bluuebunny/crossref_metadata_2025 huggingface dataset:
Toxic Mercury Reduction and Remediation using a Modified Bacterial Gene in Transgenic Plants
Authors: Rugh Clayton L. , Merkle Scott A. , Meagher Richard B.
Published: February 2019

The use of plants to stabilize, reduce, or detoxify aquatic and terrestrial pollution is known as phytoremediation. We have employed a molecular genetic approach for the development of potentially phytoremediative species using a bacterial gene for ionic mercury detoxification. One gene of the bacterial mercury resistance operon, merA, codes for mercuric ion reductase. This enzyme catalyzes the reduction of toxic, ionic mercury to volatile, elemental mercury having far lower toxicity. Early attempts to confer Hg++ resistance to plants using the wildtype merA gene were unsuccessful. We hypothesized the highly GC-skewed codon usage was ineffective for efficient plant gene expression, and sequence modification would be necessary to confer merA gene activity and ionic mercury resistance in plants. A directed mutagenesis strategy is being used to develop modified merA gene constructs for transformation and analysis in plants species. Transgenic Arabidopsis and yellow-poplar plants having modified merA codon usage display Hg++-resistance. Arabidopsis plants with modified merA were observed to evolve ≈4 times the quantity of Hg0 from aqueous Hg++ in controlled experiments. In contrast, plants with unaltered merA coding sequences display unstable and inactivated gene expression. Our progress towards further merA modification and transgenic plant development will be reported. Additionally, the theoretical phytoremediative benefits and potential advantages of merA-expressing plant species will be discussed as part of our long-term goals.
Exploiting Tissue Culture-generated Variation and Natural Plant Population Diversity for Wetland Creation
Authors: Seliskar Denise M.
Published: February 2019

Several salt marsh functions were found to be directed by the genotype of the vascular plant. Tissue culture regenerants of Distichlis spicata and Sporobolus virginicus, along with plants from natural populations of these species, were compared in a common garden study. Significant differences among genotypes were found in several characteristics of importance in the functioning of the salt marsh food web. Specifically, potential detritus production, belowground organic matter production, and canopy structure were affected. Selections from five morphologically distinct populations of Spartina patens, including one tissue culture regenerant, also maintained differences in a common marsh setting. In a newly created salt marsh near Lewes, Dela., three populations of short-form Spartina alterniflora from different latitudes (Massachusetts, Delaware, and Georgia) were planted. After 5 years in the new site, the plants maintained distinct morphologies characteristic of plants at their site of origin; e.g., aboveground biomass, canopy structural characteristics, and root and rhizome biomass, composition, and distribution. The magnitude of marsh functional processes associated with the latitude of the population source persisted in the created wetland. The edaphic algal community, the activity of the aerial microbial decomposers, and the edaphic community respiration were significantly influenced by vascular plant genotype in the created marsh, and they reflected the values characteristic of these functions at the latitude of origin of the vascular plants. Indications are that higher trophic levels may also be affected. In creating new wetlands, this plant genetic variation can be used to accentuate different functions, thus optimizing wetland values on the specific site and at the landscape ecology scale.
Delaying Flowering using Ethephon during New Guinea Impatiens Production
Authors: Walker Scarlett L. , Harkess Richard L.
Published: February 2019

Flowering of Impatiens hawkeri Bul. during production results in an accumulation of dead plant material and directs energy away from vegetative growth. Ethephon is currently used at 500 ppm during the production of cuttings to eliminate flowering on stock plants. In this study, the timing and rate of ethephon application during production was examined. Two cultivars were used: `Innocence' and `Shadow'. Ethephon was adjusted to pH 5.0 and applied at planting (0), or 1, 2, 3, or 4 weeks after planting at 0, 250, or 500 ppm. An additional control of water adjusted to pH 5.0 was also included. Five replications were used in a completely randomized experimental design. The experiment was conducted twice—26 June 26 and 7 Oct.1995—each lasted 10 weeks. The number of branches, plant size, fresh:dry weight ratio, and days to first flower were recorded. `Innocence' did not significantly respond to the treatments, except for branch number and fresh:dry weight ratio, which decreased when treated with ethephon. In `Shadow', a treatment of ethephon at 250 ppm 1 or 3 weeks after transplanting provided the best control of flowering with a minimal delay in production and high plant quality.
Effects of Paclobutrazol and Uniconazole on the Growth and Development of Miniature Kalanchoes (Kalanchoe blossfeldiana)
Authors: Meer Linda F. , Faust James E. , Starman Terri Woods
Published: February 2019

An experiment was conducted to determine the effect of plant growth regulator, application concentration, and time of application on five cultivars of Kalanchoe (Stromboli, Majestic, Heirloom, Keepsake, and Revelry). Kalanchoe cuttings were propagated in 5.2-cm-diameter containers under a short-day photo-period, then placed into a greenhouse maintained at 20C. Spray applications of paclobutrazol (25 or 50 ppm) and uniconazole (1 or 5 ppm) were made prior to visible flower bud (VB), after VB, or before and after VB. Across all cultivars and spray application dates, paclobutrazol applied at 25 and 50 ppm reduced total plant height by 20% and 29%, respectively, while uniconazole applied at 1 and 5 ppm reduced total plant height by 16% and 24%, respectively. Plant height was reduced by 13% with the pre-VB application, 23% with the post-VB application, and 32% with the pre- and post-VB applications. In general, the greater the treatment effectiveness at reducing plant height, the greater the increase in time to flower. For example, a post-VB Bonzi (50 ppm) application caused a 6-day delay in time to first open flower. With the appropriate plant growth regulator application, all five Kalanchoe cultivars tested could be used for commercial production in 5.2-cm-diameter pots.
Biostimulants can Increase Growth of Greenhouse-grown Ornamental Annuals
Authors: Gibbons Brian P. , Smalley Timothy J. , Armitage Allan M.
Published: February 2019

