bluuebunny/crossref_metadata_2025 huggingface dataset:
Japanese Snowbell Exhibits Variability for Time of Vegetative Budbreak and Susceptibility to Spring Freeze Damage
Authors: Reed Sandra M.
Published: June 2019

Japanese snowbell (Styrax japonicus Sieb. & Zucc.) is an outstanding small ornamental tree that is underused in the U.S. One of the reasons this Asian native is not more widely planted is that it is subject to spring freeze damage. The objectives of this study were to determine if there was variability within S. japonicus for time of budbreak and if this variability could be used for selecting plants better adapted to areas of the country that frequently experience late spring freezes. During Spring 1999 and 2000, budbreak was evaluated weekly in 224 open-pollinated seedlings. While weather conditions varied greatly between the 2 years, there was good consistency between 1999 and 2000 data. There was a 4-week difference between the earliest and latest plants to break dormancy. Based on the 1999 and 2000 data, 28 plants were selected and propagated. A replicated trial involving these selections and three cultivars was carried out in 2002, 2003 and 2004. All of the selections broke bud later and suffered less freeze damage than the cultivars `Emerald Pagoda' and `Carillon', but many performed similarly to `Pink Chimes'. Variation in height, width, caliper and canopy shape was observed among the selections. There is an opportunity to utilize the genetic variability in S. japonicus for developing cultivars with reduced susceptibility to spring freeze damage.
Cold-induced Antioxidant Enzymes Changes in Leucanthemum maximum`Silver Princess'
Authors: Zhou Suping , Sauvé Roger J. , Mmbaga Margaret T. , Frenkel Chaim
Published: June 2019

Leucanthemum maximum `Silver Princess' plants, that were gradually acclimated for 7 days at 10 °C followed by 28 days at 7 °C, were subjected to the following cold treatments: 30 days at 4 °C; 4 or 5 days at 0 °C and for 3 hours at –1 °C to identify cold inducible proteins that may be responsible for cold tolerance in this cold tolerant species. Change in antioxidant enzymes activity in fully expanded leaves was assessed after each treatment. Catalase activity began to increase after 30 days at 4 °C and reached its peak after a 5-day exposure to 0 °C. The activity of cellular glutathione peroxidase and glutathione reductase significantly increased after a 4-day exposure to 0 °C. Changes in activity of four active superoxide dismutase isoforms, one basic guaiacol peroxidase and two o-dianisine peroxidase isoforms were also detected following the full series of cold treatments (30 days at 4 °C; 4 or 5 days at 0 °C and for 3 hours at –1 °C).
Effects of Low-growing Perennial Ornamental Groundcovers on the Growth and Fruiting of `Seyval blanc' Grapevines
Authors: Krohn N.G. , Ferree D.C.
Published: June 2019

Greenhouse and field-grown `Seyval blanc' grapevines (Vitis sp.) were grown with low-growing, shallow-rooted, mat-forming, ornamental perennial groundcovers, and the effect of the groundcovers on the vegetative and fruiting growth of the grapevines was evaluated. The groundcovers used in this experiment were `Kentucky-31' tall fescue (Festuca arundinacea); white mazus (Mazus japoonicus albus); english pennyroyal (Mentha pulegium); dwarf creeping thyme (Thymus serpyllum minus); strawberry clover (Trifolium fragiferum); `Heavenly Blue' veronica (Veronica prostrata `Heavenly Blue'); and a companion grass mixture of 75% perennial ryegrass (Lolium perenne) and 25% red fescue (Festuca rubra). A control treatment grown without any groundcover was also used in both the greenhouse and field experiments. All of the groundcovers reduced `Seyval blanc' total shoot length from 22% to 85% in the vineyard. Cluster size was reduced in the field from 7% to 68% by the groundcovers compared to the herbicide control treatment, and from 9% to 66% in the greenhouse experiment, but none of the groundcovers in either the greenhouse or field experiments affected the pH, total acidity, or soluble solids concentrations of the `Seyval blanc' juice. English pennyroyal was the only groundcover that reduced in the leaf area of the grapevine. Single-leaf photosynthesis of the `Seyval blanc' grapevines in the field experiment was reduced by all groundcovers except mazus and creeping thyme. Water infiltration rates were 10 to 50 times higher in the groundcovers compared to the bare soil of the herbicide control treatment. Weed growth in the field caused reduction in shoot length similar to the most competitive groundcovers. Weed growth was reduced in the early season by the english pennyroyal and companion grass, and in the late season by all groundcovers. The reduction in growth of the grapevines caused by groundcovers in the greenhouse was a reasonable screen for the affect of groundcovers in the field. The mazus treatment was the only groundcover in our experiments that coupled fast growth with low competitive ability.
High Dissolved Oxygen Concentration of Floodwater Reduces Carbohydrate Concentration of Cranberry Uprights during Flooding
Authors: Botelho Michelle R. , Vanden Heuvel Justine E.
Published: June 2019

Cranberry production involves the use of flooding for several purposes during the growing season, including pest control, winter protection, and harvest. The effect of the dissolved oxygen concentration in floodwater on carbohydrate concentration of uprights and roots during flooding was investigated using potted `Stevens' cranberry (Vaccinium macrocarpon Ait.) vines. Pots were placed in large bins filled with water to simulate a spring pest control flood (called late water) over a 21-day period. Two treatments were applied: oxygenated and nonoxygenated (control). Uprights and roots were collected every 3 days and prepared for HPLC analysis to quantify nonstructural carbohydrate concentration. Soluble sugar (sucrose, glucose, and fructose) and starch concentration, as well as total nonstructural carbohydrate (TNSC) concentration, decreased over the 3-week period in uprights but not roots regardless of treatment. Interestingly, the sucrose, glucose, fructose, and starch concentrations of uprights in the oxygenated treatment were lower than those of uprights in the control treatment throughout the experiment. This research indicates that vines in flooded bogs demonstrate a net carbon loss, resulting in reduced carbohydrate concentration available for growth and fruit production.
Compost for Nitrogen Fertility Management of Bell Pepper in a Drip-irrigated Plasticulture System
Authors: Aram Kamyar , Rangarajan Anusuya
Published: June 2019

