bluuebunny/crossref_metadata_2025 huggingface dataset:
Total Nonstructural Carbohydrate Storage in Creeping Bentgrass Treated with Trinexapac-ethyl
Authors: Han Sangwook , Fermanian Thomas W. , Juvik John A , Spomer Louis A.
Published: February 2019

Total nonstructural carbohydrates (TNC) are important for summer recuperation from injury for cool-season turfgrass. The objectives of this study were to determine if trinexapac-ethyl (TE) [4-(cyclopropyl-a-hydroxy-methylene)-3,5-dioxo-cyclohexane-carboxylic acid ethyl ester] affects TNC content and turf quality of a creeping bentgrass at various application frequencies and rates and to investigate any interactions between the effects of TE and traffic treatments on TNC content. Field experiments were conducted in 1995 and 1996 on a mature stand of `Pennlinks' creeping bentgrass grown on a Flanagan silt loam soil maintained at a height of 1.9 cm. Treatments included a single application (0.28 kg·ha-1) or repeat applications at 2 (0.06 kg·ha-1) or 4 (one at 0.28 kg·ha-1 and one at 0.09 kg·ha-1) week intervals during the first 8 weeks of each experiment. Treatments were arranged in a strip-plot design with TE applications as whole plots and traffic treatments as strip plots. Traffic treatments began at 2 weeks and 2 days after initial applications in 1995 and 1996, respectively and continued until the last evaluation date. Traffic treatments consisted of 4 passes of a 102.2 kg smooth roller, 2 days·week-1 in 1995 and 8 passes daily in 1996. A single aqueous extraction method was used for quantification of glucose, fructose, sucrose, and fructan. TNC was the total of all analyzed fractions. Single applications of TE at 0.28 kg·ha-1 significantly reduced turf quality for 4 weeks in both experiments. Sequential applications of TE at 0.06 kg·ha-1 exhibited reduced quality compared to the control at 4 and 8 weeks in 1995 and 2 weeks in 1996. When TE was applied once at 0.28 kg·ha-1, there was a significant reduction in TNC from 4 to 8 weeks after treatment. In 1996 when TE applications were repeated at 2 and 4 week intervals at 0.06 and 0.09 kg·ha-1, a reduction of TNC from week 4 to week 14 was observed. After 14 weeks the TNC content showed incremental increases. There was no interaction effect between traffic treatments and TE applications in the verdure TNC in either year. In 1996, verdure TNC content was 6% to 17% lower in plots receiving traffic from weeks 4 to 18. These results suggest that high rates of TE, either sequential or single applications, might reduce turf quality or carbohydrate content. While this study has not examined if this is detrimental, multiple TE applications at low rates may minimize any TNC reduction while providing effective growth suppression for extended periods.
Ultraviolet-B Radiation Damage on Kentucky Bluegrass II: Hormone Supplement Effects
Authors: Ervin Erik H. , Zhang Xunzhong , Fike John H.
Published: February 2019

High ultraviolet-B (UV-B; 290-320 nm wavelength) radiation may significantly contribute to the quality decline and death of kentucky bluegrass (Poa pratensis L.) sod during summer transplanting. Antioxidants and protective pigments may be involved in plant defense against oxidative stress caused by UV-B. Selected exogenous hormones may alleviate UV-B damage by upregulating plant defense systems. The objectives of this study were to determine if exogenous hormone or hormone-like substances could alleviate UV-B damage to `Georgetown' kentucky bluegrass (Poa pratensis L.) under greenhouse conditions. The hormone salicylic acid at 150 mg·m-2 and the hormone-containing substances, humic acid (HA) at 150 mg·m-2 and seaweed extract (SWE) at 50 mg·m-2, were applied to plugs of kentucky bluegrass and then subjected to UV-B radiation (70 μmol·m-2·s-1). The UV-B irradiation stress reduced turf quality by 51% to 66% and photochemical efficiency by 63% to 68% when measured 10 or 12 days after initiation of UV-B. Endogenous alpha-tocopherol (AT) and antioxidant enzymes (superoxide dismutase (SOD) and catalase) were reduced by UV-B stress. Anthocyanin content was increased from day 1 to 5 and then decreased from day 5 to 10 of continuous UV-B irradiation. Application of SA and HA + SWE enhanced photochemical efficiency by 86% and 82%, respectively, when measured 10 or 12 days after UV-B initiation. In addition, application of the hormonal supplements increased AT concentration, SOD, catalase activity, and anthocyanin content when compared to the control at 10 days after UV-B initiation. Bluegrass with greater AT concentration and SOD and catalase activity exhibited better visual quality under UV-B stress. The results of this study suggest that foliar application of SA and HA + SWE may alleviate decline of photochemical efficiency and turf quality associated with increased UV-B light levels during summer.
Renovating Golf Course Fairways with Zoysiagrass Seed
Authors: Patton Aaron J. , Williams David W. , Reicher Zachary J.
Published: February 2019

