bluuebunny/crossref_metadata_2025 huggingface dataset:
Clippings Disposal and Fertilization Influence Disease in Perennial Ryegrass Turf
Authors: Dunn J.H. , Minner D.D. , Fresenburg B.F. , Bughrara S.S.
Published: February 2019

We evaluated the effect of fertilization treatments in combination with clippings disposal on perennial ryegrass (Lolium perenne L.) in two adjacent locations. Clippings left on turf during mowing decreased dollar spot (Sclerotinia homoeocarpa F.T. Bennett) in both locations during three summers compared with clippings removed in mower baskets. However, brown patch (Rhizoctonia solani Kuhn) increased during July and Aug. 1995 when clippings were left on turf. Dollar spot was more severe with N (kg·ha–1·year–1) at 120 compared to 240; brown patch was more severe at 240. While clippings disposal had significant effects on disease incidence, implementation may not be practical because of the contrary responses of the observed diseases to this management approach.
Benzyladenine and Gibberellic Acid Increase Runner Production in Dayneutral Strawberries
Authors: Dale Adam , Elfving Don C. , Chandler Craig K.
Published: February 2019

In greenhouse and field studies, benzyladenine (BA) and gibberellic acid (GA3) applied together as a foliar spray increased runner production in dayneutral strawberries (Fragaria ×ananassa Duch.) but not when applied separately. Runner production increased linearly with increased BA concentration to 1800 mg·L–1. At high dosages, GA3-treated plants produced elongated internodes that, in the field, led to fewer daughter plants. In Florida, daughter plants derived from plants sprayed with the growth regulators increased yield by up to 10% in fruiting experiments. To induce runnering in the field and greenhouse, a treatment with BA at 1200 mg·L–1 and GA3 at 300 mg·L–1 is recommended. Chemical names used: N-(phenylmethyl)-1H-purine-6-amine (benzyladenine); gibberellic acid A3; gibberellic acids A4 and A7.
Testing the Light Acclimatization Potential of Chrysalidocarpus lutescens Wendl.
Authors: Reyes Trinidad , Nell Terril A. , Barrett James E. , Conover Charles A.
Published: February 2019

This experiment was conducted to evaluate the interior performance of Chrysalidocarpus lutescens grown for 8 months under 481, 820, and 1241 μmol·m–2·s–1 and fertilized weekly with a 20N–4.7P–16.6K soluble fertilizer at 440, 880, and 1660 mg/pot. Afterwards, plants were placed indoors and maintained at 20 μmol·m–2·s–1 for 12 h daily at 21±1C and a relative humidity of 50%±5% for 3 months. At the end of the production phase, light compensation point (LCP) varied from 243 μmol·m–2·s–1 at the high irradiance level to 140 μmol·m–2·s–1 at the lowest one. Chlorophyll concentration in the leaves was not affected by irradiance or fertilizer rate. Starch concentration in stems and roots were higher the lower the fertilizer rate applied during production and the higher the irradiance level. After 3 months indoors, LCP declined for all the treatments, but the lowest LCP reached, 126 μmol·m–2·s–1, was still too high if the plant has to survive an interior environment. After the interior holding period, a 45% to 55% reduction was observed on leaf, stem, and root soluble sugar concentrations, and stem and root starch concentrations decreased by 97%, and 62% to 72%, respectively, compared to the concentration at the end of production. The number of fronds increased in all treatments during the postproduction evaluation. However, the drastic carbohydrate concentration depletion during the interior holding period indicates that C. lutescens is not a species for extended use under very low interior light conditions.
Simultaneous Screening for Resistance to Blackeye Cowpea Mosaic Virus and Root-knot Nematode in Southernpea
Authors: Hunter A.G. , Chambliss O.L. , Williams J.C.
Published: February 2019

Four southernpea (cowpea) [Vigna unguiculata (L.) Walp.] cultivars representing various combinations of resistance and susceptibility to blackeye cowpea mosaic virus (BlCMV) and southern root-knot nematode [Meloidogyne incognita (Kofoid and White) Chitwood] were used to determine effectiveness of simultaneous screening of plants for resistance to both pathogens. Plants were inoculated with both pathogens simultaneously, each pathogen separately, or left uninoculated as controls. The resistance classification of the cultivars based on treatments with only one pathogen was not different from that based on the treatment with both pathogens. Virus × nematode interaction was not a significant source of variation in BlCMV symptoms and root-knot nematode galls. Simultaneous screening for both pathogens in southernpeas appears to be a feasible option.
Direct Shoot Regeneration from Vaccinium pahalae (Ohelo) and V. myrtillus (Bilberry) Leaf Explants
Authors: Shibli Rida A. , Smith M.A.L.
Published: February 2019