Two types of commercial compost produced from manure and food waste or brewery waste solids were tested for supplying the N requirements of a bell pepper crop in a drip-irrigated plasticulture system over two seasons. Composts were tested at 40 and 80 Mg·ha-1, and combined with 67 and 133 or 0 and 67 kg·ha–1 N applied as mineral fertilizer in the first and second seasons, respectively. Both types of compost increased total soil carbon and N content relative to unamended soil. Compost amendment also increased soil NO3-N, NH4-N and N mineralization potential throughout the season, but yields were not affected. Increasing compost amendment rate from 40 to 80 Mg·ha–1 did not increase N levels in soil or plants. Yield was not affected and season biomass accumulation was inconsistently affected by compost amendment. Commercial composts thus released mineral N in the first year of application, but supplementation with mineral fertilizer may be necessary depending on seasonal variation of N release and crop need.
Management of Nitrogen and Irrigation in Lettuce Transplant Production affects Transplant Root and Shoot Development and Subsequent Crop Yields
Authors: Soundy Puffy , Cantliffe Daniel J. , Hochmuth George J. , Stoffella Peter J.
Published: June 2019

Lettuce (Lactuca sativa L.) `South Bay' transplant growth and development were evaluated at 0, 30, 60, 90, and 120 mg·L–1 N fertigated at frequencies of every 1, 2, 3, or 4 days in a floatation production system to produce plants with optimum roots and shoots which easily pull from trays. Greenhouse experiments (four) were conducted to evaluate root and shoot weight, percent transplant pulling success, and leaf N content, 28 days after sowing (DAS). Field trials, using transplants produced in Greenhouse experiments 2 and 4, were conducted to evaluated subsequent yield, head quality characteristics, and leaf N content. Generally, as N concentrations increased, dry shoot weight and leaf N concentration increased, and root:shoot ratios decreased linearly or quadratically. Lettuce transplants grown in a floatation irrigation system fertigated every second to third day with 60 to 90 mg·L–1 N resulted in transplants with optimum root systems to achieve the highest pulling success rate from flats. Subsequent yields and head quality were optimum for pretransplant production fertigation N concentration of 60 to 90 mg·L–1, regardless of irrigation frequency.
Production Environment and Nitrogen Fertility Affect Carrot Cracking
Authors: Hartz T.K. , Johnstone P.R. , Nunez J.J.
Published: June 2019

Carrot (Daucus carota L.) root cracking and breakage during harvest and handling operations result in serious losses. The environmental and management factors affecting carrot cracking and breakage susceptibility were investigated in a survey of fields and a series of trials conducted in California from 2000–02. Roots, leaves and soil were collected from a total of 31 commercial fields of `Sugar Snax' carrot, and soil texture and plant and soil fertility status were determined. Soil moisture was monitored in 10 fields to determine whether irrigation management was correlated with root cracking susceptibility; in 4 of these fields roots were harvested both before 0800 hr and at 1300 hr on the same day to directly compare the effects of root water status on cracking. The effect of N fertilization on cracking and breakage was investigated in 5 field trials. The relative susceptibility of 10 cultivars to cracking and breakage was also compared. Cracking susceptibility was determined with an impact test, and breakage with a loading test. Roots were selected by size (18 to 24 mm diameter) and cooled to 5 °C before testing. The percentage of roots cracked in the impact test varied from 7% to 75% among survey fields. Initial root water potential was not correlated with cracking incidence. However, after hydrating roots to minimize differences in water potential among fields, cracking incidence was correlated with turgor potential (r = 0.41). Soil sand content and mean air temperature in the 30 days preceding harvest were also correlated with cracking (r = –0.48 and 0.36, respectively), suggesting that cracking susceptibility may be minimized in cool weather and in light-textured soil. Irrigation management in the final 30 days preceding harvest had no consistent effect on root cracking. Time of day of harvest had a small but significant effect, with roots harvested before 0800 hr being more crack-susceptible. N fertilization in excess of that required to maximize root yield significantly increased cracking susceptibility. Cultivars varied widely in cracking susceptibility, with less variation in tissue strength and stiffness. Removal of the periderm dramatically decreased susceptibility to both cracking and breakage.
Effect of Foramsulfuron and Isoxaflutole Residues on Rotational Vegetable Crops
Authors: Soltani Nader , Sikkema Peter H. , Robinson Darren E.
Published: June 2019

