabScan 5100 Spectrocolorimeter, varied in relation to fatty acid composition for `Osage' and `Pawnee': as oleic acid content increased, kernel lightness decreased. High oleic acid content and light kernel color are associated with high-quality pecans. The pattern of decreasing oleic acid content associated with increasing kernel lightness raises questions concerning the role kernel color evaluation should play in selecting high-quality pecan cultivars.
REMEDIATION OF THE POLLUTANT CONTENT OF RUNOFF WATER FROM A CONTAINERIZED PLANT NURSERY
Authors: Briggs Jeanne A. , Riley Mellissa B. , Whitwell Ted
Published: February 2019

The pesticides isoxaben, trifluralin, chlorpyrifos, and thiophanatemethyl were applied at recommended rates to a 4-ha growing bed at an operating container nursery. Runoff samples produced by overhead irrigation were collected from three waterways, 300 feet long × 6 feet wide. The waterways were a sodded hybrid bermudagrass, a plantation of common cattails (Typha latifolia), and a gravel–clay waterway used as a reference. A 2-ha area drained into the sodded waterway, which flowed into the cattails, and a 2-ha bed flowed into the reference waterway. Samples were collected throughout the duration of runoff on day of treatment and at 1, 2, 8, 15, and 22 days after treatment. Runoff volumes were recorded over time as measured at weirs. Analysis was by HPLC following solid-phase extraction. Only isoxaben was detected at 2 days after treatment. Initial concentrations of all pesticides were lower in the vegetated waterways than in the reference.
INDUCTION OF MEALINESS DURING SHORT-TERM STORAGE FOR A NOVEL PEACH GENOTYPE
Authors: Maness Niels O. , Chrz Donna , Goffreda Joseph C.
Published: February 2019

The peach mutation `Stony Hard' confers a slow softening attribute to the fruit and also confers a highly reproducible predisposal of fruit to soften abnormally to a mealy texture. Induction of mealiness required continuous 48-hour 100-ppm ethylene exposure. `Stony Hard' fruit exposed to low ethylene concentrations (l ppm) or discontinuous 100 ppm ethylene softened more rapidly than fruit exposed to ethylene-free air but to a normal texture. Ethylene treatment failed to induce mealiness in selections without the `Stony Hard' gene. As quantitative methods for assessment of mealiness, mesocarp-extractable juice decreased, and buffer soluble solids and soluble polysaccharide galacturonic acid content increased for mealy fruit. `Stony Hard' peach fruit represent the only known system in which the concentration and duration of exposure to ethylene can be used to manipulate softening and textural properties of the fruit. Supported by U.S. Dept. of Agriculture grant 93-34150-8409 and the Oklahoma Agricultural Experiment Station.
IMPLEMENTATION OF A HACCP IN A COMMERCIAL TOMATO PACKINGHOUSE: A MODEL FOR THE INDUSTRY
Authors: Rushing James W. , Angulo Frederick J.
Published: February 2019

In response to epidemiological studies that linked outbreaks of salmonellosis to consumption of raw tomatoes in 1991 and 1993, a model HACCP was designed and implemented in a commercial tomato packinghouse in South Carolina in 1994. Testing of tomato fruit and packinghouse water samples by CDC and by a private laboratory for the presence of Salmonella confirmed that the HACCP was effective in controlling the risk of contamination in the packinghouse. Critical control points are identified and application of this model HACCP to other fresh fruit and vegetable handling systems is proposed.
REGENERATION OF COWPEA [VIGNA UNGUICULATA (L.) WALP.] FROM SEEDLING SHOOT APEX CALLUS
Authors: Al-Khayri Jameel M. , Morelock Teddy E. , Anderson Edwin J.
Published: February 2019

Cowpea, or southernpea, is an important food legume that provides a source of high-quality protein, especially in the mature seeds. In the United States, industries exist to supply dry and processed seeds. Our aim is to develop a regeneration system for cowpea as a prerequisite for genetic engineering. Our objective was to examine the in vitro responses of shoot tips to growth regulators. Shoot tips isolated from in vitro-germinated seedlings (`Coronet') were cultured on MS medium containing 2,4-D at 0, 0.01, 0.1, or 1 mg·liter–1 and kinetin at 2.5, 5, 10, or 20 mg·liter–1. Cultures were maintained at 12-hour photoperiods and 24C. Callus, shoots, and roots or combinations thereof developed depending on the treatment. Callus formed on 1 mg 2,4-D/liter, regardless of the kinetin level, but at 0.1 mg 2,4-D/liter and 5 or 10 mg kinetin/liter, shoots also grew. Callus, shoots, and roots developed on 2,4-D lower than 0.1 mg·liter–1. Callus induced on 5 mg kinetin/liter and 0.01 mg 2,4-D/liter regenerated shoots on transfer to 5 mg kinetin/liter and 0.1 mg NAA/liter. This work may assist in the development of a micropropagation system for cowpea.
COVER CROPS MAY DECREASE WEED GROWTH IN STRAWBERRY FIELDS
Authors: Whitworth Julia
Published: February 2019

