bluuebunny/crossref_metadata_2025 huggingface dataset:
COMMUNICATING IN PHOTOMORPHOGENESIS
Authors: Pollock Robert , McMahon Margaret J. , Kelly John W.
Published: February 2019

Description of the light environment used in photomorphogenic research varies greatly among research teams. The environment is often described as the ratio of red (R) to far-red (FR) light, particulary when involvement of the phytochrome system is suspected. There is disagreement in the appropriate center and range of values for each ratio component. Often the center for R is reported as 660 nm. However, in chlorophyll-containing tissue 645 nm may be more appropriate because of the absorption of chlorophyll at 660. Band widths around a selected peak also vary. The widths generally are 10 or 100 nm. Comparison of experiments that describe different peaks or ranges is difficult. Much of the variation in description results from the behavior of phytochrome. Phytochrome has absorption and action spectral peaks, however wavelengths that cause absorption and/or action to a lesser extent may extend more than 50 nm from the peak. Integration formulas such as Pfr/P consider the effects of all wavelengths. However, even the integration formulas do not explain all photomorphogenic responses. A description of the entire photomorphogenic spectrum may be the most appropriate means of communication.
HARVEST TIMING AND HEIGHT OF CUT EFFECT ON SAGE (SALVIA OFFICINALIS)
Authors: Motes James E. , Maness Nancy E. , Bostian Bruce
Published: February 2019

Dalmation sage was transplanted in rows 92 cm apart with in-row spacing of 30 cm on 12 April 1989 at the Vegetable Research Station, Bixby, Oklahoma. Plots one row by 55 m long were established to determine the best timing for harvest and to observe the effect of cutting height and date on yield and regrowth in the fall and regrowth the following season.

Four harvest dates in 1989 were 15 August, 25 August, 18 September and 8 November. In addition, one half of the plots harvested 15 August were recut on 5 November. Cutting height was 10 cm on 15 August, 12 cm on 25 August and 15 cm at all other harvest dates in 1989 and 1990. Four harvests were made on all plots during the 1990 season except those cut or recut in November 1989. Spring 1990 regrowth was very poor and no harvest was possible in April 1990 on November 1989 harvested plots. Highest total dry weight yields for the 1989 and 1990 seasons were produced by the 15 August initial cut with a 5 November recut (11,522 kg·ha-1) and the 8 November 1989 cut plots (10,881 kg·ha-1). Other plots that were harvested once in August or September 1989 plus four separate harvests in 1990 produced a total yield near 9,500 kg·ha-1. The 15 cm height of cut appeared to be superior to cutting closer to the soil.
YIELD OF TRIPLOID WATERMELONS IS INFLUENCED BY POLLENIZERS AND INCIDENCE OF MATURE SEEDS BY PARENTS
Authors: Maynard D. N. , Elmstrom G. W.
Published: February 2019

Mature seeds occur occasionally in triploid watermelon fruit. In one trial, the average number varied from 0.3 to 28.7 seeds per fruit in 30 entries and from 0.5 to 8.6 seeds per fruit in the cultivars within this group. The frequency of mature seed in triploid fruit with the same tetraploid parent ranged from 0.3 to 3.0 and from 1.25 to 5.0 seeds per fruit in triploid fruit having the same diploid parent. Tetra A, with 151 seeds per fruit, produced triploids with 6 seeds per fruit; whereas Tetra B, with 74 seeds per fruit produced triploids with only 1.3 seeds per fruit. Date-of-flowering of diploid watermelon cultivars used as pollenizers for triploids affected maturity date of the triploids. Icebox-types that flower early produced higher early yields of triploid fruit; whereas standard cultivars that flower later produced higher yields late in the season.
INTERCROPPING OF SOUTHERNPEAS AND CORN
Authors: Rhoden E. G. , Jere P. , Biswas P. K.
Published: February 2019

Intercropping increases land use efficiency and provide prolonged yields between compatible crops. A study was conducted to evaluate the yield advantage of intercropping southernpeas (Vigna unguiculata) with corn (Zea mays) in addition to determining the yield advantage of corn, `Yellow Trucker', and two southernpeas cultivars; `Mississippi Silver' and `Pinkeye Purolehull', in an intercrop. Cropping method significantly affected the yield of corn but not southernpeas. Cropping method also influenced leaf area, dry matter and plant height of both southernpeas cultivars. Corn had higher yields in alternate-single row (45×30 cm) with southernpeas intercrop than within (90×15 cm) or alternate row (90×15). Competition for light and nutrients may have accounted for the reduction in dry matter and leaf area of southernpeas in intercrop. The average yield advantage, as measured by the land equivalent ratio, ranged between 1.39 and 1.70. When area time equivalent ratio was used to measure the yield advantage, the range was 1.2 to 1.45. `Pinkeye Purplehull' is more compatible with corn in intercropping than `Mississippi Silver'.
SWEET POTATO TRANSPLANT PRODUCTION AS INFLUENCED BY BED COVERS
Authors: Porter Wayne C.
Published: February 2019

Black polyethylene, perforated clear polyethylene, double-slitted clear polyethylene, spunbonded polyester, and a bare soil control were evaluated for their effect on the number, size, and distribution of production of sweet potato transplants. The perforated and double-slitted bed covers increased the weight and number of sweet potato transplants compared with the control or with black polyethylene at the first harvest in 1986 and 1987, Seed roots covered with the spunbonded polyester bed cover produced more plants of greater weight than seed roots covered with bare soil at the first harvest in 1986 only. Black polyethylene treatments produced the greatest weight and number of transplants at the second harvest (8 to 12 days later) in both years. There were no significant differences in total weight and number of transplants among black polyethylene, perforated or double-slitted clear polyethylene treatments in 1986. Total transplant number and weight from plots covered with spunbonded polyester were lower than those from plots with any other bed covers.
SWEET POTATO GROWTH IN RESPONSE TO RELATIVE HUMIDITY
Authors: Mortley D. , Loretan P. , Bonsi C. , Hill W.
Published: February 2019

