bluuebunny/crossref_metadata_2025 huggingface dataset:
POSTPRODUCTION CHARACTERISTICS OF `FREEDOM' POINSETTIA AS AFFECTED BY PRODUCTION AND POSTPRODUCTION CONDITIONS
Authors: Nell Terril A. , Leonard Ria T. , Barrett James E.
Published: February 2019

Postproduction characteristics of the new poinsettia cultivar `Freedom', as influenced by production and postproduction treatments, were evaluated. In one study, plants were grown under three production irradiance levels consisting of 450, 675 or 900 μmol s-1m-2 at 18/24C or 22/28C night/day temperatures and moved at anthesis to postproduction conditions (10 μmol s-1m-2 for 12 hr/day, 21±2C). Anthesis was delayed, plant height and diameter decreased, and a reduction in the number and development of cyathia occurred when maintained at low production temperature and irradiance. Leaf drop, which was minimal after 30 days postproduction (< 25%), was unaffected by production treatments, while cyathia drop was accelerated by low production irradiance and temperature, but not reduced after 30 days.

Leaf retention and quality in postproduction conditions are excellent. Cyathia drop averages 40 to 50% after 2 weeks in postproduction conditions. Bracts and leaves maintain their color well, with only slight fading after 30 days. Plants exhibit slight epinasty after shipping, but recover within a couple of days. These characteristics of `Freedom' make it a promising variety for the future.
IMPROVED DOWNY MILDEW CONTROL IN WINE GRAPES WITH VOSSEN BLUE
Authors: Fiola Joseph A. , Pavlis Gary C.
Published: February 2019

Downy Mildew, Plasmopara viticola, causes major damage and economic loss to many wine grape cultivars grown in the Northeast. The purpose of the experiment was to test the efficacy of Vossen Blue (VB; iron pigment) in association with fungicides for the control of Downy Mildew disease of wine grapes in New Jersey. The experimental plot was a planting of `Seyval Blanc' (5th leaf). Treatments (applied via back-pack sprayer) included no fungicide (control I), full fungicide (FF) (RCE commercial recs; control II), FF + 4%VB, FF + 8%VB, 8%VB, Half Rate Fungicide (HF) + 4%VB, HF + 8%VB. There were no significant differences between treatments for total yield, average cluster weight, average berry weight, Brix %, and pH. Spectrophotometric (Hunter's Lab) analysis of foliage samples revealed that leaf samples from the VB treatments had greater green color (correlate: increased chlorophyll). Analysis of subjective (1-9) disease incidence data: FF8 significantly lower disease score that FF; FF4, HF4, HF8, and FF no difference. Compared to normal full fungicide: superior Downy Mildew control was achieved by adding VB to full fungicide; equal control was achieved with half fungicide and VB.
EFFECTS OF K-IBA AND RADICLE-CLIPPING TREATMENTS ON ROOT DEVELOPMENT OF NORTHERN RED OAK
Authors: Krueger Daniel G. , Swanson Bert T.
Published: February 2019

To increase root fibrosity, acorns of northern red oak (Quercus rubra L.) were germinated and subjected to several radicle clipping (+/-) and K-IBA concentration treatments combintations prior to planting. Taproots and laterals ≥ 1 mm in diameter at the point of origin were counted. Low concentrations of K-IBA (0-4000 ppm) resulted in four root morphologies: 1) a single taproot and 3-6 laterals (no clipping/no K-IBA), 2) 4-5 taproots and 1-3 laterals (clipped only), 3) a single taproot and 5-12 laterals (not clipped/K-IBA) and 4) 6-12 taproots and 1-2 laterals. High concentrations of K-IBA (4000-10,000 ppm) `clipped' unclipped radicles resulting in root systems similiar to those clipped by hand. Stem height was unaffected by treatment. Radicle-clipping may increase stem caliper. K-IBA treatments may decrease root dry weight.
AN EVALUATION OF THREE PUTATIVE PREDICTORS OF PHASEOLUS VULGARIS FIELD PERFORMANCE UNDER HIGH TEMPERATURE
Authors: Sauter Karl J. , Davis David W. , Beaver James S.
Published: February 2019

184 random F2 plants from a high temperature (HT) sensitive X HT tolerant snap bean cross were advanced to the F5 by single seed descent. At anthesis and after HT pre-treatment, all plants in each generation were evaluated in the laboratory for leaf ethylene evolution (EE), % viable pollen (VP), and leaf cell membrane thermostability (CMT). Population means among generations differed significantly for VP and CMT in a paired t-test, while EE means in the F3, F4, and F5 were similar. Correlations among traits were very low (≤.25) with a consistent negative correlation between VP and the others (high VP is a positive trait while low EE and CMT are considered positive). VP and total pollen were highly correlated (r≤.81). To determine if the 3 traits might predict HT tolerance in the field, F5-derived F6 lines were grown at Becker, MN (control), and Isabella, PR (HT environment). Yield component data were collected at both locations. Tolerance may be computed as % yield of the lines in the HT vs. the control environment for any or all of the yield components. Regression analysis showed a very low r2 (≤.16) when EE, VT, and CMT were used to predict tolerance as estimated by pod production. However, as expected, the F5 best predicted F6 performance. Further results from Minnesota field and greenhouse and from Puerto Rico field data will be discussed.
RESISTANCE TO LEAF SCALD IN PLUM
Authors: Norton J.D. , Boyhan G.E. , Abrahams B.R.
Published: February 2019