There is little information published on the effect of residues from postemergence (POST) applications of foramsulfuron and preemergence (PRE) applications of isoxaflutole, and isoxaflutole plus atrazine in the year after application on vegetable crops. Three trials were established from 2000 to 2002 in Ontario to determine the effects of residues of foramsulfuron, isoxaflutole, and isoxaflutole plus atrazine on cabbage, processing pea, potato, sugar beet, and tomato 1 year after application. Aside from a reduction in sugar beet plant stand, there were no visual injury symptoms in any crop at 7, 14, and 28 days after emergence (DAE) in any of the herbicide carryover treatments. Isoxaflutole residues reduced shoot dry weight and yield as much as 27% and 28% in cabbage, and 57% and 60% in sugar beets, respectively. The addition of atrazine to isoxaflutole caused further reductions in shoot dry weight and yield of cabbage and sugar beet. Isoxaflutole plus atrazine residues reduced shoot dry weight and yield as much as 42% and 43% in cabbage, and 58% and 82% in sugar beets, respectively. There were no adverse effects on shoot dry weight and yield of processing pea, potato, and tomato from isoxaflutole or isoxaflutole plus atrazine residues in the year following application. Foramsulfuron residues at either rate did not reduce shoot dry weight or yield of any crops 1 year after application. Based on these results, it is recommended that cabbage and sugar beet not be grown in the year following the PRE application of isoxaflutole or isoxaflutole plus atrazine.
Organic Vegetable Transplant Production
Authors: Russo V.M.
Published: June 2019

The efficacy of using potting media and fertilizers that are alternatives to conventional materials to produce vegetable transplants needs clarification. Bell pepper, onion and watermelon seed were sown in Container Mix, Lawn and Garden Soil, and Potting Soil, which can be used for organic production in greenhouse transplant production. The alternative media were amended with a 1× rate of Sea Tea liquid fertilizer. Comparisons were made to a system using a conventional potting medium, Reddi-Earth, fertilized with a half-strength (0.5×) rate of a soluble synthetic fertilizer (Peters). Watermelon, bell pepper and onion seedlings were lifted at 3, 6, and 8 weeks, respectively, and heights and dry weights determined. Watermelon were sufficiently vigorous for transplanting regardless of which medium and fertilizer was used. Bell pepper and onion at the scheduled lifting were sufficiently vigorous only if produced with conventional materials. Additional experiments were designed to determine the reason(s) for the weaker seedlings when the alternative products were used. Seedlings maintained in transplant trays, in which media amended weekly with Sea Tea were required to be held for up to an additional 34 days before being vigorous enough for transplanting. Six-week-old bell pepper, or 8-week-old onion, seedlings were transferred to Reddi-Earth in pots and supplied with Sea Tea or Peters fertilizer. Bell pepper treated with Peters were taller and heavier, but onions plants were similar in height and weight regardless of fertilizer used. Other pepper seed were planted in Reddi-Earth and fertilized weekly with Sea Tea at 0.5×, 1×, 2×, or 4× the recommended rate, or the 0.5× rate of Peters. There was a positive linear relationship between seedling height and dry weight for seedlings treated with increasing rates of Sea Tea. Other pepper seed were planted in to Potting Soil, or an organically certified potting medium (Sunshine), and fertilized with a 2× or 4× rate of Sea Tea or a 1×, 2×, or 4× rate of an organic fertilizer (Rocket Fuel), or in Reddi-Earth fertilized with a 0.5× rate of Peters. There was a positive linear relationship between the rate of Rocket Fuel and heights and dry weights of bell pepper seedlings. However, even at the highest rate seedlings were not equivalent to those produced with conventional practices. Plants treated with the 4× rate of Sea Tea were similar to those produced using conventional materials. Use of Sunshine potting medium and the 4× rate of Sea Tea will produce bell pepper seedlings equivalent in height and dry weight to those produced using conventional materials. The 4× rate of Rocket Fuel used in Sunshine potting medium will produce adequate bell pepper seedlings. The original poor showing of seedlings in the alternative potting media appears to be due to fertilization with Sea Tea at a rate that does not adequately support seedling development.
Pinch Height of Stock Plants during Scaffold Development Affects Cutting Production
Authors: Faust James E. , Grimes Larry W.
Published: June 2019

Stock plants of six herbaceous species (Antirrhinum ×hybrida `Primrose with Vein' L., Chrysocephalum apiculatum `Golden Buttons', Diascia ×hybrida `Sunchimes Coral' Link & Otto, Lavendula dentata `Serenity' L., Osteospermum ×hybrida `Zulu' L., and Verbena ×hybrida `Lanai Bright Pink' L.) received nine different pinch treatments. Stock plants received a first pinch treatment at one of three pinch heights [low (L1), middle (M1), and high (H1)] followed by a second pinch at one of three pinch heights [low (L2), middle (M2), and high (H2)] in a 3 × 3 factorial arrangement. After the two pinches, cuttings were removed weekly from the stock plants. Cutting yield per stock plant increased as pinch height increased from L to H for both the first and second pinch for all species. A low first pinch followed by a low second pinch (L1L2) produced stock plants with the lowest cutting yield, while a high first pinch followed by a high second pinch (H1H2) produced the stock plants with the highest cutting yield for all species, e.g., the percentage increase in cutting yield was 133% for Antirrhinum, 98% for Chrysocephalum, 144% for Diascia, 80% for Lavendula, 250% for Osteospermum, and 44% for Verbena. This study suggests that pinch height during scaffold development of the stock plant is an important tool for increasing cutting production.
Evaluation of the Transmission of Different Field Sources of Citrus Tristeza Virus and the Separation of Different Genotypes by Single Brown Citrus Aphids
Authors: Huang Zhipeng , Rundell Phyllis A. , Guan Xiong , Powell Charles A.
Published: June 2019