An experiment was conducted in environmental growth chambers to study the response of sweet potato to relative humidity (RH). Twenty-four vine cuttings of `TI-155' sweet potato were planted in growth channels in a modified half Hoagland's solution using the nutrient film technique. Plants were exposed to constant RH levels of 50% or 85%. Temperature regimes of 20/22 C were maintained during the light/dark periods with an irradiance level of 600 umol m-2 s1, and a 14 hr/10 hr photoperiod. Plants were harvested 120 days after planting and yield data was taken. High RH (85%) resulted in significant increases in number of storage roots/plant, storage root fresh and dry weight, single leaf photosynthesis and stomatal conductance than at 50% RH. Foliage dry weight and leaf temperature was higher at 50% than 85% RH.
PHYSIOLOGICAL CHANGES ASSOCIATED WITH HARDCORE DEVELOPMENT IN SWEETPOTATOES
Authors: Bardwell Tonda , Xing Huang Jin , Garner J. O. , Silva J. L.
Published: February 2019

Storage roots of `Jewel', `Centennial' and `Beauregard' were chilled at 5C for 0, 10, 20, 30 or 40 days. After chilling, the roots were placed at 21C for two days to allow hardcore development. Hardcore was measured as weight of root that remain hard after boiling for 45 minutes. Hardcore and fatty acid composition of total lipids were compared for the three cultivars. Hardcore was present at 10 days in both `Jewel ' and `Centennial' and at 20 days for `Beauregard'. Severity of hardcore increased with time of chilling. Linoleic acid content of 'Beauregard ' was higher for the 0, 10, and 20 day sampling periods, and decreased to a level equal to that found in 'Jewel ' and `Centennial'.
RESPONSE OF TWO SWEETPOTATO GENOTYPES (IPOMOEA BATATAS L. LAM.) TO CHILLING TEMPERATURE
Authors: Phromtong Chana , Garner James O.
Published: February 2019

Ten day old potted rooted cutting of sweetpotato genotypes `Travis' and MS 21-1 were exposed for seven days to cold (12°C) or 21°C (control) temperatures. Chemical changes that may accompany tolerance or susceptibility to chilling were monitored. No consistent differences in total fatty acid composition were found between the two genotypes. There was an increase in peroxidase (POD) activity of the crude enzyme extract for MS 21-1, the chilling tolerant genotype, when exposed to 12°C for seven days. No differnces were found in POD activity for `Travis', the chilling sensitive genotype. Superoxide dismutase (SOD) and catalase (CA) activity for crude enzyme extracts did not differ between genotypes and was not influenced by storage temperature.
YIELD COMPARISONS OF SWEETPOTATO VINE CUTTINGS AND TRANSPLANTS PULLED OR CUT FROM THE PLANT BED
Authors: Hall Melvin R.
Published: February 2019

Plots grown from `Georgia Jet', `Red Jewel', and `Jewel' sweetpotato [I pomoea batatas (L.) Lam.] plants cut from the propagating bed (cut-plants) yielded more than plots grown from plants pulled from the bed (plants). Presence or absence of the shoot apex had little influence on yields of `Georgia Jet' and `Red Jewel' when evaluated in combination with plants or cut-plants or when evaluated in combination with vine cuttings transplanted in an upright or an inverted position. Chlorine dips did not influence yield of `Jewel' plants or cut-plants. Plots grown from `Red Jewel' vine cuttings transplanted in an inverted position generally yielded slightly less than plots grown from vine cuttings transplanted in an upright position, but these differences were not significant.
THE EFFECTS OF UNDERGROUND DRIP FERTIGATION ON SWEET CORN PRODUCTION
Authors: Brown James E. , Porch Daniel W. , Shumack Ronald L. , Gilliam Charles H. , Curtis Larry
Published: February 2019

In sweet corn field plots in Alabama, urea-ammonia nitrogen was applied to the soil through underground and aboveground drip fertigation systems. Dry nitrogen in the form of ammonium nitrate was surface band-applied as a control. Nitrogen rates of 67 kg/ha and 135 kg/ha were applied in either 2 or 4 applications by each of the 3 methods. P and K fertilizers were applied to all treatments in a dry form according to soil test recommendations. The underground drip pipe was placed 23 cm beneath the soil surface in each row. Nitrogen (wet or dry) rate of 135 kg/ha produced greater sweet corn yield than the 67 kg/ha rate with no effect of application number on yield in 1988, when rainfall was less than adequate. In 1987 and 1989, when rainfall was adequate, no differences occurred in yields regardless of number, rate, or method of application of nitrogen.
STORAGE TEMPERATURE AND DURATION INFLUENCE DETERIORATION OF FILM-BAGGED AND NONBAGGED MUSTARD
Authors: Bracy Regina P. , Fontenot J.F. , Constantin R.J.
Published: February 2019

Brassica juncea var crispifolia was stored in perforated polyethylene bags, polyolefin heat-shrinkable films, and nonbagged at 1, 4, or 15C during three experiments in the spring of 1989 and 1990. Bagging mustard in perforated polyethylene bags or polyolefin films of Cryovac D-955 60-gauge or Cryovac D-955 100-gauge significantly reduced weight loss over nonbagged mustard. Bag type had a highly significant effect on CO2 concentrations in the atmosphere within bags of mustard, with highest CO2 concentrations occurring in the bags made of Cryovac film. Mustard stored in all bags retained marketable quality significantly better than nonbagged mustard. Bagged mustard was stored for 12 days at 1 or 4C with excellent quality, whereas nonbagged mustard was unacceptable after only 5 days in storage. Color, turgor, and appearance of all mustard were poor after 5 days in storage at 15C. Sensory evaluations indicated bagging and storing mustard for 12 days at 1 or 4C did not affect the flavor and quality of cooked mustard.
USE OF REFRACTIVE INDEX TO MONITOR CHANGES IN SUGAR CONTENT OF STORED SWEETPOTATOES.
Authors: Walter william M.
Published: February 2019