The usefulness of cover crops for weed management in strawberries were evaluated. Wheat (Triticum aestevum L.), rye (Secale cereale L.), and crimson clover (Trifolium incarnatum L.) were grown in individual pots then killed by tillage or herbicide and followed in the same pots by plantings of bermuda grass [Cynodon dactylon (L.) Pers.], yellow nutsedge (Cyperus esculentus L.), crabgrass [Digitaria ischaemum (Schreb.) Schreb. ex Muhl.], or strawberries (Fragaria ×ananassa `Cardinal'). Rye and wheat tilled into the medium generally increased the growth of strawberries and decreased the growth of bermuda grass. Rye and wheat residues appeared to suppress growth of weeds and strawberries when the residues remained on the medium surface. Crimson clover had little affect on the growth of weeds or strawberries. Yellow nutsedge and crabgrass were not significantly affected by cover crop residues.
EFFECT OF RATE OF BANDED PHOSPHORUS ON SWEET CORN YIELD
Authors: Kemble Joseph M. , Guertal Elizabeth A.
Published: February 2019

In 1994, a study was conducted in Crossville, Ala., to determine if differences in leaf P concentration and crop yield occurred when P was applied as either a broadcast or banded treatment. Phosphorus (0, 34, 67, 101, and 134 kg·ha–1) was banded (2 × 2) or broadcast applied and incorporated before planting. Other nutrients were applied based on current recommendations and soil testing. As level of P increased from 0 to 134 kg·ha–1, fresh weight of harvested ears increased quadratically. There was no difference in fresh weight of harvested ears between banding and broadcasting. Yields were not maximized within the range of applied P, although it seems that yield reaches a plateau near the highest rate of applied P. Percent of P in corn ear leaves did not differ among treatments. There was no difference in P leaf concentrations between the banded and broadcast treatments, indicating that response in yield occurred due to rate of P application, not method.
EVALUATION OF GRAPE GERMPLASM FOR DOWNY MILDEW RESISTANCE
Authors: Brown Maurus V. , Moore James N. , Fenn Patrick
Published: February 2019

Trials were established in Fayetteville, Ark., in 1993 and in 1994 to evaluate grape germplasm for downy mildew resistance. Accessions were obtained from the national grape repositories in Geneva, N.Y.; Davis, Calif.; and the Univ. of Arkansas fruit substation, Clarksville. The 1993 trial contained 26 cultivars, eight selections, and 24 Vitis species; the 1994 trial contained 37 cultivars. Each trial had four single-plant replications. Plants were rated on a scale of 0 to 5 for sporulation, chlorosis, and necrosis on 23 Aug. and 26 Sept. 1994. Fungicides were not applied to the vineyard to better determine the level of natural downy mildew resistance. The results from both trials indicated that several grape accessions showed little or no symptoms of downy mildew, which suggests these have resistance that would be beneficial to use in a breeding program.
INFLUENCE OF PHOSPHORUS ON GAS EXCHANGE AND PLANT DEVELOPMENT AND NUTRIENT UPTAKE OF CHILE ANCHO AND BELL PEPPER PLANTS
Authors: Davies Fred T. , Duray Sharon A. , Phavaphutanon Lop , Stahl Randy
Published: February 2019

