bluuebunny/crossref_metadata_2025 huggingface dataset:
TIMING OF OSMOCOTE REAPPLICATION ON GROWTH OF CONTAINERIZED `HELLERI' HOLLY.
Authors: Wright Robert D. , Witt Mike , Leda Carol
Published: February 2019

Ilex crenata `Helleri' rooted cuttings were container grown for one summer with Osmocote 18N-2.6P-7.6K which was reapplied at different times. Beginning in April and every month thereafter until October, five plants were harvested and separated into roots and shoots for dry weight and nitrogen (N) analysis. Plants that had received a reapplication of Osmocote in June or July were larger in October than those that received no supplemental fertilizer. If reapplication occurred in August or September, no influence on growth was realized. Plants that were not supplemented had lower percent tissue and medium solution N. These data demonstrate that tissue nutrient analysis as well as the medium nutrient levels extracted with the pour-through procedure can be used to determine when reapplication of a slow-release fertilizer is necessary to promote optimal growth.
ABNORMAL SEGREGATION FOR MORPHOLOGICAL MARKER GENES IN PROGENIES OF TISSUE CULTURE-DERIVED REGENERANTS OF HETEROZYGOUS TOMATO HYBRIDS
Authors: Oh Dae-Geun , Chrzastek Maria , Tigchelaar Edward C.
Published: February 2019

Heterozygous multiple marker genetic stocks were synthesized by crossing three multiple genetic marker stocks to a common inbred parent PU812. The four parents and 3 F1's were cultured to obtain regenerants from leaf discs. Fifty four regenerants were derived from 3 F1's and 12 from the 4 parents, Among the regenerants, 16 plants were identified as tetraploid (24.2%); low fertility was usually associated with tetraploidy, however there were a few exceptions.

Selfed seeds, identified by cluster number, were harvested from sexual F1's and R0 plants for F2 progeny tests for the known marker genes. While there were no abnormal segregations for marker genes in the sexual progenies, 13 of 46 progenies from tissue culture derived regenerants showed significant deviations from expected normal segregations for a number of markers. Two of the abnormal progenies were identified as tetraploids by root-tip examinations; segregation ratios fit duplex random chromatid segregation for gene a on chromosome 11 and random chromosome segregation for gene c on chromosome 6. The cams of abnormal segregations in other progenies remain unknown. Results suggest that unknown genetic events arising during tissue culture may distort segregations for marker genes in the subsequent sexual progeny of tissue culture regenerants.
CHANGES IN THE ESSENTIAL OILS AND TRICHOME DENSITY OF OCIMUM BASILICUM L.
Authors: Murray Renee G. , Simon James E.
Published: February 2019

Essential oil content of Ocimum basilicum, cv. sweet basil, increases with plant maturity. The increase in essential oil content may correspond to the formation of glandular trichomes during leaf expansion. Greenhouse grown plants were harvested every 2 weeks. Leaves were grouped according to size, examined with a stereo microscope, and trichome densities compared. Results indicate that trichome formation continues throughout leaf expansion. In young basil plants, leaves ranged in size from 2-30cm2 Highest density (416 trichomes/cm2) occurred in leaves 2–6c m2. Prior to open bloom, leaves ranged in size from 2-49cm2. Highest density occurred in leaves 18-24c m2. In flowering plants leaves ranged in size from 2-34cm2, yet there was NSD in trichome density in leaves of different sizes. Analysis of the entire leaf surface of plants at each harvest showed the greatest density of trichomes in plants at full bloom (280 trichomes/c m2). All leaves have visible glandular trichomes. These glandular trichomes are most likely formed both prior to and during leaf expansion.
STRAWBERRY LEAF PHOTOSYNTHESIS ACCLIMATION TO TEMPERATURE
Authors: Caldwell J.D. , Hancock J.F. , Flore J.A.
Published: February 2019

The commercial strawberry Frageria × ananassa and several clones of F. chiloensis and F. virginiana were preconditioned in growth chambers under the following conditions: 500 μmol m-7s-1 PAR and 20° day, 10° night or 30° day and 20° night. After at least 3 weeks of preconditioning at the two different temperature regimes, leaf photosynthetic rate (A) was determined for temperatures ranging from 10 to 35° in 2-3° increments with an open gas exchange system under laboratory conditions. The objective was to determine if F. virginiana and F. × ananassa can photosynthesize at higher temperatures than F. chiloensis, and if any of these would acclimate to higher temperatures. F. chiloensis did not acclimate to higher temperatures, and bad maximum A between 16 and 20°. F. virginiana did acclimate to higher temperatures, with maximum A for the low temp treatment between 18 and 24°, and for the high temp treatment between 24 and 30°. The commercial cultivars of `Earliglow' and `Redchief' acclimated to higher temperature and responded similar to F. virginiana.
TRAINING PERMANENT AND TEMPORARY TREES
Authors: Connell Joseph H. , Micke Warren , Yeager James , Hasey Janine , Krueger Bill , Weakley Craig
Published: February 2019

High orchard establishment costs require greater production early in an orchard's life. Our goal was to develop temporary trees at the least cost with the best early production. Health and longevity of permanent trees is essential. Six pruning treatments were evaluated in five-tree plots using a randomized complete block design. Each treatment was replicated four times on the `Butte' and `Mission' almond cultivars. After six years, temporary trees receiving the least pruning had the highest yields. Permanent trees had lower yields since more pruning was done in the second through fourth dormant seasons to develop branch framework for the long term. `Butte' and `Mission' responses to treatment varied due to varietal growth habits. Effects on tree development and the need for later corrective pruning were noted. After four harvests, yields were greater with less pruning.
INFLUENCES OF NH4+ AND NO3- ON UPTAKE OF Cl- IONS BY AGERATUM, PETUNIA, AND SALVIA
Authors: Jeong Byoung Ryong , Lee Chi Won
Published: February 2019