The sugar content of the sweetpotato cultivars Centennial, Coroner, Georgia Red, Jewel, and Sweet Red was measured by nign performance liquid chromatography (HPLC) and compared to the sugar content found by measuring the refractive index of cellular sap and converting the refractive index value to sugar concentration. The sugar content and refractive index values were measured for just-harvested, cured and stored roots. Changes in the sugar content as determined by refractive index were found to be linearly related to changes 1n sugar content measured by HPLC, indicating that this method can be used to monitor changes in postharvest sugar content.
INFLUENCE OF SEAWEED BASED FOLIAR FEED FERTILIZER ON YIELD OF TOMATOES AND CUCUMBER
Authors: Hanna H. Y. , Adams A. J.
Published: February 2019

Seaweed extract has been reported to have various beneficial effects on many crops. A study was conducted in 1989 and 1990 to evaluate the effects of Response 9-9-7, a seaweed extract fortified with NPK, on yield of staked tomatoes and cucumbers. Plants were sprayed to the runoff weekly, biweekly, every 3 weeks and every 4 weeks with 1:500, 1:250, 1:150 and 1:125 v/v Response/water respectively. Results indicate that spring tomatoes sprayed with Response 9-9-7 at all rates outyielded the check which was sprayed with plain water. However, the only significant difference was obtained when tomatoes were sprayed with 1:150 Response/water in 1989 and 1:500 in 1990. Response/water at 1:500 rate significantly increased the quality and marketable yield of cucumber in both years. Response 9-9-7 had no effect on yield of tomatoes grown in the summer under heat stress.
CONTROL STIMULATION OF PHYTOCHROME ACTIVITY AND BIOLOGICAL PEST CONTROL FOR ENHANCED PLANT GROWTH IN A CONTROLLED ENVIRONMENT
Authors: Wollard Dennis L. , Carlisi-Dunlop Jacqueline
Published: February 2019

The objectives of the greenhouse tomato industry are to optimize production while simultaneously abating the use of pesticides. A variety of mulch colors were evaluated to enhance production: black, white, yellow, red and no mulch. Black mulch yielded an average of 17.05 kg of marketable frui per plant. Yellow, red and white produced slightly less and the no mulch resulted in the least yield. Two greenhouses were used to evaluate two pest management programs. House One was established as the biological control where whitefly parasites – Encarsia formosa, aphid predators – Chrysopea carnea, thrips predators – Amblyseius mckenziei and worm predators – Trichogramma pretiosum were released at regular intervals within the greenhouse. House Two was established as the traditional control where pesticides such as Thiodan 50% WP, Malathion 57% EC and DDVP were utilized to control insect peats. There was a comparable economic return for both pest management programs where each yielded 23 kg for every $1.00 invested.
IN VITRO BLACKSPOT DISEASE RESISTANCE OF ROSES
Authors: Sherman J. M. , Reddy K. S. , Newman S. E. , Spencer J. A.
Published: February 2019

The objective of this study was to determine if blackspot (Diplocarpon rosae, Wolf) resistance and susceptibility is expressed in callus derived from known resistant and susceptible genotypes of roses. Established callus lines of blackspot susceptible hybrid tea roses `Pascali' and `Tropicana' and blackspot resistant species roses Rosa roxburghii and R. setigera were inoculated directly with a blackspot conidia suspension. Uninoculated callus served as controls. Cultures were incubated at 25°C for 28 days in the dark. An evaluation of the appearance and precent change in fresh weight indicated that for all genotypes tested, inoculation resulted in a decline in tissue appearance and rate of weight increase. These results indicated that in vitro. resistance to blackspot differs from the resistance found in whole plants.
THE EFFECT OF COPPER SULFATE FILTERS ON GROWTH OF TOMATO AND PEPPER TRANSPLANTS
Authors: Benson Jodie , Kelly John
Published: February 2019

Tomato and pepper transplants were grown in an environment with a high red to far-red light ratio, to determine if this was an effective method for controlling plant height. This light environment was provided by placing plants under copper sulfate filters, which absorb most of the light in the far-red region of the spectrum. Copper sulfate solutions were 4%, 8%, and 16% w/v. Tomato transplants grown under the filters were approximately 40% shorter than control plants, had less dry weight and leaf area, and increased leaf chlorophyll. Leaf number data was less clearly affected. Differences were not observed among the three different CuSO4 concentrations. Similar results were observed for peppers. Field trials on tomatoes indicated that total yield, earliness of fruiting, and fruit quality were not affected by growing transplants under the CUSO4 filters.
COMPENSATORY GROWTH AND PHYSIOLOGICAL RESPONSES TO DEFOLIATION OF APPLE TREES.
Authors: DenHerder Mark A. , Rom Curt R.
Published: February 2019

Defoliation by pests was simulated with potted tree model systems and field-grown trees. `Redchief'/M.7 apple trees were grown in 10 1 pots as a single shoot. Forty-five days after 25%, 50%, or 75% removal of apical or basal leaf number, new leaf dry weight (produced after treatment) was 23%, 53%, and 45% higher, respectively, for apically treated trees, and -7%, 61%, and 64% higher for basally treated trees, than control trees. Root dry weight was reduced by as much as 59% (apical 75% removed). Photosynthesis following 75% leaf removal was inhibited 1 day after treatment, but increased above the control within 3 days. However, by 35 days after treatment photosynthesis had declined to 53% of control. Leaf removal (50%) June 15 (1990) of 4-year old `Early Granny'/Mark increased net photosynthesis by 40% within 8 days of treatment. Trunk cross-sectional area increase of June- and twice-(June 15 and July 30) defoliated trees was 35% of control trees. Leaf nitrogen content (% dry wt.) in September was 1.75 for twice-defoliated trees compared to 1.58 for control trees.
Out-of-season Prickly Pear: Fruit Characteristics and Effect of Fertilization and Short Droughts on Productivity
Authors: Nerd Avinoam , Karady Avraham , Mizrahi Yosef
Published: February 2019