Three biostmulants, Grow-plex (Menefee Mining Corp., Dallas, Texas), Roots 2 (LISA Product Corp., Independence, Mo.), and Root n' Shoot (Natural Organic Products International, Mount Dora, Fla.) were applied to transplanted plugs of Salvia splendens `Empire Red' and Begonia semperflorens-cultorum `Varsity Pink' and `Varsity Brite Scarlet'. Root n' Shoot drench (0.78%) solutions at transplant increased root weight, but a 1.56% solution decreased root weight of salvia; however, shoot growth was unaffected. Root n' Shoot decreased shoot growth of begonia, but did not affect root growth of begonia. Roots 2 treatments (0.25% or 2.00%) increased shoot weight of salvia, but did not affect salvia root growth or root or shoot growth of begonia. Spraying Grow-plex (0.78% or 1.56%) to runoff at transplanting and 2 weeks after transplanting did not affect root or shoot growth of salvia or begonia.
Physiological and Molecular Changes in Aeroponically Grown, Phosphate-starved Tomatoes
Authors: Biddinger Eric J. , Liu Chunming , Raghothama K.G.
Published: February 2019

We are interested in understanding the molecular changes that occur in response to phosphate starvation in the roots of tomato plants. Aeroponics offers a unique way to study the changes that occur in the roots of plants. Tomato plants were grown in an aeroponic system developed by L.A. Peterson at the Univ. of Wisconsin. Aeroponically grown tomato plants were treated with various concentrations of phosphate (Pi) ranging from 0 to 250 μm. Plants were harvested at different times after the initiation of Pi deficiency treatments for nutrient analysis and gene expression studies. Several changes in essential nutrient content were observed. A differential accumulation of magnesium between the root and shoot tissue of phosphorus-starved plants was noticed. The expression of a recently cloned phosphate starvation induced gene (TPSI1) increased with decreasing concentration of Pi in the growth media. There is a strong correlation between the concentration of the Pi in the growth media and expression of the gene. The effect of Pi starvation on the gene expression in different parts of the plant, including old and young leaves, will be discussed.
BUILDING THE LAND-GRANT CONCEPT INTO THE WORLD WIDE WEB
Authors: Lineberger R. Daniel
Published: February 2019

The land-grant system was founded on the principle that education and information make a critical difference in people's lives, and that the government plays an important role in providing education and information by funding teaching, research, and extension programs. This mission was interpreted previously as a charge to establish great educational institutions to provide a low-cost, quality education to everyone who applied, to place extension professionals within every county in the nation, and to build massive research centers to provide a continuous flow of new, science-based information to all at no charge. My thesis is that the World Wide Web and other emerging information technologies represent the only solution to the dilemma faced by the land-grant system for providing research-based, high-quality education and information to a growing clientele at a reasonable cost. Aggie Horticulture (http://aggie-horticulture.tamu.edu), a Web server that is modeled on the land-grant principle, will be used as an example of one approach to land-grant programs of the 21st century.
THE FUTURE OF EXTENSION
Authors: Cantliffe Daniel J.
Published: February 2019

Extension gained strength from its inception in the early 1900s until the early 1980s. Then things changed—trends led to the notion that extension should get out of social programs and let producers pay their own way. These were the Reagan/Thatcher years. England, New Zealand, Australia, and Canada largely dismantled their extension services. This was supposedly due to financial reasons. They let the private sector take up whatever was released. In the U.S. during the 1980s the Extension Service came under similar attacks and some erosion of the services took place in various states. This has led to a reorganization of the extension service at the federal level, bringing the ARS and Extension Service closer together. I believe that this is the future for Extension—to bind and to build with research to improve and promote continued transfer of new technology. I see this as very difficult for the private sector to do. The ARS and university researchers have to be intimately involved with extension personnel. Program development must be two-fold and must begin to cross state lines both at the state and county levels. Extension workers are doing many of the research jobs of the 1960s and 1970s. For example, our Florida county agents are now doing demonstration and applied research studies that the experiment station personnel did up until 1980. For survival, county operations will need further combining and refining. The basis of the future lies in accountability of extension programs to the public and continued public relationships to express the good job that extension does for all Americans.
ENHANCING HORTICULTURAL EDUCATION THROUGH WORLD WIDE WEB TECHNOLOGY
Authors: Lineberger R. Daniel
Published: February 2019

The World Wide Web and other emerging information technologies are bringing about a quiet revolution in higher education. Networked computers deliver high-quality educational enhancements to students at little per unit cost to the teacher. Slide presentations, course handouts, on-line color photographs, and interactive modules are accessible from the computer desktop via high-speed Ethernet or modem connections. Aggie Horticulture, the Web server of the Texas Horticulture Program, will be used as a model to demonstrate the impact of Web technology on delivery of enhancements to “traditional” lecture-format courses and its potential for delivery of “nontraditional” courses to large audiences independent of space and time constraints.
ENZYME ACTIVITY IN TABASCO FRUIT SEPARATION ZONES
Authors: Arancibia Ramón A. , Motsenbocker Carl E.
Published: February 2019