This study was carried out to determine the interaction among NH4+, NO3-, and Cl- ion uptake and to find the causes of NH4+ -related toxicity symptoms in plants fed with NH4+ as a sole nitrogen source. Seedling plants established in peat-lite and rockwool media were fed with nutrient solutions containing either NH4+ or NO3- or both NH4+ plus NO3- with or without Cl-. Plants grown with NH4+ + Cl- contained the highest levels of Cl-. Plants fed with NO3- + Cl- also showed high levels of Cl- in the tissue. The growth and tissue Cl- contents of plants fed with NH4+ were not affected by changes in Cl- concentration in the nutrient solution. Plants fed with NH4+ that was ion-balanced by high levels of SO42- plus low or no Cl- still developed the NH4+ -related toxicity symptoms. This indicates that NH4+ -related toxicity symptoms occur independently of Cl-. It was also shown that the activity of Cl-, a counterion for NH4+ uptake, was suppressed by NO3-.
LENTICEL HYPERTROPHY OF FLOODED MANGO TREES
Authors: Larson Kirk D. , Schaffer Bruce , Davies Frederick S.
Published: February 2019

One-year-old potted `Peach' mango (Mangifera indica L.) trees were flooded at soil temperatures of 15, 22.5 or 30°C. Hypertrophied lenticels were observed after 5-6 days at 30°C and 6-8 days at 22.5°C, but were not observed after 30 days at 15°C. Cells of hypertrophied lenticels were more spherical and randomly arranged than those of nonhypertrophied lenticels, resulting in increased intercellular airspace. Lenticel hypertrophy also occurred on sterns of trees which were kept moist from intermittant misting, and on excised and intact stem sections. Therefore, formation of hypertrophied lenticels in mango occurs independently of root anaerobiosis and is dependent on floodwater temperature.
HIGH TEMPERATURE RESPONSE IN BEAN -BREEDING CONSIDERATIONS
Authors: Davis David W. , Sauter Karl J.
Published: February 2019

Attention has been given in recent literature to crop breeding for heat tolerance, but, as with certain other physiological traits, such as photosynthetic efficiency, practical gain has lagged. The question remains as to whether heat tolerance can be improved, and, if so, if it can most efficiently be improved by a holistic approach, as in breeding for yield following timely high temperature levels in the field environment, or whether the breeding for heat (and drought) tolerance components in the laboratory would be feasible. At issue is the identification and repeatability of key plant responses, such as cell membrane damage, heat shock protein formation, increased ethylene output and other responses, and the relevance, effectiveness and cost of screening for such traits. Results from our laboratory, and the work of others, will be reviewed.
MINIMIZING ENVIRONMENTAL STRESS IN BEDDING PLANT AND GREENHOUSE PRODUCTION
Authors: Armitage Allan M.
Published: February 2019

Minimizing environmental stress in bedding plant and greenhouse and seedling development has occupied many researchers in academia and industry for many years. The dependence on single plant germination units (plugs) for bedding plant production and high value hybrid seed demand high rates of germination and successful seedling establishment. Pre-germinating or priming of seed is an important method of germination enhancement and methods and benefits of “priming” will be discussed. Environmental options to enhance seed germination of non-primed seed include control of vapor pressure deficit (VPD) and temperature.

Enhancement of seedling establishment through growth room and greenhouse technology includes the optimal use of CO2, temperature and light. Carbon dioxide fertilization on seedlings is receiving serious study and will be further elucidated.
INTERACTION OF WATER SUPPLY PLANNING AND ENVIRONMENTAL PROTECTION
Authors: Luecke Daniel F.
Published: February 2019

Water resource development, particularly dam construction and inter basin diversions, can cause substantial environmental damage. Minimizing future damage can best be accomplished by using existing systems more efficiently, thus. reducing the need for supply augmentation: In the U.S., agriculture accounts for 83% of the annual total water consumption. The municipal and industrial sectors account for the remaining use. These shares are inversely related to economic value; agricultural water is worth between $30 and $75 per acre-foot in most applications while water in the municipal sector may be worth as much as $300 to $500 per acre-foot. The system inefficiencies implied by the sectors' use and relative economic values make it clear that water supply planning can be improved. If cost-effectiveness were the criterion against which water supply options and alternatives were assessed, system management and end–use efficiency would replace supply augmentation. Institutional, not technical, constraints prevent the adoption of the mote efficient options. Were these constraints relaxed, the monetary and environmental savings would be substantial.
Response of Radish to Phosphorus and Potassium Fertilization on Histosols
Authors: Sanchez C.A. , Lockhart M. , Porter P.S.
Published: February 2019

Five field experiments were conducted from 1986 through 1988 to evaluate the response of radish (Raphanus sativus L.) to rate and source of P (triple superphosphate and phosphoric acid) and to rate of K (KC1) on Histosols. Marketable radish root yields increased with P fertilization when the soil tested <13 mg P/dm3 using a test for water-soluble P. No significant differences were due to P source. Results of leaf tissue analysis suggested that the critical concentration of P in radish leaves was 0.45%. Radish did not respond to K fertilization in any of the five experiments, even though preliminary soil-test K levels ranged from 20 to 102 K/dm3. Histosols used for crop production in Florida rarely test below 20 mg K/dm3; thus, radish rarely would require supplementary K fertilization for optimal yield.
Nutrient Concentration and Fruit Thinning Affect Shelf Life of Long English Cucumber
Authors: Lin W.C. , Ehret D.L.
Published: February 2019

