bluuebunny/crossref_metadata_2025 huggingface dataset:
489 PB 137 LIME REACTION AND pH BUFFERING IN SOILLESS MEDIA
Authors: Elliott George C.
Published: February 2019

Addition of lime to increase pH is generally essential for soilless media based on acidic organic materials. Media pH may decrease over time as the result of addition of acidic fertilizers. The objectives of this research were: to characterize reactions of conventional or finely ground lime in soilless media; to compare resistance to acidification in soilless media amended with conventional or finely ground lime; and to evaluate, for media containing rockwool, an equation to predict H+ activity (HA) of binary mixtures from HA of components. Various soilless media were amended with each type of lime at rates from 1 to 16 kg m-3 and incubated 8 weeks at 20 C. Subsamples were removed and pH was measured in saturated slurries. Finely ground lime was about twice as effective as conventional lime in adjusting pH to 6.0 within 1 week after mixing and wetting. Neither initial nor final HA of unlimed peat-rockwool mixes could not be predicted from HA of components. Three media were amended with each type of lime, planted or left unplanted, and irrigated with fertilizer solution with and without 1.0 N H2SO4. Final pH of media amended with finely ground lime averaged 0.2 units lower than media amended with conventional lime. Final pH of unplanted media averaged 0.5 units lower than planted media. Final pH of media fertilized with solution containing H2SO4 averaged 0.6 units lower than without. Addition of H2SO4 to fertilizer stimulated growth of New Guinea Impatiens (Impatiens xhybrida).
494 PB 172 Use of Thin-Beam Load Cells as Pot Lysimeters in Greenhouse Studies
Authors: Yelanich Mark V. , Faust James E. , Heins Royal D. , Biernbaum John A
Published: February 2019

The measurement of evaporation and transpiration from container-grown crops is labor intensive and expensive if measurements are made by periodic weighing of the plants with electronic scales. Thin-beam load cells (LCL-816G, Omega Engineering) measured with a datalogger provides a method of making continuous mass measurements over time. Four load cells were tested to determine the feasibility for use in greenhouse studies. The sensors were calibrated to an electronic scale at a range of air temperatures. The electrical signal (μV) was a linear function of mass from 0 to 816 g. The change in mass per change in electrical signal (i.e. the slope) was the same for all four load cells (1.26 g ·μV-1), however the absolute electrical signal (the intercept) was unique for each sensor (-246 to + 101 g). The effect of temperature on sensor output was unique for each sensor in terms of both the magnitude and direction of change. A two-point calibration of mass performed at a range of temperatures is required to properly use thin-beam load cells to continuously measure evapotranspiration of container-grown crops.
498 PB 204 PROVIDING A CONSTANT, OPTIMUM, MOISTURE/AIR RATIO IN PLUG TRAYS DURING SEED GERMINATION AND SEEDLING GROWTH
Authors: Buxton Jack W. , Jia Wenwei , Hou Guoqiang
Published: February 2019

The automatic subirrigation system consists of a capillary mat placed above a constant water level in a reservoir. The optimum mat height above the water level was established by slanting a flat surface so the difference in vertical height from one end of the surface to the other was 25 cm. A ground cover providing water movement but not root penetration was placed over the mat. The capillary mat extended beyond the lowest end of the slopped surface and into the reservoir, the mat at the lowest end of the slopped surface was at the same vertical height as the water in the reservoir and remained constantly saturated. Plug trays were placed at intervals of 2.5 cm in vertical height above the water level. An average of 96-100% germination was obtained with marigold, tomato, impatiens and pepper seed in trays placed 5-7.5 cm in vertical height above the water level. These seedlings continued to develop and reached transplanting stage quicker than other trays. The rate and % germination was less in trays placed on the surface nearer to the height of the water in the reservoir. Germination in trays above 12.5 cm was greatly reduced and seed that did germinate did not develop and eventually died.
501 PB 213 THE EFFECT OF ALTERING THE N:S RATIO ON THE FLOWERING OF CUT CHRYSANTHEMUMS
Authors: Huang Li-Chun , Paparozzi Ellen T.
Published: February 2019

previous studies indicate that there is a significant relationship between the levels of nitrogen and sulfur applied and the growth of floricultural crops. Poinsettia and roses grew well in experiments involving hydroponic solutions that contained reduced nitrogen and some sulfur.

Cuttings of Dendranthema grandiflora cv Dark Yellow Fuji Mefo, were grown in hydroponics with either 64, 127, or 254 ppm N in combination with either 0, 1, 2, 4, 8, 16, 32, 64 ppm S. Plants were grown unpinched and short day treatment started at the end of week 3. Data recorded included symptoms of S deficiency, date of flower initiation, stem length, flower diameter and visual observation of root growth. Color difference of leaves was measured with a chromameter. New leaves and flower heads were taken for sulfur analysis; mature leaves were used for N analysis.

Plants receiving no S showed depressed initiation and development of branch roots, delayed flower initiation, reddened lower leaves and reduced plant growth. Plants receiving some S in combination with any level of N showed good color and acceptable flower diameter and stem length.
505 PB 245 RADIANT COOLING LEADS TO COOLER TEMPERATURES UNDER BLACK CLOTH
Authors: Heins Royal D. , Faust James
Published: February 2019