Field experiments were conducted to examine the effect of fertilization and short periods of drought on the out-of-season winter crop in prickly pear [Opuntia ficus-indica (L.) Mill.]. In addition, the winter and summer crops were compared regarding floral bud production and fruit characteristics. Under both continuous fertigation (N, P, K applied with the irrigation water) and continuous irrigation, the number of floral buds per plant was much lower in the winter than in the summer crop. Fertilization increased production of floral buds in both crops, but to a greater extent in the winter crop. The increase in floral bud production in fertilized plants was associated with an increase in NO3-N content in the cladodes. Suspension of fertigation for 4 or 8 weeks immediately after the summer harvest decreased cladode water content and delayed and reduced floral bud emergence as compared with continuous fertigation (control) or late drought (4 or 8 weeks) applied 4 weeks after the summer harvest. The plants subjected to early drought suffered from high mortality of floral buds. The fruits of the winter crop ripened in early spring, following the pattern of floral bud emergence the previous autumn. Mean fresh weight and peel: pulp ratio (w/w) were higher in fruits that ripened in the spring (winter crop) than in fruits that ripened in the summer.
Canopy Position, Defoliation, and Girdling Influence Apple Nectar Production
Authors: Campbell Richard J. , Fell Richard D. , Marini Richard P.
Published: February 2019

Flowering spurs located at interior and exterior canopy positions of `Stay-man' and `Delicious' apple (Malus domestics Borkh.) trees were girdled and/or defoliated to determine the influence on nectar production and composition. Nectar volume was less at exterior than interior canopy positions for `Delicious', but not for `Stayman'. Girdling suppressed nectar production by 92% and reduced the sugar concentration of the remaining nectar. Defoliation of nongirdled spurs had no effect on nectar sugar concentration, but defoliation of girdled spurs reduced nectar sugar concentration by 24%. Relative percentages of sucrose, glucose, and fructose, and the sucrose: hexose ratio were unaffected by any treatment. Nectar production of nongirdled spurs did not depend on the presence of spur leaves.
The Effects of Black Plastic Mulch and Weed Control Strategies on Herb Yield
Authors: Ricotta Jacqueline A. , Masiunas John B.
Published: February 2019

Black polyethylene mulch and weed control strategies were evaluated for potential use by small acreage herb producers. In both 1988 and 1989, the mulch greatly increased fresh and dry weight yields of basil (Ocimum basilicum L.) and rosemary (Rosmarinus officinalis L.). Parsley (Petroselinum crispum Nym.) yield did not respond to the mulch. Preplant application of napropamide provided weed control for 2 weeks, but was subsequently not effective on a heavy infestation of purslane (Portulaca oleracea L.). Hand-hoed and glyphosate-treated plots (both with and without plastic) produced equivalent yields. Chemical names used: N, N -diethyl-2(1-napthalenoxy)-propanamide (napropamide); N- (phosphonomethyl) glycine (glyphosate).
Growth and Ripening of Persimmon Fruit at Controlled Temperatures during Growth Stage III
Authors: Sugiura A. , Zheng G.H. , Yonemori K.
Published: February 2019

Fruit temperature of persimmons (Diospyros kaki L. f. cv. Hiratanenashi) was regulated at a constant 14, 22, or 30C during growth stage III. Fruit growth and ripening were greatly accelerated at 22C compared with control fruit grown at ambient air temperature (range 9.3 to 28.5C). At harvest (30 days after treatment), fruit kept at 22C was much heavier, more deeply colored, and softer than the controls. In contrast, 30C delayed the onset of rapid fruit expansion and ripening. At harvest, however, the fruit, though still green, were about the same size as tbe controls. With the exception of rapid chlorophyll degradation, 14C had little effect on fruit growth and ripening. Little difference in sugar content and composition was found between temperature treatments and controls.
Apparent Nucleation and Freezing in Various Parts of Young Citrus Trees during Controlled Freezes
Authors: Yelenosky George
Published: February 2019

One- to 4-year-old sweet orange trees, Citrus sinensis (L.) Osbeck cv. Valencia on rough lemon (C. jambhiri Lush.) rootstock, were used in a series of tests on the depth and stability of supercooling in various parts of greenhouse-grown trees held in pots during controlled freezes. Thermocouples were attached to flowers, fruit, leaves, and wood. Supercooling levels were inconsistent, ranging from – 3C to – 7C. Nucleation was spontaneous and well defined by sharp exotherms. Rapid progression of crystallization (≈ 60 cm·min–1) indicated no major obstacles to ice propagation throughout the tree above soil level. The site of initial freezing was variable, with a tendency for trees to freeze from the base of the stem toward the top. The location of tissue damage did not necessarily correspond to the location of initial freeze event. Freezing in the wood often preceded freezing of flowers.
Polygalacturonase and Pectinmethylesterase Activities in Developing Highbush Blueberries
Authors: Proctor Andrew , Miesle Terrence J.
Published: February 2019

Polygalacturonase (PG, E.C. 3.2.1.15) and pectinmethylesterase (PME, E.C. 3.1.1.11) activities, berry size, and texture were measured in fruit of developing high-bush blueberries (Vaccinium corymbosum L.). Peak PME activity occurred in red berries and preceded peak PG activity, which was observed in blue-red fruit. Extensive softening occurred with the transition in berry color from red to blue-red. Both peak enzyme activities and maximum softening occurred by the time the fruit were =70$%0 of their maximum fresh weight.
EFFICACY AND POSTHARVEST LONGEVITY OF UNICONAZOLE TREATMENT ON POLKA-DOT PLANT
Authors: Starman Terri Woods , Auerswald Estella , Gibson P.T.
Published: February 2019