Red-mature Tabasco (Capsicum frutescens) fruit (`McIlhenny Select') normally separate easily at the junction of the fruit and receptacle or calyx. Differences in fruit detachment force (FDF) between two lines, one that separates readily (`McIlhenny Select') and one that does not (`Hard Pick'), have been reported previously (Motsenbocker et al., 1995). In this study, enzyme activity from the detachment area was analyzed by viscosity reduction. The reaction mixture was 0.3% pectin in 20 mm NaAc, pH 5.5, for polygalacturonase (PG) and 0.6% carboxymethyl cellulose (CMC) in 20 mm NaPO4, pH 6.0, for cellulase. Preliminary data indicated that PG and cellulase enzyme activity increased during fruit ripening in both lines. Only cellulase activity, however, correlated with FDF. In addition, the activity of both enzymes was higher in the `McIlhenny Select' line than the `Hard Pick' line at the orange and red-mature stages.
VEGETABLE FARMING IN ROMANIA
Authors: Wilson Mack A.
Published: February 2019

I received an Eisenhower Exchange Fellowship (the fellowship's office is based in Philadelphia). The purpose of my fellowship was to work as a horticulture consultant on a 12-acre community development vegetable farm located in Curtea de Arges, Romania. The farm was designed to produce vegetables for market in the town or community of Curtea de Arges. Romania, a former part of the communist regime, is considered a poor country. Money was siphoned away from the people through corrupt government practices and mismanagement. The result of a political upheaval has the people now living in primitive conditions and they need help to feed themselves. Vegetable farming in Romania is still reliant on manual labor and manure fertilizer. Romania is at least 50 years behind other Western European countries or the United States in knowledge and farming technologies. Crops on the 12-acre farm were manually seeded, transplanted, watered, hoed, weeded, sprayed, and harvested. My concerns, along with those of the director of the community development project, were to advise and set up demonstrations on modern farm techniques to assist the farm manager in doing a better job. Some of the tasks that I was successful at were 1) setting up demonstrations of clear plastic and rowcovers on cabbage and potatoes to increase earliness of crops, 2) setting up drip irrigation systems in low tunnel greenhouses, and 3) determining the feasibility and profitability of crops grown at the farm.
CROP YIELD AND BIOMASS AS CORRELATED WITH N LEVELS AND COVER CROPS
Authors: Batal K.M. , Decoteau D.R. , Garrett J.T. , Granberry D.M. , Sanders D.C. , Davis J.M. , Hoyt G.D. , Dufault R.J.
Published: February 2019

Cucumber and potato crops were tested in a rotation with winter cover crops at different locations in Georgia, North Carolina, and South Carolina from 1991 to 1994. Biomass DM of vegetable crops was greatest when grown after crimson clover. Clover plantings resulted in a greater biomass than wheat when preceded spring cucumber crop. Vegetable biomass produced on clover plots or with N rates of 60 to 120 kg·ha–l was equivalent. Nitrogen recovery by cover and vegetable crops was enhanced by clover plantings. Clover biomass (tops only) provided an average of 138 kg N/ha for the cucumber crop, compared to an average of 64 kg N/ha provided by wheat. Nitrogen recovery by vegetable crops was also enhanced with 60–120 kg N/ha rates. Yields were highest when high N rates were used and when crops were produced on clover plots. Vegetable yield, cover crop biomass, and N recovery were positively correlated with vegetable biomass and applied N.
THE USE OF WINTER CROPS TO REDUCE NITROGEN LEACHING
Authors: Genio Emmanuel , Garrett Tom , Hoyt Greg , Wells Gary , Bauer Larry , Batal Dean , Sanders Doug , Wells Contact G.
Published: February 2019

The cost-effectiveness of using winter cover crops to reduce nitrogen leaching was estimated. Costs were based on cucumber and sweetpotato grown in rotation, three fertilizer application levels (0, 60, and 120 kg N/ha), and three winter covers (weeds/bare, wheat, and clover). Soil N was measured in 15-cm intervals to a depth of 90 cm at the 1993 harvest and 1994 planting. The cover crop biomass was also analyzed. Nitrogen trapping by wheat and clover was compared to bare ground with adjustment for N fixing by clover. Four scenarios—sweetpotato/both covers/high N and cucumber/wheat cover/low and medium N—yielded increased leaching compared to their bare ground counterparts. Leaching prevented from the other scenarios ranged from 1.07 to 20.11 kg·ha–1. Costs, yields, and vegetable prices were used to calculate profit changes from the bare ground method on a dollar/kg basis. Profit changes ranged from negative $2372.74/kg for cucumber/wheat cover/high fertilizer to the only positive change of $16.53 for sweetpotato/clover/medium fertilizer. Negative costs resulted from yield increases when nonwinter weed covers were used.
GREENHOUSE SOLARIZATION OF RECYCLABLE MEDIA FOR GROWING MARIGOLDS
Authors: Wilson Mack A. , Khan Victor A. , Stevens Clauzell
Published: February 2019

An experiment was conducted to determine the influence of manure and fertilizer, with and without solarization, on the growth of marigolds. Average plant height was significantly greater in media that was solarized and covered with a plastic film to retain heat. Leaf length was significantly greater in amended media with fertilizer application. Plants grown in covered media produced significantly more flower buds than those grown in noncovered media, while flower numbers were significantly greater for fertilized plants. Plant fresh and dry weights were significantly affected by covering the media during solarization and the application of fertilizer. Media amended with manure significantly affected plant fresh weight only. Flower size showed significant interactions between all factors evaluated in this study.
CHANGES IN CARBOHYDRATE LEVELS AND SUCROSE-METABOLYZING ENZYMES DURING DEVELOPING AND RIPENING IN WATERMELON
Authors: Woods F.M. , Himelrick D.G. , Aynaou R. , Boyhan G.E. , Brasher T.M.
Published: February 2019