Photoperiod studies in a greenhouse usually require that the natural photoperiod be modified to increase or decrease the daylength. Modification involves using lights to extend the daylength or using some opaque material (e.g., black sateen cloth or black plastic) to shorten the photoperiod by excluding light. Air temperatures under the material can deviate from those of the surrounding air. It is common knowledge that when plants are covered by the cloth prior to sunset, solar radiation will increase the temperature under the it. It is not as widely known that temperature under the cloth will be lower than surrounding air temperature during the night. Radiant cooling of the material occurs when the greenhouse glazing material is cooler than the air temperature, resulting in cooling of the air and plants contained under the material. We have observed radiant cooling exceeding 150 W·m-2 when glazing is cold (-7°C), resulting in a temperature reduction under the material of up to 4°C. The difference in temperature between short-day and normal- or long-day treatments can lead to incorrect conclusions about the effect of photoperiod on plant development rate. Data will be presented with a sample control system to correct the problem.
511 PB 283 SEASONAL COMPARISONS OF THREE ROSE (ROSA HYBRIDA L.) CULTIVARS
Authors: Story Virginia S. , Hopper Douglas A. , Meinke Troy T.
Published: February 2019

Two-year-old Rosa hybrida L. `Royalty', `Emblem', and `Samantha' plants were pinched 20 Oct. and 28 Dec. 1992 for Christmas and Valentine's Day crops. At 10 and 25 days after pinch, and at flowering, 5 shoots from each bench location were destructively sampled for leaf (node) number, stem diameter, stem length, and fresh and dry weights of stem, leaves, and flower bud. Time to visible bud, to color, and to flower from pinch were also recorded.

Results were tabulated; an analysis of variance showed that the three rose cultivars produced flowers which were not significantly different within crops but were different between seasonal crops. The Christmas `Royalty' crop produced more flowers (but also more blind shoots) than did the Valentine's Day crop. Days to flower, stem diameters, and stem lengths were similar within and between crops for all cultivars. Total fresh and dry weights for all three cultivars tended to be greater for the Valentine's Day crop than for the Christmas crop. The seasonal photosynthetic photon flux (PPF) variation may account for these differences.
515 PB 447 `POTOMAC': A NEW FIRE BLIGHT-RESISTANT PEAR CULTIVAR
Authors: Bell Richard L. , van der Zwet T. , Chandler C.K. , Scheerens J.C.
Published: February 2019

`Potomac' has been released as a new pear cultivar which combines a high level of resistance to fire blight with excellent fruit quality. Selected from a cross of `Moonglow' × `Beurre d'Anjou', it was tested under the seedling number, US 62537-048. Fruit are ovate-pyriform in shape, and average 73mm in diameter. Skin color is light green and the finish is glossy at harvest maturity, which occurs about 2 weeks after `Bartlett'. Flesh texture is moderately fine, buttery, and juicy; grit cells are small and limited to a thin layer under the skin. Flavor is subacid, with mild aroma, and similar in character to `Beurre d'Anjou'. Fruit may be ripened after harvest without cold storage, but `Potomac' is more susceptible to superficial scald than Beurre d'Anjou if stored for more than eight weeks. The tree is moderately vigorous. Yield and precocity are moderate. Fire blight resistance is greater than that of `Seckel', with a high degree of resistance in both shoots and blossoms. The cultivar is recommended for home orchards and limited commercial trial.
522 THE EVALUATION OF COLD HARDINESS IN HAZELNUT
Authors: Chozinski Annie M. , Mehlenbacher Shawn A.
Published: February 2019

Laboratory freezing tests were conducted for two consecutive winters to determine the cold hardiness (CH) of hazelnut trees (Corylus).Thirty-six different genotypes were evaluated. LT50s were calculated for female inflorescences, catkins and vegetative buds. Most (> 70%) female flowers achieved their maximum hardiness in January. Nearly half (45 %) of all female flowers had LT50s between -38.0 C and -21.4 C. Catkins were most hardy in December after which they began to elongate and lose their CH. In December, catkin CH ranged from -33.0 to -13.4 C. Vegetative buds were more hardy than both female flowers and catkins. LT50s ranged from, -40.0 to -26.8 C with 95% achieving maximum CH in January. More than half (54%) had LT50s between -30.0 and -20.0 C. In summary, vegetative buds are more CH than female buds which in turn are more hardy than catkins.
544 PB 084 AIR SUPPLY FOR LETTUCE TIPBURN PREVENTION AND ITS EFFECTS ON TRANSPIRATION AND PHOTOSYNTHESIS
Authors: Kossowski Jan M. , Wilcox Darlene A. , Langhans Robert
Published: February 2019

Tipburn is considered a major limiting factor to lettuce production in greenhouses and controlled environment agriculture facilities. Conditions which promote optimal growth also result in high levels of tipburn incidence. It has been reported that air flow directed at inner leaves of rapidly growing lettuce can prevent tipburn without a concurrent reduction of growth, assumedly due to increased transpiration with increased air movement over leaf surfaces.

Lettuce was grown in the greenhouse in nutrient film technique, with additional lighting providing total of 17 to 19 mol m-2 d-1 of PAR. Control plants developed tipburn 20 to 25 days after seeding. Plants with air supplied to inner leaves by a perforated plastic sleeve did not develop tipburn up to 35 days after seeding. Diurnal changes in physiological parameters were measured starting one week prior to harvest. Leaves of control plants had significantly higher stomatal conductance and transpiration than did those of air-supplied plants, although diurnal patterns of control and air-treated plants were similar. Air flow treatment had no significant effect on the rate of photosynthesis. However, air-supplied plants had a slightly lower percentage of dry matter than control plants. The apparent growth reduction resulting from the air flow treatment evidently reduced the demand for calcium.
545 PB 087 SUMMER LETTUCE PRODUCTION POTENTIALS FOR HIGHER ELEVATIONS
Authors: Welbaum Gregory , O'Dell Charlie
Published: February 2019