Forty eight cultivars and seedlings of plum involving the species Prunus americana, P. auqustifolia, P. cerasifiera, P. munsoniana, P. salicina, P. simoni, and P. triflora were evaluated for the presence of xylem limiting bacteria (Xyllela fastidiosa) and tree longevity. Plum leaf scald (PLS) ratings, based on the percent of scalded leaves in the tree were correlated with the concentrations of bacteria in the twigs and leaf petioles. Observations of symptoms of PLS and monitoring of progeny from interspecific crosses, cultivars, and seedlings indicate that resistance to the PLS organism is present in the Auburn material and heritable. Uniform infection of seedlings was made by double budding of one year whips with buds from infected trees. Resistance to PLS has been incorporated into horticultural types and seedlings are currently being evaluated for possible release for commercial and home use.
INHERITANCE OF CHILLING RESISTANCE IN CUCUMBER
Authors: Wehner Todd C.
Published: February 2019

Cucumber (Cucumis sativus L.) is one of the more chilling sensitive crops. Chilling resistance could provide growers with protection against late spring frost. Significant differences for chilling resistance were observed among a set of 9 diverse cucumber cultigens when grown at 22 C to 1st true leaf stage, then given a chilling treatment of 4 C for 7 hours in full light (PPFD 500 μmol.m-2.s-1). Two populations, NCWBP and NCES1, were used to measure narrow-sense heritability (estimated as twice the parent-offspring regression coefficient) for chilling resistance. Sets (256/population) of parents and offspring were evaluated in separate tests for seedling resistance. Plants were rated for damage 0 (none) to 9 (dead) on the cotyledons and 1st true leaf, 3 and 5 days after chilling. Ratings were corrected for position in the Phytotron chamber, and log transformations used to normalize the data. Generally, correction reduced the heritability estimates and transformation improved them. Heritability was highest for cotyledon ratings made 5 days after chilling, ranging from 0.35 for NCWBP to 0.70 for NCES1. Ratings of the 1st true leaf were more difficult to make, and produced lower estimates of heritability. Breeders should be able to make good progress in selecting for chilling resistance using this seedling test.
SEASONAL CHANGES OF ASPARAGINE AND ARGININE CONTENTS IN SPUR BUDS, LEAF BUDS, AND FLOWER BUDS INDUCED BY SUMMER PRUNING IN `FUJI' AND `JONAGOLD' APPLE TREE
Authors: Oh Sung-Do , Bunemann G.
Published: February 2019

Asparagine and arginine contents in spur buds, leaf buds and terminal buds of shoot were compared in Fuji and Jonagold apple trees during dormant and growing season. Amino acid contents in dormant spur buds were significantly higher in Jonagold than in Fuji, whereas the amino acid contents in shoot bark were not different in two cultivars. Asparagine and arginine contents were considerably higher in leaf and terminal buds of shoot. This phenomenon was quite obvious in Fuji than Jonagold but there was no significant difference in asparagine and arginine contents in spur buds. Flower buds differentiated on summer pruned shoots had higher contents of asparagine and arginine as compared with weak spur buds in Fuji but this was not quite obvious in Jonagold. It suggested that the irregular spur size and poor development of spur buds in Fuji cultivar might be caused by the poor translocation of amino acids as well as nitrogen compounds from shoots and other vegetative organs.
POSTHARVEST QUALITY OF ALSTROEMERIA CUT FLOWERS AFFECTED BY PREHARVEST SOIL AND AIR TEMPERATURE
Authors: van Gorsel Rik , Verlind A. , van de Wiel A. , van Leeuwen G.
Published: February 2019

Low root zone temperatures in summer stimulate generative development of Alstroemeria, resulting in a higher flower production in winter. The effects of greenhouse soil and air temperatures on vase life and ornamental value were evaluated. Preharvest treatments were two locations (field stations), four air temperatures (9, 12, 15, 18C), four root zone temperatures (11, 14, 17C, uncontrolled) and three varieties ('Flamengo', 'Jubilee', 'Wilhelmina') in a factorial design. The flowers were placed in a commercial pretreatment solution for 24 hours immediately after harvest. After a two day transport simulation and rehydration for 3 hours at 5C, flowers were kept at 1.5 W.m-2 PAR (12hr/day), 20C and 60% RH. The experiment was done three times. Results from the first harvest showed that lowering the soil temperature increased the number of stems that had two whirls of flowers opening after harvest. Average vase life was two weeks. Low air temperatures increased whirl opening as well, and increased vase life by one or two days. Ornamental value and number of flower branches per stem were not affected.
CPPU IN THE MEDIUM FOR SEED GERMINATION PROMOTES EMBRYOGENESIS FROM SEEDLING EXPLANTS IN COMMON BEAN.
Authors: Mohamed Mohamed F. , Read Paul E. , Coyne Dermot P.
Published: February 2019

Few studies on embryogenesis in common bean (Phaseolus vulgaris L.) have been reported and only the early stages of somatic embryogenesis were observed. Dry seeds from two common bean lines were germinated in darkness on L-6 medium containing 4% sucrose, 0.2 g casein hydrolysate /liter and 2.0 g phytagel /liter. The medium for seed germination was supplemented with 0, 2, 4 or 6μM forchlorfenuron (CPPU). Explants from cotyledonary leaves, petioles, hypocotyls and shoot apices were prepared from 14 day-old seedlings. Callus was derived from explant cultures incubated in darkness at 26C on the medium containing 4 μM 2,4-D and 1 μM Kinetin. The callus was transferred after 4 weeks into 125 ml Erlenmeyer flasks containing 50 ml liquid medium and placed on a gyrotary shaker (120 rpm) under cool-white light (12 μmol.m-2.s-1). The liquid medium was used with 2, 4 or 6 μM of 2,4-D alone or with zeatin supplements at relative concentrations of 0.25 and 0.5. Up to 200 somatic embryos from 40 to 50 mg callus inoculations were induced after 4 to 5 weeks. Callus derived from seedlings grown on CPPU-containing medium gave more repetitive somatic embryos. Cotyledonary stage embryos with clear bipolar structure were observed only from callus derived from seedlings grown on CPPU when transferred to suspension cultures containing 2,4-D and zeatin. All somatic embryos differentiated strong roots and some developed leaf-like structures on conversion medium.
PRODUCTIVITY IN APPLE PRODUCTION SYSTEMS: THE ROLE OF LIGHT INTERCEPTION BY DIFFERENT SHOOT TYPES
Authors: Wünsche Jens-Norbert , Lakso Alan N. , Denning Steven S. , Robinson Terence L.
Published: February 2019