The influence of P nutrition on gas exchange, plant development, and nutrient uptake of Capsicum annuum chile ancho `San Luis' and bell pepper `Jupiter' plants was studied. Plants were fertilized weekly using 250 ml of a modified Long-Ashton solution, containing 0, 11, 22, 44, 66 or 88 μg P/ml. Phosphorus stress was evident with both pepper cultivars at 0 and 11 μg P/ml, with reduced plant growth and development: leaf number and area and fruit, leaf, stem, root, shoot, and total plant dry weight. The root: shoot ratio was greatest at 0 μg P/ml, reflecting greater dry matter partitioning to the root system. Greater P stress occurred at 0 μg·ml–1 in `San Luis' compared to `Jupiter' (88% vs. 58% reduction in total plant dry weight compared to optimum P response). `San Luis' was also more sensitive to P stress at 11 μg P/ml than `Jupiter', as indicated by the greater reduction in growth responses. With increasing P nutrition, leaf tissue P increased in both cultivars with maximum leaf tissue P at 88 μg P/ml. In `San Luis', there were no differences in tissue P between plants treated with 0 and 11 μg P/ml, whereas the `Jupiter' plants treated with 0 μg P/ml had the lowest tissue P. Low P plants generally had the highest tissue N and lowest S, Fe, Mn, Zn, B, Mo, and Al. With both cultivars, gas exchange was lowest at 0 μg P/ml, as indicated by low transpiration (E), stomatal conductance (gs), and net photosynthesis (A). Internal CO2 (Cj) and vapor pressure deficit were generally highest at 0 μg P/ml, indicating that Cj was accumulating with lower gs, E, and A in these P-stressed plants. Generally, no P treatments exceeded the gas exchange levels obtained by 44 μg P/ml (full strength LANS) plants.
COMPARATIVE CARBON BALANCE OF MYCORRHIZAL AND NONMYCORRHIZAL PEPPER PLANT
Authors: Davies Fred T. , Stahl Randal S. , Duray Sharon A.
Published: February 2019

Symbiotic mycorrhizal fungi increase the P uptake of agronomic, horticultural, and forestry crops. Little is known about the real-time dynamics of carbon balance (net gain of biomass resulting from photosynthesis less the respiratory costs) of plants colonized with mycorrhizae. Our objective was to determine the carbon balance of endomycorrhizal (VAM) chile pepper `San Luis' (Capsicum annuum L.) as a model system for predicting plant response to limited P availability under elevated CO2. The increase in atmospheric CO2 is expected to result in increased plant productivity and greater demand for soil P, however, the lack of available soil P may become the most important nutritional problem limiting crop productivity. Under current conditions, the limitation of soil-P availability is an enormous problem that affects 25% of the world's arable lands. We are quantifying the carbon costs paid by the mycorrhizal plant under varying levels of P deficiency over the life cycle of the plant. Preliminary results from this study under ambient CO2 conditions indicate that there is a lower maintenance respiration and higher growth efficiency with mycorrhizal pepper plants under low soil-P conditions.
A FIELD STUDY ON THE HEAT TOLERANCE OF `GERMAN RED' CARNATION
Authors: Davis Tim D. , Sankhla Daksha , Sankhla Narendra
Published: February 2019

Carnation cultivars `German Red' and `Chabaud' were planted in the field in Dallas, Texas, on 26 May 1994. During the subsequent 3 months, the average daily high temperature was 33C, and the average daily low temperature was 22C. `German Red' plants increased in height and diameter several-fold during this period. In contrast, `Chabaud' did not increase in height or diameter. `German Red' plants began flowering in early August, and by 2 Sept., all of the plants were blooming. None of the `Chabaud' plants produced flowers, and only 50% of the original plants were still alive on 2 Sept. Mean shoot dry weight per plant on 2 Sept. was 71.6 g for `German Red' and only 2.4 g for `Chabaud'. These results document the extraordinary heat tolerance of `German Red' carnation. This plant not only survived the summer, but also grew and began blooming during the hottest time of the year.
CULTIVAR COMPARISON OF BUDDLEIA AS A CUT FLOWER
Authors: Krentz T.S. , Behe B.K. , Allen V.V. , Montgomery C.C.
Published: February 2019

Buddleia sp., butterfly bush, is a large, arching shrub with spike-shaped inflorescences in a wide range of colors including pink, purple, yellow, and white. Our objective was to determine which cultivars of Buddleia had an acceptable postharvest life and potentially could be used as cut flowers. Stems of `Black Knight', `Charming Summer', `Empire Blue', `Lochinch', `Nanho Blue', `Nanho Purple', `Pink Delight', `Royal Red', `White Profusion', and `Sungold' were harvested when one-third to two-thirds of the florets had opened. Within 2 hours of harvest, flower stems were recut under water, placed in vases containing 10 g Floralife/liter, and placed in a simulated consumer environment. Daily fresh weight, open and total length of inflorescence, and inflorescence color were measured. `Charming Summer', `Pink Delight', `Royal Red', `Sungold', `Lochinch', `White Profusion', and `Nanho Blue' performed best.
RESPONSE OF SWEETPOTATO CULTIVARS TO METOLACHLOR
Authors: Porter Wayne C.
Published: February 2019