Greenhouse grown transplants of 23 lettuce varieties were produced in 1” diameter speedling flats, seeded May 1, transplanted to the field in early June when plants were 4 weeks of age. Transplants were grown in a commercial potting media of peat-vermiculite-perlite. Loose leaf, butterhead, crispbead or iceberg and cos types were included, field-planted at the Elam Swarey farm in Burkes Garden, Tazewell County, Virginia, at an elevation of 3,400 ft. above sea level. No crisphead (iceberg) varieties were found to be satisfactory in yield or quality for area conditions. Of loose leaf varieties, `New Red Fire' and `Red sails' were judged highly adapted for high elevation summer production at sites above 2,000' elevation and/or for fall production at lower Piedmont and coastal areas for October and November harvests. `Tiara', a dark green loose leaf was judged the best of its type in this test. Of the cos types, `Pyramid' and `Ideas' were best adapted to high elevation summer production or lower elevations fall production. Of the butterhead types, `Condor' and `Encore' were suited to higher elevations, `Condor' showing more heat tolerance.
547 PB 093 EFFECT OF THE APPLICATION OF SPROUTING PROMOTERS ON TWO POTATO CULTIVARS (Solanum tuberosum L.)
Authors: Quintero Ibis , Ojeda Maritza , Pérez Yolanda , Zambrano Judith , Mazano Juan
Published: February 2019

In tubers `Kennebec' and `Russet' were applied acetylene, carbide and ethylene to promote sprouting, subsequently the tubers were stored at temperatures of 10 and 15 C. The experiment was a completely randomized, factorial design. The evaluations were done weekly. `Kennebec' sprouted from the second week of applied the treatments to 10 and 15 C while `Russet' sprouted only to 15 C. In the fourth evaluations the effect of promoters was not significantly different to the control. `Kennebec' at 10 C showed greater percentage of sprouting and number of sprout/tuber with respect to `Russet', but at 15 C were not detecte significant differences between the cultivars for these parameters. Number of sprout/tuber in `Kennebec' was not affected by the promoters but `Russet' treated with acetylene and carbide at 10 C showed the largest number of sprout/tuber. The greater sprout length was presented by `Kennebec' in both temperatures.
557 PB 374 EFFICACIES OF CRYOPROTECTANTS APPLIED TO STRAWBERRY PLANTS INOCULATED WITH ICE-NUCLEATION-ACTIVE BACTERIA
Authors: Warmund Michele R. , English James T.
Published: February 2019

Cryoprotectants were applied at labeled rates to primary flowers of `Honeoye' strawberry (Fragaria × ananassa Duch.) plants at full bloom to determine their effects on the floral organs. Frostgard at 50 ml/liter or KDL at 22 ml/liter injured pistils and resulted in misshapened fruit. Floral buds that were closed when cryoprotectants were applied were uninjured. In other experiments, efficacies of cryoprotectants were determined after floral tissues of `Honeoye' strawberry plants were inoculated or not inoculated with the ice-nucleation-active (INA) bacteria, Pseudomonas syringae van Hall and subjected to sub-freezing temperatures. None of the products protected primary or secondary flowers against freezing injury regardless of the occurrence of INA bacteria. INA bacteria were not recovered from primary flowers of treated plants that were killed by low temperature exposure, indicating that non-bacterial nuclei may incite freezing in these tissues.
571 EVALUATION AND PROPAGATION OF SUPERIOR CADDO MAPLES
Authors: Pair John C.
Published: February 2019

In 1983, a trial was initiated to compare numerous selections of sugar maple (Acer saccharum) for adaptability to stressful conditions in south central Kansas (zone 6). Included were seedlings of Caddo maple, a southern ecotype, collected from a population native to central Oklahoma. Selected trees have shown superior resistance to scorch and leaf tatter compared to cultivars in the trade. Pre-dawn measurements indicated higher xylem water potential than `Green Mountain' and `Fairview' under drought stress. Leaf emergence of Caddo maples has been earlier in the spring, and fall color develops later than other sugar maples. Propagation of potential cultivars with early fall color has been principally by T-budding on Caddo understock in July and August, although side-veneer grafting in winter has been successful. In addition to superior summer leaf quality, growth in caliper and total height has been greater than other A. saccharum cultivars.
579 PB 082 FACTORS AFFECTING REGENERATION AND ROOTING OF APRICOT SHOOTS DERIVED FROM IMMATURE EMBRYOS
Authors: Goffreda Joseph C. , Scopel Anita
Published: February 2019

Immature embryos or cotyledons were cultured at three stages of development (PF1=3, 30-60, or 100) from two unrelated apricot genotypes. Explants were cultured on MS medium supplemented with 2.4-D (0 or 1 μM) and either BA or TDZ (0, 0.5. 5.0 or 20 μM). Stage 1 embryos cultured on MS media without hormones tended to form embryoid-like structures. Regeneration was highest with stage 2 cotyledons on media containing between 5-20 μM TDZ and 1.0 μM 2.4-D; shoot morphology was abnormal at the highest level of TDZ. In another factorial experiment, stage 2 cotyledons were cultured on media containing TDZ (six levels, 0 to 20 μM) in combination with either 2.4-D (0 or 1 μM) or IBA (0, 1, or 5 μM), Regeneration of normal shoots was highest on the medium containing 5 μM IBA and no TDZ. Regenerated shoots were transferred to woody plant medium (WP) containing 3% sucrose and supplemented with 6 μM 2iP and 2.2 μM BA to promote stem elongation. Shoots were transferred to WP media supplemented with NAA or IBA to induce rooting. Culture on media containing 10 μM IBA in total darkness induced rooting in less than two weeks.
582 PB 091 PLANT REGENERATION FROM EMBRYOGENIC CALLUS TISSUES OF KENTUCKY BLUEGRASS
Authors: Ke Shanqiang , Lee Chiwon W.
Published: February 2019