A 14-year-old trial of `Empire' apple production systems (Slender Spindle/M9, Central Leaders on M7 and 9/111 interstems, and Y-trellis/M26) had shown significant yield differences that were primarily related to total light interception, but yield of fruit/MJ light interception, however, was still higher in the Y-trellis. The hypothesis tested was that in healthy orchards yields are related primarily tototal light intercepted by the spur canopy. In 1991 seasonal leaf area development, exposed leaf photosynthesis, fruit growth, total light interception (by image analysis of fisheye photos) and relative light interception by different shoot types (by a laser sunbeam simulator) were estimated. The results reflected the mature, spurry nature of these trees. The final LAI values were CL/7=1.8, CL/9/111=2.3, SS/9=2.6 and Y/26=3.6. Exposed leaf photosynthesis showed few differences. Yields of the pyramid forms were 40-42 t/ha while Y-trellis gave 59 t/ha, with similar fruit sizes. Again, yields were primarily related to % total light interception (48-53% for pyramid forms versus 62% for the Y). Laser analyses showed that the Y intercepted more light with the spur canopy than the pyramid forms, supporting the hypothesis. Yields were better correlated with spur canopy LAI and spur canopy light interception than with shoot canopy LAI and light interception.
THE EFFECTS OF CROP ROTATIONS AND NITROGEN RATES ON PROCESSING TOMATO YIELDS
Authors: Johnston Russell , Shattuck Vernon , Seliga John
Published: February 2019

The influence of various crop rotations on the marketable yield of processing tomatoes (Lvcopersicon esculentum) in southwestern Ontario was investigated. The study was conducted for three years using nine and eight crop rotations at Leamington and Dresden, respectively. Four rates of nitrogen, 0, 45, 90, and 135 kg/ha were applied to each rotation. The treatments were arranged in a split-plot experimental design. Tomato yields were generally higher at both locations for all rotations compared to continuously grown tomatoes (control). The highest yields were obtained when tomatoes were grown in an alfalfa (Medicago sativa) rotation and rotations involving rye (Secale cereale) or winter wheat (Triticum aestivum). Tomato yields from the soybean (Glycine max) rotation and from continuously grown tomatoes were similar. At both locations, yields from continuously grown tomatoes increased with increasing rates of nitrogen fertilizer. Optimal yields for each rotation varied with each individual rate of nitrogen. Tomatoes grown in the alfalfa rotation showed the least response to higher rates of applied nitrogen. Our data indicates that certain crop rotations and nitrogen fertilization rates can be used together to enhance the yield of processing tomatoes.
RESPIRATORY CLIMACTERIC IN ATTACHED AND HARVESTED MELON FRUIT
Authors: Shellie Krista C. , Saltveit Mikal E.
Published: February 2019

The CO2 and C2H4 conc in the internal cavity of three melon (Cucumis melo L., var. reticulatus and inodorus Naud.) cultivars was periodically measured in fruit attached to the vine and in fruit harvested 30 days after pollination (DAP). Gas samples were withdrawn through sterile serum stopper sampling ports aseptically installed near the equator of each fruit at ca. 20 DAP. Sampling continued until either 60 DAP or until fruit abscised. Internal CO2 and C2H4 conc increased in harvested fruit as they ripened (i.e., increased percent soluble solids, decreased flesh firmness, characteristic external color change). Fruit allowed to ripen on the vine also exhibited a rise in C2H4, but lacked a ripening associated climacteric rise in respiration, CO2 conc in attached fruit remained constant or declined as the C2H4, conc increased around 40-fold and the fruit ripened. The increase in CO2 conc, so commonly observed in ripening climacteric fruit, was observed in harvested melons, but not in fruit ripening on the vine. In melons, the respiratory climacteric may be an artifact of harvest. Implications of these observations will be discussed.
CARBOHYDRATE PARTITIONING TO ROOTS OF `FRENCH PRUNE' TREES AS RELATED TO CROP LOAD AND POTASSIUM NUTRITION.
Authors: Ponchner Salo , Carlson R.M.
Published: February 2019

Effects of crop load and potassium on seasonal trends in root starch concentrations were studied in a commercial orchard. Treatments were a factorial combination of fruit thinning and potassium fertilization. Root samples were divided into <10mm and >10 mm diameter categories. Large crop load was associated with lower starch concentrations in the >10 mm roots after stage III of fruit growth. Highest root starch concentrations occurred in low crop trees that had been fertilized with potassium. Roots <10mm diameter also accumulated starch throughout the season but the concentrations were much lower than found in the >10 mm roots and there was little difference among treatments at any sampling date. On the basis of these results, roots >10mm appear to be more important than smaller roots as storage organs and therefore are more affected by stresses and competition with other organs. Continuation of the project will seek relationships between early season root starch concentrations and tree performance including alternate bearing.
REGULATION OF APPLE FRUIT GROWTH RATE BY TURGOR PRESSURE?
Authors: Archbold Douglas D.
Published: February 2019

Maintenance of positive cell turgor is an essential factor in cell, and fruit, expansion. Since apple fruit partition carbohydrates between the starch and soluble pools to maintain turgor, variation among cultivars in this osmoregulatory aspect may play an important role in defining cultivar-specific fruit growth rates. Cultivar-specific apple fruit growth rates were determined over a 6 week period following June drop during 2 seasons. Fruit water relations parameters and carbohydrate levels were also measured. Although cultivar differences were evident, generally, fruit absolute growth rate increased, relative growth rate (RGR) declined, water potential and osmotic potential declined, and turgor potential increased as the season progressed. Soluble carbohydrate levels increased over 6 weeks, while starch levels fluctuated. Soluble carbohydrates contributed 50 to 90% of the osmotic potential. RGR was not correlated to either turgor potential or the relative allocation of carbohydrates between the soluble and starch pools. Thus, although positive turgor was maintained, factors other than turgor per se determine fruit growth rate.
STRESS TOLERANCE INDEX- A NEW INDICATOR OF TOLERANCE
Authors: Fernandez George C.J.
Published: February 2019