Changes in the activities of sucrose-metabolizing enzymes as related to ontogeny and ripening were studied in fruit mesocarp tissues of watermelon [Citrullus lanatus (Thunb.) Matsum & Nakai, cvs. A.U. Producer and Sweet Scarlet]. The levels of soluble sugars and the activities of sucrose synthase (SS; EC 2.4.1.13), sucrose-phosphate synthase (SPS; EC 2.4.1.14), and invertase (INV; EC 3.2.1.26) were measured. The temporal pattern of these enzymes relative to the levels of soluble sugars were similar for both cultivars. `Sweet Scarlet' was characterized by having higher INV and SPS activities, while SS activities tended to be similar in both cultivars during fruit development. During later stages of ripening, `Sweet Scarlet' tended toaccumulate reducing sugars, while `AU Producer' tended to accumulate sucrose and therefore had lower sucrose-cleaving enzyme activity. Results indicate that SPS and INV appear to play a prominent role in carbohydrate metabolism in developing and ripening tissues of watermelon.
RAPID PREDICTION OF ALUMINUM TOLERANCE IN ALFALFA
Authors: Powell D. , Kelley R. , Yang G. , Kamp-Glass M.
Published: February 2019

Alfalfa (Medicago sativa L.), one of the most important forage legumes in the United States, has been recognized as an aluminum-sensitive species (Kemp-Glass et al., 1993). Hematoxylin staining has been used to evaluate differences in root growth and stain uptake between sensitive and resistant individuals in wheat (Ruiz-Torres et al., 1992). Attention in this study is focused on the hematoxylin staining pattern because the procedure is simple and rapid. Ten alfalfa cultivars were used: `Apollo', `ARC', `Foundation Vemal', `Shenandoah', `Spreador 2', `WL 311', `Saranac', `Saranac AR', `Cimarron', and `Cimarron VR'. Twenty seeds of each were stained in a solution of hematoxylin for 2 days. After staining, the seedlings were transferred to a potting medium for 14 days. After 14 days, plantlets were transferred to Porters soil (pH 4.5, 80% aluminum saturation) and grown in the greenhouse for 60 days. After 60 days, fresh and dry root and shoot weights were taken. Root length densities were determined and these parameters were compared to the tolerance level predicted by hematoxylin stain. Results of stain correlate with biomass at highly significant levels and will be of great use in the development of an acid/aluminum-tolerant alfalfa.
THE EFFECTS OF LIGHT QUALITY ON ENDOGENOUS CYTOKININ LEVELS IN IPT-TRANSGENIC TOBACCO
Authors: Wilson Sandra B. , Decoteau Dennis R.
Published: February 2019

Similarities exist between the effects of phytochrome and cytokinins on plant growth and development (e.g., chloroplast development, amaranthin synthesis, seed germination). It is unclear, however, if and how these two systems interact. The coaction between phytochrome and cytokinins was investigated by using Nicotiana plumbaginifolia plants transformed with the isopentenyl transferase (ipt) cytokinin gene and treated with end-of-day (EOD) red (R) and far-red (FR) light. The ipt gene was under control of either a constitutive cauliflower mosaic virus promoter (35S-plants) or an inducible, heat shock promoter (HS-plants). When treated with EOD FR light, whole plants were characterized by decreased chlorophyll concentrations and increased fresh weights. When treated with EOD R light, 35S-plants contained high concentrations of zeatin riboside (ZR) compared to plants treated with EOD FR light. When treated with EOD FR light, HS-plants contained high concentrations of ZR compared to plants treated with EOD R light. Both cytokinin responses were photoreversible. The reasons for the differences between the 35S- and HS-plant responses are not known. Results appear to implicate interactions between phytochrome and cytokinins in plant growth and development.
EFFECT OF LOCATION ON VITAMIN C CONTENT OF SELECTED BELL PEPPER CULTIVARS
Authors: Simonne Amarat H. , Simonne Eric H. , Eitenmiller Ronald R. , Green Nancy R. , Little Joe A. , Owen John T. , Ruf Marvin E. , Pitts Jim A.
Published: February 2019

Vitamin C (VC) levels (mg/l00 g FW) were determined in 10 varieties of colored bell pepper grown under different field conditions. VC was determined by the microfluorometric method. `Orobelle' (169 mg), `King Arthur' (143 mg), `Valencia' (141 mg), and `Chocolate Bell' (134 mg) had significantly higher VC levels than `Dove' (109 mg), `Ivory' (106 mg), `Blue Jay' (93 mg), `Canary' (90 mg), and `Black Bird' (65 mg). The largest variability (53 mg) in VC levels were observed for varieties that had the highest VC content. Mean VC levels were 143a, 143a, 141a, 136a, 108ab, 93bc, and 63c for the yellow, red, orange, brown, white, purple, and black colors, respectively. Since the Recommended Daily Allowance (RDA) for VC is 60 mg per day, these results suggested that a 100-g serving of fresh bell pepper or less would supply 100% RDA of VC. Therefore, after selecting a color, growers still have the freedom to grow a variety that performs well in their area to produce peppers of high VC contents.
EFFECT OF FOLCYSTEINE AND KINETIN ON `KAPOHO' PAPAYA (CARICA PAPAYA)
Authors: Morales-Payan Jose Pablo
Published: February 2019

Flowering plants of `Kapoho' papaya were sprayed with aqueous solutions of kinetin and folcysteine. Plants were treated four times at 3-week intervals with 0-, 50-, 90-, or 130-ppm solutions of either biostimulant or their combinations. Fruit number, size, and weight were recorded weekly during 15 weeks after treatment. Folcysteine treatment at 90 to 130 ppm significantly increased `Kapoho' papaya yield. Kinetin treatment alone did not significantly affect fruit yield at any rate tested. Moreover, none of the kinetin plus folcysteine combinations significantly differed from the control in terms of fruit yield. These findings suggest that folcysteine rates of 90 to 130 ppm can increase fruit yield in this cultivar, and that kinetin had an antagonistic effect on the activity of folcysteine on the yield of `Kapoho' papaya.
USE OF BIOLUMINESCENCE FOR THE DETECTION OF THE EFFECTIVENESS OF BIOLOGICAL CONTROL AGENTS ON BLACK ROT DISEASE OF CABBAGE
Authors: Dane Fenny
Published: February 2019