Zoysiagrass (Zoysia japonica Steud.) requires few inputs and provides high-quality turf in the transition zone, but is expensive to sprig or sod. Establishment by seed is less expensive than vegetative establishment, but little is known about renovation of existing turf to zoysiagrass using seed. Two experiments were performed to determine effects of herbicides and seeding rates on establishment of zoysiagrass in Indiana and Kentucky. In the first experiment, interseeding zoysiagrass into existing perennial ryegrass (Lolium perenne L.) without the use of glyphosate before seeding resulted in 2% zoysiagrass coverage 120 days after seeding (DAS). In plots receiving glyphosate before seeding, zoysiagrass coverage reached 100% by 120 DAS. In the second experiment, MSMA + dithiopyr applied 14 days after emergence (DAE) or MSMA applied at 14+28+42 DAE provided the best control of annual grassy weeds and the greatest amount of zoysiagrass establishment. Applying MSMA + dithiopyr 14 DAE provided 7% less zoysiagrass coverage compared to MSMA applied 14 DAE at one of the four locations. Increasing the seeding rate from 49 kg·ha-1 to 98 kg·ha-1 provided 3% to 11% more zoysiagrass coverage by the end of the growing season at 3 of 4 locations. Successful zoysiagrass establishment in the transition zone is most dependent on adequate control of existing turf using glyphosate before seeding and applications of MSMA at 14+28+42 DAE, but establishment is only marginally dependent on seeding rates greater than 49 kg·ha-1. Chemical names used: N-(phosphonomethyl) glycine (glyphosate); monosodium methanearsenate (MSMA); S,S-dimethyl 2-(difluoromethyl)-4-(2-methylpropyl)-6-(triflurormethyl)-3,5-pyridinedicarbothioate (dithiopyr).
Genetic Evidence of Intra-cultivar Variability within Iberian Olive Cultivars
Authors: Lopes Maria Susana , Mendonça Duarte , Sefc Kristina M. , Gil Fabíola Sabino , da Câmara Machado Artur
Published: February 2019

A collection of 130 olive samples, originating from diverse areas in Europe and corresponding to 67 different cultivars denominations, was genotyped at 14 microsatellite loci. In total, 135 alleles with a mean number of 9.6 alleles per locus were detected. All but 30 accessions showed unique genotypes. Several cases of synonymy listed in the FAO database of olive germplasm could not be confirmed, as different allelic profiles were obtained from putatively synonymous cultivars. The existence of homonyms or mislabeled samples in olive germplasm collections was evidenced by allele differences of up to 60% between samples of the same denomination. An allele-sharing phenogram of the analyzed genotypes revealed several cultivars with high levels of intra-varietal polymorphism, as well as cultivar families consisting of closely related cultivars with similar denominations. Our work shows that the current designations of olive cultivars fall short of describing the genetic variability among economically important plant material. A thorough investigation of the existing variability will prove of major importance for both management and economic production of olive trees.
Discrimination of Diploid Crucifer Species Using PCR-RFLP of Chloroplast DNA
Authors: Cunha Claudia , Tonguç Muhammet , Griffiths Phillip D.
Published: February 2019

Chloroplast DNA (cpDNA) was used to identify polymorphisms between crucifer species using the polymerase chain reaction-random fragment-length polymorphism (PCR-RFLP) technique. Ten primer pairs based on cpDNA gene sequences were used to amplify cpDNA fragments in Brassica oleracea L., B. rapa L., B. nigra (L.) Koch, B. napus L., B. carinata Braun, B. juncea (L.) Czern, and Raphanus sativus L. accessions. Amplified DNA sequences were then digested using 11 restriction enzymes to identify polymorphisms between the 7 species. Of the 110 combinations, 38 generated polymorphisms that discriminated one or more of the species. Genotyping of these polymorphisms in 10 accessions of each of the diploid species (B. oleracea, B. nigra, B. rapa and R. sativus) did not reveal segregating polymorphisms among accessions within species, indicating that they can be used to help determine species identity. Ten accessions of each of the amphidiploids B. napus, B. carinata and B. juncea were genotyped to infer their maternal ancestry. The diploid source of cpDNA in B. carinata was B. nigra in all accessions tested and B. rapa for nine of ten B. juncea accessions tested. Two B. napus accessions amplified polymorphisms shared with B. rapa, and eight accessions produced unique polymorphisms from neither B. rapa, B. oleracea or B. nigra. The polymorphisms identified in this study can be used to help confirm identity of the diploid crucifer species for taxonomic and conservation studies.
Heritability of the Resistance to Potato Leafhopper in Dry Bean
Authors: Gonzales J.W. , Coyne D.P. , Lindgren D.T. , Schaaf D. , Eskridge K. M.
Published: February 2019

The potato leafhopper (PLH), Empoasca fabae Harris is the most important Empoasca species attacking dry beans (Phaseolus vulgaris L.) in North America. The objective of this study was to determine the heritability (h2) of PLH injury based on parent-offspring regression analysis of F3 means on individual F2 plants derived from crosses of pinto `Sierra' (resistant) × great northern `Starlight' (susceptible), and black bean `Tacarigua' (resistant) × `Starlight' (susceptible). Low narrow-sense heritability values of 0.29 ± 0.06 and 0.28 ± 0.10, respectively, were obtained for the above crosses. The low narrow-sense heritability estimates indicated large environmental effects on the expression of PLH injury in dry beans. An allelic test showed that both resistant parents possessed the same genes for resistance.
A Hybrid of Buddleja davidii var. nanhoensis `Nanho Purple' and B. lindleyana
Authors: Elliott W. , Werner D.J. , Fantz P.R.
Published: February 2019

A controlled cross between Buddleja davidii var. nanhoensis (Chitt.) Rehd. `Nanho Purple' and B. lindleyana Fort. ex Lindl. produced a hybrid. Pollen viability, male fertility, and the floral and vegetative characters are presented with a Latin diagnosis. Buddleja × luteolufaucia Elliott and Fantz is proposed as the name for this hybrid. Hybridity was confirmed using RAPD analysis.
Essential Oil Yields and Quality of Fennel Grown in Nova Scotia
Authors: Bowes Kelly M. , Zheljazkov Valtcho D.
Published: February 2019