Selection criteria for identifying genotypes with high stress tolerance and high yielding potentials were compared using a moderately stressed, (Stress intensity, [1-(mean stress yield (Yp̄)/mean potential yield (Ys̄)] 0.73) and a severely stressed (Stress intensity, 0.24) mungbean yield data sets. Selection based on tolerance (T), difference between potential yield (Yp) and the yield in stress environment (Ys) favored genotypes with tolerance and low yield potentials. Selection based on the mean productivity (MP), [MP=(Yp+Ys)/2] favored the genotypes with high yielding potential. The Stress Susceptibility Index (S), (S = [(Yp-Ys)/Yp]/[(Yp̄-Ys̄)/Yp̄], also favored the low yielding and stress tolerant genotypes. These selection criteria failed to identify genotypes with high yielding and stress tolerance potentials. Thus, a selection criterion, Stress Tolerance Index (STI) is proposed here which identifies genotypes with high yield and stress tolerance potentials. The STI takes into account both stress tolerance and yield potentials. The STI is estimated as: [Yp/Yp̄][1-(T/Yp̄)]. The higher the value of STI for a genotype in a given stressed environment, the higher was its stress tolerance and yield potential. The interrelationships between these stress tolerance criteria are discussed by a biplot display.
INFLUENCE OF APOPLASTIC SOLUTES ON THE TURGOR OF TOMATO PERICARP CELLS
Authors: Shackel Kenneth A. , Ahmadi H. , Greve C. , Labavitch J.
Published: February 2019

The pressure microprobe was used to measure cell turgor (ψp) in tomato pericarp tissue, and also to sample vacuolar fluid for the measurement of cell osmotic potential (ψs) in a nanoleter freezing point osmometer. In fresh tissue, cell ψs agreed well with the ψs of frozen-thawed whole tissue measured with a vapor pressure osmometer. Under a wide range of ripeness conditions however, and for both intact fruit and discs of fruit tissue, fruit cell turgor was consistently lower than expected, based on the values of cell ψs. When tissue discs were hydrated in aerated distilled water, disc fresh weight increased substantially (20 - 50+%), and both cell turgor and tissue ψs increased. Cell ψs however, remained relatively constant. These and other observations suggest that the turgor increase during hydration was largely due to losses of solute from the apoplastic space, partly by direct losses from the tissue, and partly by cell solute accumulation.
APPRESSORIUM FORMATION IN THE PECAN SCAB FUNGUS
Authors: Cason K.M.T. , Yates I.E.
Published: February 2019

Pecan scab, caused by the fungus Cladosporium caryigenum (Ell. et Lant) Gottwald, produces more damage to pecan than all other diseases and insects combined. Early events during infection are critical to disease establishment and to expression of host resistance, but have not been examined previously. Objectives of this research were to determine if there is regulation of appressorial formation and if it is related to resistance. Pre-infectional host-pathogen interactions were studied in vivo (on leaves) and in vitro (on callus, dialysis membrane, and agar) with light and electron microscopy. Leaves, callus tissue, dialysis membranes, and agar were inoculated with scab conidia and were incubated under conditions optimum for germination. Conidia germinate and produce a germ tube on agar and dialysis membrane, but appressoria are not formed. Appressoria form on pecan callus, but germ tubes are long. Long germ tubes are often associated with resistant disease reactions. In vivo, appressoria form readily, but germ tube length varies depending on the location of the spore on the leaf surface. Preliminary evidence indicates that surface topography affects induction of appressorium formation in the scab fungus.
INFLUENCE OF INTEGRATED PEST MANAGEMENT ON PESTICIDE RESIDUES IN TOMATO PACKINGHOUSE WASTEWATER
Authors: Rushing James W. , Cook Wilton P. , Schumann Stanley
Published: February 2019

Water analyses from all commercial tomato packinghouse dump tanks in South Carolina in 1989 revealed that heavy metals and pesticides accumulate in the dump tank water throughout the course of daily operation. The amount that accumulated varied widely as follows: esfenvalerate, 0.6 to 13.8 ppb; chlorothalonil, 0.1 to 2.85 ppm; copper, 2.0 to 7.3 ppm; manganese, 0.3 to 2.4 ppm. Contamination was lowest when growers were implementing integrated pest management (IPM) practices during production.

In 1990, tomatoes were grown under the following pest management practices: IPM protocol; modified IPM with more frequent spray; or weekly pesticide application regardless of pest pressure. In a small scale dump tank study the water used for tomatoes on the weekly spray schedule had from 2 to 10 times the amount of pesticide and metal residues found in water used for tomatoes grown under IPM. These results confirm that IPM programs can be effective in reducing residues in tomato packinghouse wastewater.
THE WHITEFLY UPSURGE: IMPACT ON CALIFORNIA VEGETABLE PRODUCTION
Authors: Mayberry Keith S. , Perring Thomas M.
Published: February 2019

In the fall of 1990, a new form of whitefly, tentatively identified as the poinsettia strain of Bemisia tabaci (Gennadius), was introduced into the agricultural regions of the desert southwest. Large densities of whitefly nymphs developed on cruciferous crops and substantial increases in pesticides for whitefly control were used. After overwintering in active stages on these crops, whiteflies moved into spring cantaloupes and developed moderate populations levels in some fields. In March, whiteflies migrated to newly-planted cotton and developed huge densities by August. At this time emerging fall cantaloupe was attacked and over 95% of this crop was destroyed by whitefly feeding. Whiteflies also developed to damaging numbers on alfalfa, grapes, citrus, crops not known to host the cotton strain of B. tabaci. Population densities remained high through the fall crucifer and lettuce seasons causing crop losses and delayed maturity. Damage estimates presently rest at roughly $122 million.
SORBITOL METABOLISM IN BACTERIA PATHOGENIC TO THE ROSACEAE FAMILY
Authors: Fujii Dwight S. , Dandekar Abhaya M.
Published: February 2019