Coleoptile tissues from dark-germinated seedlings of Kentucky bluegrass (Poa pratensis L.) cv. Touchdown were excised and cultured on MS medium supplemented with 1.5-2.5 mg/liter picloram plus 0.2 mg/liter benzyladenine (BA) or with 4 mg/liter 2,4-D. Embryogenic calli were formed on media containing 1.5 mg/liter picloram plus 2.5 mg/liter 2,4-D in the dark. When these embryogenic calli were subcultured on MS medium containing either 0.15-0.3 mg/liter picloram or 0.2-0.5 mg/liter 2,4-D in a 16-h day/8-h night photoperiod, 10.5% of the cultures regenerated shoots. Pretreatment of cultures in the dark for 2 weeks prior to light exposure slightly increased the plant regeneration efficiency to 15.5%. Pigmentation of the regenerants varied with a ratio of 8.5 completely green: 2.5 green plus albino: 1 completely albino plants. The shoots were multiplied in the medium containing 0.5 mg/liter BA plus either 0.2 mg/liter picloram or 0.1 mg/liter indoleacetic acid (IAA). Over 90% cultures in the shoot proliferation medium produced roots after 4 weeks.
587 PB 126 MICROPROPAGATION OF SPIGELIA MARILANDICA (L.) L.
Authors: Kitto S.L.
Published: February 2019

Spigelia marilandica, an herbaceous perennial native to the temperate eastern United States, has great potential for the sunny garden due to a fairly long flowering period-and long (3.5-5.5 cm) tubular corollas that are scarlet on the outside and yellowish within. Non-wild collected seeds were disinfested using conventional procedures, and after 8 wk at 4°C, four seeds germinated in vitro. Preliminary experiments examined seedling lines (# 1, 2, 5 and 6) and media (MS versus DKW.) Line 6 was found to be consistently more proliferative over a six month period. Trend analysis demonstrated no difference in total number of axillary shoots produced on full versus 1/2 MS media. MS-derived microcuttings were chlorotic but appeared to root better than DKW-derived microcuttings.
598 PB 202 EFFECT OF UNICONAZOLE ON FLOWERING AND FRUIT SET OF MACADAMIA
Authors: Nagao Mike A. , Ho-a Elodie B. , Yoshimto Judy
Published: February 2019

Uniconazole at 0.20 g-ram of a.i./cm of trunk diameter was applied as a drench to potted 2 year-old M. integrifolia cv. Kau trees in July 1990, and reapplied in August 1991, August 1992 and August 1993. Observations between December 1991 to December 1993 showed that elongation of newly emerging vegetative flushes was inhibitedwithin 6 months after the initial treatment. Shoots had a compact appearance, and the overall height of the trees was shorter than in untreated trees. By December 1993, diameters of the treated trees were also signficantly smaller than the controls. Uniconazole increased the number of racemes, number of racemes with mature fruit set and fruit production in young trees during the 1992 and 1993 seasons. The effect was more pronounced in 1992 compared to 1993. Results from this study show that young macadamia trees can be brought into heavier bearing at an early age with uniconazole treatments.
600 PB 208 ROOT ADAPTATION TO COMPETITION
Authors: Glenn D. M. , Welker W. V.
Published: February 2019

The effect of ground covers on water uptake was studied using peach trees grown in a 4-part split root system. In 1992, one section of the root system was in bare soil and 3 sections were in combination with `K-31' tall fescue. In 1993, K-31 was eliminated in 2 additional sections, leaving 1 section in combination with `K-31'. When grass transpiration was suppressed by covering the K-31, tree water uptake/cm of root length was greater in the presence of grass compared to bare soil under well watered conditions. These data indicate that peach trees compensate for interspecific competition by increasing root hydraulic conductivity.
607 PB 249 THE EFFECT OF PRUNING ON FRUIT SET OF `ANJOU' PEAR TREES
Authors: Ketchie Delmer O. , Fairchild Eugene D.
Published: February 2019

Five different pruning techniques were begun in 1990 on Anjou pear trees to determine their effect on fruit set: (1) unpruned; (2) central leader, (3) central leader modified to Verner method; (4) stubbed into 2- to 4-year-old wood first year and then developed to central leader; and (5) mold-and-hold. Half of each treatment was spread, the other half not spread. Half of each of the combination training and spreading were tipped back to the first fruit bud at cluster bud time. The trees were 9 years old and on OHXF97 rootstock. The unpruned trees had the highest yield, 81 Kgm/tree. The other treatments ranged between 52 and 58 Kgm/tree. Regardless of pruning treatment, the spread trees out yielded the non-spread trees by 16 Kgm/uee.. There was essentially no difference between trees tipped in the spring and those that were not tipped.
632 PB 490 FIELD TRIALS WITH COMPOSTED, PELLETIZED POULTRY LITTER APPLICATIONS IN SPINACH AND COLLARDS
Authors: Teague Tina Gray
Published: February 2019

On farm studies in 1994 with a composted, poultry litter (PPL) product, Organigro (Organigro Inc., Watts, OK), were conducted with fall spinach and collards in eastern Arkansas. In a small plot study with `Cascade' spinach grown on Dubbs fine sandy loam soil (pH 6.5 to 6.8) in a large commercial field receiving fertilizer inputs of 102-0-70 NPK + 29.5 S + 0.5 B, additions of as little as 280 kg PPL ha-1 significantly increased yield. In collard studies, effects of applications of PPL, NPK and a transplant water applied fertilizer solution were compared in a trial with transplanted `Blue Max grown in a silt loam soil (pH 5.8 to 6.2) that had been damaged from precision leveling. PPL applied at 560 kg ha resulted in significantly higher yields than plots receiving NPK (applied as 516 kg 13-13-13 ha-1) alone. Applications of a fertilizer solution containing secondary and micronutrients (Golden Harvest Plus, Smeller Chemical. Houston, TX) in transplant water (50 ml/plant solution containing .95 1 GH+/378 1 H2O) resulted in comparable yields as those treatments with PPL. These results indicate that shallow rooted vegetable crops such as spinach and collards grown in damaged soils or light textured soils with low organic matter can he improved with additions of poultry litter. The PPL product used in these studies is produced with a guaranteed analysis of 4-4-4 NPK, and because it has been composted, problems with weed seeds and pathogenic organisms have been eliminated The pelletized form of the product also, facilitates field application. These properties make this type product ideal for use in vegetable production systems, particularly where problems with secondary or micronutrients may he likely.
EVALUATION OF ALTERNATIVE FUMIGANTS FOR TOMATO PRODUCTION
Authors: Olson Stephen M. , Noling Joe W.
Published: February 2019