Long English cucumber (Cucumis sativus L.) plants were treated with one of three nutrient concentrations in combination with two fruit thinning treatments forming a 3 × 2 factorial greenhouse experiment. High nutrient concentration enhanced fruit color at harvest and prolonged shelf life but reduced marketable fruit per plant. Thinning of one-third of the fruit from the main stem and laterals had a similar effect. Cucumbers harvested from the upper canopy generally had longer shelf life than those from the lower canopy. Shelf life was correlated with fruit color at harvest.
Induction of Tumors in Anthurium andraeanum by Agrobactemium tumefaciens
Authors: Kuehnle A.R. , Sugii N.
Published: February 2019

A method was devised for infecting Anthurium andraeanum Linden ex André, an economically important ornamental monocot, with Agrobacterium tumefaciens. Tumors were obtained on plant stems 7 to 10 weeks after inoculation with oncogenic A. tumefaciens strains C58 and A281 cultured previously in an induction medium containing 200 μm acetosyringone at pH 5.5. A higher percentage of tumors were formed in vitro on etiolated internodes (32%) than on green leaf (2%) or petiole explants (3%) 4 weeks after inoculation with induced C58. All explants treated with nontumorigenic A. radiobacter or with induction medium alone failed to produce tumors. Chromatograms showed an accumulation of nopaline in internode explant tumors induced with C58. DNA amplification and hybridization studies showed that the DNA from these tumors, but not from noninoculated anthurium tissue, contained sequences homologous to the nopaline synthase gene of A. tumefaciens T-DNA. Chemical names used 3,5-dimethoxy 4-hydroxyacetophenone (acetosyringone).
Production of Cuitlacoche [Ustilago maydis (DS) Corda] on Sweet Corn
Authors: Pataky J.K.
Published: February 2019

In parts of central Mexico, galls of common smut, caused by Ustilago maydis (Syn = Ustilago zeae Ung.), on ears of corn (Zea mays L.) are an edible delicacy known as cuitlacoche. Preliminary studies were done to identify methods to increase formation of ear galls on sweet corn. Of 370 sweet corn hybrids evaluated in disease nurseries, 38 hybrids were identified for which incidence of ear galls exceeded 40% in 1987 or 1988 or exceeded 12% in 1990. Inoculation techniques for inducing ear galls were: 1) spraying sporidial suspensions between leaf sheaths and stalks at the sixth to eighth nodes; 2) injecting sporidial suspensions into the sixth to eighth internodes; 3) wounding leaf sheaths at the sixth to eighth nodes with sand, followed by spraying a sporidial suspension into wounds; and 4) wounding leaf sheaths at the sixth to eighth nodes with sand in which teliospores were mixed. Only the sporidial injection technique substantially increased the incidence of smut, but it increased the incidence of stalk, tassel, and leaf galls more than ear galls. Thus, additional research is needed to determine when and how to inoculate with U. maydis to induce the formation of ear galls necessary to commercially produce cuitlacoche and to screen for disease resistance.
Effect of Manganese Source on Manganese Uptake by Pygmy Date Palms
Authors: Broschat Timothy K.
Published: February 2019

Pygmy date palms (Phoenix roebelenii `O'Brien') growing in a pine bark-Canadian peat-sand container medium and in a sandy field soil were fertilized with one of five commercially available Mn sources. Fertilization with Mn sulfate plus ammonium sulfate consistently increased Mn uptake above that of control palms. Four soluble Mn sources were applied to the foliage of container-grown palms, but only Mu sulfate consistently increased Mn concentrations in the leaves. Addition of urea, calcium hydroxide, or dimethylsulfozide did not improve Mn uptake from foliar sprays, and foliar sprays and soil applications were equally rapid in their effects on leaf Mn concentration.
Stability of Strawberry Genotypes in the Annual Hill Cultural System
Authors: Chandler Craig K. , Stoffella Peter J. , Albregts Earl E. , Howard Charles M.
Published: February 2019

Plants of `Selva', `Pajaro', and three Univ. of Florida strawberry (Fragaria × ananassa Duch.) selections were grown near Dover, Fla., for five seasons using the annual hill cultural system. Genotype × environment interactions were significant for both marketable yield and fruit weight; therefore, stability analyses were performed. None of the genotypes had consistently high marketable yield, but one of the selections, FL M-1350, had relatively large and stable average fruit size. A genotype was desirable if it had a mean yield (or fruit weight) above the grand mean of all five genotypes, a regression coefficient 1, and a nonsignificant deviation from regression.
Time of Flooding and Cultivar Affect Sweetpotato Yield
Authors: Roberts Warren , Russo Vincent
Published: February 2019

The sweetpotato [Ipomoea batatas (L.) Lam] cultivars Jewel, Shore Gold, and Cordner, and the breeding line W241 were either 1) not flooded, 2) flooded for 5 days during midseason, or 3) flooded for 5 days just before harvest. Flooding just before harvest did not affect marketable yield, but flooding at midseason reduced marketable yield by 36% in 1989 and by 53% in 1990 and reduced the No. 1 grade yield by 46% in 1989 and by 57% in 1990. Marketable yield of `Jewel' was higher than that of `Cordner' in 1989, and that of `Shore Gold' exceeded that of `Jewel' in 1990. There were no interactions between flooding treatments and cultivars.
Stand Establishment of Fluid-drilled Tomato in Rye and Wheat Tillage Systems
Authors: Drost D.T. , Price H.C.
Published: February 2019