The objective of the research was to determine the effectiveness of uniconazole on Hypoestes phyllostachya Bak. cv. Pink Splash and to compare the effect and persistence of uniconazole with chlormequat and daminozide for limiting stem elongation during post-greenhouse, low light conditions. Uniconazole at 5.0 mg·liter-1 reduced all measured plant dimensions to the same degree as chlormequat at 2500 mg· liter-l when both chemicals were applied twice as foliar sprays at a two week interval. These treatments resulted in the most compact and aesthetically pleasing 0.4-liter potted plants. However, this uniconazole treatment was not as persistent in postproduction low light conditions as chlormequat. By the fifth week under low light conditions, only the highest drench concentration of uniconazole tested (0.10 mg a.i. per pot) remained the same height as chlormequat treated plants.
A NONDESTRUCTIVE METHOD TO MEASURE CHLOROPHYLL IN CITRUS LEAVES
Authors: Rouse Robert E. , Perez Sandra P. , Davenport Sally B.
Published: February 2019

The Minolta chlorophyll meter SPAD-502 (Minolta Camera Company, 101 Williams Drive, NJ 07446, USA) was evaluated as an accurate, nondestructive means to measure chlorophyll content in citrus leaves. Meter readings from leaves of sweet orange and grapefruit citrus cultivars were used to develop a standard curve for citrus. A significant correlation value of 0.96 was calculated between the chlorophyll meter readings and actual chlorophyll extraction levels. The development of a standard curve using the SPAD-502 chlorophyll meter had not been established on citrus. The SPAD-502 chlorophyll meter proved to be a quick, accurate, simple, and nondestructive way to determine chlorophyll content in citrus leaves.
AN EXPERT SYSTEM FOR DIAGNOSING CHILLING INJURY OF VEGETABLES
Authors: Bergsma K. , Sargent S. , Brecht J. , Peart R.
Published: February 2019

Temperature management is the most widely used method to extend the postharvest life of vegetables. Unfortunately, during less than optimal commercial conditions, certain commodities can be exposed to low, nonfreezing temperatures that may shorten their market life due to chilling injury (CI). CI is difficult to diagnose since not all commodities exhibit the same symptoms. Environmental factors may also affect the expression of CI The services of an expert are usually required to positively diagnose CI, however, experts are not always readily available, particularly during routine commercial handling. An expert system, a computer program that emulates a human expert's thought processes, will be developed to diagnose CI symptoms for several commodities. A prototype developed with Level5 Object, an expert system shell, will be presented. Diagnosis is determined by applying rules and certainty factors based on user responses to queries on the type and extent of visual symptoms. The applicability and advantages of this system will be discussed.
POSTHARVEST LONGEVITY OF BAILEYA MULTIRADIATA AND ASTER BIGELOVII
Authors: Ricci M.J. , Lownds N.K. , Berghage R.D.
Published: February 2019

Studies were conducted to determine postharvest longevity of field grown Desert Marigold (Baileya multiradiata) and perennial Aster (Aster bigelovii) cut flowers. Flower stems were cut and placed into storage at 4, 7, 15 and 24C in the dark. Storage treatments included DI water, citric acid (CA), floralife (F), silver thiosulfate (STS) and modified atmosphere packaging (MAP). Flowers were rated daily using a scale of 1 (optimum condition) to 4 (unsaleable). Postharvest longevity of Baileya decreased quadratically with increasing temperature, (r2=0.67, P=0.001) between 4 and 24C. For Aster, postharvest longevity was greatest at 7C (13.3 days), slightly less at 4C (10.5 days) and only 5 days at 15 and 24C. Postharvest longevity of Baileya at 4C was doubled using STS, but was not affected by CA or F. MAP increased postharvest longevity of Aster 1.6- to 2.2-fold at each temperature. Other storage treatments for Aster were ineffective. The results suggest MAP may have potential as a storage technique for commercial cut flowers.
BIRCH SEEDLING RESPONSE TO IRRIGATION FREQUENCY AND A HYDROPHILIC POLYMER AMENDMENT IN A CONTAINER MEDIUM
Authors: Tripepi Robert R. , George Mary W. , Dumroese R. Kasten , Wenny David L.
Published: February 2019

European birch (Betula pendula Roth) seedlings (1+ 0 plugs) were planted in a container growth medium amended with 0, 1.2, 2.4, or 3.6 kg/m3 of a commercial hydrogel and watered either daily or once every 3 or 5 days. When hydrogel was incorporated in the growth medium, shoot and root dry weights and lea area were reduced by 19, 29 and 18%, respectively, compared to controls. Shoot height, stem diameter and shoot:root ratio were unaffected by hydrogel amendment rate. Compared to seedlings in polymer-amended media, plants growing in medium without hydrogel had significantly lower stomata1 conductance and transpiration on fewer than 25% of the measurement dates. Irrigation frequency significantly affected all plant growth Indices and stomata1 parameters; seedlings irrigated daily grew the most and had the highest stomata1 conductance and transpiration. Although polymer-amended media held more water than the medium without hydrogel at all measured tensions, this moisture was retained in the expanded gel rather than being available for plant uptake at higher tensions. The hydrogel appeared to have little benefit for container production of birch.
ABNORMAL ROOT MORPHOLOGY OF CATHARANTHUS ROSEUS GROWN IN SOLUTION CULTURE
Authors: Mattis Pamela R. , Hershey David R.
Published: February 2019