Four field sources of citrus tristeza virus (CTV) (Y3, Y6, Y7 and Y23) collected from grapefruit trees at groves in Fort Pierce, Florida, and isolate T36 were used to evaluate the transmission and separation of different virus genotypes by single brown citrus aphids (BrCA). Analysis of the field sources of CTV by inoculation to indicator plants, ELISA and RT-PCR showed that Y6 was a decline-inducing isolate and Y23 a nondecline-inducing isolate. Assays of genotype by RT-PCR indicated that Y6 contained the T36 genotype while Y23 contained the T30 genotype. Both Y3 and Y7 were a mixture of decline-inducing and nondecline-inducing CTV isolates and were a mixture of T36 and T30 genotypes. When Y6 and Y23 were the acquisition host for single BrCA, only the T36 or T30 genotypes, respectively, were detected by RT-PCR in `Mexican' Lime receptor plants. Only the T36 genotype was transmitted to receptor plants from infected Y3 and Y7 plants although these acquisition plants contained more than one genotype. No T3 or VT genotypes were detected in any acquisition or receptor plants. CTV genotype mixtures in the various field sources were separated by single BrCA transmission and that the T36 genotype in T36/T30 mixtures was more easily transmitted than the T30 genotype when the acquisition plant was `Duncan' grapefruit and the receptor plant was `Mexican' lime.
Dahlia Mosaic Virus: Molecular Detection and Distribution in Dahlia in the United States
Authors: Pappu H.R. , Wyatt S.D. , Druffel K.L.
Published: June 2019

Dahlia is an important ornamental crop in the U.S. The economic value of the crop is often affected by viral diseases. Of several viruses that infect dahlia, dahlia mosaic virus (DMV) is of most concern. However, little or no information is available about its distribution. A survey of dahlias in several states in the U.S. was carried out during 2003 and 2004. Samples from CA, GA, MD, ME, MT, NM, PA, OR, and WA were tested for DMV. To develop a molecular detection assay, the viral genome was cloned and sequenced and based on the sequence information, DMV-specific primers were used in a PCR-based assay. DMV was detected in >90% of the samples tested. Based on the detection of DMV, a wide range of symptoms were found to be associated with DMV infection. A real-time PCR assay was adapted for rapid detection of DMV. Considering its widespread occurrence, steps are needed to limit its further spread. An effective intervention program would include use of virus-free material to minimize its impact. Availability of a rapid and sensitive detection method such as the once described should facilitate not only production of virus-free dahlias but elimination of virus infected material from breeding and propagating stocks. This is the first report of a survey to determine the extent of DMV incidence in dahlias.
Halosulfuron Has a Variable Effect on Cucurbit Growth and Yield
Authors: Webster Theodore M. , Culpepper A. Stanley
Published: June 2019

Halosulfuron is a proposed alternative to methyl bromide for managing nutsedges (Cyperus spp.) in several vegetable crops, including cucurbits. Field studies were conducted to evaluate the crop sensitivity to halosulfuron in a spring squash (Cucurbita pepo L.)—fall cucumber (Cucumis sativus L.) rotation from 2000 to 2002. Treatments included application of halosulfuron to the soil surface after forming the bed, but before laying mulch (halosulfuron-PRE), halosulfuron applied through drip irrigation (halosulfuron-DRIP) after forming bed and laying mulch, metham applied through drip irrigation after forming bed and laying mulch, a nontreated control with mulch, and nontreated control without mulch. Each treatment was applied to both direct seeded and transplanted zucchini squash. Halosulfuron treatments reduced squash plant diameter relative to metham, however plant diameters in halosulfuron-PRE (transplant and direct seed) and halosulfuron-DRIP (transplant) treatments were not different from the nontreated control. Halosulfuron-PRE delayed squash fruit production relative to the mulched nontreated control. However, application of halosulfuron-PRE and halosulfuron-DRIP did not reduce squash yield at the conclusion of the season, relative to the nontreated control. Cucumbers were transplanted and direct seeded into previous squash plots and received either an application of halosulfuron-DRIP, or were not treated. Differences in cucumber yields were not detected with second crop treatments. Cucumbers appear to have adequate tolerance to halosulfuron, making it a potential replacement for methyl bromide for nutsedge control. Suppression of early season squash growth by halosulfuron may hinder the adoption of halosulfuron as a methyl bromide alternative for squash.
Evaluation of Allelopathic Potential of Wood Chips for Weed Suppression in Horticultural Production Systems
Authors: Rathinasabapathi Bala , Ferguson James , Gal Mark
Published: June 2019

Shredded and chipped wood mulches are used for weed suppression in perennial fruit crops, in urban landscapes, and occasionally in vegetable crops. Wood chip mulches with weed-suppressing allelochemicals may be more effective for weed control, especially under sustainable and organic production systems, than mulches without such properties. The objective of this study was to test for the presence of water-soluble allelochemicals in wood chips derived from tree species, often found in wood resource recovery operations in the southeastern US. Presence of allelochemicals in water eluates of woodchips and leaves was evaluated in a lettuce bioassay. Eluates of wood chips from red maple (Acer rubrum L.), swamp chestnut oak (Quercus michauxii Nutt.), red cedar (Juniperus silicicola L.H. Bailey), neem (Azadirachta indica A. Juss.), and magnolia (Magnolia grandiflora L.) highly inhibited germinating lettuce seeds, as assessed by inhibition of hypocotyl and radicle growth. The effects of wood chip eluates from these five species were more than that found for eluates from wood chips of black walnut (Juglans nigra L.,) a species previously identified to have weed-suppressing allelochemicals. Tests on red cedar, red maple, and neem showed that water-soluble allelochemicals were present not only in the wood but also in the leaves. In greenhouse trials, red cedar wood chip mulch significantly inhibited the growth of florida beggarweed (Desmodium tortuosum DC.), compared to the gravel-mulched and no-mulch controls.
Noninvasive Localization of Petroleum-derived Spray Oil in Plants with Chemical Shift Selective Magnetic Resonance Imaging
Authors: Tan B.L. , Reddy N. , Sarafis V. , Beattie G.A.C. , Spooner-Hart R.
Published: June 2019