A genetically engineered, bioluminescent strain of Xanthomonas campestris pv. campestris (Xcc) was used to study the effectiveness of plant growth-promoting rhizobacteria (PGPR) as disease control agents. Black-rot-susceptible cabbage plants were wound-inoculated with PGPR and wound- or mist-inoculated with bioluminescent Xcc 10 days later. Growth of the bioluminescent strain in the plants was followed over time with a low-light, charge-coupled device camera. Several PGPR strains effectively reduced growth of the bioluminescent pathogen in the plants when bacteria were introduced into the plant by wound. PGPR inoculation was less effective when bioluminescent bacteria were introduced into the plant by mist inoculation. Little effect on symptom reduction was observed.
SEEDBORNE MOSAIC VIRUSES IN SOUTHERNPEA CULTIVARS
Authors: Hunter A.G. , Boyhan G.E. , Simonne E.H. , Chambliss O.L.
Published: February 2019

Seed harvested from 41 entries in the 1994 southernpea variety trial was grown in a greenhouse for evaluation of seedborne mosaic viruses. When second trifoliate leaves were fully expanded, 100 plants per plot per block (4) were evaluated for blackeye cowpea mosaic virus (B1CMV), cucumber mosaic virus (CMV), cowpea severe mosaic virus (CSMV), and southern bean mosaic virus (SBMV). The average number of plants with virus symptoms ranged from 2% (Pinkeye Pinkpod) to 44% (Bettergreen). Plants with symptoms were assayed using enzyme-linked immunosorbent assay (ELISA). At least one virus was detected with ELISA in all entries, except for `Zipper Cream' in which none were evident. All viruses were detected in seven entries. B1CMV and CMV were present in 13. CMV was present in all but `Zipper Cream', `Mississippi Cream', and `Texas Pinkeye'. Symptomatology was poorly correlated to ELISA results: six entries having all four viruses had symptoms on less than 13% of their plants.
No Adverse Effect of Early Season Fungicide and Zinc Sprays on Leaf Area, Fruit Set, and Nut Quality of Pecan
Authors: Reilly Charles C. , Wood Bruce W.
Published: February 2019

Propiconazole, a fungicide, suppressed leaf area of a wide variety of young pecan [Carya illinoinensis (Wangenh.) K. Koch] seedling genotypes but did not reduce leaf area of orchard trees. Leaf area declined linearly as dosage increased from 0.16 to 1.25 mL·L–1. Suppression of leaf area by propiconazole was inversely proportional to leaf age. No reduction of leaf area was detected in orchards where `Cheyenne', `Desirable', and `Pawnee' were treated with three applications (14-day intervals) of fungicide (either propiconazole, fentin hydroxide, or fenbuconazole) from budbreak to early May. Spring application of the three fungicides alone or in combination with zinc sulfate did not influence fruit set. Control of pecan scab [Cladosporium caryigenum (Ell. et Lang) Gottwald] was achieved with either fentin hydroxide or fenbuconazole for the full season, or with early season use of dodine, then propiconazole, and then followed by fentin hydroxide for late-season disease control. Fungicide treatments had no effect on nut weight. These data indicate that fungicides applied to pecan during pollination at commercially recommended dosages and intervals, with or without zinc sulfate, do not adversely influence leaf area or fruit set of orchard trees. Chemical names used: n-dodecylguanidine acetate (dodine); triphenyltin hydroxide (fentin hydroxide); 1-[[2-(2,4-dichlorophenyl)-4-propyl-1,3-dioxolan-2-yl] methyl]-1H-1,2,4-triazole (propiconazole); α-[2-(4-chlorophenyl)ethyl]-α-phenyl-1H-1,2,4-triazole-1-propanenitrile (fenbuconazole).
High-temperature Tolerance of Heritage River Birch Roots Decreased by Pot-In-Pot Production Systems
Authors: Ruter John M.
Published: February 2019

Membrane thermostability of Heritage river birch (Betula nigra L. Heritage) was measured by electrolyte leakage from excised roots of plants grown in pot-in-pot (PIP) and conventional aboveground production systems (CPS). The predicted critical midpoint temperature (Tm) for a 30-min exposure was 54.6 ± 0.2 °C for PIP and 56.2 ± 0.6 °C for CPS plants. Plants grown PIP had a steeper slope through the predicted Tm, suggesting a decreased tolerance to high root-zone temperatures in relation to plants grown aboveground. Since the root systems of Heritage river birch grown PIP are damaged at lower temperatures than plants grown aboveground, growers should prevent exposure of root systems to high temperatures during postproduction handling of plants grown PIP.
The Potential of AMMI Analysis for Field Assessment of Musa Genotypes to Virus Infection
Authors: Ortiz Rodomiro
Published: February 2019