Tomatoes (Lycopersicon esculentum Mill.) were grown in conventional tillage (CT), rye (Secale cereale L.) mulch no tillage (RNT), and wheat (Triticum aestivum L.) mulch no tillage (WNT). Either germinated seeds (GS) or raw seeds (RS) were fluid drilled on several dates in 1981 and 1982. Tomato stands in no tillage (NT) generally were equal to or higher than in CT, and stands improved with later plantings in each year. Plant stands were unaffected by GS and RS. Time to 50% emergence (T50) was up to 4 days less in NT than in CT and 2 to 3 days less from GS than RS. Yields with CT were twice as high as those with NT for early planting dates. Yields decreased in CT with successive planting dates to levels equal to NT plantings. Use of GS increased fruit yields as compared to RS, regardless of the planting date.
A New Culture Medium for in Vitro Rhizogenesis of Grapevine (Vitis spp.) Genotypes
Authors: Roubelakis-Angelakis K.A. , Zivanovitc S.B.
Published: February 2019

A modified culture medium is presented that promotes in vitro rooting of grapevine rootstock and Vitis vinifera L. cultivars even in the absence of plant growth regulators. Study of 15 Vitis genotypes indicated a strong genotype-dependent response to culture medium and growth regulators with respect to formation of roots in onenode shoot segments.
Changes in Metabolic Enzyme Activities during Thidiazuron-induced Lateral Budbreak of Apple
Authors: Wang Shiow Y. , Jiao Hong J. , Faust Miklos
Published: February 2019

The activity of glucose-6-phosphate dehydrogenase (G6PDH), 6-phosphate gluconate dehydrogenase (6PGDH), isocitrate dehydrogenase (ICDH), pyruvate kinase (PK), and glyceraldehyde-3-phosphate dehydrogenase (GAPDH) were studied in apple (Malus domestics Borkh.) buds during dormancy and thidiazuron-induced budbreak. When buds were dormant, the activity of the glycolytic enzymes GAPDH and PK and the tricarboxylic acid (TCA) cycle enzyme ICDH was low compared to that in nondormant buds. The activity of these enzymes increased during budbreak, peaked when buds were in the green tip stage just before the start of rapid expansion (at 8 days after thidiazuron treatment), and declined thereafter. The activity of pentose-phosphate cycle enzymes G6PDH and 6PGDH was higher in dormant buds than in nondormant buds. 6PGDH was about twice as high as G6PDH. During budbreak and resumption of growth, G6PDH and 6PGDH activity decreased.
Relative Virulence of Agrobacterium Strains on Strawberry
Authors: Uratsu Sandra L. , Ahmadi Hamid , Bringhurst Royce S. , Dandekar Abhaya M.
Published: February 2019

Several strains of Agrobacterium tumefaciens and A. rhizogenes were shown to form tumors on runners of the diploid strawberry species Fragaria vesca L. Tumors, weighing from 0.1 to 8.3 mg, appeared from 2 to 4.5 weeks after infection. The majority of tumors tested for opine synthesis by high-voltage paper electrophoresis analysis showed positive results. These results demonstrate that diploid strawberry plants are susceptible to infection with Agrobacterium and that there are differences in the relative virulence of Agrobacterium strains.
Nitrogen Application Frequency for Drip-irrigated Tomatoes
Authors: Cook Wilton P. , Sanders Douglas C.
Published: February 2019

Studies were conducted to determine the effect of N application frequency through drip irrigation on soil NO3-N movement in the bed profile and on yield and N uptake by tomato plants (Lycopersicon esculentum Mill. `Sunny') at two locations. Increasing N application frequency resulted in increased yields at Clayton, N. C., but not at Charleston, S.C. The number of fruit produced was not affected by N treatment at either location, but fruit size increased with increasing N application frequency at Clayton. Foliage N concentration decreased seasonally, but neither foliage N concentration nor total N content of the above-ground portion of the plants was affected by N application frequency. Regardless of N application frequency, NO3-N concentrations within the raised bed decreased with time due to plant uptake and leaching. Nitrogen levels declined most rapidly in the area closest to the drip tube.
Creeping Bentgrass Damaged by Low Levels of Atrazine in Irrigation Water
Authors: Nus J.L. , Sandburg M.A.
Published: February 2019

Throughout the north-south climatic transition zone of the eastern United States, cool- and warm-season turfgrasses are used adjacently. A greenhouse study with creeping bentgrass (Agrostis palustris Huds.) was initiated to determine threshold concentrations of atrazine, an effective pre- and postemergence herbicide for warm-season turfgrasses, that would result in unacceptable levels of phytotoxicity to seedling and mature creeping bentgrass. Mature and 8-week-old seedling `Penncross' creeping bentgrass were given 6.5 mm of daily irrigation of untreated water or water containing atrazine at 0.01, 0.02, 0.04, 0.08, 0.16, 0.32, 0.64, 1.28, or 2.56 mg·liter-1. A model of quality ratings taken 20 days after the initiation of treatments indicated threshold concentrations resulting in unacceptable turf quality to be approximately 0.05 and 0.08 mg·liter-1 for seedling and mature bentgrass, respectively. Chemical name used: 2-chloro-4-ethylamino-5-isopropylamino-s-triazine (atrazine).
ORGANOGENESIS FROM CEPHALOTAXUS HARRINGTONIA CALLUS: ESTABLISHMENT OF SHOOTS AND ROOT CULTURES
Authors: Wickremesinhe Enaksha R. , Arteca Richard N.
Published: February 2019

Fast growing callus was derived from Cephalotaxus harringtonia stem explants placed on MS basal salt medium with B-5 vitamins, 3% sucrose, 1 μM kinetin and 4.5 μM 2,4-D. Callus placed on basal medium with 10 μM kinetin and 0.45 μM 2,4-D turned green and organogenesis was observed upon subculture onto basal medium without hormones. Shoots were excised and placed on 1/2 strength MS salts and 10% sucrose for further shoot development. During the process of organogenesis, we also observed the differentiation of roots. Rapidly growing root cultures were established by culturing them under a 24 hour light regime of 35 μM/m2/s. Two grams of root tip explants cultured on B-5 medium with 2% sucrose were capable of producing an average of 24 grams of roots within 11 days. A 20-fold increase in fresh weight was achieved within 3 weeks when 15 grams of these roots were cultured in a 3 liter air-sparged bioreactor. C. harringtonia contains a number of alkaloids that exhibit cytotoxicity and are being evaluated as chemotherapeutic agents. We are currently in the process of establishing growth characteristics for these roots and assaying roots for the presence of these alkaloids. All cultures were grown under a 12 hour light regime unless otherwise stated.
LOW INPUT CRANBERRY PRODUCTION: FIELD DEMONSTRATION AND ANALYSIS
Authors: Averill A. , DeMoranville C. , Deubert K. , Morzuch B. , Edwards S.
Published: February 2019