Nuclear magnetic resonance (NMR) spectroscopy and magnetic resonance imaging (MRI) were used to detect petroleum-derived spray oils (PDSOs) in citrus seedlings and trees. The NMR spectrum of the phantom containing 10% (v/v) of a nC24 agricultural mineral oil (AMO) showed the resonance of the water protons at δ ≈ 5 ppm, while the resonance of the oil protons at δ = 1.3 to 1.7 ppm. The peak resolution and the chemical shift difference of more than 3.3 ppm between water and oil protons effectively differentiated water and the oil. Chemical shift selective imaging (CSSI) was performed to localize the AMO within the stems of Citrus trifoliata L. seedlings after the application of a 4% (v/v) spray. The chemical shift selective images of the oil were acquired by excitation at δ = 1.5 ppm by averaging over 400 transients in each phase-encoding step. Oil was mainly detected in the outer cortex of stems within 10 d of spray application; some oil was also observed in the inner vascular bundle and pith of the stems at this point. CSSI was also applied to investigate the persistence of oil deposits in sprayed mature Washington navel orange (Citrus ×aurantium L.) trees in an orchard. The trees were treated with either fourteen 0.25%, fourteen 0.5%, four 1.75%, or single 7% sprays of a nC23 horticultural mineral oil (HMO) 12 to 16 months before examination of plant tissues by CSSI, and were still showing symptoms of chronic phytotoxicity largely manifested as reduced yield. The oil deposits were detected in stems of sprayed flushes and unsprayed flushes produced 4 to 5 months after the last spray was applied, suggesting a potential movement of the oil via phloem and a correlation of the persistence of oil deposit in plants and the phytotoxicity. The results demonstrate that MRI is an effective method to probe the uptake and localization of PDSOs and other xenobiotics in vivo in plants noninvasively and nondestructively.
Ripening of Ethylene-pretreated Bananas Is Retarded Using Modified Atmosphere and Vacuum Packaging
Authors: Pesis Edna , Arie Rosa Ben , Feygenberg Oleg , Villamizar Fanny
Published: June 2019

Bananas have a short shelf life after ethylene treatment and there is a high commercial demand to increase the storage life of individual clusters at the retail stage. To extend the shelf life of ethylene-pretreated banana, two different forms of modified atmosphere packaging (MAP) were used. In the first, individual clusters of ethylene-pretreated bananas were stored in a range of microperforated polyethylene (PE) bags (25 μm) creating various MAPs. Storage in PE bags with low microperforation (PE8) that created an atmosphere with 11% CO2 and 12% O2 was the most effective treatment for delaying banana ripening. The banana clusters kept firmer with nice peel color after 1 week at 20 °C, but the humidity inside the bags caused some decay development on the crown cut. In the second type of MAP individual clusters of ethylene-pretreated bananas were stored in air-evacuated PE bags (80 μm) under light vacuum (550 mm Hg) for short periods of 24 to 48 hours followed by storage in the same PE bags after releasing the vacuum. Storing bananas in air-evacuated bags for 24 to 48 hours reduced O2 levels to 1% and increased the production of CO2 up to 30%, but perforating the bags dramatically reduced the CO2 level to around 9% and increased the O2 level to 12%. Storing ethylene-pretreated banana clusters under vacuum for a limited time (24 to 48 hours), did not cause any damage, although the levels of acetaldehyde (AA) and ethanol increased dramatically. The AA and ethanol levels of 150 and 300 μL·L–1, respectively, that accumulated in the PE bags did not cause any off-flavors; on the contrary, the taste panelists preferred these bananas. Adding ethylene absorbents (EAs) to the air-evacuated PE bags reduced the ethylene levels as well as the AA and ethanol levels in the bags, which indicate that EAs also absorbed the AA and ethanol volatiles. Storing ethylene-pretreated banana clusters under vacuum for 24 to 48 hours was the most effective treatment for delaying ripening and senescence in yellow bananas (stage 3 to 4).
Effect of Inflorescence Removal on Propagule Formation of Astilbe ×arendsii, Hemerocallis spp., and Hosta spp.
Authors: Leclerc Mélanie , Caldwell Claude D. , Lada Rajasekaran R. , Norrie Jeffrey
Published: June 2019

Field experiments conducted in 2002 and 2003 evaluated the effects of timing of inflorescence removal on propagule formation, growth and development of Astilbe ×arendsii, Hemerocallis spp. and Hosta spp. Four timings of inflorescence removal were tested: 1) no removal (control), 2) removal at inflorescence emergence, 3) removal at preflower, and 4) Removal at full flower. Propagule formation in Astilbe was not enhanced by inflorescence removal. Hemerocallis plants with their inflorescences removed at emergence produced 25% more divisions than plants with their inflorescences removed at preflower. For Hosta, plants with inflorescences removed at pre- and full flower produced respectively 40% and 53% more divisions than control plants. These results have economic implications for commercial bare-root production, which need to be verified on a larger field scale.
Time Course Study of Ancymidol for Micropropagation of Hosta in a Liquid Culture System
Authors: Maki Sonja L. , Delgado Maria , Adelberg Jeffrey W.
Published: June 2019