Field and laboratory experiments were conducted at two sites in Nova Scotia during 2001 and 2002 to assess the potential to grow fennel (Foeniculum vulgare Mill.) as an essential oil crop in the Maritime region of Canada. Three cultivars—`Shumen', `Berfena', and `Sweet Fennel'—and two seeding dates—24 May and 8 June—were evaluated. Essential oil yields and composition were determined and compared to commercially available fennel essential oil from the U.S. The highest herbage yields were produced by `Shumen' from the earlier seeding date. Essential oil content and yields were lowest in `Sweet Fennel' and highest in `Shumen'. The major component of the essential oil was anethole, 47% to 80.2%. Other major components of the essential oil were methyl chavicol, fenchone, α-phellandrene, α-pinene, ortho cymene, β-phellandrene, fenchyl acetate, β-pinene, and apiole. The essential oil composition was unique to each cultivar. The highest methyl chavicol content was in `Shumen', while the highest concentration of phellandrene, fenchyl acetate and apiole were detected in `Sweet Fennel' oil. Fenchone, ortho cymene, β-pinene, α-phellandrene, and α-pinene were the highest in `Berfena'. The composition of the oil was similar to the commercially purchased oil and met industry requirements of oil composition. The results suggest there is potential to grow fennel as an essential oil crop in Nova Scotia.
Vernalization and Devernalization of Campanula `Birch Hybrid' and Leucanthemum ×superbum `Snow Cap'
Authors: Niu Genhua , Heins Royal , Cameron Arthur , Carlson William
Published: February 2019

The influence of vernalization temperature and duration and devernalization treatments on subsequent growth and flower development of Campanula `Birch Hybrid' and Leucanthemum ×superbum Bergman ex J. Ingram `Snow Cap' was determined. In the vernalization experiment, plants of `Birch Hybrid' were vernalized at 0, 2.5, 5, 7.5, or 10 °C for 2, 4, 6, or 8 weeks. `Snow Cap' was vernalized at 0, 2.5, 5, or 10 °C for 2, 4, 6, or 8 weeks. In another devernalization experiment, plants of both species were moved to a high temperature (30/10 °C, day/night) growth chamber for 2 or 4 days at various times during or after the 6-week vernalization period. A 6-week vernalization was necessary to obtain 100% flowering in `Birch Hybrid', and 8 weeks of vernalization decreased time to flower by 7 to 10 days compared with 6-week vernalization. Exposure to high temperature for 2 days during or immediately after vernalization did not devernalize `Birch Hybrid' plants, while a 4-day exposure decreased flowering percentage in some treatments and delayed flowering by 7 to 10 days. There were no significant differences in flowering characteristics of `Snow Cap' plants vernalized at 0 to 5 °C for 4 to 8 weeks. A 2-week vernalization at 0, 2.5, 5, or 10 °C or 4 to 8 week vernalization at 10 °C delayed flowering by 5 to 10 days compared with those vernalized at 0 to 5 °C for 4 to 8 weeks. Exposure to high temperature for 2 d did not devernalize `Snow Cap' plants regardless of exposure times, but a 4-day exposure delayed flowering by 4 to 5 days in some treatments. Combined, the data indicate that `Birch Hybrid' has an obligate 6-week vernalization requirement and `Snow Cap' has a facultative 4-week vernalization requirement that can be fulfilled in the 0 to 10 °C range. Exposure to temperatures of 30 °C (9 h·d-1) for 12 out of 42 days did not devernalize either species but in some cases caused a small delay in time to flower.
Ethephon Concentrates and Advances Harvest for Limited Cluster Greenhouse Tomato Crops
Authors: Logendra Logan S. , Mun Jonathan G. , Gianfagna Thomas J. , Janes Harry W.
Published: February 2019

Ethephon (2-chloroethylphosphonic acid) was applied to single cluster greenhouse tomato crops (1000 ppm) at the green mature stage of fruit development or when 35% of the plants had fruits at the breaker stage. Fruits were harvested at the pink stage. Untreated fruit were harvested from 95 to 116 days after sowing whereas fruit from the green mature ethephon treatment were harvested from 92 to 102 days, three days earlier and with a reduction in the harvest window from 22 to 11 days. Fruit treated with ethephon at 35% breaker were harvested at the same time as untreated fruit, but harvest was completed after only 12 days. Fruit yield from the green mature ethephon treatment was reduced by about 30%, but there was no significant difference in fruit yield as a result of ethephon treatment at 35% breaker. Fruit color, firmness and soluble solids were evaluated one and six days after harvest. Fruit firmness and soluble solids were unaffected by treatment; however, fruit from the ethephon treatments were significantly redder in color. In a second experiment, ethephon was applied at 500 or 1000 ppm when 100% of the plants had fruit at the breaker stage. Fruit were harvested over a 7-day time interval compared to untreated fruit that were harvested over 14 days, and there was a small but significant increase in fruit yield for the 1000 ppm treatment. Both ethephon treatments also increased fruit soluble solids. For limited cluster tomato production systems, ethephon is effective in reducing the harvest window without loss in postharvest fruit quality.
Preventing Side Shoot Development with C8/C10 Fatty Acids Increases Yield and Reduces Pruning Time in Greenhouse Tomato
Authors: Logendra Logan S. , Gianfagna Thomas J. , Janes Harry W.
Published: February 2019

A mixture of C8/C10 fatty acid methyl esters (FAME) when applied directly and exclusively to leaf axils of greenhouse-grown tomato (Lycopersicon esculentum Mill.) significantly inhibited side shoot development. Plants grown in a single cluster production system in winter produced 8.9 side shoots/plant, whereas those treated with C8/C10 FAME 45 days after sowing, produced only 0.7 side shoots/plant. Total pruning weight of the side shoots was reduced from 40.2 g/plant to 1.3 g/plant. Fruit yield increased 14% with C8/C10 FAME treatment and there was an increase in the harvest index from 0.63 to 0.70. For a spring crop, in which average daily irradiance was more than twice that in winter, overall yield increased 70% when compared to the winter crop. As in winter, side shoot number and side shoot weight/plant were significantly reduced by C8/C10 FAME, but there was no difference in crop yield between C8/C10 FAME and untreated plants. In both winter and spring, untreated plants required hand pruning three times during the production period, whereas C8/C10 FAME-treated plants were pruned only once at the time of application. A C8/C10 free fatty acid (FA) mixture was also applied to one and two-cluster plants with similar results. In the multiple cluster system, application of the C8/C10 FA mixture instead of side shoot pruning reduced plant height and increased yield from 6.4 to 7.4 kg/plant. C8/C10 FA or C8/C10 FAME treatment could be a useful labor saving strategy in greenhouse tomato production and may increase crop yield under conditions in which assimilates may be limited by environmental factors, or as a result of a high level of competition from other fruits or shoots.
Dikegulac Promotes Abscission in Citrus
Authors: Pozo Luis , Redondo Ana , Hartmond Ulrich , Kender Walter J. , Burns Jacqueline K.
Published: February 2019