Methylbromide is the standard fumigant used for tomato production in Florida. Since it been classified as a category 1 ozone depleter and is to be phased out by 1 Jan 2001 replacement methods of fumigation must be found. Several materials in 1993 were compared to methylbromide in production of `Colonial' tomatoes. These included metham sodium (applied through drip at 3 rates and applied to soil at 935 l·ha-1 and tilled in), dazomet (applied at 2 rates and tilled in), 1,3 dichloropropene + chloropicrin and untreated check. None of the treatments were as effective as methylbromide in reducing root galling by root knot nematodes. Total yields were not affected by treatments even though root system of untreated plants was severely galled. Modifications are to be made for 1994 season and materials added to trial.
647 PB 413 REACTION OF POTATO CV. BELRUS TO INFECTION WITH POTATO LEAFROLL VIRUS
Authors: Goth Robert W. , Goins Ernest W. , Haynes Kathleen G.
Published: February 2019

Potato leafroll virus (PLRV) is a serious aphid transmitted virus disease of potato (Solanum tuberosum L.). Field observations suggest that the cv. BelRus is tolerant to PLRV. Greenhouse grown BelRus and PLRV susceptible potato cvs. Green Mountain and Katahdin were tested for PLRV with enzyme linked immunosorbant assay (ELISA) and subsequently infested with PLRV infected green peach aphids (Myzus persicae). ELISA was used to test leaves from the top, middle and bottom portion of the plants at 7 day intervals beginning 7 days after aphid infestation. PLRV was detected in all tested locations of the Green Mountain and Katahdin plants 21 days after inoculation. In BelRus, throughout the 11 week test, PLRV was detected predominantly in the top portion of the plants and at low titres. These results suggest that tolerance to PLRV infection in the cv. BelRus may be due to suppression of virus replication.
652 PB 028 COMPUTER ANALYSIS OF AERIAL PHOTOGRAPHS TO DETECT N STRESSES IN LETTUCE
Authors: Sanchez C.A. , Blackmer T.M. , Meyers G.E. , Schepers J.S.
Published: February 2019

Lettuce (Lactuca Sativa L.) produced in the low desert typically shows large yield responses to N fertilization. Concern about the potential threat of nitrate-N to ground water prompted the state of Arizona to pass legislation aimed at implementing improved N management practices. Nitrogen management guidelines recommended by the University of Arizona for lettuce suggest a preplant application based on a soil nitrate-N test and subsequent sidedress applications based on plant tissue monitoring. However, growers have some anxiety that close adherence to recommendations resulting from an average plant sample may compromise crop uniformity. Aerial photographs have the potential to detect differences in N status in any portion of the field. This study evaluated digital computer analysis of aerial photographs as a tool for evaluating the N status of lettuce. The digitized photographs appeared to detect deficiencies not apparent to the human eye. There were good correlations (R2 0.83 to 0.99) between Gray-scale ratio and N status, suggesting digital analysis of aerial photographs has potential for diagnosing N deficiencies in lettuce.
657 PB 063 IRON DEFICIENCY IN POTATO IN THE MEDITERRANEAN REGION AND ITS CONTROL THROUGH RESISTANT GENOTYPES AND NUTRIENT APPLICATION
Authors: Zaiter H.Z.
Published: February 2019

Iron-deficiency symptoms are observed on some genotypes of potato (Solanum tuberosum L.) grown on high-pH and calcareous soils. seven potato cultivars differing in response to iron deficiency chlorosis (FeDC) were grown on high-pH (8.1), calcareous (38% calcium carbonate equivalent in surface 20 cm) and silty clay soil in the field (Beka'a Valley, Lebanon), to determine the effects of FeDC on tuber yield of cultivars sprayed with Fe. A significant interactions between cultivars and Fe spray treatment were noted for visual FeDC ratings and tuber yield. Even though only slight FeDC was noted on some cultivars receiving no Fe spray, tuber yields were significantly increased when sprayed with Fe. Some cultivars with moderate FeDC ratings did not show a significant increase in yield when sprayed with Fe while other cultivars did. Sprayed cultivars generally produced higher tube; yields than unsprayed ones. Indicating that Fe-deficiency chlorosis in the Mediterranean region may be a serious limitation to potato tuber yield.
660 PB 072 IDENTIFICATION OF GENETIC VARIABILITY AMONG SPECIES AND CULTIVARS OF PENSTEMON USING RANDOM AMPLIFIED POLYMORPHIC DNA (RAPDS)
Authors: Jung Guenhwa , Lindmen Dale T. , Coyne Dermot P.
Published: February 2019

Eight species and 57 selections/cultivars of Penstemon were compared for genetic variability using Random Amplified Polymorphic DNAs (RAPDs). The RAPD technique was used to help understand the genetic relationships in species and cultivars in the genus Penstemon. Ten RAPD primers (from Operon) were screened to identify polymorphisms among these eight species and 57 selections. More than 100 RAPD polymorphic bands were obtained. A principle component analysis was used to study genetic relationships. Variation among species was greater than variation among selections/cultivars within species. RAPD markers distinguished differences between most cultivars tested. DNA fingerprints generated by RAPDs should be useful to distinguish cultivars of Penstemon, as well as to assist in determining genetic relationships between species.
662 PB 078 STABLE TRANSFORMATION OF GLADIOLUS PLANTS
Authors: Kamo Kathryn , Blowers Alan , Smith Franzine , Van Eck Joyce
Published: February 2019