The gibberellin biosynthesis inhibitor, ancymidol, was used during micropropagation of Hosta `Blue Vision'. Shoot growth and bud division was monitored every 2 weeks over an 8-week period in media containing 1 μm benzyladenine (BA) and various levels of ancymidol (0, 0.1, 0.32, 1 and 3.2 μm). Ancymidol prolonged bud division from 2 to 6 weeks and increased the total number of buds produced. Shoots grown in medium containing ancymidol had greater fresh weight, shorter-broader leaves and less dry weight than those grown without ancymidol. Reduced dry weight of buds grown in the presence of ancymidol was correlated to the depletion of sugars in the medium. A bioassay using `Saturn' tall rice revealed that ancymidol was active for the entire 8-week culture period.
Stumping Height, Crown Position, and Age of Parent Tree Influence Rooting of Stem Cuttings of Fraser Fir
Authors: Rosier Christopher L. , Frampton John , Goldfarb Barry , Wise Farrell C. , Blazich Frank A.
Published: June 2019

Two experiments were conducted to develop a protocol for rooting stem cuttings from 3-, 5-, and 7-year-old fraser fir [Abies fraseri (Pursh) Poir.] Christmas trees. The first experiment tested the effect of stumping treatments and tree age on shoot production and subsequent adventitious rooting. One auxin concentration [4 mm indole-3-butyric acid (IBA)] and a nonauxin control were tested. Stock plants were stumped to the first whorl (trees in the field 3 and 5 years) or the first, third, and fifth whorls (trees in the field 7 years). Intact (nonstumped) controls were also included for each age. The second experiment was designed to create a quantitative description of the effects that crown (foliage and above ground branches of a tree) position have on the rooting of stem cuttings collected from stumped and nonstumped trees. The exact position was determined by measuring the distance from the stem, height from the ground, and the degrees from north. Crown positions were recorded as cuttings were collected and then cuttings were tested for rooting response. The rooting traits assessed in both experiments included rooting percentage, percent mortality, number of primary roots, total root length, root symmetry, and root angle. In the first experiment, rooting percentage, primary root production, and total root length increased as the age of the stock plant decreased and the severity of the stumping treatment increased. Auxin treatment significantly increased rooting percentage, root production, root lengths, and root symmetry while decreasing mortality. Overall, the highest rooting percentages (51%) and the greatest number of primary roots (8.1) occurred when 3-year-old stock plants were stumped to the first whorl and treated the cuttings with 4 mm IBA. The greatest total root lengths (335 mm) occurred in cuttings from the 3-year-old stock plants. In the second experiment, rooting percentage was significantly affected by the position from which the cuttings were collected. Cuttings collected lower in the crown and closer to the main stem rooted more frequently than cuttings collected from the outer and upper crown.
Relative Salinity Tolerance of 21 Turf-type Desert Saltgrasses Compared to Bermudagrass
Authors: Marcum Kenneth B. , Pessarakli Mohammad , Kopec David M.
Published: June 2019

Relative salinity tolerance of 21 desert saltgrass accessions (Distichlis spicata [L.] Greene var. stricta (Torr.) Beetle), and one hybrid bermudagrass `Midiron' (Cynodon dactylon [L.] Pers. var. dactylon × C. transvaalensis Burtt-Davy `Midiron') were determined via solution culture in a controlled-environment greenhouse. Salinity in treatment tanks was gradually raised, and grasses progressively exposed to 0.2, 0.4, 0.6, 0.8, and 1.0 m total salinity in sequence. Grasses were held at each salinity level for 1 week, followed by determination of relative salinity injury. Relative (to control) live green shoot weight (SW), relative root weight (RW), and % canopy green leaf area (GLA) were highly correlated with one-another (all r values >0.7), being mutually effective indicators of relative salinity tolerance. The range of salinity tolerance among desert saltgrass accessions was substantial, though all were more tolerant than bermudagrass. Accessions A77, A48, and A55 suffered little visual shoot injury, and continued shoot and root growth at a low level, when exposed up to 1.0 m (71,625 mg·L–1); sea water is about 35,000 mg·L–1), and therefore can be considered halophytes.
Response of Creeping Bentgrass to Nitrogen and Ethephon
Authors: McCullough Patrick E. , Liu Haibo , McCarty Lambert B.
Published: June 2019

Ethephon is an effective growth retardant for suppressing Poa annua (L.) seedheads in creeping bentgrass putting greens; however, ethylene induction may cause bentgrass leaf chlorosis, reduced rooting, and quality decline. Two greenhouse experiments investigated the effects of nitrogen (N) fertility and ethephon applications on `L-93' creeping bentgrass over 9 weeks. Ethephon was applied at 0, 3.8, and 7.6 kg·ha–1 a.i. per 3 weeks and N was applied at 4 and 8 kg·ha–1·week–1. Ethephon applications linearly reduced bentgrass quality on every weekly observation. Increased N rate to 8 kg·ha–1·week–1 improved turf quality about 10% to 20% and 10% to 30% from ethephon applied at 3.8 and 7.6 kg·ha–1 per 3 weeks, respectively. Increased N rate to 8 kg·ha–1·week–1 enhanced shoot growth 30% but reduced root mass and length 12% and 11%, respectively. After 9 weeks, ethephon reduced root length by about 30% and root mass about 35% at both rates. From nine weekly samples, ethephon reduced dry clipping yield 10% and 16% at 3.8 and 7.6 kg·ha–1 per 3 weeks, respectively. From 2 to 9 weeks after initial treatments, ethephon linearly increased leaf water content. Increasing N fertility effectively reduced bentgrass leaf chlorosis from ethephon; however, repeat applications of ethephon and increased N may restrict bentgrass root growth. Chemical names used: [(2-chloroethyl)phosphonic acid] (ethephon).
NC 98-608: MANAGING THE POTENTIAL NEW SWEETPOTATO (Ipomea batatas) CLONE RELEASE
Authors: Thornton Allan C. , Schultheis Jonathan R.
Published: June 2019