Two formulations of the plant growth regulator dikegulac (2,3:4,6-di-O-isopro-pylidene-α-L-xylo-2-hexulofuranosoic acid), consisting of dikegulac-sodium (Atrimmec) or dikegulac:ascorbic acid (1:1) (DAA), as well as 5-chloro-3-methyl-4-nitro-pyrazole at 200 mg·L-1, were applied as foliar sprays to `Hamlin' and `Valencia' orange trees (Citrus sinensis L. Osbeck) at two dates during the harvest season for each cultivar (11 Nov. and 10 Jan. for `Hamlin', 22 Mar. and 25 May for `Valencia'). Fruit detachment force was evaluated 10 days after application, whereas cumulative leaf abscission was monitored up to 60 days after application. In both cultivars, Atrimmec and DAA at 3,000 mg·L-1 induced moderate fruit loosening when applied at the earlier application date, but fruit loosening improved when applied at the later application date. In `Hamlin', both formulations caused higher leaf abscission when applied at the later date. DAA applications resulted in low leaf loss in `Valencia' regardless of application time, whereas Atrimmec caused unacceptably high leaf loss at either application date. No differences in internal fruit quality were found as a result of any abscission material treatment. The results indicate that DAA could be a promising option to induce fruit loosening in late harvested `Valencia' orange trees with minimal undesirable side effects.
Fruit Quality Characteristics That Affect Consumer Preferences for Satsuma Mandarins
Authors: Campbell Benjamin L. , Nelson Robert G. , Ebel Robert C. , Dozier William A. , Adrian John L. , Hockema Brandon R.
Published: February 2019

Satsuma mandarins (Citrus unshiu) have been produced intermittently along the Gulf Coast for over a century. However, very little is known about the market potential for this citrus fruit in today's consumer markets. This study evaluated consumer preferences for seven external attributes over a range of levels: price ($1.07, $2.18, or $4.39/kg), color (green-yellow, yellow-orange, or orange), size (5.08, 6.35, or 7.62 cm in diameter), seediness (0, 3, or 7 seeds), blemishes (0, 1.91, or 3 cm in diameter), production region label (Alabama or U.S.A.), and organic production (yes or no). Consumers from grocery stores in nine cities in Alabama and Georgia were asked to evaluate 20 photographs of various combinations of these attribute levels using a seven-point intention-to-buy scale. 605 useable surveys were collected and a conjoint analysis was conducted to determine the strength of preference for the attribute levels and the relative importance for attributes. Three consumer segments were identified by cluster analysis of strengths of preferences: the no-blemish segment (37% of sample), the price-sensitive segment (23% of sample), and the no-seeds segment (41% of sample). A multinomial logit analysis identified several demographic, socioeconomic, and usage variables as significant determinants of segment membership.
Micropropagation of Japanese Chestnut (Castanea crenata Sieb. et Zucc.) Seedlings
Authors: Tetsumura Takuya , Yamashita Kensuke
Published: February 2019

Japanese chestnut (Castanea crenata Sieb. et Zucc.) was micropropagated from nodal explants of 2-month-old seedlings, and the regenerated plantlets were acclimatized after potting. For in vitro establishment, 5 μm zeatin was more effective than 5 μm BA or TDZ, and Sato's (BW) medium was as effective as MS(½NO3) medium. Driver-Kuniyuki walnut medium produced more shoots showing hyperhydricity symptoms. In the multiplication culture, the higher the concentration of zeatin added to BW medium, the greater the number of shoots showing hyperhydricity, although the longest shoot was obtained when 6.9 μm zeatin was added. After planting in ½BW medium with 15 μm IBA for 5 d to induce rooting, shoots planted in ½BW medium plus vermiculite gelled with Gellan Gum (SV substrate) rooted better than those in either the gelled medium without vermiculite (S substrate) or vermiculite plus liquid medium (V substrate). One third of the shoots planted in the V substrate died, although 62% of the surviving shoots rooted well. Of the shoots planted in the S substrate, 83% survived, but only 35% of these survived rooting. Shoots rooted in the SV and V substrates survived well after the completion of acclimatization, and shoots rooted in the SV substrate grew more vigorously after potting. Chemical names used: 6-benzyladenine (BA); 6-(4-hydroxy-3-methyl-but-2-enylamino)purine (zeatin); indole-3-butyric acid (IBA); 1-phenyl-3-(1,2,3-thiadiazol-5-yl)urea (thidiazuron, TDZ).
Effect of Phosphorus Fertilization on Growth and Flowering of Scaevola aemula R. Br. `New Wonder'
Authors: Zhang Donglin , Moran Renae E. , Stack Lois B.
Published: February 2019