Low input cranberry production was carried out at 4 sites (2 each for the common MA cultivars) to demonstrate: 1. reduced pesticide and fertilizer input; 2. enhanced water quality (compared to standard management); 3. ecomonic feasibility. Presented results: 1. number of insecticide applications reduced 60%, number of fungicide applications reduced 40% (at least half were copper based non-synthetics), broadcast herbicides used at less than 1/2 allowed rate (if at all), fertilizer N input reduced 30% on average; 2. reduced chemical input impacted positively on water quality; 3. crop quality was maintained but yield was reduced. Because the MA cranberry crop was down by up to 40% due to weather-related factors, crop reductions cannot be accurately assigned to cultural and management practices. The project will continue for at least 2 more years.
EVALUATION OF STRAWBERRY CULTIVARS WITH DIFFERENT DEGREES OF RESISTANCE TO RED STELE
Authors: Khanlzadeh Shahrokh , Pelletler Robert , Lareau Michel J. , Buszard Deborah
Published: February 2019

Sixteen commercially grown strawberry cultivars with different degrees of resistance to red stele were evaluated for yield, plant characteristics and fruit quality. `Bounty', `Midway', and `Sparkle' had sufficient interior and exterior fruit color, good to satisfactory flavor and suitability for freezing. However, these cultivars as well as `Redcoat' lacked sufficient fruit firmness. `Bounty', `Redcoat', `Redchief and `Sparkle' had the highest yield in the three-year test. `Annapolis', `Earliglow' and `Scott' had reflexed calyx whereas `Allstar', `Annapolis', `Cornwallis', `Earllglow', `Guardian' and `Sunrise' were characterized by a raised neck suitable for mechanical dehulling. `Sunrise' appeared to be the only cultivar free of leaf scorch and leaf spot. `Tristar', `Redchief, `Lester', `Darrow' and `Arking' roots had the lowest incidence of red stele when planted in a naturally-infested field. No relationship between fruit characteristics was observed which suggests the necessity to examine each Individual tralt.
THE EFFECT OF SOIL SOLARIZATION ON GROWTH AND UNEVEN RIPENING OF `CARLOS' MUSCADINE GRAPES
Authors: Stevens C. , Khan V. A. , Lu J. Y. , Kabwe M. K. , Haung Z. , Wilson M. A. , Brown J. E.
Published: February 2019

In 1988 and 1989 a muscadine vineyard at Tuskegee, Alabama was treated by post soil solarization (PSS) (covering of moist soil around muscadine plants with clear polyethylene plastic mulch to achieve high soil temperature) for 30 and 75 days, respectively. The average soil temperature in 1989 of 50 and 35 C at 5cm depth for solarized and bare soil, respectively during PSS. The results showed no visible detrimental effect on `Carlos' muscadine (Vitis rotundifolia) from the increased heating of the soil. And the grape plants grown in solarized soils showed increases in growth response e.g. increased yield, revitalization of new softwood vines, vine weight/plant, etc. Uneven ripening of muscadine grapes was reduced on plants grown in PSS over bare soil as indicated by the increases in the percent soluble solids content of grape berries.
EFFECTS OF EVAPORATIVE COOLING ON COLD HARDINESS OF CHARDONNAY AND CABERNET SAUVIGNON BUDS DURING DEACCLIMATION
Authors: Lipe W.N. , Baurnhardt L. , Wendt C.W. , Rayburn D.J.
Published: February 2019

Freeze losses to grapes in March, after mild deacclimatizing winters, is the major production risk on the Texas High Plains. Earlier studies indicated the effectiveness of evaporative cooling in reducing grape bud heat summation with a correlated delay in budbreak. Parameters relating to water-use-efficiency were identified. In the current study, these parameters were incorporated to minimize water use. Water was applied through microjets for 25 seconds every 4 minutes any time air temperature exceeded 10°C, 15°C, and Control. Bud temperatures were monitored continuously by thermocouples and data logger, and correlated with budbreak and plant development. Random bud samples were taken weekly prior to budbreak and subjected to differential thermal analysis. A freeze on March 23 (-3.5°C) resulted in differential primary bud losses to Chardonnay during budbreak, and to Cabernet Sauvignon 15 days prior to budbreak. Evaporative cooling significantly increased yields in both cultivars. Differential thermal analysis verified differences in cold stress tolerance in Chardonay prior to budbreak.
THE ROLE OF A THERMOPHILIC FUNGUS IN THE ROOT ROT / VINE DECLINE DISEASE OF MUSKMELON IN TEXAS.
Authors: Martyn Ray D. , Mertely J. C. , Miller M. E. , Bruton B. D.
Published: February 2019