Over one hundred Gladiolus plants of the commercially important cultivars `Jenny Lee' and `Peter Pears' have been stably transformed following particle bombardment on regenerable callus, suspension cells, or cormel slices. The phosphinothricin acetyltransferase gene which confers phosphinothricin resistance was cotransformed with either antiviral genes or the uidA reporter gene coding for β- glucuronidase expression. Transformed plants were regenerated following selection on concentrations of phosphinothricin which varied with the type of tissue used for bombardment. Integration of foreign DNA was confirmed by polymerase chain reaction and gene expression.
677 PB 183 IDENTIFICATION OF OLIVE (Olea europaea L.) CULTIVARS WITH RAPD MARKERS
Authors: Fabbri A. , Hormaza J.I. , Polito V.S.
Published: February 2019

We have been screening olive (Olea europea L.) cultivars using the Random Amplified Polymorphic DNA (RAPD) technique. We examined 23 olive cultivars selected to represent the important olive-growing regions of the world. These include oil and table olive cultivars originating from throughout the Mediterranean area. A high degree of polymorphisms is evident in the olive germplasm we examined. Early results indicate that polymorphisms that exist within the species are sufficient to enable efficient development of RAPD markers for distinguishing olive cultivars.
680 PB 192 INRERITANCE OF KAPD PATTERNS IN THEOBROMA CACAO
Authors: Ronning Catherine M. , Schneg Raymond J.
Published: February 2019

While Random Amplified Polymorphic DNA (KAPD) has been used successfully in genetic analysis of several crop plants, the method poses difficulties with a heterozyaous species such as Theobroma cacao due to the dominant phenotypic expression of bands. A backcross family of the cultivars `Catoneo' and `Pound 12' was analyzed to determine the efficacy of this technique in analyzing cacao populations. A primary screen of the parents and F1 was conducted with 180 KAPD primers; of these, 39.5% either-did not amplify or did so poorly or irreproducibly, while 60.5% amplified well. Phenotypes produced by 42 primers represented possible test crosses, which can be used in linkage mapping. Genomic DNA from 50 individuals of the backcross population were then amplified with these 42 primers, which in most cases resulted in 1:1 segregation of bands. Preliminary experiments show that the Stoffel fragment of Taq DNA polymerase may provide additional markers. These results indicate that it should be possible to use RAPD bands as molecular markers to study the cacao genome.
707 PB 353 MODIFICATION OF EPICUTICULAR WAX STRUCTURE BY HEAT-TREATMENT IN `GOLDEN DELICIOUS APPLES AND ITS EFFECT ON POST HARVEST CALCIUM UPTAKE
Authors: Roy S. , Conway W.S. , Watada A.E. , Sams C.E. , Erbe Eric F. , Wergin W.P.
Published: February 2019

Prestorage heat treatment of apples has been shown to have a positive effect on fruit quality in storage. Postharvest treatment of apples with CaCl2 also beneficially affected fruit during storage. However, calcium uptake seems limited in heat-treated apples which indicates that the surface of the fruit may have been affected by the heat treatment. This study examined the effect of heat treatment on the subsequent uptake of CaCl2 solutions and related this process to the ultrastructure of the epicuticular wax surface of the fruit. Apples were pressure infiltrated with a 4% CaCl2 solution either without heat treatment or following 4 days at 38°C. Examination of the apple surfaces with low temperature scanning electron microscopy revealed that heat treatment changed the pattern of epicuticular wax. The epicuticular wax of non heated fruit exhibited numerous deep surface cracks. The epicotictdar wax of heated fruit did not exhibit similar cracks. This apparent obstruction or elimination of deep cracks may limit the CaCl2, solutions from entering the fruit. The heated fruit contained significantly less calcium compared to the fruit that were pressure infiltrated with the CaCl2 solution but not heated. These results indicate that cracks on the fruit surface may be a” important pathway for the penetration of CaCl2 solutions.
710 PB 382 HARVEST MATURITY STAGE AFFECT PEACH QUALITY DURING COLD STORAGE
Authors: Rodriguez-Felix Armida , Araiza-Lizarde Evelia , Villegas-Ochoa Monica A. , Brineas-Taddei Elsa
Published: February 2019

Physico-chemical and physiological changes of `Flordaprince peach fruits harvested at different maturity stages were evaluated during low temperature storage. Harvested fruits were immediately classified into four different maturity stages based on red-skin color (I, 20%; II, 40%; III, 60%; and IV, 80%). Fruits were stored at 2 C (90% R.H.) for 0, 15, and 30 days. Following cold storage conditions, fruits were transferred to a 20 C room. Physico-chemical and physiological characteristics evaluated during storage included weight loss, firmness, pH, titratable acidity, skin color (hue), total soluble solids, respiration rate, and ethylene production. Weight loss increased (up to 40%) after 27 days storage at 2C. The fruits harvested at maturity stage I showed the lowest weight loss. Flesh firmness decreased significantly during storage at 2 C. Fruits from stages I and II had higher firmness than fruits harvested at stages III and IV. A significant change from green-yellow to red color was observed in fruits of the distinct maturity stages during storage at 20 C.
723 PB 459 THE POTENTIAL EFFECTS OF POSTHARVEST CALCIUM CHLORIDE DIPS AND LIPID WAX ON RIND BREAKDOWN IN THE CHIRONJA
Authors: Maldonado Arturo Cedeño , Chesney Patrick E. , Orengo Essau
Published: February 2019