Scaevola aemula R.Br. (fanflower), an ornamental plant native to Australia, produces stunted growth when fertilized with high concentrations of P. To determine optimum P concentration, rooted cuttings were transplanted into 15 cm standard pots and grown with a water soluble fertilizer, where P concentrations were 0, 14.5, 29.0, 43.5, 58.0, 72.5, 87.0 mg·L-1 and all plants received 200 mg·L-1 N and 166 mg·L-1 K. Shoot growth and flowering data were taken every 21 days until the experiment was terminated after 84 days. Shoot length, number and dry weight, and leaf size were reduced significantly at P concentrations higher than 14.5 mg·L-1 with severe reduction at P levels higher than 43.5 mg·L-1. Number of flowers per plant was not affected by P concentrations in the range of 0 to 43.5 mg·L-1, but decreased significantly at P levels higher than 43.5 mg·L-1. Medium pH decreased with increase in P rate due to the acidic nature of the P fertilizer. When P was applied in every irrigation, the optimum concentration was 14.5 mg·L-1 or less. P greater than 43.5 mg·L-1 was detrimental to vegetative growth and flowering, possibly due to above optimum P or to medium acidification.
Late Fall and Winter Nitrogen Fertilization of Turfgrass in Two Pacific Northwest Climates
Authors: Miltner Eric D. , Stahnke Gwen K. , Johnston William J. , Golob Charles T.
Published: February 2019

Late fall N fertilization of cool-season turfgrass in northern climates is a common practice. Previous research has been focused in climates where freezing temperatures prevail. Research in more moderate northern climates where turf may not go through winter dormancy is scarce. Four fertilizer N sources and an untreated control were applied in four different months (November, December, January, or February) to perennial ryegrass (Lolium perenne L.) in Puyallup, Wash., and to kentucky bluegrass (Poa pratensis L.) In Pullman, Wash., to compare their effects in moderate (Puyallup) and freezing (Pullman) winter climates. In Pullman, only November applications of ammonium sulfate (AmS) or polymer coated sulfur coated urea (PCSCU) enhanced winter turfgrass quality. In Puyallup, November or December application of AmS, PCSCU, or polymer coated urea (PCU) resulted in enhanced winter quality. Polymer coated urea yielded a delayed initial response and a longer residual effect in the spring. Isobutylidenediurea (IBDU) did not improve winter turf quality in either Pullman or Puyallup. Although there was no quality response following January fertilizer application, there was suppression of red thread [Laetisaria fuciformis (McAlpine) Burds.] symptoms in Puyallup, indicating N uptake. Late fall fertilizer N in eastern Washington should be confined to November, using soluble or more quickly available slow-release nitrogen fertilizers. The application window can be extended to December in western Washington, and more slowly available coated ureas can be effectively used.
Rhizosphere Bacterial Population Flux in Golf Course Putting Greens in the Southeastern United States
Authors: Elliott M.L. , Guertal E.A. , Skipper H.D.
Published: February 2019

The rhizospheres of creeping bentgrass (Agrostis palustris Huds.) and hybrid bermudagrass (Cynodon dactylon (L.) Pers. × C. transvaalensis Burtt-Davy) putting greens were sampled quarterly for 4 years. Six bacterial groups, including total aerobic bacteria, fluorescent pseudomonads, actinomycetes, Gram-negative bacteria, Gram-positive bacteria, and heat-tolerant bacteria, were enumerated. The putting greens were located in four geographic locations (bentgrass in Alabama and North Carolina; bermudagrass in Florida and South Carolina) and were maintained according to local maintenance practices. Significant effects were observed for sampling date, turfgrass species and location, with most variation due to either turfgrass species or location. Bentgrass roots had significantly greater numbers of fluorescent pseudomonads than bermudagrass roots, while bermudagrass roots had significantly greater numbers of Gram-positive bacteria, actinomycetes and heat-tolerant bacteria. The North Carolina or South Carolina locations always had the greatest number of bacteria in each bacterial group. For most sampling dates in all four locations and both turfgrass species, there was a minimum, per gram dry root, of 107 CFUs enumerated on the total aerobic bacterial medium and a minimum of 105 CFUs enumerated on the actinomycete bacterial medium. Thus, it appears that in the southeastern U.S. there are large numbers of culturable bacteria in putting green rhizospheres that are relatively stable over time and geographic location.
Response of `TifEagle' Bermudagrass to Seven Plant Growth Regulators
Authors: McCullough Patrick E. , Liu Haibo , McCarty Lambert B. , Whitwell Ted
Published: February 2019

Dwarf bermudagrass morphological characteristics following the use of plant growth regulators have not been reported. The objective of this greenhouse study was to determine short-term effects of seven plant growth regulators on clipping yield, chlorophyll concentration, and root mass of `TifEagle' bermudagrass. Growth regulators tested included ethephon, fenarimol, flurprimidol, maleic hydrazide, mefluidide, paclobutrazol, and trinexapac-ethyl. Two applications of each compound were made over a 6-week period. Root mass was reduced 39% by fenarimol and 43% by flurprimidol, while other PGRs had root mass similar to untreated turf. `TifEagle' bermudagrass treated with paclobutrazol, mefluidide, fenarimol, and flurprimidol averaged 45% less root mass than trinexapac-ethyl-treated turf. Trinexapac-ethyl was the only compound to reduce clippings and enhance turf quality without negative rooting effects. Chemical names used: [4-(cyclopropyl-[α]-hydroxymethylene)-3,5-dioxo-cyclohexane carboxylic acid ethyl ester] (trinexapac-ethyl); {α-(1-methylethyl)-α-[4-(trifluoro-methoxy) phenyl] 5-pyrimidine-methanol} (flurprimidol); (+/-)-(R*,R*)-β-[(4-chlorophenyl) methyl]-α-(1, 1-dimethyl)-1H-1,2,4,-triazole-1-ethanol (paclobutrazol); (N-[2,4-dimethyl-5 [[(trifluoro-methyl)-sulfonyl] amino]phenyl]acetamide) (mefluidide); [1,2-dihydro-3,6-pyridazine-dione] (maleic hydrazide); [(2-chloroethyl)phosphonic acid] (ethephon); and (2-(2-chlorophenyl)-2-(4-chlorophenyl)-5-pyrimidinemethanol) (fenarimol).
Velvet and Creeping Bentgrass Tolerance to Fenoxaprop
Authors: Henry Gerald M. , Hart Stephen E.
Published: February 2019