A disease of muskmelon (Cucumis melo L.) characterized by a vine decline and a cortical root rot was first observed in the Lower Rio Grande Valley of Texas in 1986. In 1990, isolations from diseased plants collected from four commercial production fields yielded the fungus Monosporascus cannonballus. Pathogenicity tests with eight isolates confirmed Koch's postulates; however, there were differences in aggressiveness observed among isolates. M. cannonballus is an ascomycete fungus that typically produces only one (rarely two), round, jet-black ascospore per ascus. There is no known asexual stage. Temperature optimum of one isolate was 35 C. The optimum pH for growth was 6-7, but it grew well up to pH 9. M. cannonballus was first reported on muskmelon in 1970 from Arizona and recently was found in Japan under glass house culture. The presence of this fungus in Texas marks only the third report of this species worldwide, although a similar species (M. eutypoides) is the cause of a collapse of melon plants in Israel.
FRUITING CHARACTERISTICS OF HOT PEPPERS
Authors: McKelly Bernadette , Rhoden E. G. , Carver G.W.
Published: February 2019

Hot pepper (Capsicum annum) is gaining popularity as a food flavor additive. A study was initiated to determine the fruiting characteristics of two hot pepper cultivars; `Scotch Bonnet' and `Brown Lue'. After evaluating 100 fruits of each cultivar, it was found that `Scotch Bonnet' fruits had 34% more seeds and these seeds weighed 9% more than `Brown Lue'. Although `Brown Lue' had longer fruits (3.89 vs 3.33 cm) than `Scotch Bonnet', this difference was not significant. In addition, `Scotch Bonnet' had greater fruit circumference and circumference to length ratio than `Brown Lue'. When fruits were compared for fresh and dried weights, there was no significant difference. However, `Brown Lue' had a significantly higher percent dry matter. Based on dry matter, if fruits were to be produced for crushed peppers, it might be more advantageous to use `Brown Lue'.
Carbon Dioxide Injury and Flesh Softening Following High-temperature Conditioning in Peaches
Authors: Nanos George D. , Mitchell F. Gordon
Published: February 2019

`High-temperature controlled-atmosphere (high CO2/low O2) conditioning was investigated as a possible treatment to delay the incidence of internal breakdown of peaches and nectarines (Prunus persica L. Batsch) during subsequent cold storage. Maintaining an atmosphere of 5% to 15% CO2 added to air or to 1% to 5% O2 while conditioning peaches for 2 days at 20C partially prevented fruit ripening (compared to fruit conditioned in air), as measured by flesh softening and loss of green pigment, while no off-flavors were detected. Conditioning of peaches at 20C for 4 days in air or in air + 20% CO2 was detrimental to fruit quality, as indicated by flesh softening or detection of off-flavors.
MODIFIED-ATMOSPHERE STORAGE DOES NOT SUBSTITUTE FOR LOW-TEMPERATURE STORAGE OF STRAWBERRY
Authors: Al-Redhaiman Khalid N. , Nonnecke Gail R. , Gladon Richard J.
Published: February 2019

'Honeoye' (June-bearing) and 'Tristar' (day-neutral) strawberries were harvested, graded, and then stored for 7 days et 2C or 21C in air (control) or each of these 8 modified atmospheres: 1.5% O2, 3.5% O2, 15% CO2, 25% CO2, 1.5% O2 + 15% CO2, 1.5% O2 + 25% CO2, 3.5% O2 + 15% CO2, and 3.5% O2 + 25% CO2; all balance N2. When compared with storage at 21C, storage at 2C reduced weight loss and gray mold growth in all corresponding sets of storage atmosphere treatments. The combination of increased CO2 and decreased O2 controlled weight loss and gray mold growth more effectively than treatment with reduced O2 alone. Storage at 2C (versus 21C) reduced respiration of both cultivars. Respiration decreased as the O2 concentration decreased. 'Tristar' did not produce C2H4 at either temperature, whereas `Honeoye' produced more C2H4 at 21C than it did at 2C. Increased CO2 and/or decreased O2 concentrations in the storage atmosphere are not satisfactory substitutes for proper low-temperature storage of strawberries.
RELATIONSHIP BETWEEN CHROMATICITY VALUES AND LYCOPENE CONCENTRATION IN TOMATO FRUITS
Authors: D'Souza Mervyn C. , Ingle Morris , Singha Suman
Published: February 2019

Lycopene is the predominant carotenoid pigment in tomatoes and primarily responsible for red color. Spectrophotometric procedures for lycopene evaluation although accurate are time consuming and destructive. The objective of this study was to relate chromaticity values (L*,a*,b*) measured using a Minolta Chroma Meter CR-200b portable tristimulus calorimeter with lycopene concentrations in the pericarp of 'Celebrity', 'Mountain Delight' and 'Early Pick' tomatoes. Fruit were selected to encompass varying maturities from green to red ripe and were obtained from a commercial source. Lycopene from individual skin disks or pericarp plugs corresponding to each location of color measurement was extracted in acetone and measured spectrophotometrically at 503 nm. The L* value (a measure of lightness) or a* value (a measure of redness) was determined to be well correlated with lycopene concentration in all 3 cultivars. The linear regression of the lycopene concentration on the ratio of (a*/b*) provided the best R for all cultivars (0.75).
SONIC VIBRATION AS A NONDESTRUCTIVE METHOD FOR APPLE FIRMNESS MEASUREMENT
Authors: Abbott Judith A. , Liljedahl Louis A.
Published: February 2019

Sonic vibrational characteristics of intact apples are related to flesh elasticity which is, in turn, related to firmness. Firmness changes in Golden Delicious and Delicious apples were followed during accelerated ripening and under storage conditions. Firmness was measured by Magness-Taylor puncture force and by compression of tissue cylinders (modulus of elasticity and rupture strength) for comparison with sonic vibrational characteristics of intact apples. Influences of apple temperature, size, shape, and skin on sonic spectra were investigated. Sonic resonant frequencies were significantly correlated with destructive firmness measurements and decreased as storage time increased. Sonic amplitudes were not closely related to firmness. Regression equations incorporating sonic data and size were developed to predict Magness-Taylor force. Use of sonic vibrational characteristics is proposed as a rapid nondestructive method for firmness sorting of apples.
DEVELOPMENT OF AN EXPERT SYSTEM
Authors: McClure Janice E.
Published: February 2019