The chironja (Citrus sinensis L. Osbcek* Citrus paradisi Macf.) is a citrus hybrid of excellent quality. Attempts at commercialization has been limited by the susceptibility of the fruit to rapid rind breakdown after harvest. A study was undertaken to determine the effects of postharvest calcium chloride (CaCl2) dips and lipid waxes on rind quality of two chironja clones at two maturity stages. CaCl2 dips had no significant effect on weight loss irresponsible of clones and maturity. Waxing improved lustre of fruits. retarded aging and shrinkage and slightly inhibited degreening. Pac Rite wax was more effective than Prima Fresh wax. Clone 2-4 was less resistant than clone 3-8 to rind breakdown and made better use of the wax treatments. Mature yellow fruits had a better response to treatments than mature green fruits in retarding weight loss. Untreated fruits deteriorated rapidly after five days. Symptoms of rind breakdown were incipient in calcium treated fruits. Preharvest calcium applications and/or postharvest waxing may reduce the incidence of rind breakdown in the chimnja.
725 FB 465 OCCURRENCE AND IDENTIFICATION OF WHITE MOLD ON HAZELNUT KERNELS
Authors: Ebrahem Kais S. , Richard Daryl G.
Published: February 2019

Barcelona, Daviana, and Ennis varieties of hazelnuts were sampled in commercial orchards between Cotvallis and Portland for incidence of kernel white mold. What was thought to be storage mold actually occurred on the trees even when the nuts were in early development. There were significant differences between the three years. Mold incidence was highest in 1986, and lower in 1987 and 1988. There were some differences in mold percent between the samples from tree and ground. Ramularia was the only species of fungus that was identified in all samples and was found at high percentages. No incidence of any Aspergillus species were found. Temperatures for drying and storage had no effect on mold percentage nor did number of nuts per cluster.
730 PB 498 QUALITY EVALUATION OF FRESH PEJIBAYE PALM HEART (BACTRIS GASIPAE:)
Authors: Cavaletto Catherine G. , Nagai Natalie Y. , Clement Charles R. , Manshardt Richard M.
Published: February 2019

Fresh pejibaye palm heart samples were evaluated from 1) progenies from the Benjamin Constant population of the Putumayo landrace and 2) progenies from the Yurimaguas population of the Pampa Hermosa landrace. Favorable sensory characteristics included sweetness, tenderness, crispness, and moistness. Negative sensory characteristics found in some samples were astringency and acridity. Sensory scores for astringency and acridity were significantly different (p=.05) between sections of the heart Basal sections appear to be more acrid and astringent than the apical sections. Differences in acridity also exist between plants within a progeny (p=.05). Percent total soluble solids ranged from 3.0 to 6.6, but no obvious pattern was apparent. Samples were also provided to chefs in upscale restaurants where they received favorable comments.
737 PB 035 l-UN TOMATO PLANTS TREATED WITH EDTA DO NOT PRODUCE FRUITS THAT TURN RED
Authors: Gisslen Jennifer L. , Tong Cindy B. , Rosen Carl I.
Published: February 2019

It has been reported that 90-day old fruit of rin mutant tomato plants treated with nutrient solution containing 1 g EDTA/L attain 98% red coloration of untreated wild-type fruit. We grew rin plants in sand and watered with half-strength Hoagland's solution until flowering. After flowering, plants were watered until run-off daily with full-strength Hoagland's solution (control), full-strength Hoagland's solution with 135 μ M or 2.5 mM Na2EDTA, or full-strength Hoagland's solution lacking calcium. We did not observe any red fruit or measure any differences in ethylene production or soluble polyuronides content. Analyses of pericarp ion content indicated that fruit from plants treated with 2.5 mM Na2EDTA had higher concentrations of sodium and manganese than control fruit. Fruit from plants treated with solution lacking calcium developed blossom end rot and had less calcium and iron than control fruit.
740 PB 064 DEVELOPMENTAL AND GENETIC DIFFERENCES IN DETACHMENT FORCE OF TABASCO PEPPER
Authors: Motsenbocker Carl E. , Gersch Kay P.
Published: February 2019

Field and greenhouse studies were conducted to examine fruit detachment force and plant parameters of two strains of Tabasco (Capsicum frutescens) at different stages of maturity. The detachment force of mature red `McIlhenny Select' at the fruit-receptacle detachment area was less than that of breaker and mature green fruit. `McIlhenny Select' separated cleanly at all stages of maturity. A wild type Tabasco strain `HP' did not abscise at the red mature stage; fruit detachment force was greater than that of `McIlhenny Select'. The detachment force of mature green and breaker `HP' fruit were similar to those of `McIlhenny Select' at the same stage of maturity. Fruit weight, length, and width of the two tabasco strains were not different. The utility of the `McIlhenny Select' and `HP' strains for physiological studies of pepper fruit abscission will be discussed.
742 PB 070 NUTRITIONAL ANALYSIS OF CHENOPODIUM QUINOA GROWN IN CONTROLLED ENVIRONMENT. HYDROPONIC CULTURE
Authors: Schlick Greg , Bubenheim David
Published: February 2019

Chenopodium quinoa is being considered as a “new” crop for Contolled Ecological Life Support Systems(CELSS) due to the unique protein composition and high mineral values of the seeds and leaves. Quinoa is known to have very high protein levels (12-185 reported from field trials), with desirable amino acid proportions, and mineral concentrations suitable for a balanced human diet. Contolled environment, hydroponic culture has increased the nutritional value and has the potential of increasing the yield. Protein and mineral values have increased substantially and will be discussed in more depth. The high concentration of protein, unique amino acid profile, high mineral values, versatility in preparation and the potential for increased yields make quinoa a useful crop for CELSS and long-term space missions
745 PB 079 SINK SIZE IN GAs-TREATED AND POLLINATED RABBITEYE BLUEBERRY FRUITS
Authors: Cano-Medrano Raouel , Darnell Rebecca L.
Published: February 2019