Rose periwinkle (C. roseus `Little Linda'), a common bedding plant, grown in Hoagland solution #1 with Fe-EDTA at 5 mg/L Fe had normal shoot morphology, but abnormal root morphology. The primary root was twisted and lateral roots were extremely stunted with dichotomous branching. Over a dozen other bedding and foliage plant species had normal root morphology when grown in an identical solution, and cuttings from periwinkle with abnormal roots produced normal roots when rooted in 2 mM CaCl2. When these rooted cuttings were grown in Fe free Hoagland solution #1, root morphology was normal, indicating that the Fe-EDTA caused the problem. Seedlings were then grown in solution for 30 days with Fe supplied as Fe-EDTA (both 5 mg/L and 1 mg/L Fe), Fe-DPTA (5 mg/L and 1 mg/L Fe), Fe-EDDHA (2.75 mg/L and 0.55 mg/L Fe) or Fe2O3 (1 g/L). Solution pH for all were in a normal range of 4.8 - 5.6 Only the seedlings grown with Fe2O3, Fe-EDTA (5 mg/L Fe) and Fe-DTPA (5 mg/L Fe) developed abnormal root structure. All others had normal roots.
FLORAL INITIATION IN THE LONG-DAY PLANT Rudbeckia hirta
Authors: Harkess Richard L. , Lyons Robert E.
Published: February 2019

A study was undertaken to determine the rate of floral initiation in Rudbeckia hirta. R. hirta plants were grown to maturity, 14-16 leaves, under short days (SD). Paired controls were established by placing half of the plants under long days (LD) with the remainder left under SD. Beginning at the start of LD (day 0), five plants were harvested daily from each photoperiod group for twenty days. Harvested meristems were fixed in 2% paraformaldehyde - 2.5% glutaraldehyde in 0.1 M sodium cacodylate buffer (pH 7.0) for 24 hrs, dehydrated in an ethanol series, embedded in paraffin and sectioned at 8 μm. Serial sections were stained with Methyl-green Pyronin, with adjacent sections treated with RNase for nucleic acid comparison. All events of floral initiation were identified, The results of limited inductive photoperiod indicate that 16-18 LD were required for flowering.
MODELING DAHLIA `ROYAL DAHLIETTA YELLOW' TEMPERATURE DEPENDENT DEVELOPMENT RATE
Authors: Brondum Jens J. , Heins Royal D.
Published: February 2019

Dahlia “Royal Dahlietta Yellow” plants were grown in controlled temperature chambers under 25 different day and night temperature environments ranging from 10°C to 30°C. The day length was 12 hours with an average PPF level of 300 micromolm-2 s-1 at canopy level. Leaf unfolding rate, shoot elongation and flower development rate were determined and models developed. Leaf unfolding rate increased as temperature increased up to 25°C. Stem elongation increased as the difference between day and night temperature increased. Flower initiation was delayed at high (30°C) temperature and flower development rate increased as temperature increased from 10°C to 25°C. Plants are currently being grown under greenhouse conditions to provide data for validating the models.
SEASONAL PATTERNS OF COLD HARDINESS AND POLYPEPTIDES IN BARK AND XYLEM OF GENETICALLY RELATED (SIBLING) DECIDUOUS AND EVERGREEN PEACH TREES.
Authors: Arora Rajeev , Wisniewski Michael , Scorza Ralph
Published: February 2019

Deciduous fruit trees undergo endo-dormancy during fall at which time they also attain maximum cold hardiness (CH). Because these two processes occur simultaneously it is difficult to study them independently. We have been able to overcome this limitation with the use of genetically related (sibling) deciduous and evergreen peach trees. Using this system we conducted a time course study to characterize the seasonal fluctuations in CH and proteins in bark and xylem tissues. Cold hardiness (LT50) was assessed using electrolyte leakage method. Polypeptides were separated using SDS-PAGE. The data indicated that 1) CH of bark increased from -5°C (in August) to -49°C (in January) and from -3°C to -22°C for deciduous and evergreen trees, respectively. In January, under favorable conditions, evergreen trees were actively growing. 2) CH of xylem successively increased from -11°C to -36°C in deciduous trees and from -7°C to -16°C (in November) in evergreen trees and then plateaued. 3) LT50 of xylem in both genotypes closely approximated the mid-point of low temperature exotherms determined by differential thermal analysis. 4) As CH increased several qualitative and quantitative differences in polypeptides were noted between two genotypes. These changes during cold acclimation will be compared with those during de-acclimation.
IN VITRO GERMINATION AND DEVELOPMENT OF SHOWY LADY SLIPPER ORCHID (CYPREPEDIUM REGINAE Walt.) SEEDS.
Authors: DeMarie Ernie , Weimer Molly , Mudge K.W.
Published: February 2019

Green pods of the C. reginae orchid were collected from a bog near Ithaca, NY. Pods were surface sterilized, and seeds were plated on agar media. The 8 germination treatments were arrange in a complete 3 way factorial consisting of 2 basal media (fish emulsion, FE vs. yeast extract, YE), 2 media pHs (4.8, 6.8), and 2 temperature regimes (constant 24 C vs. 6 wks. at 5 C prior to transfer to 24 C). Sequential stages of development included embryo enlargement and rupture of the testa (l), root elongation (2), leaf primordium development (3) and finally rhizoid development with or without protocorm greening (4). After 4 months post sowing, germination (stage 1 or beyond) was 56% and 0% on FE at pH 4.8 and 6.8 respectively, and 45% and 78% on YE at pH 4.8 and 6.8 respectively. Protocorm development from unchilled seeds after 4 months was greatest on YE at the lower pH, with 14% reaching stage 3 or 4, as contrasted to only 5% reaching stage 2 (none beyond), for the other germinated treatments. Chilled seeds had higher germination for all treatments but no development beyond stage 1 at 4 months post sowing.
IN VITRO MICROPROPAGATION OF SELECTED CULTIVARS OF HOSTA
Authors: Williams David J. , Al-Juboory Karim H.
Published: February 2019

University of Illinois, Department of Horticulture, Plant Science Lab, 1201 S. Dorner, Urbana, IL.