Metolachlor herbicide is being evaluated for preemergent weed control in sweetpotatoes due to its ability to control yellow nutsedge (Cyprus esculentus) and rice flatsedge (C. iria). Registration of metolachlor has been delayed because of reports in North Carolina of injury to sweetpotato roots. This study was initiated to determine the response of sweetpotato cultivars to metolachlor rates. Metolachlor at 1.12, 2.24, and 3.36 kg·ha–1 was applied to `Beauregard', `Hernandez', `Jewel', and `Darby' sweetpotatoes after transplanting. All rates of metolachlor provided good control of sedges. No significant cultivar × metolachlor interactions were found in the yield of no. 1, canners, marketable, or percent no. 1 sweetpotatoes. In plots treated with metolachlor at 2.24 kg·ha–1, only `Beauregard' sweetpotatoes produced jumbo grade roots. No evidence of misshapen roots due to any herbicide rate was noted.
DEVELOPMENT OF TRANSGENIC SWEETPOTATO AND ANALYSIS OF TRANSGENE EXPRESSION
Authors: Prakash C.S. , Zheng O. , Porobodessai A.
Published: February 2019

Stable, transgenic, sweetpotato plants have been developed using an improved somatic embryogenesis consisting of l) stage I—explants incubated in darkness for 14 days on MS medium with 2,4D (2.5 mg·liter–1) and 6-BAP (0.25 mg·liter–1) and 2) stage II—culture in light for 14 to 28 days on MS medium with ABA (2.5 mg·liter–1). Petiole or leaf explants of the genotype PI318846-3 were co-cultivated with Agrobacterium tumefaciens EHA 101 containing gusA::nptII fusion gene. Transgenic somatic embryos were selected on a kanamycin medium (100 mg·liter–1). The PCR analysis of the transgenic sweetpotato plants showed the presence of foreign genes in the sweetpotato genome. About 100 transgenic plants are being maintained under laboratory and greenhouse conditions. All the transgenic plants showed a strong expression of gusA gene in the histochemical GUS assay but showed quantitative differences in the chemiluminescent assay. The CaMV35S promoter shows a differential expression because there was some degree of tissue- and organ-specificity in the gusA expression. All transgenic plants appear normal with no phenotypic aberrations and are being tested for productivity traits.
EFFECT OF TOPSOIL THICKNESS ON SWEETPOTATO PRODUCTION
Authors: Sloan R.C. , Pettry D.E. , Thompson P.G. , Burdine W.B. , Main J.L.
Published: February 2019

`Beauregard' and `Centennial' were planted in plots of four different topsoil thicknesses (0, 3, 6, and 9 inches) to evaluate the effect of topsoil thickness on sweetpotato production. In 1994, the 0-inch topsoil treatment produced a greater total marketable yield for `Beauregard' than did the 6- and 9-inch topsoil for `Centennial'. The 0- and 9-inch topsoil produced a greater total marketable yield than did the 3- and 6-inch treatment. When averaged over 2 years, 1993 and 1994, there were no differences in total marketable yield in either `Beauregard' or `Centennial' due to topsoil thickness. Averaged over both years, topsoil thickness had no effect on weight, diameter, or length of `Beauregard' roots.
GENETICS OF RAPD MARKERS IN SWEETPOTATO
Authors: Hong Liang L. , Ukoskit Kittipat , Thompson Paul G.
Published: February 2019

Parents and progeny of four biparental crosses were analyzed for RAPD marker segregation. A range of 57 to 122 primers were tested in each cross, with an average of 82. Average polymorphic primers and band numbers were 22 and 53, respectively. Of the 212 polymorphic bands, phenotypic segregation ratios were as follows: 133 fitted 1 dominant: 1 recessive, 58 fitted 3:1, 11 fitted ratios 4:1 to 19:1 and 10 were distorted. The 1:1 and 3:1 ratios were expected for either diploid or hexaploid segregation, and the 4:1 to 19:1 are exclusive to hexploid. A total of 14 pairs of markers were linked at map distances ranging from 2.1 to 36.5 cM. One common pair of linked markers was found in two separate crosses.
HIDDEN RESISTANCE TO CUCUMBER MOSAIC VIRUS IN HETEROGENEOUS POPULATIONS OF COWPEA (VIGNA UNGUICULATA) LINES AND CULTIVARS
Authors: Hampton R.O.
Published: February 2019