Ohelo (V. pahalae Skottsb.) and bilberry (V. myrtillus L.) shoots were regenerated via direct organogenesis from whole leaves and leaf sections and also from hypocotyl explants of bilberry. Explants preincubated for 1 to 2 weeks in darkness yielded ≈75% regeneration frequencies and the highest number of regenerating shoots/explant on TDZ-supplemented media (0.9 to 2.7 μm). When 2iP or zeatin were substituted as the cytokinin source, frequencies of regeneration and shoot productivity were significantly lower. Explants held under constant illumination (no dark pretreatment) had significantly lower regeneration frequencies in all tested cytokinin-supplemented media. 2,4-D stimulated callus formation, but did not support regeneration from vegetative explants. Cells from callus and suspension cultures did not exhibit regeneration in any of the media that supported organogenesis from leaves. Regenerants were successfully micropropagated, although callus formation caused by zeatin and high 2iP levels interfered with shoot proliferation. Zeatin induced hyperhydricity in shoots from both species, but more severely in ohelo. Ex vitro rooting after treatment with 4.9 μm IBA or 5.4 μm NAA was 95% and 60% successful for bilberry and ohelo, respectively, and plants were readily acclimatized after an interval in a fog chamber. Bilberry microshoots also rooted in vitro in the absence of growth regulator treatment. Chemical names used: 1H-indole-3-butanoic acid (IBA); N-(3-methyl-2-butenyl)-1-H-purine-6-amine (2iP); 6-furfurylaminopurine (kinetin); 1-naphthaleneacetic acid (NAA); thidiazuron=1-phenyl-3-(1,2,3-thiadiazio-5-yl)urea (TDZ); 2,4-dichlorophenoxyacetic acid (2,4-D); 6-(4-hydroxy-3-methylbut-2-enylamino) purine (zeatin).
Screening Melon (Cucumis melo) for Resistance to Gummy Stem Blight in the Greenhouse and Field
Authors: Zhang Yiping , Kyle Molly , Anagnostou Konstantinos , Zitter Thomas A.
Published: February 2019

Greenhouse and field evaluations of melon (Cucumis melo L.) for resistance to gummy stem blight, caused by the fungus Didymella bryoniae (Auersw.) Rehm, were conducted on 798 U.S. Dept. of Agriculture Plant Introduction (PI) accessions and 24 related Cucumis species. Plants were inoculated at the three to four true-leaf stage with a virulent isolate of D. bryoniae collected from Onondaga County, N.Y., and disease indices were calculated based on foliar and stem symptoms. In greenhouse screens, 43 C. melo accessions showed a high level of resistance. Results were consistent between the optimized greenhouse screening procedure described and inoculated replicated field tests. Of these accessions, a Chinese group, PIs 157076, 157080, 157081, 157082, 157084; another group from Zimbabwe, PIs 482393, 482398, 482399, 482402, 482403, 482408; and some others from different origins, PI 255478 (Korea) and PI 511890 (Mexico), showed high levels of resistance, at least equal to that in PI 140471, the leading source of resistance to date.
Selective Limb Pruning of Large Pecan Trees Reduces Yield but Improves Nut Size and Tree Characteristics
Authors: Worley Ray E. , Mullinix Ben
Published: February 2019

Pecan [Carya illinoinensis (Wangenh.) C. Koch] tree height was gradually reduced by removing one to three limbs per year at a height <12 or <9 m or none. Pruning at either height reduced yield but increased tree vigor, terminal shoot growth, nut size, and percentage of “standard” grade kernels. Pruning reduced leaf Mg and percentage of “fancy” grade kernels.
Pinch Treatment and Photoperiod Influence Flowering of Delphinium Cultivars
Authors: Garner James M. , Jones Starla A. , Armitage Allan M.
Published: February 2019

Two studies were conducted to determine the influence of decapitation (pinch treatment) and photoperiod treatments on stem length, days from planting to harvest, and flowering stem yield in two delphinium cultivars. Plants of Delphinium ×belladonna Hort. ex Bergmans `Völkerfrieden' received a hard pinch (removal of apex and all stem and leaf tissue associated with leaves ≤10 cm), soft pinch (removal of apex and all stem and leaf tissue associated with leaves ≤4 cm), or no pinch. Plants of the D. elatum L. `Barbara' series were grown under either long- or short-day photoperiod, each treatment with or without receiving a soft-pinch. Time from planting to harvest was longer in pinched plants than in nonpinched plants of both cultivars regardless of photoperiod. Flowering stems were longer in hard- and soft-pinched plants of `Völkerfrieden' compared to nonpinched plants, and with `Barbara', stem length of pinched plants was either longer or similar to that of nonpinched plants regardless of photoperiod. At 30 days after the commencement of harvest, yield of flowering stems for hard-pinched plants of `Völkerfrieden' was higher than that for nonpinched plants, but yield from soft-pinched plants was similar to that for those not pinched. Stem yield for `Barbara' was higher for pinched plants under the long-day photoperiod, but under short days, yield from pinched plants was similar to that for those not pinched. Long days appear to increase yield and reduce production time in delphinium cultivars. Commercial benefits may be realized by growing nonpinched plants for earliness and pinched plants for longer stems and higher yield.
Water Retention in Root-zone Soil Mixtures of Layered Profiles Used for Sports Turf
Authors: Taylor D.H. , Williams C.F. , Nelson S.D.
Published: February 2019

Where coarse-textured materials, such as gravel, underlie the root-zone layer of sports turf soil profiles, water retention in the root-zone layer is increased. The objective of this research was to determine the water retention characteristics in sand and sand: peat mixtures placed over coarse-textured layers and to determine how sand particle size and type of peat in the mixtures influenced water distribution after drainage. Soil profiles consisted of 30 cm of sand or sand: peat mixtures over 5 cm of predominantly coarse and very coarse sand, which in turn was over 10 cm of gravel. Excess water was added to the profile and allowed to drain for 24 or 48 h, following which water content and air-filled porosity (AFP) in the mixtures were evaluated. Regardless of the root-zone mixture, the coarse-textured sublayers resulted in a wet zone in the lower portion of the root-zone mixture. An unamended, predominantly medium and coarse sand, when used in the 30- cm root-zone layer, maintained ≈10% AFP in the lower 6 cm after drainage. Sand: peat mixtures using this sand generally maintained 3% to 8% AFP in the lower 12 cm of the root-zone layer. An unamended, predominantly fine and medium sand root-zone layer had ≈6% AFP in the lower 9 cm and sand: peat mixtures using this sand had <5% AFP in the lower 12 to 18 cm of the root-zone layer, with significant portions remaining at or near saturation after 24 or 48 h of drainage.
Resistance of Muscadine Grapes to Angular Leaf Spot (Mycosphaerella angulata Jenkins) in North Florida
Authors: Chen J. , Lamikanra O.
Published: February 2019