Many tree crops belonging to the Rosaceae family translocate and metabolize sorbitol. We have determined that some species of bacteria belonging to the genus Agrobacterium, Pseudomonas, and Erwinia pathogenic to the Rosaceae demonstrate the ability to metabolize sorbitol while those that were isolated from other hosts could not utilize sorbitol. Employing cellulose acetate electrophoresis (CAE) we have been able to demonstrate the presence of isoenzymes of sorbitol dehydrogenase (SDH) that correlate with the ability to metabolize sorbitol in these organisms. In order to study the properties of SDH in these organisms we carried out a detailed enzymatic analysis of the enzyme from A. tumefaciens. We found that the enzyme displayed activity when mannitol or xylitol were used as substrates, in addition to sorbitol. Michaelis constants (Km) were 32.8 mM, 0.19 mM, and 38.2 mM for sorbitol, mannitol, and xylitol respectively. To further distinguish the reactions with the different substrates the enzymatic extracts were further characterized on CAE using different substrates to visualize patterns of isoenzymes for a particular sugar alcohol. These analyses revealed the presence of unique isoenzymes for SDH. In addition we observed the presence of mannitol dehydrogenase (MDH) representing in most species a non-specific polyol dehydrogenase.
CYPERUS KYLLINGIA AND CYPERUS BREVIFOLIUS: A POTENTIAL MODEL FOR THE STUDY OF ALLELOPATHY
Authors: Scott C. , Nishimoto R.K. , Tang C.S.
Published: February 2019

Cyperus kyllingia and Cyperus brevifolius are problematic turfgrass weeds in Hawaii. Both are closely related weed species with similar morphology and growth characteristics. C. kyllingia appears to be a more successful weed with regards to interference than C. brevifolius. Greenhouse experiments were conducted to compare the levels of interference exerted by C. kyllingia and C. brevifolius upon Cynodon dactylon turfgrass. C. kyllingia reduced the growth of C. dactylon by about 50 %, while C. brevifolius did not significantly reduce C. dactylon growth. These results correspond with the chemical profiles of C. kyllingia and C. brevifolius. Analysis has shown that C. kyllingia contains two sesquiterpenes which have been identified as potentially allelopathic components of Cyperus rotundus. C. brevifolius contains waxes and the two sesquiterpenes found in C. kyllingia are absent. This suggests that allelopathy may be the mechanism responsible for the different levels of interference exhibited by C. kyllingia and C. brevifolius, and these species may provide an important model for the study of allelopathy.
COMPARISON OF APPLICATION METHODS OF PACLOBUTRAZOL FOR HEIGHT SUPPRESSION OF POTTED TULIPS
Authors: Deneke C. Frederick , Keever Gary J.
Published: February 2019

`Kees Nelis' tulips were potted five bulbs per 0.8-1 container using a commercial peat moss and perlite growing medium. Bulbs were exposed to 9C for 4 weeks, followed by 5C until the emerging shoots were 4 to 5 cm long. One day after plants were moved from the cooler to a greenhouse (14C minimum), the following treatments were applied: drench or spike (International Spike, Inc.) of 0.062, 0.25, or 1.00 mg paclobutrazol per pot; or drench of 0.25 mg ancymidol per pot. Flowering height was reduced linearly as concentration of paclobutrazol increased for both application methods; flowering height was 24.0 cm with the highest rate of paclobutrazol, 23.8 cm with ancymidol, and 27.7 cm with untreated plants. Treatments had no effect on flower diameter or time to flowering.
RESISTANCE TO ROOT-ZONE HEAT STRESS DIFFERS AMONG CULTIVARS OF RED MAPLE
Authors: Wilkins Lorna C. , Graves William R. , Townsend Alden M.
Published: February 2019

Use of cultivars resistant to high soil temperature could improve the performance of urban trees. The objective of this project was to examine selections of red maple (Acer rubrum L. and A. x freemanii E. Murray) for genotypic differences in resistance to root-zone heat stress. Development of roots and shoots from rooted single-node cuttings of seven genotypes grown in solution culture was optimal at about 28C. Shoot extension stopped within 3 weeks and terminal buds formed on plants of all genotypes at 36C. In a second experiment, the influence of 34C root-zone temperature on development varied significantly among six genotypes. Formation of terminal buds at 34C was observed only on plants of cv. Morgan and cv. Red Sunset. The reduction in new dry matter at 34C compared to plants at 28C ranged from 21% for cv. Schlesinger to 69% for cv. Morgan. We conclude that genotypes of red maple differ in resistance to high root-zone temperature.
DEEP SUPERCOOLING OF FLOWER BUDS WITHIN THE GENUS FORSYTHIA
Authors: Flinn Cindy L. , Ashworth Edward N.
Published: February 2019