The development of expert systems in agriculture consists of many steps such as problem definition, selection of experts, audience considerations, knowledge representation, coding, testing, and feedback. The problem definition and selection of experts for the problem domain are the foundation of a working system. Audience definition, economics and goal setting are areas that must be documented before knowledge engineering. Knowledge representation methods and system conceptual layout are the next level of development. The use of the user feedback and field testing data to improve the system are often overlooked. Benefits of expert systems for on farm decision making include education, efficiency, and adaption to changing regulations. Many aspects of agricultural expert systems are similar to traditional expert systems; yet special problem inherent in agriculture make the development interesting and challenging.
Temperature and Relative Humidity Govern Germination and Storage of Gladiolus Seed
Authors: Carpenter W.J. , Wilfret G.J. , Cornell J.A.
Published: February 2019

Gladiolus (G. grandiflorus) seed germination was light-independent, but temperature influenced the germination rate. Constant 20C promoted higher total germination (97%), fewer days (4.3) to 50% of final germination, and shorter span of days (4.8) between 10% and 90% germination than other constant temperatures, although similar results were achieved by alternating 12-h cycles of 20 to 25C. Total germination was unchanged after seed treatment for 7 days at 10 to -20C, but longer germination periods were required after treatments below -10C. Reducing seed moisture contents from 11.8% to 4.2% caused no reduction in total germination, but moisture contents below 6.6% delayed achieving 50% of final germination and extended the periods from 10% to 90% of germination. Temperature and relative humidity (RH) during storage were important in retaining seed viability, with RH having a larger effect. Smallest declines in total germination during 12 months of storage occurred at 11% and 33% RH at 15C. The statistical analysis estimated the optimum seed storage at 14C and 26% RH.
Shade Affects Yield and Stem Length of Field-grown Cut-flower Species
Authors: Armitage A.M.
Published: February 2019

Various field-grown specialty cut-flower species were subjected to full sun or 55% or 67% shade treatments for 2 to 3 years. Plants grown in shade had longer flower stems than those grown in ambient irradiance; however, yield (flower stems per plant) was species-dependent. Yield of Centaurea americana Nutt. `Jolly Joker', an annual speices, and Eryngium planum L., a perennial, declined linearly with each reduction in irradiance. However, yield of Echinops ritro L. `Taplow Blue', a perennial species, was higher in 55% shade than in ambient irradiance. Yield of transplants and tubers of Anemone coronaria L. `De Caen' were not affected by planting material (transplants or tubers). Plants grown under 67% shade had the longest stems starting 3 weeks after the beginning of harvest and the difference persisted for an additional 4 weeks regardless of planting material. A quadratic decline in yield in three of four cultivars of Zantedeschia Spreng. occurred as shade increased, but yield was similar for ambient and 55% shade. Scape length and spathe width increased as shade increased, although some cultivars were more responsive than others.
Strawberry Growth and Photosynthetic Responses to Paclobutrazol
Authors: Deyton Dennis E. , Sams Carl E. , Cummins John C.
Published: February 2019

Foliar sprays of increasing concentrations (0, 75, 150, 300, 600, and 1200 mg·liter-1) of paclobutrazol were applied to `Cardinal' strawberry plants (Fragaria × ananassa Duch.) 35 days after transplanting. The plants were established in August in cultivated plots for measurement of paclobutrazol effects on first year growth or in a double-row hill system on black polyethylene-covered raised beds for 2nd year measurements. Increasing the paclobutrazol concentration reduced the number of runners, decreased runner length, and limited biomass partitioned into daughter plants. By the end of the first growing season, paclobutrazol had increased lateral crown development but reduced leaf area per treated plant. Root growth was reduced by concentrations >600 mg·liter-1. Treatment with 75 to 300 mg·liter-1 increased total plant dry weight by 33% to 46%. The following spring, plant growth was decreased by ≥ 300 mg·liter-1. Yield was increased by all treatments, except 1200 mg·liter-1. Leaf net photosynthesis increased within 12 days after treatment with paclobutrazol and was higher than in the controls the next summer. Leaf stomata1 conductance also increased the first year and was significantly higher the 2nd year after treatment. The optimum concentration of paclobutrazol for strawberries appears to be between 150 and 300 mg·liter-1.
Extension of Postharvest Life of `Mission' Figs by CO2-enriched Atmospheres
Authors: Colelli Giancarlo , Mitchell F. Gordon , Kader Adel A.
Published: February 2019

Good quality of fresh `Mission' figs (Ficus carica L.) was maintained for up to 4 weeks when kept at 0, 2.2, or 5C in atmospheres enriched with 15% or 20% CO2. The visible benefits of exposure to high CO2 levels were reduction of decay incidence and maintenance of bright external appearance. Ethylene production was lower, and fruit softening (as measured with a deformation tester) was slower in the high-CO2-stored figs than in those kept in air. Ethanol content of the CO2-treated fruit increased slightly during the first 3 weeks and moderately during the 4th week, while acetaldehyde concentration increased during the first week, then decreased. The results may be applicable to the transport and storage of fresh `Mission' figs, as high CO2 extended their postharvest life, especially near 0C.
Controlled-atmosphere Effects on Blueberry Maggot and Lowbush Blueberry Fruit
Authors: Prange Robert K. , Lidster Perry D.
Published: February 2019