Angular leaf spot is a common but rarely studied disease of muscadine grapes (Vitis rotundifolia Michx.) in the southeastern United States. During 1994 and 1995, we performed two field evaluations of angular leaf spot on 30 muscadine cultivars. Based on disease severity data, no cultivar was immune to angular leaf spot; however, `Albermarle', `Doreen', `Higgins', `Noble', `Regale', `Scuppernong', `Southland', and `Summit' showed high degrees of resistance. `Alachua', `Darlene', `Dixie Red', `GA-3-9-2', `Jane Bell', `Janet', `Jumbo', `Pam', and `Rosa' were susceptible.
Temperature and Phosphorus Source Affect Phosphorus Retention by a Pine Bark-based Container Medium
Authors: Cole Janet C. , Dole John M.
Published: February 2019

These studies were conducted to determine the effect of 1) temperature on P leaching from a soilless medium amended with various P fertilizers, 2) water application volume on P leaching, and 3) various fertilizers on P leaching during production and growth of marigolds (Tagetes erecta L. `Hero Flame'). Increasing temperature linearly decreased leaching fraction; however, total P leached from the single (SSP) or triple (TSP) superphosphate-amended medium did not differ regardless of temperature. Despite a smaller leaching fraction at higher temperatures and no change in the total P leached, P was probably leached more readily at higher temperatures. More P was leached from the medium amended with uncoated monoammonium phosphate (UCP) than from the medium containing polymer-coated monoammonium phosphate (CTP) at all temperatures, and more P was leached from UCP-amended medium at lower temperatures than at higher temperatures. More P was leached from TSP- than from SSP-amended medium and from UCP- than from CTP-amended medium regardless of the water volume applied, but leachate P content increased linearly as water application volume increased for all fertilizers tested. Plant dry weights did not differ regardless of P source. Leachate electrical conductivity (EC) was lower with TSP than with SSP. Leachate EC was also lower with CTP than with UCP. A higher percentage of P from controlled release fertilizer was taken up by plants rather than being leached from the medium compared to P from uncoated fertilizers.
Testing for Genetic Purity in Petunia and Cyclamen Seed Using Random Amplified Polymorphic DNA Markers
Authors: Jianhua Zhang , McDonald Miller B. , Sweeney Patricia M.
Published: February 2019

This study examined the use of random amplified polymorphic DNA (RAPD) markers as a means to identify cultivars of petunia (Petunia hybrida Vilm) seedlings and cyclamen (Cyclamen persicum Mill.) seeds and to determine the genetic purity within cyclamen seeds. Bulked samples of six petunia and five cyclamen hybrid cultivars, respectively, produced consistent RAPD marker profiles. Evaluation of individual seeds from a single cyclamen hybrid produced polymorphic banding patterns that were attributed to genetic variability present in the female and male inbred parents. These results show that RAPD makers can be used to quickly assess the genetic purity of selected cultivars of these two flower seed crops.
The Use of 6-Benzylaminopurine for Rapid Multiplication of Tillandsias
Authors: Bessler Bernhard
Published: February 2019

Some species of the genus Tillandsia (Bromeliaceae) are highly endangered in their natural habitats. This report introduces a method for induced lateral shoot development in atmospheric Tillandsias using the cytokinin BAP. Spraying or dipping the plants with BAP-solutions induced many lateral shoots. Even difficult-to-propagate species like T. cacticola L.B.SM developed up to 30 times more usable shoots than the control. Applying low concentrations (1 and 5 mg·L-1) over a longer period of time (10 weeks, 3 times a week) produced results similar to those using higher concentrations (50 mg·L-1) for shorter periods (2 weeks, 3 times a week). Chemical name used: 6-benzylaminopurine (BAP).
Potential of Propane Flamers for Reduction of Apple Scab Primary Inoculum on Orchard Ground
Authors: Desilets H. , Rochefort S. , Coulombe J. , Yelle S. , Brodeur J.
Published: February 2019

The potential impact of propane flamers on the development and release of ascosporic inoculum of Venturia inaequalis (Cke.) Wint. from infected dead apple (Malus domestica Borkh.) leaves that overwintered on the soil of an experimental orchard was assessed. Thermal reduction of scab primary inoculum was first conducted under controlled conditions using an indoor testing facility. At the time of ascospore maturation, heavily infected leaves were submitted to temperature rises ranging from 150 to 200 °C with open-flame burners, thus reducing the number of ascospores subsequently released by 76% and 87%, respectively. During Spring 1995, thermal treatments of overwintered dead leaves were performed directly on the ground of an apple orchard with an experimental propane flamer design to generate uniform heat at ground level. Four thermal treatment strategies, involving two dates of flaming and two heat intensities, were tested. Flaming orchard ground, when performed in early May, before significant development of ground cover, reduced the number of ascopores released from infected dead leaves by half. A significant residual effect of the treatments on ascospore ejection was still observed 2 and 4 weeks after the treatments, thus indicating that ascospore maturation inside the leaves may be reduced by heat treatment. These results indicate potential for propane flamers to reduce apple scab primary inoculum in orchards.
Comparative Responses of Preharvest GA-treated Grapefruit to Vapor Heat and Hot Water Treatment
Authors: Miller W.R. , McDonald R.E.
Published: February 2019