Virus-like symptoms (due to banana streak virus, cucumber mosaic virus, or both) have been observed in plants of Musa hybrids (TMPx) and local landraces included in multilocational trials in sub-Saharan Africa. Virus-like symptom incidence in these multilocational trials was analyzed using the additive main effect multiplicative interaction (AMMI) model. There were significant differences in virus-like symptom incidence among environments, which was highest in the cool, rainy season (14% to 42%) and lowest in the warm, dry season (<10%). Genotypes showed significantly different responses to virus(es), which depended on the environment. There were no plants of AA and AAA bananas showing virus-like symptoms (0% incidence), whereas ABB cooking bananas and a cooking banana hybrid (ABB × AA) seldom showed virus-like symptoms (<2% incidence). The AAB French plantains appeared to have a similar genotypic response to virus(es) (about 10% virus-like symptom incidence) and were regarded as less susceptible than the False Horn plantain `Agbagba', which showed virus-like symptoms in most of the environments (average 21% incidence). Hence, `Agbagba' should be considered a susceptible indicator host because it has a stable susceptible host response to Musa virus(es). Plantain hybrids (AAB × AA) showed virus-like symptoms; however, there were significant differences in genotypic response to the virus(es) among various hybrids (11% to 60%). Epistasis due to transgressive segregation may control the susceptibility of TMPx germplasm to Musa virus(es). The AMMI1 model revealed that an increase in clonal susceptibility resulted in a more unstable response to the virus. Similarly, phenotypic instability was associated with an increase in clonal resistance. Environments with very low (dry season) or very high (rainy season) incidence of virus-like symptoms had unstable virus expression. Scoring virus symptoms in cool environments with low rainfall and low potential evapotranspiration provided an unbiased assessment of genotypic response to Musa virus(es). The AMMI2 model showed that seasonal rather than locational diversity accounted for most of the interaction patterns. This finding may indicate a low level of strain differentiation in the region.
Sensitivity of Four Sweetpotato Clones to Metribuzin Herbicide
Authors: Harrison Howard F. , Dukes Philip D.
Published: February 2019

Four sweetpotato [Ipomoea batatas (L.) Lam.] clones were evaluated for metribuzin tolerance in greenhouse and field experiments. W-262 exhibited metribuzin response similar to the highly tolerant clone Tinian (U.S.P.I. 153655). SC 1149-19 was highly sensitive to metribuzin, and the commercial cultivar Jewel was intermediate in tolerance. Due to its more desirable horticultural characteristics and higher yields, W-262 is superior to Tinian as a source of metribuzin tolerance in sweetpotato breeding. Chemical name used: 4-amino-6-(1,1-dimethylethyl)-3-(methylthio)-1,2,4-triazin-5(4H)-one (metribuzin).
Distinction of Ozothamnus diosmifolius (Vent.) DC Genotypes Using RAPD
Authors: Ko H.L. , Henry R.J. , Beal P.R. , Moisander J.A. , Fisher K.A.
Published: February 2019

An assessment was made to determine the suitability of RAPD analysis for identification of the Australian wildflower Ozothamnus diosmifolius (Vent.) DC [syn. Helichrysum diosmifolium (Vent.) Sweet] cultivars and lines. Of 19 arbitrary primer sequences tested, 16 revealed a high degree of polymorphism between the six most important genotypes with commercial significance, producing a total of 166 markers, of which 70% were polymorphic. Several primers (such as OPD-03 and OPM-07) were able to distinguish all tested genotypes from one another, showing an intracultivar consistency. These results indicate that RAPD analysis is a useful tool for establishing genetic diversity in this species as well as assisting in commercial protection of plant breeders' rights.
Prediction of Starch, Moisture, and Sugar in Sweetpotato by Near Infrared Transmittance
Authors: Katayama Kenji , Komaki Katsumi , Tamiya Seiji
Published: February 2019

Near infrared analysis was used to predict the starch, moisture, and sugar content in sliced fresh sweetpotato [Ipomoea batatas (L.) Lam.] storage roots. Samples were collected in each of three growing years. The best calibration equation for starch from combined samples (1989 to 1991) showed a multiple correlation coefficient (R) of 0.949, a standard error of calibration (sec) of 2.01, and a standard error of prediction (sep) of 1.91. The R, sec, and sep for moisture and sugar were 0.930, 1.85, and 2.00, and 0.837, 1.30, and 1.21, respectively. Calibrations based on samples from a given year adequately predicted the variables but could not account for variances introduced by samples from other years. Multiyear calibrations based on several years of data adequately predicted starch and moisture content in root slices. Thus, multiyear calibrations with annual bias adjustments can be applied to screening sweetpotato breeding germplasm for these two variables.
Apparent Male Fertility in Musa Germplasm
Authors: Dumpe Boniface B. , Ortiz Rodomiro
Published: February 2019

Current efforts to produce improved genotypes of plantain and banana (Musa spp.) depend on crossing female-fertile clones with accessions that produce viable pollen. Musa accessions (168) were screened for production of viable pollen based on staining with acetocarmine glycerol jelly. Diploid hybrids and landraces produced significantly more pollen than triploids and tetraploids, suggesting more successful crosses when using diploid accessions as male parents. There was a positive correlation between the amount of pollen produced and the level of viability in both hybrids (r = 0.65, P≤ 0.01) and landraces (r = 0.61, P≤ 0.01). This finding suggests that closely associated genetic factors determine these characteristics in Musa, while environmental conditions also may influence the quality and quantity of pollen produced. Pollen production at anthesis was absent in 28 accessions. Of the 140 accessions with pollen, 67 were sufficiently fertile for use as male parents in the breeding program.
Leaf Wounding Increases Efficiency of Agrobacterium-mediated Transformation of Apple
Authors: Norelli John , Mills JoAnn , Aldwinckle Herb
Published: February 2019

In vitro–grown leaves of Malus ×domestica Borkh. cv. Royal Gala were either crush-wounded with forceps, cut, or left whole, and then inoculated with A. tumefaciens strain EHA105 (p35SGUS_INT), with and without vacuum infiltration. Transformation was quantified 13 days after inoculation by determining the rate of β-glucuronidase (GUS) activity. Leaf wounding by crushing with nontraumatic forceps significantly increased transformation when compared with cutting leaves. Vacuum infiltration of inoculum had no effect on transformation.
In Vitro Growth and Regeneration of Drosera spatulata Labill. on Various Media
Authors: Perica Mirna Curkovic , Berljak Jasna
Published: February 2019