The tolerance of velvet bentgrass (Agrostis canina L.) to the herbicide fenoxaprop is not known. In greenhouse experiments velvet bentgrass cultivars SR7200 and Vesper had a much greater degree of tolerance to fenoxaprop at rates ranging from 0.01 to 0.30 kg·ha-1 relative to L-93 creeping bentgrass (Agrostis stolonifera L.). SR7200 and Vesper were tolerant to fenoxaprop at 0.15 kg·ha-1 or lower and growth reductions did not exceed 10% at the highest fenoxaprop rate of 0.30 kg·ha-1. In contrast, growth reduction of L-93 creeping bentgrass was evident at the lowest application of fenoxaprop at 0.01 kg·ha-1 and increased as fenoxaprop rates increased, reaching as high 58% at 0.30 kg·ha-1. Field experiments were conducted in 2002 and 2003 to compare the tolerance of established SR7200 velvet bentgrass and Penn A-4 creeping bentgrass maintained at 3.2 mm to three sequential applications at 21 day intervals of fenoxaprop at 0.02, 0.04, and 0.07 kg·ha-1. Turf quality of SR7200 was equal to the untreated following all fenoxaprop applications except the third sequential application at 0.07 kg·ha-1. Penn A-4 turf quality was consistently reduced compared to the untreated following fenoxaprop applications of 0.04 and 0.07 kg·ha-1. Turf density of SR7200 was not affected by three sequential applications of fenoxaprop at 0.02 and 0.04 kg·ha-1 but was reduced by 8% at 0.07 kg·ha-1. Penn A-4 turf density was reduced by 10 and 33% following three sequential applications of fenoxaprop at 0.04 and 0.07 kg·ha-1, respectively. Results from these studies showed that the velvet bentgrass cultivars were more tolerant to fenoxaprop, compared to the creeping bentgrass cultivars evaluated. Chemical names used: (+)-ethyl2-[4-[(6-chloro-2-benzoxazolyl)oxy]p henoxy] propanoate (fenoxaprop). 3,5-pyridinedicarbothioic acid, 2-(difluoromethyl)-4-(2-methylpropyl)-6-(trifluoromethyl)-S,S-dimethylester (dithiopyr).
(184) Effects of Colored Plastic Mulches on Muskmelon Growth and Yield
Authors: Ogutu Maurice
Published: February 2019

Colored plastic mulches can influence muskmelon (Cucumis melo L.) growth and yield. A study was carried out at the St. Charles Horticulture Research Center, St. Charles, Ill., to compare the effects of different colored plastic mulches on vine length and yield of muskmelons. An experiment was carried out with 10 treatments, namely, control (bare ground), and plastic mulches (black smooth, red, black embossed, blue, olive, yellow, clear, white, and reflective) in a complete randomized block and replicated four times. Muskmelon variety `Athena' seeds were started in the greenhouse in late Apr. 2004 in flats filled with Jiffy Mix, and transplanted in mid-May 2004. Seedlings planted in black embossed, olive, red, blue, and white plastic mulches had longer vines than seedlings transplanted in black smooth, reflective, clear, and yellow mulches by 24 July. Seedlings planted on the control (bare ground) had much shorter vines compared to seedlings in other treatments. The cumulative fruit number and weight was higher in blue, olive, red, and black embossed plastic mulches than in plants grown in clear, yellow, and reflective plastic mulch treatments. Plants grown in white and reflective mulch treatments had larger fruits than plants in other treatments. In comparison with black embossed plastic mulch, plants grown in blue, olive, and red plastic mulches had higher fruit number and yields.
(185) Response of Vegetable Crops to Mycorrhizal Inoculation in a Calcareous Soil in the Tropics
Authors: Marutani Mari , Tuquero Joseph , Schlub Robert , McConnell James
Published: February 2019

The effects of a vesicular–arbuscular mycorrhizal fungus, Glomus aggregatum inoculation were examined on growth of vegetable crops in pot culture and field experiments with Guam cobbly clay loam soil (clayey, gibbsitic, nonacid, isohyperthermic Lithic Ustorthents). In pot experiments, the growth response of yard-long beans (Vigna unguiculata subs. sesquipendalis), sweet corn (Zea mays), watermelon (Citrullus lanatus), cucumber (Cucumis sativus), okra (Abelmoschus esculentus), green onion (Allium fistulosum), eggplant (Solanum melongena), and papaya (Carica papaya) were significantly improved with mycorrhizal inoculation. A pot experiment was also conducted to evaluate effects of G. aggregatum inoculation on the growth of corn seedlings at four different water regimes. Seedlings inoculated with G. aggregatum significantly improved the plant growth and the mineral uptake at all levels of water treatments. In the first field trial, prior to seed sowing the media in seedling trays were either inoculated or not inoculated with G. aggregatum. Treated watermelon and eggplant seedlings were transplanted in field. It was found that inoculating seedlings did not improve the harvest yield of two fruit-bearing crops. The second field experiment was conducted to study G. aggregatum inoculation and different levels of inorganic fertilizer application on growth of corn. Mycorrhizal colonization had positive effects on corn development and uptake of some minerals such as Fe. Experiments in the study suggested potential uses of a mycorrhizal fungus in an alkaline soil in the tropics.
(186) Vegetable Yields under Sustainable Production Systems
Authors: Hoyt Greg D.
Published: February 2019