`Marsh' grapefruit (Citrus paradisi Macf.) produced in Florida must be certified for security against unwanted pests before entry into some domestic and export markets. Application of heat by hot water (HW) has been shown to cause severe injury to grapefruit; however, direct comparisons between forced vapor heat (VH) and HW have been lacking. Grapefruit preharvest-treated with gibberellic acid (GA) or not treated, were postharvest-treated with VH or HW such that the surfaces of fruit were exposed to the same rate of temperature increases and treatment durations. Condition and quality attributes were then compared with ambient air (AA) and ambient water (AW) controls after storage. After 4 weeks' storage at 10 °C plus 1 week at 20 °C, scald affected 5% of HW and 20% of VH-treated fruit. No scald developed on control fruit. At the end of storage, mass loss for HW and VH fruit was ≈5%. HW-treated fruit had a 5-fold higher incidence of aging than VH fruit; however, control fruit showed significantly more aging than all heat-treated fruit. Gibberellic acid (GA) and the heat treatments reduced decay relative to the control. GA-treated fruit remained greener during storage than control fruit. These findings indicate that VH and HW treatments at the temperatures and durations to control the Caribbean fruit fly (Anastrepha suspensa, Loew) will likely cause peel injury to `Marsh' grapefruit produced in Florida, regardless of treatment with GA.
Determination of Water Vapor in a Small Air Sample by a Nondispersive Infrared Gas Analyzer
Authors: Lin W.C. , Block G.S. , Saltveit M.E.
Published: February 2019

A portable, nondispersive infrared (NDIR) gas analyzer was modified to measure the concentration of CO2 and water vapor in small gas samples. A 2-mL gas sample was taken from a series of sealed flasks partially filled with a saturated solution of chemicals known to produce various levels of relative humidity (RH). The modified NDIR instrument quantified water vapor content by its absorption at 2.59 μm. Peak height was displayed on a strip chart recorder and a standard curve constructed. At a specific temperature, the vapor pressure (VP) and vapor pressure difference (VPD) were calculated for sweet pepper (Capsicum annuum L., cv. Mazurka) fruit packed in trays that were covered with plastic films having several levels of perforations. Water loss from the fruit was highly correlated with VPD inside the packages. The modified NDIR instrument has an advantage over other instruments used to measure RH because it can rapidly and simultaneously determine the concentration of water vapor and CO2 in a single injection of a small gas sample.
Amphidiploid Induction from Diploid Rose Interspecific Hybrids
Authors: Ma Yan , Byrne David H. , Chen Jing
Published: February 2019

A high priority in rose (Rosa spp.) breeding research is the transfer of disease resistance, especially to black spot (Diplocarpon rosae Lib.), from wild diploid Rosa species to modern rose cultivars. To this end, amphidiploids (2n = 4x = 28) were induced with colchicine from five interspecific diploid (2n = 2x = 14) hybrids involving the black spot resistant diploid species R. wichuraiana Crép, R. roxburghii Thratt., R. banksiae Ait., R. rugosa rubra Hort., and R. setigera Michaux. Two application procedures (agitation of excised nodes in colchicine solution or tissue culture of shoots on medium with colchicine), five colchicine concentrations (0.0, 1.25, 2.50, 3.76, and 5.01 mmol), and five durations (2, 3, 5, 8, and 10 d) were used. After colchicine treatment, the materials were cultured in vitro and the surviving explants were examined for the “gigas” characteristics typical of doubled diploids. Chromosome counts of morphologically suspect genotypes confirmed 15 amphidiploids among 1109 plants that survived colchicine treatment. Although the effect of colchicine treatment varied some among interspecific hybrids, 2.50 mmol for 48 h of node agitation or 1.25 mmol for at least 5 d of shoot culture were optimal.
Genetic Potential for Salt Tolerance During Germination in Lycopersicon Species
Authors: Foolad M.R. , Lin G.Y.
Published: February 2019

Seed of 42 wild accessions (Plant Introductions) of Lycopersicon pimpinellifolium Jusl., 11 cultigens (cultivated accessions) of L. esculentum Mill., and three control genotypes [LA716 (a salt-tolerant wild accession of L. pennellii Corr.), PI 174263 (a salt-tolerant cultigen), and UCT5 (a salt-sensitive breeding line)] were evaluated for germination in either 0 mm (control) or 100 mm synthetic sea salt (SSS, Na+/Ca2+ molar ratio equal to 5). Germination time increased in response to salt-stress in all genotypes, however, genotypic variation was observed. One accession of L. pimpinellifolium, LA1578, germinated as rapidly as LA716, and both germinated more rapidly than any other genotype under salt-stress. Ten accessions of L. pimpinellifolium germinated more rapidly than PI 174263 and 35 accessions germinated more rapidly than UCT5 under salt-stress. The results indicate a strong genetic potential for salt tolerance during germination within L. pimpinellifolium. Across genotypes, germination under salt-stress was positively correlated (r = 0.62, P < 0.01) with germination in the control treatment. The stability of germination response at diverse salt-stress levels was determined by evaluating germination of a subset of wild, cultivated accessions and the three control genotypes at 75, 150, and 200 mm SSS. Seeds that germinated rapidly at 75 mm also germinated rapidly at 150 mm salt. A strong correlation (r = 0.90, P < 0.01) existed between the speed of germination at these two salt-stress levels. At 200 mm salt, most accessions (76%) did not reach 50% germination by 38 days, demonstrating limited genetic potential within Lycopersicon for salt tolerance during germination at this high salinity.
Plant Regeneration from Leaf Tissues of Siberian Elm
Authors: Kapaun James A. , Cheng Zong-Ming
Published: February 2019