The goal of this research was to determine the effects of in-row spacing and planting time on yield and root grade of NC 98-608 over time. Two plantings were made in two grower locations (four total). An early planting was made 19 and 25 May and a late planting 19 and 24 June. NC 98-608 was evaluated at the following in-row spacings; 23, 31, 38, and 46 cm. `Beauregard' spaced at 23 cm in-row and was used as the standard comparison. Roots were harvested and graded into canner, number one, jumbo and cull grades 90, 105, and 120 days after planting for each of the planting dates and locations. Each grade was weighed. An early planting in late May resulted in roots reaching the highest percentage grade of U.S. number one roots as early as 100 days after planting, while the late planting in June resulted in roots never reaching their full number one yield potential in some cases. For an early harvest after planting (90 days after planting) the 38 cm in-row spacing produced the most marketable number one yields compared with the 23, 31, and 46 cm in-row spacings. For a later harvest time after planting (105 days or later), it appeared as though the 31 cm in-row spacing was the most economical spacing to use. Roots from the early plantings (late May) and finer textured soils appeared to have shorter roots than roots harvested from later plantings (after 15 June) or coarser textured soil. Root shape and yield was more uniform with NC 98-608 than with the Beauregard clone. With yields comparable to Beauregard, the NC 98-608 clone provides an excellent opportunity to produce a quality sweetpotato with consistent shape.
HANDS-ON TECHNIQUES TO REINFORCE READING PESTICIDE LABELS THOROUGHLY
Authors: Lamberts Mary , Hunsberger Adrian
Published: June 2019

Many people, including growers and gardeners, fail to carefully read pesticide labels before each use because they assume they know what the label contains. The UF Miami-Dade County Extension pesticide trainer developed several hands-on exercises where participants had to find information on labels chosen for specific features. The first group was people taking the Core/General Standards training. Five pesticide labels were used. Participants were asked to find information from three different categories: 1) basic information used for record keeping and about the product;2) Personal Protective Equipment (PPE) and Precautionary Statements; and 3) additional product information such as irrigation and tank mix warnings. A second group, Private Applicators (growers and their employees), studied 6 labels (1 overlap with Core training). They were asked information that focused on Worker Protection Standard issues, resistance management, limits on number total amount applied, and pre-harvest intervals. For both types of licensed applicator training, participants were divided into groups of 5 to 6. On several occasions, growers and other licensed applicators said they thought labels should have greater uniformity regarding location of key information. Master Gardeners (MGs), the third group, were first given three general publications on labels and 1 on protecting the applicator. They then received labels of four homeowner products and were guided through finding information such as: labeled crops/sites, pests controlled, signal words, mixing instructions, preharvest intervals and replant information. MG knowledge was evaluated with a five-question quiz. All participants commented that they learned a lot about reading labels.
HORTICULTURE IN A CAN
Authors: Karsh Kathryn L. , Bush Edward W. , MIller Julian C.
Published: June 2019

Science is a challenging subject to teach at the middle school level. The state of Louisiana requires public school teachers to plan their curriculum around Grade-Level Expectations or state mandated educational benchmarks. A program titled Horticulture in a Can has been designed to teach horticulture lessons to middle school students while targeting the state regulated grade-level expectations. All lessons use a hands-on approach as it has been proven more effective than traditional classroom teaching. Horticulture in a Can was developed by a cooperative effort between the Louisiana Sea Grant College Program and the LSU AgCenter's Department of Horticulture within the Coastal Roots Nursery Program. Eight lesson plans have been created to meet twenty-six Grade-Level Expectations for 463 students in 4 schools. Pre- and PostHorticulture tests were given to each class in addition to pre- and postChildren's Attitude Towards the Environment Scale (CATES). All tests were given to both treatment and control classes within each school. The evaluations tested both short and long-term memory on material contained in the lesson plans. The data was analyzed by school, treatment, sex, and grade-level.
COMPARISON OF COMMERCIAL POLLINIZERS FOR TRIPLOID WATERMELON PRODUCTION, 2003
Authors: Schultheis Jonathan R. , Maynard Donald N.
Published: June 2019

Market demand for diploid fruit has been declining over the past ten years, especially the past three years. Thus, the watermelon industry is looking for ways to produce triploid fruit more efficiently. Several companies have developed pollinizers for planting in-row so as not to take up space like a commercial diploid cultivar. The objective of our experiment was to determine the effects of `Companion' and `SP-1' pollinizers on triploid yield compared with a traditional diploid pollinizer which until recently were routinely sold to grocery chain stores. The experimental locations were Bradenton, Florida and Kinston, NC. Treatments included two triploid cultivars; Tri-X-313 (Syngenta, Rogers Brand Seeds) and Olympia (Seminis Seed Co.), and three pollinizers; `Companion' (Seminis Seed Co.), `SP-1' (Syngenta, Rogers Brand Seeds), and `Summer Flavor 800' (Abbott & Cobb Seed Co.). A seventh treatment included `Tri × 313' in which no pollinizer was planted next to the triploid cultivar. `Companion' was interplanted every two triploid plants. `SP-1' was interplanted every three triploid plants, and `Summer Flavor 800' planted every third hill. All fruit were harvested when ripe and each watermelon was weighed. Results in the Florida location were compromised due to the close proximity of pollen from adjacent watermelon cultivar trials. In North Carolina, some pollen movement did occur between treatment plots as evidenced by fruit set in the `Tri-X-313' plots which did not contain a pollinizer. Yields; however, were 25% to 33% of those treatments which contained a pollinizer. `Tri × 313' yielded greater fruit numbers but individual fruit weights were less than those harvested from `Olympia'. Early fruit yield was similar regardless of pollinizer, while late yields were greater using `SP-1' rather than `Companion' or `Summer Flavor 800'. Cumulative yields (three total harvests) were highest with `SP-1' than the other pollinizers. The use of `SP-1' provided the greatest potential for improved yields over traditional diploid pollinizers.
DEVELOPING GENETIC LINKAGE MAP AND CDNA SUBTRACTION LIBRARY FOR WATERMELON
Authors: Levi A. , Thomas C. E. , Davis A. , Reddy O.U.K. , Xu Y. , Zhang X. , King S. , Hernandez A. , Gusmini G. , Wehner T.
Published: June 2019