Calli were initiated from immature inflorescences of selected cultivars of Hosta in the light on Hosta initiation medium (Carolina Biological Supply Company, 1986). Three cultivars, Francee, Birchwood Park's Gold, and Wide Brim Sum & Substance, produced microshoots. The calli were compact and green in color. The highest percentage of callus formation occurred with the Francee cultivar. Nakaiana, Golden Edger, Golden Scepter, Obscura, Sum & Substance, and Shade Fanfare produced only calli. The calli were transferred to modified Murashige and Skoog salts. The media containing 5 × 5 factorial combinations of NAA and BA (0.0, 0.1, 0.5, 1.0, or 2.0 mg/l). The results show that media with NAA at 1.0 and 2.0 mg/l in combination with BA from 0.5 to 2.0 mg/l produced the highest number of microshoots per explant.
GENETIC IMPROVEMENT OF SLICING CUCUMBER, 1786 TO 1982
Authors: Wehner Todd C.
Published: February 2019

Cucumber (Cucumis sativus L.) breeders have provided growers with many useful cultivars since production began in the U. S. in the 1600s. The objective of this study was to determine how much breeding progress has been made for yield, earliness, quality, and anthracnose resistance. The experiment was a split-split-split plot in a randomized complete block with 3 replications. Treatments were 2 years (1989, 1990), 2 seasons (spring, summer), 2 production systems (stress, elite), and 14 cultivars (2 important ones from each of 7 time periods, from 1786 to 1982). Plants were grown at Clinton, N. C. using recommended cultural practices, except for the stress treatment, which received half the recommended amount of fertilizer, irrigation, and pesticides. Total yield over 8 harvests increased from approximately 20 Mg/ha for the old cultivars to 30 Mg/ha for the new cultivars. Similar increases were measured for marketable and early yield. Fruit quality (rated 1 to 9) also was improved by breeding, with shape improved 2, and fruit color improved 3 rating points. Part of the improvement in yield was probably due to improved anthracnose resistance. However, improved yield also was obtained in the spring season where anthracnose was absent. In conclusion, the relatively small cucumber breeding effort produced large gains for most traits measured.
EFFECT OF ROOT PRUNING ON WATER RELATIONS AND SHOOT GROWTH OF `BELLAIRE' PEACH.
Authors: Santos Roberto , Taylor Bradley H. , Kjelgren Roger
Published: February 2019

The effect of root pruning on shoot length and water relations of `Bellaire' peach was investigated as a means of controlling vegetative growth. On 27 April, 25 May, and 23 June, 1990, five-year-old trees were root pruned to a 0.35 m depth at either 0.4 or 0.8 m from the tree trunks along both sides of the row. Shoot growth was measured biweekly through the growing season, and the diurnal pattern of stomatal conductance and water potential was followed in late June, July, and August. Stomatal conductance of the root-pruned treatments was less than the control, while there were no differences in water potential among treatments. Reduced shoot elongation was evident within a month of root pruning at 0.4 m for all timing treatments, but at 0.8 m it varied with the date of pruning. The first root pruning at 0.4 m reduced cumulative shoot elongation 39% compared to the un-pruned control trees, while the remaining treatments reduced it 14%. While root pruning limited cumulative shoot elongation in all treatments, the earliest 0.4 m treatment was most effective, possibly due to pruning of a larger percent of the root system prior to rapid shoot elongation. Stomatal closure in root-pruned trees appeared to moderate diurnal water deficits at levels similar to the control.
EFFECT OF ROW COVERS ON WINTER HARDINESS AND SEED YIELD OF `BRUNSWICK' AND `GOLDEN ACRE' CABBAGE (BRASSICA OLERACEA L. VAR. CAPITATA L.)
Authors: Hummel Rita L. , Anderson Wilbur C.
Published: February 2019

Cabbage seed production in western Washington is at risk from freeze damage in the months of November to February. During the 1987-1988, 1988-1989 and 1989-1990 winters, the cold protection efficacy of 5 floating row covers (Agryl P17, Dewitt N-sulate, Reemay 2014, DuPont Typar, VisQueen Porous Row Cover) and straw was tested on field-grown cabbage. Air temperature in the cabbage crown, Tk50 of cabbage leaves, plant winter survival and seed yield were measured. During a severe freeze in February 1989, an average temperature of -11.1 °C was recorded in the uncovered controls while temperatures under the row covers were -6.7°C, -6.8°C and -8.4 °C under the N-sulate, VisQueen and Agryl covers, respectively. When compared to controls in June of 1989, row covers increased the survival of the more cold hardy `Brunswick' plants but did not significantly increase seed yields. The duration and severity of the February 1989 freeze was such that all of the less cold hardy `Golden Acre' plants were killed.
EVALUATION OF RUBUS GERMPLASM FROM THE ECUADOREAN ANDES
Authors: Thompson M. M.
Published: February 2019

Seeds and herbarium specimens of 47 accessions from 11 Rubus taxa native to the Andean Region of Ecuador were collected in October and November 1990 and deposited at the USDA/ARS Germplasm Repository in Corvallis, OR. Plants will be grown from these seeds and evaluated for taxonomic identity and potential breeding value. Characteristics of the plants will be discussed. Taxa obtained include: R. adenothallos Focke, R. acanthophyllus Focke, R. bogotensis Kunth, R. coriaceus Poiret, R. glabratus H.B.K., R. glaucus Benth., R. robustus C. Presl., R. roseus Poiret, R. urticifolius Poiret. These taxa will contribute unique genes to the improvement of Rubus crops by breeders throughout the world. Seeds may be requested from the curator, USDA/ARS NCGR-Corvallis.
PHYSIOLOGICAL MANIFESTATIONS OF CHILLING INJURY IN PROCESSING AND NON-PROCESSING TOMATO CULTIVARS
Authors: Mohammed Majeed , Wilson L.A. , Gomes P.I.
Published: February 2019