Plants were regenerated from leaf tissue of greenhouse-grown seedlings of Siberian elm (Ulmus pumila L.). Shoot regeneration was induced on Murashige and Skoog (MS) medium containing 5 to 10 μm of BA. Up to 55% of the leaf explants formed shoots with an average of 2.4 shoots per explant. Addition of 2.5 or 5 μm of IBA failed to enhance regeneration. Thidiazuron at 0.5 or 1.0 μm also induced shoot regeneration, but the shoots failed to elongate as well as shoots regenerated from media containing BA. Incubation in darkness for 7, 14, or 21 d had little effect in promoting shoot regeneration, except that incubation for 21 d increased shoot regeneration on the medium with 5.0 μm BA. Genotypes differed in shoot regeneration potential, with regeneration frequencies ranging from 13% to 55%. Regenerated shoots were micropropagated on Driver and Kuniyuki Walnut medium. Ninety percent of microcuttings rooted directly in potting soil. This regeneration system will be valuable for genetic transformation and cell selection of Siberian elm. Chemical names used: 6-benzylaminopurine (BA); indole-3-butyric acid (IBA); N-phenyl-N′ -1,2,3-thiadiazol-5-ylurea (thidiazuron, TDZ).
Rooting of Apple, Rhododendron, and Mountain Laurel Cuttings from Stock Plants Etiolated under Two Temperatures
Authors: Hansen Ole Billing , Potter John R.
Published: February 2019

Dormant stock plants of apple (Malus domestica Borkh.) rootstocks M.26 and Ottawa 3; Rhododendron `Britannia', `Purple Splendour', and `Unknown Warrior'; and mountain laurel (Kalmia latifolia L.) `Ostbo Red' and seedlings were forced to grow at 18 or 28 °C in continuous darkness or 14-h photoperiods. Etiolated shoots were then acclimated to light with or without aluminum foil wrapped around their bases to keep the bases etiolated. Shoots forced in diurnal light were neither etiolated nor wrapped and served as controls for the etiolation treatments. Compared to controls, wrapping etiolated stems improved rooting of M.26 (60% vs. 82%) and `Ottawa 3' (81% vs. 97%) apple and of `Britannia' (76% vs. 90%) and `Unknown Warrior' (80% vs. 91%) rhododendron. Etiolation improved rooting percentage of `Unknown Warrior' regardless of wrapping. Regardless of etiolation, forcing `Ottawa 3' at 18 °C improved rooting percentage (92% vs. 74%) and roots per cutting (12 vs. 7) compared to forcing at 28 °C. Etiolated mountain laurel cuttings generally rooted best at 18 °C; control cuttings rooted best at 28 °C.
Micropropagation of Antelope Bitterbrush [Purshia tridentata (Pursh) DC.]
Authors: Edson John L. , Wenny David L. , Leege-Brusven Annette
Published: February 2019

In vitro—derived microshoots of antelope bitterbrush, incubated for 1 month in media supplemented with 0.44 μm BA, grew 0.8 and 1.1 cm longer in woody plant medium (WPM) compared to full-strength and half-strength Murashige and Skoog (MS) media, respectively. Explants cultured in WPM supplemented with 0.44 μm BA and 0.54 μm NAA produced a mean of five axillary shoots per explant. Explants dipped in 0.1% IBA or 0.1% NAA rooted best in 0.1% IBA with 89% success ex vitro vs. 60% success in vitro. Survival of acclimatized plantlets rooted ex vitro was 95%, while 50% survived when rooted in vitro. After 1 year of greenhouse growth, 98% of plantlets survived and flowered. Chemical names used: benzyladenine (BA), 3-indolebutyric acid (IBA), 1-naphthaleneacetic acid (NAA).
Consumer Perceptions of Service Quality in the Texas Retail Floral Industry
Authors: Becker Wayne A. , Behe Bridget K. , Johnson James L. , Townsend Christine D. , Litzenberg Kerry K.
Published: February 2019

After a survey describing the range of products and services offered by Texas florists and supermarket floral departments, a modified SERVQUAL instrument measured customer perceptions and expectations of floral service quality. Florist customers were 3.2 years older, had a slightly higher household income, bought floral products twice as often from a florist, spent $14.53 more on each florist purchase than supermarket customers; they also made four fewer floral purchases from supermarkets during the previous 6 months. Supermarket customers spent $14.40 more on each supermarket floral purchase than did florist customers. Reliability was the most important and tangibles were the least important of the five service quality dimensions. Although expectations for both groups were similar on 18 of 22 service quality items, florists' customers perceived higher service quality than did supermarket customers. Although customers of both retail outlets had expectations higher than perceptions, florist customers had smaller, less negative gap scores. This result showed that florists better met customer expectations than did supermarket floral departments, a potential competitive advantage.
Living Mulch for Strawberry Production Fields
Authors: Gupton C.L.
Published: February 2019