Cowpea cultivars Early Ramshorn and Dixie Queen, reported to be resistant to cucumber mosaic virus (CMV) by Sinclair and Walker in 1955, were reexamined for the existence of individual CMV-resistant genotypes within seedling populations. CMV-inoculated populations of these two cultivars became CMV-infected at rates of 60% and 80%, respectively, as determined by DAS-ELISA. CMV-free plants were grown to maturity, seeds from these sources were planted, and second-generation seedlings were inoculated again with CMV. Rates at which these seedlings became CMV-infected were 10% and 24%, respectively. The complementary 90% and 76% of these populations remained completely free of ELISA-detectable CMV and were saved to maturity. Evaluations of third-generation populations are being performed. Twenty additional cultivars and breeding lines also are being evaluated. Seedlings of 14 of the 22 cultivars/lines became 95% to 100% infected when inoculated with CMV. Results from eight of the 22 suggested that seedling populations contain CMV-susceptible and -resistant plants. Near isogeneic sublines of susceptible and resistant plants per cultivar/line are being conveyed to cowpea breeders for genetic analyses and breeding purposes.
INFLUENCE OF NITROGEN APPLICATION ON YIELD AND QUALITY OF `BEAUREGARD' IN NORTH CAROLINA
Authors: Jester Wilfred R. “Bill” , Schultheis Jonathan R. , Averre Charles W.
Published: February 2019

Sweetpotato varieties differ in their ability to efficiently use N. This study was conducted to determine if time of N application affected root yield and quality in the variety Beauregard. Nitrogen sidedress single-application treatments were applied at 10, 21, 28, and 35 days after transplanting. Two split application treatments were evaluated: l) 44.8 kg N/ha were applied 10 days after transplanting and 22.4 kg N/ha applied 21 days after transplanting and 2) 33.6 kg N/ha were applied 21 and 35 days after transplanting. The N source was calcium nitrate (15.5–0–0) and totaled 67.3 kg N/ha for all treatments. Plots were four rows and 6 m long, and treatments were randomized in five blocks. Harvested roots were sorted according to U.S. Dept. of Agriculture grading standards and weighed. Highest yields of U.S. no. 1 grade roots were obtained by applying N 21 to 35 days after transplanting. Total marketable yield was highest when application was made at 28 or 35 days after transplanting. Root length, at the 10% level of significance, was shorter when one vs. two N applications were applied. Using one N application compared with two N applications seems to be beneficial as shown by increased total marketable yields and yield of U.S. no. 1 roots and reduced root length.
Postharvest Attributes of `Virosa' Tomato Fruit Produced in an Enriched Carbon Dioxide Environment
Authors: Behboudian M. Hossein , Tod Colin
Published: February 2019

The effect of preharvest CO2 enrichment (1000 μl·liter–1) on postharvest quality of tomato fruit (Lycopersicon esculentum Mill. `Virosa') was studied with an emphasis on soluble sugars, ripening, and mineral composition. High-CO2 fruit had higher concentrations of sucrose, glucose, fructose, and total soluble solids than ambient-CO2 fruit. High-CO2 fruit also ripened more slowly and was characterized by lower respiration and ethylene production rates than ambient-CO2 fruit. Concentrations of N, P, and K were lower in the high-CO2 fruit than in the ambient-CO2 fruit, whereas those of S, Ca, and Mg were the same for both treatments. Preharvest CO2 enrichment of `Virosa' tomato enhances fruit desirability in terms of slower postharvest ripening and higher concentrations of soluble sugars and total soluble solids.
Field Performance Comparison of Two Transgenic Summer Squash Hybrids to Their Parental Hybrid Line
Authors: Arce-Ochoa Juan Pablo , Dainello Frank , Pike Leonard M. , Drews David
Published: February 2019

`Pavo', a commercially grown, virus-susceptible squash (Cucurbita pepo L.) hybrid, and two experimental virus-resistant transgenic squash hybrids, XPH-1719 and XPH-1739, were tested for field performance. The two transgenic squash hybrids possess the desired fruit and plant characteristics of their parental line, `Pavo', plus resistance to zucchini yellow mosaic virus and watermelon mosaic virus 2 (XPH-1719), and resistance to zucchini yellow mosaic virus, watermelon mosaic virus 2, and cucumber mosaic virus (XPH-1739). Percent emergence and days to flowering were similar among the three hybrids. XPH-1719 and XPH-1739 were equally effective in producing a high percentage of quality marketable fruit and yields with 90% and 13,800 kg·ha–1 and 87% and 16,500 kg·ha–1, respectively. XPH-1719 and XPH-1739 demonstrated their outstanding virus resistance over `Pavo' by producing only 3% and 14% symptomatic plants, respectively, compared to 53% for `Pavo'. They also produced the lowest percentage of infected fruit, 0% and 7%, respectively, with `Pavo' at 26%.