Genetic linkage map is being constructed for watermelon based on a testcross population and an F2 population. The testcross map comprises 262 markers (RAPD, ISSR, AFLP, SSR and ASRP markers) and covers 1,350 cM. The map comprises 11 large linkage groups (50.7–155.2 cM), 5 medium-size linkage groups (37.5–46.2 cM), and 16 small linkage groups (4.2–31.4 cM). Most AFLP markers are clustered on two linkage regions, while all other marker types are randomly dispersed on the genome. Many of the markers in this study are skewed from the classical (Mendelian) segregation ratio of1:1 in the testcross or the 3:1 ratio in the F2 population. Although the skewed segregation, marker order appeared to be consistent in linkage groups of the testcross and F2 population. A cDNA library was constructed using RNA isolated from watermelon flesh 1 week (rapid cell division stage), 2 weeks (cell growth and storage deposition stage, 4 weeks (maturation stage), and 5 weeks (postmaturation stage) post pollination. Over 1,020 cDNA clones were sequenced, and were analyzed using the Basic Local Alignment Search Tool (BLAST). The sequenced cDNA clones were designated as expressed sequenced tag (EST) markers and will be used in mapping analysis of watermelon genome.
WATERMELON SEEDLING MORTALITY ASSOCIATED WITH Pythium aphanidermatum
Authors: Roberts Warren , Bruton Benny , Edelson Jonathan , Lu Wenhua , Perkins-Veazie Penny , Shrefler Jim , Stanghellini Michael E.
Published: June 2019

Forty-one cultivars of triploid and diploid watermelons (Citrullus lanatus) were grown at Lane, Oklahoma in 2003. Seeds were placed in Jiffy-9 pellets in a greenhouse on 21 May. Fields were prepared with raised beds 1 m wide covered with black plastic. Plots were 3 m wide by 15 m long, with 4 replications, arranged as a randomized complete block. Seedlings were transplanted to the field on 4 June. From 4–9 June, rainfall occurred 5 days. Maximum soil temperatures at 5 cm, under bare soil, from 1–9 June were 34, 34, 35, 26, 22, 26, 31, 29, and 32 °C, respectively. On 9 June, 84% of the seedlings were dead. Lesions were observed on the roots and stems and isolations were made from symptomatic tissues. The predominant pathogen isolated from the seedlings was Pythium aphanidermatum. Some of the cultivars appear to have some degree of resistance to P. aphanidermatum. Mortality among the cultivars, averaged across all replications, ranged from 33% to 100%. The cultivars with the lowest mortality were “Tri-X Carousel” (33%), `Sunny' (40%), `WT-02-31' (53%), `Ole' (58%), and `Tri-X Palomar' (68%). New seeds were seeded in the greenhouse on 16 June, and transplanted to the field on June 30. The replacement seedlings were planted in the same field, in the same location as the previous plants. Maximum soil temperatures for the two week interval following the second planting ranged from 33 to 39 °C, with only one rain of 0.8 cm occurring 10 days after planting. There was no apparent plant loss due to P. aphidermatum in the second planting.
HERBICIDE USE ON GOLF COURSE NATIVE AREAS CONTAINING WEEPING LOVEGRASS
Authors: Pippin E.T. , Bush E.W. , Lee D.J. , Strahan R.E.
Published: June 2019

Weeping lovegrass (Eragrostis curvula) is commonly used in native areas bordering golf courses in the Southeastern United States. These areas do not receive significant levels of maintenance, thus weed encroachment is a problem that can negatively impact the functional and aesthetic values of the golf course. The objectives of this study is to determine which selective postemergent herbicides labeled for use on golf courses can remove weeds from Weeping Lovegrass and to determine the level of phytotoxicity. Herbicides included monosodium methane arsenate (MSMA 6.0) applied at 3.0 lb/acre a.i., sulfosulfuron (Certainty) at 0.047 lb/acre a.i., metribuzin (Sencor 75 DF) at 0.5 lb/acre a.i., and imazaquin (Image 70 DG) at a rate of 0.5 lb/acre a.i.. Treatments were applied on July 20, 2004 to 9.6 × 9.6 plots arranged in a randomized complete block design (RCBD) using Teejet 8005 nozzles at 40 psi calibrated to deliver 40 ga/acre. Plots were monitored daily and data was collected 0, 7, 14, 21, 28, 35, and 42 DAT. Sulfosulfuron and MSMA provided the highest level of weed control 35 DAT. Metribuzin and imazaquin provided limited weed suppression compared to the control. Initial phytotoxic damage to the Lovegrass was observed in all herbicide treatments. The highest level of phytotoxic damage was observed in the MSMA and Metribuzin treatments; however there was no apparent damage at 42 DAT. Herbicide applications of sulfosulfuron and MSMA are effective in reducing weed populations with acceptable levels of phytotoxicity to the Lovegrass.