Annual ryegrass (Lolium multiflorum), which grows prolifically during the strawberry production season in the Gulf South, has the potential to serve as a living mulch if its growth is controlled. Sublethal dosages of Embark, a plant growth regulator, and the herbicides Poast and Rely were determined on ryegrass. Growth retardation was rated from 0 = none to 6 = dead. In 1993, all Poast dosages (1/8X – 1X, where X = 8 ml·L–1) were lethal. Embark regulated ryegrass growth, but its study was discontinued because of the unlikelihood that it could be labeled for use on strawberries. Results of the 1994 study suggested that prime oil in the spray may cause an inordinate amount of vegetative browning. In 1995, three levels of oil (1/256X, 1/64X, and 1/32X, where X = 8 ml·L–1) were used with each of four levels of Poast (0, 1/32, 1/64, and 1/128X). Increased levels of oil generally caused increased browning at each level of Poast, but no browning occurred where oil only was applied in the spray. In contrast to results in 1995, oil at 1/32X with no Poast caused considerable browning (score = 3.25) in 1996. The most desirable control (score = 2.75) was accomplished by a spray containing 1/128X Poast and 1/64X oil. The most desirable control by Rely (score = 3.25) was accomplished by 1/64 and 1/32X sprays. Rely is not labeled for strawberries although it is labeled for other fruit crops. Chemical names used: 2-[1-(ethoxylmino)buty1]-5-[2-(ethylthio)propy1]-3-hydroxy-2-cyclohexen-1-one (Poast); Paraffin Base Petroleum Oil + polyol Fatty acid Esters (Prime oil); N-[2,4dimethyl-5-[[(trifluoromethyl)-sulfony]amino]phenyl] acetamide (Embark); ammonium-Dl-homoalanin-4-yl-(methyl) phosphinate (Rely).
Root Distribution of `Gulfcoast' Southern Highbush Blueberry
Authors: Spiers J.M.
Published: February 2019

A field study was conducted to evaluate individual and collective influences of three soil moisture-supplementing practices (irrigation, incorporated peatmoss, and mulching) on root system development in `Gulfcoast' southern highbush blueberries. Root growth was least in plants not mulched and greatest in plants receiving all three supplements. Ranking of individual treatments on root dry weight production was mulch > incorporated peatmoss = irrigation. Mulching resulted in uniform root distribution from the plant crown outward and in root growth concentrated in the upper 15 cm of soil. Other practices (peatmoss > irrigation) tended to concentrate the root system near the crown area and resulted (peatmoss = irrigation) in greater root depth. Soil moisture appeared to be the major factor influencing root distribution.
Study of the Regular and High Application of Water with Drip Irrigation and Its Effect in the Floral Buds of `Thompson Seedless' Grapes
Authors: Fontes Adán Fimbres , Contreras Raúl Leonel Grijalva , de Jesus Valenzuela Ruiz Manuel , Díaz Gerardo Matínez
Published: February 2019

The region of Caborca is actually the largest grape-growing area in Mexico, with 14,000 ha. The main problem in this zone is the lack of water, and it is important to use this resource rationally. During 1990 and 1991, a drip irrigation experiment in `Thompson Seedless' table grapes was conducted. The four treatments were 120%, 166%, 206%, and 250% of the evaporation from a evaporation pan type A. The crop coefficients (Kc) applied were 7.5%, 15%, 52.5%, and 80% from the beginning of budding until 1 week after harvest, and 7.5% after harvest (postharvest). The results indicated that the best treatments were 120% (105 cm of total water applied) and 166%, with no reduction in the floral buds (5.4 per cane for 120); however, 206% and 250% (202 cm of total water applied) got the lowest number of floral buds (0.90 per cane) for the following year, and, because of that, the lowest clusters per cane.
Dry Mass and Nitrogen Distribution in Papaya Seedlings in Response to Varied Fertilization of Divided Root Systems
Authors: Marler Thomas E. , Discekici Haluk M.
Published: February 2019

`Known You 1' papaya seedlings were grown in split-root containers and fertilizer was applied to one (1/2) or two (2/2) halves of the root system to determine the influence on transport of assimilates from canopy to roots and transport of nitrogen from fertilized roots to non-fertilized roots and canopy. Following 6 weeks of growth, the plants were bare-rooted and the root system halves and canopy were dried to constant mass at 70°C. Tissue was then analyzed for total nitrogen content. Fertilization increased root mass more than 250% and total plant mass 300% compared with control plants, which received no fertilization during the 6 weeks. Total root or plant mass did not differ between the 1/2 and 2/2 plants. Roots were evenly distributed between the two halves for 2/2 plants, but the fertilized half in the 1/2 plants accounted for 60% of the total root mass. Nitrogen content of roots and canopy were increased by fertilization. Nitrogen content of the non-fertilized roots of 1/2 plants was not different from that of the fertilized roots. These results indicate that fertilizing a portion of the papaya root system increased the sink activity of that portion and that the absorbed nitrogen from that portion is efficiently transported throughout the plant.
Evaluation of Herbicides for Phytotoxicity to Rose Plants and Efficacy
Authors: Karlik John F. , Gonzalez Martha P.
Published: February 2019

Roses are likely the most popular garden plant in the United States, and cultivars are also used as landscape plant materials. Three herbicide trials with two main objectives were conducted with rose plants. The first objective was to evaluate injury to the roses when over-sprayed at various stages of growth. The second objective was to evaluate the efficacy of the herbicides. All herbicides were used at label rates and applied over the top of rose plants. In the first trial, the pre-emergent herbicides pendimethalin, oryzalin, trifluralin, metolachlor, napropamide, and oxyfluorfen were applied to plots containing dormant roses with ≈1-cm shoots just pushing. Evaluations of shoot length taken over the next 6 weeks showed no differences in growth of rose plants, but weed populations were reduced. In the second trial, five post-emergent herbicides were applied to plots containing dormant roses. Herbicides evaluated included the grass herbicides fluazifop-p-butyl, sethoxydim, and clethodim. The nonselective herbicide glyphosate was included in the trial, as was a combination herbicide containing 2,4-D, mecoprop, and dicamba. There was no visible injury to rose plants until 6 weeks after treatment. At that time, roses treated with glyphosate had shorter shoots. Recovery from glyphosate appeared more rapidly than recovery from the combination herbicide. Weed control varied with each herbicide. The third trial evaluated the same five herbicides for control of bermudagrass in late spring. Injury to roses was noted immediately from the combination herbicide and glyphosate. All the grass herbicides and glyphosate were effective in controlling bermudagrass.
Effect of Formulation on Soil Movement of Hexazinone
Authors: Yarborough D.E. , Hess T.M.
Published: February 2019