Exogenous applications of GA, have induced pathenocarpic fruit set in blueberry; however, size of GA,-treated fruit is smaller than pollinated fruit. The small fruit size in GA3-treated fruit may be related to either cell number and/or cell size. Thus, these parameters were examined throughout development in pollinated, non-pollinated and GA3-treated fruits. Fruit growth followed a double sigmoid pattern. During Stage I (0-25 DAA), fruit size in GA,-treated, pollinated, and non-pollinated fruits averaged 0.33, 0.39, and 0.16 g, respectively. There was little change in fruit size in Stage II (25-45 DAA). At ripening, fruit size averaged 1.7 g for GA,-treated and 2.6 g for pollinated fruits. Non-pollinated fruit abscised in Stage II. At anthesis, mesocarp cell number averaged 9910 cells per median cross sectional area and remained constant up to ripening. In Stage I, cell size in G A3-treated and pollinated fruits increased 7X and 9X respectively. Cell size in both fruit types increased 1.5X and 2.8X during Stage II and Stage 111, respectively. Fruit cell number was set at anthesis and differences in fruit size were due to differences in cell ellongation in Stage I.
749 PB 111 EVIDENCE FOR STRUCTURAL AND COMPOSITIONAL CHANGE IN PHLOEM OF BLIGHT-AFFECTED CITRUS
Authors: Taylor Kathryn C. , He Xi
Published: February 2019

Citrus blight is a decline disorder of unknown etiology. Its earliest symptom is redistribution of Zn within the tree. The canopy exhibits symptoms of Zn deficiency while Zn accumulates in trunk phloem just above the bud union. Phloem Zn was associated with complexing agents. Zn-binding proteins (ZBPs) were isolated from phloem tissue extracts of mature healthy and blight citrus trees. After purification by ion exchange chromatography (IEC) and size exclusion chromatography, ZBP's from healthy and blight-affected citrus trees {`Valencia' sweet orange [Citrus sinensis (L.) Osbeck] on rough lemon [C. jambhiri (L.)]) were compared for relative abundance. Size exclusion chromatography indicated that the proteins were and 19.5 kD Mr. IEC demonstrated that the 5 kD ZBP was slightly anionic and that the 19.5 kD ZBP was highly anionic. There were 2.5 × times more of the 5 kD ZBP in blight material than in healthy (purified on an equal prot basis). Levels 19.5 kD ZBP were equivalent in blight and healthy phloem tissue extracts, on both fresh weight and total protein bases. The amino acid composition of the 5 kD ZBP was much more complex than would be expected for phytochelatins. Altered phloem structure also was apparent in blight versus healthy trees, with phloem fresh and dry weights increased in the blight-affected citrus. Phloem specific expression of the ZBPs was also apparent.
751 PB 117 ROOT AND SHOOT GROWTH PATTERNS OF `MAURITIUS' LYCHEE TREES
Authors: Marler Thomas E. , Willis L.E.
Published: February 2019

`Mauritius' lychee (Litchi chinensis Sonn.) trees were planted in root observation chambers in July 1990 to determine the pattern of root and shoot growth during a 12 month period. Root and shoot lengths were measured at intervals ranging from 7-18 days, from Aug. 1990 until Aug. 1991. During each period of active canopy growth, up to six shoots were tagged and measured. Root growth was determined by measuring tracings the extension of each root in a visible plane from the glass wall of the observation chambers. Shoot growth was cyclic, with distinct periods of extension followed by no extension. Alternatively, root growth was fairly continuous with only a few periods of no apparent extension. There were no consistent relationships observed between root and shoot growth patterns.
753 PB 143 POLLEN-PISTIL INCOMPATIBILITY DIFFERENCES BETWEEN MANZANILLO AND FRANTOIO OLIVE (Olea europaea L.) CULTIVARS
Authors: Cuevas J. , Rallo L. , Rapoport H.F.
Published: February 2019

We have compared reproductive processes and fruit set in Manzanillo and Frantoio olive cultivars which are reported in the literature respectively as incompatible and partially compatible. The same incompatibility reaction was observed in both cultivars. Pollen tube growth was almost completely inhibited beyond the stigma, but some degree of self-fertilization was accomplished. However, in both cultivars cross-pollination provided a earlier and higher level of fertilization. Differences in self-incompatibility behavior seemed related to the level and the amount of delay in self-fertilization. In the compatible variety, Frantoio, self-pollen tube growth was accomplished more rapidly and showed a higher level of self-fertilization than in the incompatible Manzanillo cultivar. Fruit set matched reproductive behavior.
758 PB 158 COMPARISON OF SEASONAL PATTERNS OF POLYAMINES DURING FRUIT AND SEED GROWTH OF PEACHES
Authors: Kushad Mosbah M.
Published: February 2019

Seasonal variation in polyamines were evaluate during growth of fruit and seed of peach (Prunus persica L. cvs. Loring and Biscoe) starting at fruit set. In both cultivars, putrescine and spermidine increase significantly while spermine increase only slightly during the early stages of development then declined at the later stages. During pit hardening, polyamines in the flesh remained unchanged but their level in the seed continued to decrease. In both cultivars, polyamine levels corresponded to changes in fruit and seed sizes. when polyamines were vacuum infiltrated into commercially mature Biscoe fruits, flesh firmness, ethylene biosynthesis, and flesh color were significantly different from untreated tissue. The relationship between polyamines, seed development, and fruit development and ripening will be examined.