Larvae of the blueberry maggot (Rhagoletis mendax Curran) were raised on apples (Malus domestics Borkh. cv. Idared), and exposed larvae were treated 48 hours with CO concentrations ranging from 0% to 100% at O concentrations of 2%, 5%, or 20% (0% for the 100% CO) at 5 or 21C. Blueberry maggot survival was reduced to 10% when the larvae were subjected to CO concentrations > 45% at 21C. Fumigation was more effective at 21C than at 5C. Oxygen at 2% or 5% did not reduce larval survival when compared with treatments containing 20% O. In a separate experiment, six commercial shipments, each consisting of four hundred eighty 0.5-liter containers of infested lowbush blueberries (Vaccinium angustlfolium Ait.), were placed in a large fiberglass tank and fumigated with 54% CO at 21C. The blueberries were sampled for quality and larval survival after 24 and 48 hours of CO treatment. Atter 48 hours, 9% of the blueberry maggots in infested blueberries survived fumigation with 54% CO, while 68% of maggots survived in air. The quality of fumigated lowbush blueberries was not adversely affected by fumigation with 54% CO for up to 48 hours, as indicated by marketable berries, berry weight, split berries, shriveled berries, epicuticular wax (bloom), firmness, soluble solids and titratable acid concentrations, offflavors, and skin browning.
Evaluation of Spinach Germplasm for Resistance to a New Race (Race 4) of Peronospora farinosa f. sp. spinaciae
Authors: Brandenberger L.P. , Morelock T.E. , Correll J.C.
Published: February 2019

Spinach germplasm (707 accessions) from collections from six countries were screened for resistance to race 4 of the downy mildew pathogen Peronospora farinosa f. sp. spinaciae; these collections contained germplasm that originated from 41 countries. The predominant species examined was Spinacia oleracea L., however, eight accessions of S. turkestanica Iljin and two accessions of S. tetrandra Stev. were also tested. About 40 seedlings of each accession were inoculated. The cultivar St. Helens was included as a susceptible control in each test. The majority of accessions tested (>98%) were susceptible to race 4. Nine accessions exhibited some resistance to race 4 (9% to 38% of the seedlings within an accession were resistant), and two accessions, CGNO 9546 and SPI 82/87, exhibited a high level of resistance (60% and 80% resistant, respectively). Resistance identified in several of the accessions in this study may be useful for breeding for race 4 resistance.
INFLUENCE OF CANOPY POSITION ON CHR0MATICITY OF PEACH FRUIT.
Authors: Bible Bernard B. , Singha. S.
Published: February 2019

The objective of this study was to determine the difference in color development between exposed and shaded fruit of `Loring' and `Raritan Rose' peach (Prunus persica L. Batsch). Chromaticity values (L* a* b*) were measured with a Minolta CR-200b colorimeter on 10 tagged fruit on each of 3 trees of each cultivar. Five fruit were fully exposed to sunlight and 5 were shaded. Measurements were made on each fruit from July 17, 1991 through harvest. Differences in the a*/b* ratio between shaded and exposed fruit were observed at the first sampling date and increased towards maturation; shaded fruit approached a*/b* values similar to exposed fruit at a significantly later time. Shading reduced relative fruit color development more in `Loring' than in `Raritan Rose'.
THE SEARCH FOR IMPROVED LIMA BEANS YIELDS: A STARTING POINT
Authors: Wootten Tracy
Published: February 2019

Delaware lima bean yields have averaged 1700 lbs per acre for the last 30 years. California averages 3500-4000 lbs per acre. Varieties M-15 and 1072 are used by both states for production. In an effort to increase lima bean yields in Delaware, the evaluation of the effect of weather events on plant development, the relationship of ethylene and abscission of reproductive structures, and the comparison of both California and Delaware lima bean production is being conducted. Preliminary observations of 1991 data show a difference in plant size and population between the two states. Although pods per plant are the same in both states, the number of pods per acre is greater in California. California yielded 4303 lbs. per acre and Delaware 1651 lbs. per acre. The average maximum and minimum temperatures in California was 92.7 and 60.7 degrees Fahrenheit respectfully compared to 83.1 degrees and 61.2 degrees Fahrenheit in Delaware.
COLD HARDINESS OF PASSIFLORA SPECIES
Authors: Quesada Patricia , Matta Frank B.
Published: February 2019

Two species of Passiflora, P. edulis f. edulis (purple passion fruit) and P. edulis f. flavicarpa (yellow passion fruit), and P. incarnata (maypop), were evaluated for acclimation and cold hardiness, using differential thermal analysis, electrolyte leakage and the tetrazolium stain test. The two species showed the capacity to acclimate several degrees during the evaluation period and the three tests gave similar lethal temperatures for the two species; –9C to –10C for yellow passion fruit, –10C to –12C for purple passion fruit and –11C to –13C for maypop. Purple and yellow passion fruit were also assayed for survival after a freeze-thaw cycle, using a tissue culture regeneration technique called “feeder plate”. Yellow passion fruit did not show the capacity to regenerate at any of the temperatures used (0, –3, –6C). Purple passion fruit showed callus formation even at the lowest temperature (–6C).
EFFECT OF ROOTSTOCK AND ORCHARD FLOOR MANAGEMENT ON CARBOHYDRATE LEVELS OF `REDHAVEN' PEACH
Authors: Ellis Danielle R. , Reighard. Gregory L.
Published: February 2019

Trees of `Redhaven' peach [Prunus persica (L.) Batsch] budded to `Lovell', `Bailey', and `Nemaguard' rootstocks were grown with bahiagrass or cultivated orchard middles. Terminal shoots were collected once a month through the dormant season. `Redhaven' on `Lovell' had significantly higher levels of sucrose, sorbitol, total soluble sugars, starch and total non-structural carbohydrates than `Redhaven' on `Nemaguard'. However, there were no significant differences in any carbohydrate fraction between `Redhaven' on `Bailey' and the other rootstocks. Orchard floor management system had no significant effect on carbohydrate levels.