In order to assess the effect of hexazinone formulation on movement through the soil profile, soil samples were taken on 25 June 1995, 25 Aug. 1995, 22 Nov. 1995, and 24 May 1996 (1, 3, 6, and 12 months, respectively) at 0–5, 5–15, and 15–25 cm from plots treated 25 May 1995 with either hexazinone liquid formulation of Velpar L at 1.1 kg/ha, or as a granular in Pronone 10G, Pronone MG at 11.1 kg/ha, or Diammonium Phosphate (DAP) at 220 kg/ha impregnated with Velpar L at 1.1 kg/ha and an untreated control. The hexazinone liquid had the most leaching, the Velpar DAP formulation had the least leaching, and the Pronone formulation were intermediate. If hexazinone leaching into groundwater is a concern a particular site, then the Velpar/DAP fertilizer or Pronone formulations should be used over the liquid formulation. This project was done under a low rainfall year, 1995, and it should be reassessed with the new Velpar DF formulation and irrigation.
Control of Canary Grass and Nutsedge Weeds with Microbially Derived Herbicides
Authors: Gurusiddaiah S. , Ahmedullah M.
Published: February 2019

For the control of Reeds Canary grass (Phalaris arundinaceae) and yellow nutsedge (Cyperus esculentus) in blueberry fields, no satisfactory control measures are available. We tried microbially derived aerobic fermentation extracts of Pseudomonas syringae strain 3366 (P. S. 3366) as pre- and -post-emergence applications for the control of Reeds Canary grass and yellow nutsedge. In greenhouse studies using “conetainers,” 2 mg of extract per g of soil applied as preemergence completely inhibited seed germination and aerial growth of Canary grass, but had no effect on nutsedge. In addition, the same level of concentration of P. S. 3366 (2 mg of extract/g of soil) under field conditions also showed 99% inhibition of germination and growth of Canary grass, but had no effect on germination of nutsedge. However, 4-fold increase in concentration of P. S. 3366 extract completely inhibited the sprouting of yellow nutsedge in greenhouse studies. These studies indicate microbially derived extract of P.S. 3366 can be used and has potential for the control of these weeds. Post-emergence foliar sprays of P. S. 3366 extract in blueberry fields failed to inhibit the aerial growth of Reeds canary grass and yellow nutsedge.
Tomato Production using Spring-sown Cover Crops' Mulch for Weed Control
Authors: Christine Akemo Mary , Bennett Mark , Regnier Emily
Published: February 2019

In the tropics, cover crops do not have to over-winter, but can be established in the same season as the vegetable crops. To emulate this situation, winter rye `Wheeler' (Secale cereale) and field peas (Pisum sativum) in pure stands and bi-culture combinations in decreasing levels and varying ratios were established early in Spring 1996 and mown down 2 months later prior to transplanting tomato seedlings. Both cover crops grew to the flowering stage before being mown down. There were significant differences (P = 0.05) between the treatments in weed control and tomato growth. The best tomato growth and yield was in the conventionally hand-weeded control and the worst in the un-weeded control, with almost no fruit yield. The cover crop treatments with comparable performance to the best treatment were the highest rates of pure field peas, 0.25 rye + 0.75 field peas, and 0.5 rye + 0.5 field peas. The pure rye treatments suppressed weeds best, but also suppressed tomato plant growth. Weeds were suppressed for the first month in most of the mulch covers, but 2 months after mowing down most of the mulch covers were overcome by weeds. Dicotyledonous weeds appeared first and grew faster than grass weeds. This work showed that there is potential for the use of cover crops for weed control in tropical vegetable production.
Influence of Nitrogen on the Interference of Purple and Yellow Nutsedge (Cyperus rotundus and Cyperus esculentus) with Tomato (Lycopersicon esculentum)
Authors: Morales-Payan J.P. , Stall W.M. , Shilling D.G. , Dusky J.A. , Bewick T.A.
Published: February 2019

Field trials were conducted in Gainesville, Fla., to determine the influence of nitrogen fertilization on the interference effect of purple or yellow nutsedge on the yield of fresh tomato. Nitrogen (N) rates of 50, 100, 150, 200, 250, 300, and 350 kg·ha–1 were applied broadcast to the soil. Before transplanting, 1-m-wide soil beds were covered with plastic and fumigated with methyl bromide to suppress the growth on undesired weeds. Nutsedge-free and purple or yellow nutsedge-infested tomato plots were separately established. `Solar Set' tomatoes were transplanted in the middle of the soil beds, 50 cm apart in a single row. In nutsedge-infested plots, weed densities known to cause significant yield reduction in tomato (100 purple nutsedge plants/m2 and 50 yellow nutsedge plants/m2) were uniformly established perforating the plastic and transplanting viable tubers in the perforations. Purple and yellow nutsedge tubers were transplanted the same day as tomatoes and were allowed to interfere during the whole crop season. Results indicate that N rates had a significant effect on tomato fruit yield in both nutsedge-free and nutsedge-infested treatments. The presence of either purple or yellow nutsedge significantly reduced the fruit yield of tomato at all N rates. As N rates increased, tomato fruit yield reduction caused by the interference of either nutsedge species also increased. When yellow nutsedge was allowed to interfere with tomato, fruit yield loss was as low as 18% at 50 kg N/ha and as high as 42% at 350 kg N/ha. In purple nutsedge-infested tomato, fruit yield reductions ranged from 10% at 50 kg N/ha to 27% at 350 kg N/ha. N effects on nutsedge-free and nutsedge-infested tomato yields were described by quadratic equations, with maximum tomato fruit yield values being reached between 200 and 250 kg N/ha in both nutsedge-free and nutsedge-infested treatments.
Effect of Purple Nutsedge (Cyperus rotundus) Population Densities on the Growth of Transplants of Three Papaya (Carica papaya) Cultivars
Authors: Morales-Payan J.P. , Stall W.M.
Published: February 2019