Thermal analysis of Forsythia × intermedia `Spectabilis' flower buds had previously detected the occurrence of low temperature exotherms (LTE) during freezing. The LTE apparently resulted from the freezing of supercooled water and corresponded to the death of the florets. The genus Forsythia encompasses a wide array of species and interspecific crosses ranging in flower bud hardiness and floret size. The ability of buds to supercool, the relationship between the LTE and flower bud hardiness, and the extent to which floret size affects both were studied in flower buds of the following Forsythia species: F. × intermedia `Spectabilis', F. × intermedia `Lynwood', F. `Meadowlark', F. suspensa var. fortunei, F. `Arnold Dwarf, F. europaea, F. giraldiana, F. × intermedia `Arnold Giant', F. japonica var. saxatilis, F. mandshurica, F. ovata, and F. viridissima. Flower buds used for thermal analysis were also used in subsequent size determinations. Hardiness evaluations were conducted using controlled freezing tests, and the sampling interval defined using the temperature range of the LTEs. Initial evaluation indicated a high degree of correlation (α>.50) between mean LTEs and mean killing temperatures. The Forsythia genus, with its broad range of bud hardiness and size provides an excellent system in which to study the mechanisms of supercooling. Thermal analysis of cultivars which exhibit LTEs can accurately assess bud hardiness with minimal plant material.
WATER STRESS DETECTION WITH FOLIAGE TEMPERATURE FOR IRRIGATION SCHEDULING IN NURSERY PRODUCTION
Authors: Kjelgren Roger
Published: February 2019

Changes in foliage temperature with environmental conditions were investigated for use in detecting water stress and scheduling irrigations of woody nursery plants. Midday leaf-minus-air temperature (Tl-Ta) and vapor pressure deficit (VPD) were monitored seasonally for container-grown shrubs--prostrate juniper, upright juniper and dwarf red-stem dogwood--at open and closed spacings. There was an inverse relationship between Tl-Ta and VPD for all species and spacings but with substantial scatter. Slopes for openand closed-spaced shrubs were not significantly different for any species. As container moisture and predawn leaf water potential declined during a dry-down cycle Tl-Ta increased significantly over well-watered levels for open-spaced plants and closed-spaced dogwood. In a field experiment Tl-Ta and VPD were monitored in young London plane, flowering pear, and redbud with-and-without irrigation. Only irrigated London plane Tl-Ta was inversely related to VPD. Leaves coated with petroleum jelly, however, had Tl-Ta levels consistently greater than uncoated leaves in all species, and non-irrigated Tl-Ta rose to those levels during a mid-summer drought. These results suggest that irrigation of container shrubs can be timed to increases in Tl-Ta with VPD, while comparing coated and non-coated Tl-Ta may be more successful for irrigated field production.
EFFECT OF DORMANT PRUNING REGIMES ON CANOPY LIGHT DISTRIBUTION, FRUIT AND SPUR QUALITY, AND FRUIT PACKOUT OF `MCINTOSH' APPLES.
Authors: Clements Jon M. , Costante Joseph F.
Published: February 2019

A randomized complete block study was initiated in 1991 in a fifteen year old `Rogers Red McIntosh'/9-106 interstem orchard to investigate the effect of three dormant pruning regimes- an unpruned control, selectively thinned, and heavily structured or “tiered”, on tree canopy light distribution and fruit and spur quality. Fruit quality parameters being measured for the 1991 and 1992 harvests include skin color (% red blush), weight (g.), flesh firmness (kg.), soluble solids concentration (% Brix), and packout (% fancy grade). Pruning treatment effect on fruit spur quality, in terms of spur bud diameter (mm.) and spur efficiency (leaf dry weight/spur), is also being evaluated at time of harvest. Light distribution is being measured (% PAR, umol/s/m2.) within the tree canopy from petal fall through harvest. Preliminary findings indicate there is a difference in tree canopy light distribution and some fruit quality measurements, including red skin color, between pruning regimes. Complete analysis of results from 1991 will be presented.
SQUASH ROOT DISTRIBUTION AND GROWTH AS AFFECTED BY IRRIGATION LEVEL
Authors: Ells James E. , Kruse E. Gordon , McSay Ann E.
Published: February 2019

Roots of acorn squash were washed from soil cores, dried and weighed. The cores were taken in a pattern about individual plants to reflect the roots present in each selected zone at different periods during the season. A different plant was sampled at each period so that there would be no effect from previous sampling. The root weights were multiplied by factors commensurate with the volume of soil represented by each core sample. Two years data have indicated that irrigation level effects the size of the root system but not its distribution. Density of roots was always greatest in the top 15 cm of soil and this zone of the greatest density progressively moved out from the center of the plant with time. Pattern of root distribution was not effected by plastic mulch, bare ground, trickle or furrow irrigation treatments. Root distribution was the same on all sides of the plant.
`EARLY ACRE': A NEW SOUTHERNPEA FOR ARKANSAS
Authors: Morelock T.E. , Bowers J.L. , Davis D.R. , Motes D.R.
Published: February 2019

Southernpeas are an important crop to Arkansas processors, market gardeners and home gardeners. While the bulk of the acreage produced in the state is pinkeye purple hull types, there is a demand for other horticultural types. At present some processors consider `White Acre' to be the standard of cream pea quality, but under Arkansas conditions, `White Acre' produces excessive vine growth, is very late to mature and is susceptible to bacterial blight. For these reasons, the Arkansas Agricultural Experiment Station announces the release of `Early Acre'. `Early Acre' has been widely tested under the designation Arkansas 84-154 and produces a very compact bush plant that has seed similar in size and shape to `White Acre', but matures 8-10 days earlier under Arkansas conditions. Although the plant type is well suited to narrow row spacing, `Early Acre' has produced yields similar to `White Acre' when both are planted at conventional row spacings. Samples have been canned by the Dept. of Food Science at the University of Arkansas and the samples have been rated equal to `White Acre' in processed quality. “Early Acre' has exhibited high levels of resistance to bacterial blight in replicated yield trials under field epidemics in both Arkansas and Texas.
INHERITANCE OF PGM-1, ADH-1, AND 6-PGDH-1 in ALLIUM FISTULOSUM L.
Authors: Mangum Paul D. , Peffley Ellen B.
Published: February 2019