This experiment was designed to compare best management practices for conventional and conservation tillage systems, chemical IPM vs. organic vegetable production, and rotation effect on tomatoes. Four vegetables were grown under these management practices with peppers (first year), yellow squash and fall broccoli (second year) on half of the field plots and tomatoes on the other half. For the third year, both sections of the field plots were tomatoes. The treatments were: 1) conventional-tillage with chemical-based IPM; 2) conventional-tillage with organic-based IPM; 3) conservation-tillage with chemical-based IPM; 4) conservation-tillage with organic-based IPM; and 5) conventional-tillage with no fertilizer or pest management (control). This poster describes pepper, yellow squash, fall broccoli, and tomato yields from the various treatments over the 3-year rotation. These results are for the third rotation sequence (years 79). Pepper yields were higher in treatments with chemical fertilizer and pest control. Fall broccoli yields were in the order: strip-tilled-chemical ≥ strip-till-organic ≥ conventional-tilled-chemical ≥ conventional-tilled-organic ≥ control. Yellow summer squash yields were in the order: conventional-tilled-chemical ≥ conventional-tilled-organic ≥ strip-till-chemical ≥ strip-tilled-organic ≥ control. Tomato yields were in the order: conventional-tilled chemical ≥ strip-till-chemical ≥ conventional-tilled-organic ≥ strip-tilled-organic ≥ control for each of the 3 years.
(168) Long-term Growth of Live Oak from Seed or Cutting
Authors: Wang Yin-Tung , Niu Genhua
Published: February 2019

Live oak trees raised from acorns are highly non-uniform and many produce numerous undesirable rhizomic shoots. The objectives of this study were to 1) compare the growth rates between (Quercus virginiana Mill.) trees from seed and cutting in four production systems and 2) determine if trees from cuttings produce rhizomic shoots. Rhizomic shoot cuttings 25–30 cm long were taken from a single tree about 50 years old in late Aug. 1990, rooted, and planted in 2.6-L pots after 2 months. During the same week, acorns were collected from the same tree and germinated. All trees were planted into 13-L pots in July 1991 and then to a field in July 1992. Trees from both sources were planted either directly in the ground, in 36.6- or 45.7-cm-diameter polypropylene fabric bags buried in the ground, or in 13-L pots on the ground. Trunk circumference 10 cm above the soil line was roughly measured yearly between 1992 and 1999. Initially, trees from cuttings grew slightly slower than seedlings, having a smaller trunk circumference, diameter, and cross-sectional area. These differences diminished and all trees had similar circumferences after 1996. In 1992, trees in 36.6-cm bags and pots had more growth than trees in the ground. In 1993, trees in pots had better growth than those in the ground. After 1993, all trees had similar circumferences until the end of this study, probably due to roots extending beyond the bags and pots into the surrounding soil. About one-third of the seedling trees produced rhizomic shoots, whereas none of the trees from cuttings did. The rhizomic shoots of trees in pots were contained within the pot and none from the ground. Another significance of this research is that the cloned trees from cuttings were extremely uniform in growth habit and form.
(235) Genetic Diversity Analysis of Five Passiflora Genotypes
Authors: Stafne Eric , Lindstrom Jon , Clark John
Published: February 2019

Passiflora is an important ornamental genus, mainly within tropical zones. However, two cold-hardy, North American Passiflora species exist. Previous work has been done to incorporate these species into breeding programs with some success. The intent of this study was to evaluate the extent of genetic diversity among five different Passiflora genotypes, including the two native North American species, P. incarnata L. and P. lutea L. Results indicate low genetic similarity among all genotypes with none at 50% or greater. P. incarnata and the ornamental cultivar `Lady Margaret' displayed the highest relationship at 49%. P. incarnata averaged 35.5% similarity with the other genotypes and P. lutea was 29.5%. Average overall similarity among all genotypes was 31.1%. These and other results show that the Passiflora genus has a high degree of genetic variation and breeding efforts could expand interest within North America.
(236) Evaluation of Styrax japonicus for Time of Budbreak and Susceptibility to Spring Freeze Damage
Authors: Reed Sandra
Published: February 2019

Japanesesnowbell(Styrax japonicus Sieb. & Zucc.) is an outstanding small ornamental tree that is underutilized in the United States. Many of the cultivars of this Asian native frequently suffer spring freeze damage, especially when grown in the areas of the country that routinely experience dramatic fluctuations in late winter and early spring temperatures. 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 with reduced susceptibility to spring freeze damage. In 1998, 224 open-pollinated seedlings were planted in the field. Percent budbreak was evaluated weekly during a 6-week period in Spring 1999 and 2000. While weather conditions varied greatly between the 2 years, there was good consistency between mean budbreak ratings in 1999 and 2000. 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 `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.
(243) Ovule and Embryo Culture of × Chitalpa tashkentensis Hybrids
Authors: Olsen Richard T. , Ranney Thomas G. , Viloria Zenaida
Published: February 2019