Differences in sensitivity of 8 processing and 8 non-processing tomato cultivars to chilling injury packaged in sealed and non-sealed low density polyethylene bags were evaluated after 21 days at 7-8°C, 21 days at 7-8°C + 1 day at 30°C and 21 days at 7-8°C + 2 days at 30°C respectively. Parameters investigated were bioelectrical resistance, electrolyte leakage, in-package and in-fruit Co2 and C2H4 production, firmness, percentage fresh weight losses, percentage decay-free and percentage marketable fruits. Among processing cultivars Advantage was least sensitive while Caraibe was most sensitive to chilling injury. Similarly, for non-processing cultivars Walters was least sensitive while Carnival was most sensitive to chilling injury.
EDUCATION PUBLICATIONS IN HORTTECHNOLOGY
Authors: Fails Barbara
Published: February 2019

HortTechnology offers educators an opportunity to publish articles on many topics of interest to other educators, as well as those in related horticultural communications fields. Topics suitable for publication are numerous; methods of incorporating analytical skills into the curriculum, practical laboratory exercises, new audiovisual and computer technologies for the classroom, and successful internship programs are but a small sample. Manuscripts submitted for publication are circulated for review, as with other refereed papers. Publishing enables innovative teachers to share and receive recognition for ideas, and rewards readers with useful skills and concepts that can improve teaching effectiveness.
Response of Kientzler New Guinea Impatiens to Manual and Chemical Pinching
Authors: Starman Terri Woods
Published: February 2019

Manually and chemically pinched plants of 18 cultivars of Impatiens hybrids (Kientzler New Guinea impatiens) were compared to control plants to determine the effect of shoot apex removal on flowering, plant size, and branching characteristics. Either pinching treatment delayed flowering by ≈3 days compared with nonpinched controls. Pinching had no effect on plant height or fresh or dry weight. Plant diameter and form changes due to pinching depended on cultivar. Total branch count was increased by chemical but not manual pinching although both pinching methods affected mode of branching. The 18 cultivars of Kientzler New Guinea impatiens were best grown as 0.4-liter potted plants without the aid of pinching.
Screening Cover Crops for Use in Conservation Tillage Systems for Vegetables Following Spring Plowing
Authors: Nelson Wendy A. , Kahn Brian A. , Roberts B. Warren
Published: February 2019

Several prospective cover crops were sown into 1-m2 monoculture plots on 9 Mar. 1987 and 10 Mar. 1988 at Bixby, Okla., and on 14 Mar. 1988 at Lane, Okla., after sites were plowed and fitted. Densities and dry weights of cover crops and weeds were determined in late April or early May of both years. Plots also were evaluated for degree of kill by glyphosate in 1988. Fourteen cover crops were screened at Bixby in 1987. Kentucky bluegrass (Poa pratensis L.) and three fescues (Festuca rubra L., Festuca rubra L. var. commutata Gaud.-Beaup., and Festuca elatior L.) were eliminated from further consideration due to inadequate cover density and inability to suppress weeds. Screenings of the 10 remaining covers were conducted at both locations in 1988. Annual ryegrass (Lolium multiflorum L.) and three small grains [rye (Secale cereale L.), barley (Hordeum vulgare L.), and wheat (Triticum aestivum L.)] were the most promising cover crops with respect to cover density, competitiveness against weeds, and degree of kill by glyphosate. Crimson clover (Trifolium incarnatum L.) and hairy vetch (Vicia villosa Roth) were the most promising legumes, but they generally were less satisfactory than the grassy covers in all tested aspects. A single application of glyphosate was ineffective in killing hairy vetch at both locations. Chemical name used: N-(phosphonomethyl)glycine (glyphosate).
Nitrogen Fertilization of Radishes on Histosols: Response and 15N Recovery
Authors: Sanchez C.A. , Ozaki H.Y. , Schuler K. , Lockhart M.
Published: February 2019

Experiments were conducted from 1985 to 1989 to evaluate the response of radishes (Raphanus sativus L.) to N fertilization on Histosols. Three of these experiments used 15N-labeled fertilizer to evaluate the recovery of N by radishes. There was no response to N fertilization in seven of the eight experiments, even though some of them were conducted under conditions of high rainfall. The one experiment in which radish yields increased with N was conducted in a poorly drained, waterlogged field that was atypical of normal radish production fields. Recoveries of fertilizer N in the marketable radish roots averaged 19%. The results of N and 15N analysis showed that although fertilizer N was available for uptake, so was an ample amount of soil mineralized N. These results indicate that under typical growing conditions, radishes produced on Florida Histosols do not respond to N fertilization.
Response of Young Olive Trees to Sodium and Boron Excess in Irrigation Water
Authors: Benlloch M. , Arboleda F. , Barranco D. , Fernández-Escobar R.
Published: February 2019

The influence of sodium and boron excess in the irrigation water on shoot growth and on the distribution of these elements within various leaf types was studied on rooted olive cuttings (Olea europaea L.). `Lechín de Granada' was more tolerant than `Manzanillo' to sodium excess, as indicated by greater shoot growth and lower accumulation of sodium, especially in the young leaves. `Picual' was more tolerant to boron than `Manzanillo', with less accumulation in adult leaves. The results suggest the avoidance of toxicity by an ionic exclusion mechanism that is more effective in some cultivars than others. Also, the results reveal cultivar differences in the tolerance of olive to sodium and boron excess in the culture medium.
Susceptibility of Pear Cultivars to Blossom Blast Caused by Pseudomonas syringae
Authors: Whitesides Steven K. , Spotts Robert A.
Published: February 2019

Conditions were established for inducing pear (Pyrus communis L.) blossom blast caused by Pseudomonas syringae (Ps) on detached shoots. Highest incidence of infection followed occurrence of a major exotherm in the presence of Ps suspended in water drops on blossom tissue. Eight pear cultivars were evaluated for susceptibility to blossom blast, with the red-fruited `Beurré d'Anjou' sports `Gebhart' and `Columbia' least susceptible and `Doyenné du Cornice', `Beurré d'Anjou', and `Beurré Bosc' most susceptible.