Nursery experiments were conducted in Santo Domingo, Dominican Republic, to determine the effect of increasing population densities of purple nutsedge (Cyperus rotundus) on the growth of papaya (Carica papaya) transplants. Seeds of `Sunrise Solo', `Red Lady', and `Cartagena Ombligua' were separately sown in plastic 12 × 15-cm containers filled with a 1:1 mixture of sand and loamy soil. Viable purple nutsedge tubers were planted 5 cm apart from the papaya seeds. The purple nutsedge initial population densities were 0, 1, 2, 4, and 6 tubers per container. The crop and the weed were sown the same day and allowed to interfere during 6 weeks. Purple nutsedge density had a significant effect on the height, leaf area, and shoot dry weight of the three papaya cultivars. There was no significant difference in the response of the three papaya cultivars to purple nutsedge densities. In general, as purple nutsedge density increased, papaya growth decreased. Nutsedge interference caused papaya shoot dry weight losses of 15% at the density of one plant per container and 73% at six plants per container.
Video and Photography Assignments from Field Trips Build Communication and Teamwork Skills
Authors: Moser Bruno C.
Published: February 2019

Employers of undergraduates tell us there is a need to turn out students with greater communication and teamwork skills in addition to good horticultural and business training. Field trips are an important tool to expose students to the real world of horticulture. The course “Nursery Crop Production” has adopted a class project that enhances these skills and experiences. Teams of three students each are assigned a production nursery to visit and to bring back documentation to the class in the form of an edited video tape and a written report containing pictures. Their report is presented in class and each student receives a composite video tape and written report of all team efforts. Quality of the reports has been remarkable. Each part of the project (video, written report, and class presentation) is graded independently, with all team members receiving the same final grade. The department has purchased video cameras and editing equipment, which are essential to the success of this educational experience. Student evaluations indicate enthusiasm for this approach and the role of video in the class. Copies of finished projects are returned to each nursery for their information. A collection of these projects is being assembled to provide the Nursery and Landscape Crops Extension Specialist with additional information about the production nursery industry.
Mini-essays: Using Writing for Fun and Creativity
Authors: Lownds N.K.
Published: February 2019

Good written communication skills are essential for the success of our graduates. To promote good writing, students in Ornamental Plant Identification classes have been required to write mini-essays, one-page responses to real-world scenarios. Student's responses have been good and their writing has been very acceptable. The mini-essays were, however, just assignments to complete. In an attempt to get students truly involved and passionate about their writing, assignments were designed to illicit creative, fun responses. Students were asked to explain concepts to fourth graders. This brought responses that ranged from exercises where kids were to stick out their tongues to imitate humming birds, to a short play demonstrating the importance of plant nomenclature. Another assignment asked students to complete a story about the famous detective, Hortus paradoxa. Student responses were incredibly creative, and some of the best writing I have ever seen. In addition, students had fun. It seems clear that, if students know that it is OK to be creative, they will greatly exceed your expectations. Just be prepared to have lots of fun while learning. Samples of the assignments, responses, and what is next will be presented.
A Laboratory Exercise to Demonstrate Meristem-tip Culture of Strawberry
Authors: Kane Michael E. , Chandler Craig K.
Published: February 2019

Many horticultural crops are infected with bacterial, fungal, or viral pathogens that reduce yield and/or quality. Recovery and maintenance of pathogen eradicated crops, such as strawberry (Fragaria × ananassa Duch.), have been possible following the isolation and culture of apical meristems or meristem-tips in vitro. A laboratory exercise has been developed to provide experience in the procedures required for the isolation, surface disinfection, and in vitro establishment of meristem-tip explants excised from strawberry stolons. Stolons are obtained from greenhouse-grown strawberries (`Sweet Charlie') maintained in hanging baskets under a 14-h photoperiod. Stolons are cut into single-node segments and terminal tips. The leaf blades are removed and the nodal sections are rinsed and then surface-disinfected by successive agitation in 70% ethanol and 1.05% sodium hypochlorite, followed by three rinses in sterile deionized water. In the transfer hoods, each student attempts to isolate meristem-tips and shoot tips of various sizes under high magnification provided by a stereomicroscope. Explants are inoculated onto Murashige and Skoog basal medium (Murashige and Skoog, 1962) supplemented with 30 g/liter sucrose, 80 mg/liter adenine sulfate, 1.0 mg/liter benzyladenine, 1.0 mg/liter indole-3-acetic acid, and 0.01 mg/liter gibberellic acid (GA3) and solidified as 45°slants with 1.25 g/liter Phytagel and 3.0 g/liter TC agar. Growth responses are monitored weekly. After 6 weeks, students record the percentage of visibly contaminated cultures and number shoots produced per explant. The relationship between initial explant size and in vitro growth is also determined. Students index their cultures for the presence of cultivable bacteria and fungi using sterility test media.