The inheritance and linkage relationships among PGM-1, ADH-1, and 6-PGDH-1 were determined for Allium fistulosum (Japanese bunching onion) individuals. Individuals expressing Pgm-11/Pgm-12, Adh-13/Adh-14, Adh-13/Adh-15, or 6-Pgdh-11/6-Pgdh-12 were selfed seperately. These backcrosses and their reciprocals were made: Pgm-11/Pgm-12 to Pgm-11/Pgm-11 or Pgm-12/Pgm-12; Adh-13/Adh-14 to Adh-13/Adh-13 or Adh-14/Adh-14, 6-Pgdh-11/6-Pgdh-12 to 6-Pgdh-11/6-Pgdh-11 or 6-Pgdh-12/6-Pgdh-12. Progeny segregations were tested for Mendelian inheritance using a chi-square goodness of fit test. Expression of 6-Pgdh has not been previously reported in onion. Two zones of activity were detected and were designated as 6-PGDH-1 and 6-PGDH-2. 6-PGDH-2 was monomorphic for all individuals tested. Progeny segregation of 6-PGDH-1 fit a model for a dimeric enzyme encoded by one disomic locus with two alleles, expressed as fast (1) and slow (2), in a dimeric enzyme pattern in heterozygous individuals.
SWEET CORN EAR RESISTANCE TO THE EUROPEAN CORN BORER (Ostrinia nubilalis, Hubner) AND ITS RESPONSE IN SINGLE CROSSES.
Authors: Joyce Mary S. , Davis Dave W.
Published: February 2019

Development of sweet corn hybrids having resistance to ear feeding by the European corn borer (ECB) (Ostrinia nubilalis, Hübner) would save growers millions of dollars annually. Sweet corn breeding lines have been developed which show resistance to ear feeding. To determine whether resistance in these lines was heritable, testcrosses were made between 6 resistant lines and 2 susceptible inbreds. The testcrosses, resistant lines, susceptible inbreds, and Jubilee, a standard susceptible hybrid, were planted in randomized complete blocks replicated 8 times at each of 2 locations. Primary ears were infested, on the ear tip, at mid-silk (R3) with approximately 50 neonate larvae and were evaluated for damage 25 - 30 days later using a 9 point scale. The resistant parents and their testcrosses had 15% to 64% more resistant ears (less than 1% kernel damage at the tip only) than Jubilee. The inbreds and their commercial hybrid did not differ in resistance from Jubilee. Resistance to ECB appears to be polygenic and it has been suggested that some level of non-additive gene action is important. While the specific traits responsible for ear resistance are not known, the resistance of the breeding lines was transmitted to the testcrosses.
DEVELOPING ENHANCED PEPPER GERMPLASM RESISTANT TO VERTICILLIUM WILT
Authors: González-Salán Max M. , Bosland Paul W.
Published: February 2019

A Verticillium wilt-resistant population of pepper (Capsicum) is being developed from the USDA P.I. 215699 accession. Three selfing cycles with disease screening and selection have been done. The disease screen was conducted at a soil temperature of 25 ± 1°C and at an inoculum level of 2000 microsclerotia per gram of soil. Sixty days after inoculation, individual plants were scored using an interaction phenotype scale (IP), ranging from 1 to 9, where 1= no aerial symptoms, and 9=death. Plant shoot height was also measured. Even after three selfing cycles, P.I. 215699 segregates for Verticillium wilt resistance. The percentage of resistant plants at S3, is 75%. Another cycle of selection (S4) was done and the progeny are being tested. The S4 progeny data, interaction phenotype, shoot height, and percentage of resistant plants, will be analyzed by using standard analysis of variance followed by appropriate means separation. An analysis of correlation for shoot height by interaction phenotype variables will also be conducted.
EVALUATION OF THREE TREATMENTS TO CONTROL THE COMMON CITRUS PEST, ARGENTINE ANT Iridomymex humilis (Mayr)
Authors: Tollerup Kristen E. , Shelton Mark
Published: February 2019

Three different treatments were evaluated for preventing the common citrus pest, Argentine ant Iridomymex humilis (Mayr), from foraging in skirt pruned citrus trees. The treatments were: 1) 1% (AI) chlorpyrifos 4 EC applied to the basal 15 cm portion of the trunk, 2) 32 g (AI) diazinon 14G broadcast in a 60 cm radius around the trunk, and 3) a trunk barrier of petroleum wax applied in a 10 cm wide strip around the trunk. The treatments were evaluated in two-week increments from August 1, 1991, to October 20, 1991, by counting the number of ants to cross an arbitrary line 10 cm above the soil surface on the trunk of each tree. Each of the three treatments resulted in a highly significant reduction in the number of ants entering trees compared to untreated control trees. There were no significant differences among the three treatments.
CELL WALL COMPOSITION AND SYNTHETIC CAPACITY OF THE PERICARP OF RIPENING `JACKPOT' TOMATO
Authors: Huysamer Marius , Greve L. Carl , Labavitch John M.
Published: February 2019

Discs from outer pericarp of mature green (MG) and light red (LR) tomatoes were incubated with 13C6-glucose as precursor to cell wall constituents, to determine biosynthetic capacity of the outer 2mm (including cuticle) and adjacent inner 2mm of tissue. Cell wall material was fractionated into pectic and hemicellulosic classes by sequential extraction, and alditol acetates and partially-methylated alditol acetates were prepared. Neutral sugars (NS), glycosidic linkage compositions and incorporation of label were determined by GC-FID and GC-MS. Rhamnose, arabinose and galactose accounted for ca. 90% of both labeled and total NS in the pectic fractions (sugar ratios within ripeness stage were the same for labeled and total NS). Xylose and glucose accounted for ca. 70% of both labeled and total NS in the hemicellulosic fraction (sugar ratios within ripeness stage were different between labeled and total NS). In the crude cell wall, galactose and glucose contents were significantly higher in the inner than in outer tissues for both MG and LR tomatoes. Loss of galactose during ripening was higher from outer tissues. These results show compositional differences between inner and outer tissues, and suggest that ripening-related wall synthesis may give rise to pectic polymers similar in NS composition to existing polysaccharides, and hemicellulosic polymers which may differ in composition.
ASPECTS OF ETHYLENE BIOSYNTHETIC PATHWAY IN TOMATO FRUITS DURING THE RIPENING PROCESS
Authors: Terai Hirofumi , Tsuchida Hironobu , Mizuno Masashi
Published: February 2019