Conditions for in vitro multiplication and flowering of Drosera spatulata plants were established. Shoot tips of greenhouse-grown plants were sterilized with 1% or 0.5% sodium hypochlorite. The influence of different media concentrations, hormone supplementation, and pH was investigated. Full MS medium without growth regulators was the best for regeneration and multiplication of plants. Regenerated shoots rooted spontaneously on medium without growth regulators and without transfer to additional medium. In 3 months, 100 to 200 plants were generated per explant. Flowering was induced on media supplemented with plant growth regulators. Plants were acclimatized on sterile peat.
METHODS OF FERTILIZER APPLICATION EFFECTS ON DISTRIBUTION OF NUTRIENTS IN ORCHARD SOILS
Authors: Stiles Warren C. , Robinson Terence L. , Reid W. Shaw
Published: February 2019

Fertilizer treatments were applied by spreading over an herbicide-treated in-row strip, with or without irrigation using single-drip emitters per tree, or through drip irrigation. Distribution of nutrients in soils was evaluated by analysis of soil samples collected at various depths and distances from the irrigation emitters at the end of the 8-year experimental period. NO3-N was increased in the 0- to 40-cm depth by soil surface application but below 40 cm with fertigation. Fertigation increased P in the wetted zone within the 0- to 40-cm depths. Surface application of K increased levels primarily in the 0- to 20-cm zone, while fertigation increased K to depths of 80 cm. Zinc and Cu concentrations were increased by fertigation to 80-cm depth. In general, nutrients applied to the soil surface were less readily moved into the soil profile, while fertigation resulted in greater movement of nutrients to greater depths within the wetted zone of soil.
USE OF SPRING FLOOD FOR PEST CONTROL IN CRANBERRY PRODUCTION: IMPACT ON NITROGEN USE, PLANT GROWTH, AND YIELD
Authors: DeMoranville Carolyn
Published: February 2019

Extensive study of the use of late water (LW, a 4-week spring flood used to control pests) in modern cranberry production systems began in 1993, focused on the effects of the flood on pests and the cranberry plants, and compared LW to companion early water (EW, no spring flood) bogs and to their own histories. In 1993 and 1994, LW bogs had yields comparable to EW controls with N fertilizer reductions of 35% and 60%. In the year following LW, N use returned to pre-LW levels. In 1995, N use was reduced by 65%. However, yield on LW bogs was reduced in 1995, at least in part due to anomalous winter weather and drought. Upright length and density did not differ between LW and EW bogs (1993–95). This may have been due to reduced N dose offsetting any growth-promoting effects of LW. In 1994 and 1995, LW bogs had fewer flowers than EW bogs, but increased fruit set compensated in 1994. LW may adversely affect yield in some years but this could be offset by reduced production costs or increased yields in following years. Cost/return budgets are being studied.
SEEKING POTATO CLONES WITH ELEVATED TUBER METHIONINE USING PROTOPLAST REGENERATION PROTOCOLS
Authors: Langille Alan R. , Lan Yu , Gustine D.L.
Published: February 2019

`Russet Burbank' leaf protoplasts were cultured in cell layer (CL) media containing the amino acid analog, ethionine (ETN), at concentrations ranging from 0 to 9 μm. A decrease in plating efficiency was observed when ETN concentrations in CL exceeded 3 μm. Calli that developed were placed on C media containing ETN concentrations up to 200 μm. Regenerated plants were grown to maturity in a growth chamber and resulting tubers were analyzed for free methionine. Selected protoclones produced tubers whose free methionine content exceeded that of the `Russet Burbank' control by ≈3-fold. Methodology used will be discussed.
REGIONAL CLIMATE DIFFERENCES HAVE VARYING EFFECTS ON SCALD SUSCEPTIBILITY OF `DELICIOUS' APPLES
Authors: Weis Sarah A. , Bramlage William J.
Published: February 2019

Cool preharvest temperatures and increasing fruit maturity at harvest reduce poststorage superficial scald incidence. In the absence of cool preharvest temperatures, the role of fruit maturity in determining scald susceptibility becomes greater. Larger amounts of preharvest rainfall also contribute to reduction in scald incidence. Data from `Delicious' grown in a number of locations worldwide will be used to demonstrate this.
GROWTH AND SOIL RESPIRATION OF PEPPER INOCULATED WITH VAM FUNGI UNDER TWO TEMPERATURE REGIMENS
Authors: Martin Chris A. , Stutz Jean C. , Goodnight Shanyn
Published: February 2019

Pepper (Capsicum sp. L.) seedlings were inoculated with either Glomus sp. AZ 112 (isolated from Wickman, Ariz.), Glomus intraradices Smith and Schneck (isolated from Santa Theresa, N.M.), a mixture of the two isolates, or a nonmycorrhizal control, and were grown for 8 weeks in a moderate (20.7 to 25.4C) or high temperature (32.1 to 38.0C) environment. Plants in moderate temperatures were larger and had lower specific soil respiration (Rspsoil) (μmol CO2/m2/s per gram root tissue dry weight) compared with those in high temperatures. In moderate temperatures, mycorrhizal plants were smaller and had higher Rspsoil than nonmycorrhizal controls. In high temperatures, plants inoculated with the isolate mixture grew nearly twice as large and had lower Rspsoil compared with plants inoculatedwith the individual isolates or the nonmycorrhizal control. Results suggest an improved carbon economy and a synergistic enhancement of pepper growth caused by the mixture of VAM fungal isolates that was not achieved by inoculation with single isolates alone under conditions of high-temperature stress.
EPIDEMIOLOGY OF PEPPER STIP
Authors: Smith Richard , Mullen Bob , Hartz Tim
Published: February 2019