A series of studies were conducted to determine medium components necessary for ovule and embryo culture of ×Chitalpatashkentensis Elias & Wisura hybrids in order to improve recovery of interploid crosses. Ovules were collected at 2, 3, 4, 5, and 6 weeks after pollination (WAP) from selfed tetraploid × Chitalpa (S) and tetraploid × Chitalp × diploid Catalpabignonioides Walt. (3×) hybrids. Excised ovules were placed in petri dishes with Schenk and Hildebrandt (SH) medium and 0.7% agar, with or without coconut-water (2%) and three sucrose concentrations (20, 40, or 80 g·L-1). No ovules germinated for either cross in any treatment at 2, 3, and 4 WAP. Selfed ovules germinated at 5 WAP, in both 20 and 40 g·L-1 sucrose. At 6 WAP, 3× ovules germinated in 20 g·L-1 sucrose. Coconut water provided no apparent benefit. Embryos were apparent at 6 WAP, so a new study was initiated to compare ovule vs. embryo culture at this sample date. Excised embryos germinated in greater percentages than ovules, in all treatment combinations at 6 WAP. Germination in 80 g·L-1 sucrose was observed only for S embryos without coconut water. Greatest 3× germination (16.7%) was observed for embryos in 20 g·L-1 sucrose without coconut water. A final study was conducted to investigate the effect of gibberellic acid (GA3) on embryo germination. Embryos were harvested at 7 WAP for both crosses and grown in SH medium supplemented with 20 g·L-1 sucrose and 0, 1, 2, or 4 μm GA3. The addition of GA3, regardless of concentration, increased germination from 30.6% to 99.1% for S embryos and from 11.1% to 99.1% for 3× embryos.
(244) Interspecificic Hybridization of a White-flowered, Cold-hardy Alstroemeria
Authors: Kollman Elizabeth L. , Bridgen Mark P.
Published: February 2019

Alstroemeria, the Inca Lily or Lily-of-the-Incas, is becoming a popular garden plant in the United States. In past years, the primary interest in Alstroemeria has been for its cut flowers. However, recent cold-hardy introductions (USDA hardiness zone 5) have expanded the interest of this colorful plant as a garden perennial throughout the United States. Previously, garden interests were restricted to warmer zones in the southern United States where Alstroemeria could overwinter. This research describes a breeding procedure that has been used with the objective to develop a cold-hardy, white-flowered Alstroemeria. The interspecific hybrids were bred with the use of in ovulo embryo rescue. Reciprocal crosses were made between several white-flowered cultivars and the cold-hardy Chilean species Alstroemeriaaurea during Summer 2004. Ovaries were collected 10–23 days after hand pollination and their ovules were aseptically excised. Ovules were placed in vitro on 25% Murashige and Skoog (MS) medium under dark conditions until germination. Three weeks after germination, they were then placed on 100% MS medium, and subcultured every 3–4 weeks thereafter until they were large enough for rooting. After rooting and acclimation, plants were transferred to the greenhouse. Successful hybrids that were produced in 2004 were evaluated under greenhouse and field trials during 2005, and the number of plants with white-colored flowers was noted. Although certain morphological characteristics indicate if plants are coldhardy, the hybrids will be overwintered outside in Ithaca, N.Y. (USDA zone 5), during the next several years to determine winter hardiness.
(29) MCP Treatment Makes Delayed Application of Ethoxyquin Effective in Control of Superficial Scald of `d'Anjou' Pears
Authors: Bai Jinhe
Published: February 2019

Superficial scald of `d'Anjou' pears usually develops after storage of 2 months or longer. MCP application controls scald; however, fruit lose their ripening capacity if the dosage is >30 ppb, but lower dosages cannot control scald substantially. In this study, fruit treated with or without 25 ppb MCP within 2 d after harvest were stored at –1 °C for up to 5 months. After 1, 7, 30, or 70 d of storage, part of the fruit were pulled from storage and treated with 1000 ppm ethoxyquin line spray and immediately returned to the storage, left untreated as non-ethoxyquin control. Incidence of superficial scald along with the concentrations of α-farnesene and conjugated trienes (CTs), and the ripening capacity of fruit were investigated after 3, 4, and 5 months storage. All fruit ripened properly within 7 d of conditioning at room temperature regardless of treatments. Both of MCP or ethoxyquin-1d (ethoxyquin was applied after 1 day storage at –1 °C) alone controlled scald for only 3 months; however, MCP + ethoxyquin controlled scald for 5 months, whenever ethoxyquin was applied between 1 to 70 d after storage. Thus, with 25 ppb MCP treatment, which is simple, with rapid and mass treatment available, a delayed application (up to 70 d) of ethoxyquin becomes effective to control scald. Furthermore, the later application of ethoxyquin within 70 d after MCP treatment, the less incidence of scald was observed. Scald is caused by the CTs oxidation products of α-farnesene. MCP and ethoxyquin inhibited accumulation of CTs of fruit peel by different mechanisms. MCP inhibited the production by influencing ethylene production through control of α-farnesene synthesis; however, ethoxyquin worked by inhibiting the oxidation of α-farnesene to the CTs.
(31) Quality Changes in Oriental Melon as Affected by Washing after Fruit Harvest and 1-MCP Treatment
Authors: Park Yu-Jin , Cha Duk-Hee , Jung Ki-yun , Kang Bong-Hwa , Lee Jung-Myung
Published: February 2019

Washing oriental melon (Cucumismelo var. makuwa Makino) is a standard procedure because it facilitates the precise elimination of defective fruit, such as fruit having internal decay symptoms, and also facilitates easier handling of fruit by the elimination of gummy substances on the fruit surface. In most fresh fruits and vegetables, however, washing has never been recommended unless it is related to other practices, such as waxing or immediate processing. Harvested oriental melons were placed in a big water tank and washed with a brush machine immediately before grading, using an automatic grader. Fruit that had sunk down to the bottom of the tank were discarded, as they were premature-fermented fruit with no commercial value. Fruit, intact or washed, were treated with 1-MCP at 0.5–2.0 ppm for 12 hours and stored at room temperature for 3 weeks. Flesh firmness, soluble solids contents, fruit petiole color, and changes of surface suture color were measured to evaluate storability of the fruit. The washed fruit exhibited poor skin color and early suture-browning as compared to the non-washed fruit, regardless of 1-MCP pretreatment. 1-MCP treatment was also effective in maintaining fresh fruit quality as compared to the non-treated fruit. 1-MCP effects were, however, more pronounced in relatively smaller and less mature fruit as compared to the fully mature fruit. 1-MCP was also effective in maintaining white suture color, the most important visual factor currently used for quality evaluation in oriental melon.