Green fruits of normal ripening type of tomatoes (Lycopersicon esculentum Mill) were picked 13-39 days after anthesis and stored at 20°C. Although more days were required for the ripening of the fruits if the stage of picking was earlier, all fruits became red and soft during storage. This result shows that considerably immature fruits have the ability of ripening. Green tomato fruits at three stages (18. 29 and 38 days after anthesis) were treated with ethylene for one day. The activity of ethylene forming enzyme (EFE) and the conversion of applied 1-aminocyclopropane-1-carboxylic acid (ACC) to N-malonyl-ACC (MACC) in the three stages of tomato fruits were accelerated by exogenous ethylene, though endogenous ethylene production was hardly observed. When the green tomato fruits (31-34 days after anthesis) were treated with ethylene for one day and then transferred to air. the activity of EFE and the conversion of applied ACC to MACC were depressed. The activity of ACC synthase was not accelerated by ethylene treatment of only one day, but was accelerated by a longer term treatment, followed by increased ethylene production and the onset of ripening.
EFFECT OF ALLYLISOTHIOCYANATE ON ASCORBIC ACID CONTENT OF SHREDDED CABBAGE
Authors: Nagata Masayasu , Yamashita Ichiji
Published: February 2019

Allylisothiocyanate (ATTC) is known as a main pungent compound in cabbage, which indicates several biological activities. Our previous studies have suggested that AITC acts as a natural regulator which inhibits browning and ethylene evolution of shredded cabbage. It was found that AITC mainly inhibits de novo protein synthesis and in some case, it partially inhibits enzymatic reactions directly. This time we investigated the changes in ascorbic acid (AsA) content and AsA oxidase activity of shredded cabbage, treated with various amounts of AITC.

AsA content of shredded cabbage was initially 16.9 mg/100g fresh wt. After 24 h incubation at 10°C, it was reached to 26.3 mg/100g fresh wt. This increase was suppressed by AITC and also by cycloheximide, well known inhibitor of protein synthesis. It was suggested that the increase in AsA was a result of wounding reaction that took place in shredded cabbage. AsA oxidase activity increased during incubation, which was suppressed by AITC, too.

From these results, AITC was thought to be a natural regulator of wounding reactions in cabbage.
QUALITY EVALUATION OF CANTALOUPES FROM AHPID-INFESTED PLANTS
Authors: Perkins-Veazie P.M. , Collins J.K. , Maness N. , Cartwright B.
Published: February 2019

High populations of melon aphid (aphis gossypii) reduce cantaloupe plant growth and yield; effects on subsequent fruit quality are unknown. The purpose of this study was to evaluate fruit quality from plants with high and low aphid populations. Up to 50% of melons from plants having high aphid populations were unmarketable due to surface sooty mold. Melons from plants with high or low aphid populations, but not cultivars, were similar in flesh quality. The internal color of `Perlita' and `Sweet Surprise' was a more yellow hue while that of `TAM Uvalde' was more orange. `Sweet Surprise' melons were lower in percent soluble solids concentration and titratable acidity, but were higher in mg fructose/ml juice compared to the other cultivars. A trained taste panel of 30 people evaluated melons from 2 cultivars showing little damage from melon aphid infestations and from 2 cultivars exhibiting high damage. All melons had similar taste qualities with acceptable sweetness, flavor, odor and texture. These results show that high aphid populations deleteriously affect cosmetic appearance, but not flesh quality, of melons.
PURIFICATION AND CHARACTERIZATION OF POLYGALACTURONASE OF `FUJI' APPLES.
Authors: Shin Seung-Ryeul , Byun Jae-Kyun , Chang Kyung-Ho
Published: February 2019

Polygalacturonase (PG) was purified from apple, Malus domestica Borkh, cv. Fuji by gel filtration, CM cellulose ion exchange column chromatography and characterized by means of several biochemical methods. Two forms of isozymes, PG-I and PG-II, were detected and the activities of PG-I were found to be higher than PG-II. The Km and Vmax values were calculated to be 1.54 mg/ml and 0.25 μM with reducing sugar 1 ml/30min., respectively. The PG was active between pH 3 and 8 with the optimum pH of about 4-5. The stable temperature for the PG was below 55°C with 30°C optimum. The PG activities were increased by Na* and Cu**, but were inhibited by Ag*, EDTA and SDS.
NAD-DEPENDENT AND NADP-DEPENDENT ALCOHOL DEHYDROGENASE ENZYMES: ANALYSIS OF THEIR FUNCTIONAL SIGNIFICANCE IN STRAWBERRY FRUITS
Authors: Mitchell William C. , Jelenkovic Gojko
Published: February 2019

Assays of enzyme activity, in vivo inhibition studies and the developmental analysis of strawberry (Fragaria × ananassa Duch.) fruit alcohol dehydrogenases (ADH) suggest that both the NAD-(E.C. 1.1.1.1) and the NADP-dependent (E.C. 1.1.1.2) forms of ADH enzymes play integral roles in the development and ripening of fruits. One role of ADH enzymes appears to be the evocation of changes in sugar, soluble solids, acidity and volatile compounds necessary for the normal organoleptic character of strawberry fruits. The data presented includes: 1.) The wide substrate specificity of both ADH enzymes for the “fragrance and flavor alcohols and aldehydes” synthesized by ripe strawberry fruits, 2.) the effect of inhibitors of ADH activity upon strawberry fruit ripening, and 3.) the comparative regulation of NAD- and NADP-ADH enzymes including 4.) the developmental control of ADH enzymes in strawberry fruits.