Pepper stip is a physiological disorder manifested as gray-brown to greenish spots occurring on fruit of bell, pimento, Anaheim, and other types of peppers, most noticeably on red fruit produced under fall conditions. The spots, ≈0.5 cm in diameter, occur singly or in groups; marketability for either fresh market or processing use is severely affected. The factors controlling the occurrence or severity of the disorder are not well understood; to date, control has been achieved primarily by the use of resistant cultivars. In 1995 replicated plots of susceptible (`Yolo Wonder L' and `Grande Rio') and resistant (`Galaxy' and `King Arthur') cultivars were grown in seven commercial fields in central California. `Galaxy' and `King Arthur' were essentially free of symptoms, while `Yolo Wonder L' and `Grande Rio' showed significant damage at all sites, with 23% to 88% of fruits affected at the mature-red stage. Petiole tissue analysis showed that resistant cultivars consistently had lower N and K, and higher Ca concentrations than susceptible cultivars; the same trend was apparent in fruit tissue. Stip was most severe at sites with low soil Ca and/or very high N and K fertilization rates. It is hypothesized that Ca nutrition significantly influences stip expression.
SUPERDWARF WHEAT RESPONSES TO GRADIENT IRRADIANCE
Authors: Biesinger H. , Campbell W.F. , Strickland T. , Salisbury F.B. , Hole P.S. , Gillespie L. , Levinskikh M. , Ivanova I.
Published: February 2019

The objectives of this research were to mimic the gradient irradiances to which wheat (Triticum aestivum L. cv. SuperDwarf) plants were exposed aboard the Russian space station Mir, and to determine whether these irradiances inhibit growth and floral development. SuperDwarf wheat plants were exposed to irradiances of 20–40, 60–80, 100–120, and 140–180 (PPF = μmol·cm–2·s–1) and grown to maturity. Twenty plants were randomly selected from each irradiance level and chlorophyll, total leaf area, shoot biomass, and total soluble leaf and plasma membrane (PM) proteins were recorded. Irradiance at increasing levels of intensity increased the fresh biomass, leaf area, chlorophyll content, and the total soluble PM and leaf proteins of wheat tissue. There were significant differences between the abaxial and adaxial sides of the wheat leaves in stomatal density, stomatal index, stomatal length and width, and number of stomata along 1-mm length of leaf. These data may be uniquely valuable for further studies of relationships between chlorophyll content, photosynthetic rate, and productivity of wheat grown aboard the Russian space station Mir, space missions of long duration, or future manned space stations to generate oxygen, purify water, remove carbon dioxide, produce food and recycle waste materials. (Supported by NASA Grant NCC 2-831 and the Utah Agr. Expt. Station.)
ALTERNATIVES TO SULFUR DIOXIDE FUMIGATION FOR TABLE GRAPE STORAGE
Authors: Ahmedullah A.
Published: February 2019

Clusters of four varieties of table grapes were packed in TKV lugs and fumigated with 4, 6, or 8 Deccodione Smoke Tables (DST) for a period of 30 minutes in a fumigation chamber. After fumigation, inoculum of Botrytis cineraria was placed among the berries in the clusters in predetermined locations. Fruit was stored at 0C and high relative humidity for up to 16 weeks. Fruit was examined at 4, 8, 12, and 16 weeks of storage. Decay control index, freshness of stems, and bleaching of pigments around the capstem was recorded at each evaluation time. Size of aerosol particles was determined. Satisfactory control of decay was obtained with 8 DSTs. Lower doses failed to give satisfactory decay control. Bleaching of capstems typically seen with sulfur dioxide fumigation was not noticed with DST fumigation.
Accumulation of a 60-kD Dehydrin Protein in Peach Xylem Tissues and Its Relationship to Cold Acclimation
Authors: Arora Rajeev , Wisniewski Michael
Published: February 2019

The seasonal pattern of dehydrin accumulation was characterized during cold acclimation and deacclimation in the xylem tissues of genetically related (sibling) deciduous and evergreen peach (Prunus persica L.). Immunological studies indicate that a 60-kD polypeptide in peach xylem tissues is a dehydrin protein. Comparison of its accumulation pattern with seasonal fluctuations in cold hardiness indicate that dehydrin accumulated to high levels during the peak of cold acclimation. However, its accumulation was only weakly associated with cold hardiness during early stages of cold acclimation and during deacclimation. Our results indicate that factors related to supercooling rather than dehydrin accumulation may be primarily responsible for determining levels of cold hardiness during transition periods.
Optimum Planting Time, Plant Spacing, and Nitrogen and Potassium Rates to Maximize Yield of Green Cauliflower
Authors: Csizinszky A.A.
Published: February 2019

Green cauliflower (Broccoflower) (Brassica oleracea L. Botrytis Group cv. Alverda) is a relatively new vegetable crop in the United States. Experiments were initiated to investigate the yield potential of `Alverda' green cauliflower in three consecutive plantings (10 Oct. and 24 Nov. 1992 and 12 Jan. 1993) at two in-row spacings (31- and 38-cm) with the factorial combinations of N and K at 98, 196, and 294 kg·ha–1 under subtropical conditions. Crops were grown in an Eau Gallie fine sand with the full-bed polyethylene mulch-seepage (modified furrow) irrigation system. Marketable yields were highest in the January planting with N at 294 kg·ha–1 when 71% of the plants had marketable size (≥0.34 kg) and desirable quality curds. Yields were higher at 38- than at 31-cm spacing. Yields and curd size increased with increasing N rates at all three planting dates (P ≤ 0.01). Potassium rates had no significant effect on yields.