bluuebunny/crossref_metadata_2025 huggingface dataset:
Genetic Improvement of Vegetables for Enhanced Cancer Chemoprevention
Authors: Juvik John A.
Published: February 2019

Extensive epidemiological evidence suggests that carotenoids (including vitamin A), ascorbate (vitamin C), tocols (including vitamin E), and glucosinolate breakdown products exert anticarcinogenic effects in a range of human tissues. Consumption of fresh and processed vegetables with enhanced levels of these phytochemicals could reduce human risk of cancer. The vitamins play a major role as antioxidants, offering protection against cancer by preventing or reversing oxidative damage to DNA and other cellular components. Cruciferous vegetables contain glucosinolates (GSs), which, during mastication, are hydrolyzed by the enzyme myrosinase into bioactive breakdown products (BBPs), including sulforaphane. BBPs appear to induce synthesis of drug metabolism enzymes resulting in increased detoxification rates of carcinogens. This paper describes an interdisciplinary investigation designed to develop vegetable cultivars that offer chemoprotection from cancer at doses commensurate with a normal American diet. Initial work has focused on surveying sweet corn and Brassicae oleraceae germplasm for variation in vitamin and glucosinolate content in conjunction with in vitro and in vivo bioassays to determine which compounds and concentrations optimize chemoprotectant activity. Segregating populations from crosses between sweet corn and Brassica lines that vary in vitamin and GS concentrations will be assayed for chemical content and chemoprotectant activity, and genetically characterized using DNA marker technology to identify and map genes controlling these traits. This information will improve selection methodology in a breeding program aimed to develop brassica and sweet corn germplasm with enhanced cancer chemoprevention.
Use of a Small Hydroponic System to Grow Marigolds in the Greenhouse
Authors: Wilson Mack , Rogers Dianna , Khan Victor , Stevens Clauzell
Published: February 2019

Styrofoam ice trays were used to grow `Discovery Yellow' marigolds transplanted 4 weeks after seeds were germinated and then grown in two nutrient cultures. The cultures were Hoagland at the rate of 1/2 ml/6 gal water and nutraculture (20-10-20) at 2.4 ozs/6 gal water. Half containers were aerated and other half were not aerated. Data collected were root, stem, bloom fresh and dry weight, and stem length and number of blooms and leaves. Results showed that stem length, and number of leaves and blooms were significantly greater when grown in Hoagland solution. Fresh and dry weight of roots, stems, and blooms were significantly greater when grown in Hoagland solution. Nonaerated treatments performed significantly better than aerated treatments for either hydroponic solutions.
Modelling Moisture Loss of Onions in Storage Using Moisture Loss Information Obtained from Individually Measured Onions
Authors: Mullinix Benjamin , Maw Bryan , Lahue Steve
Published: February 2019

Vidalia onions were grown following recommended cultural practices in 1994-1996 and they were harvested at early, optimum, or late maturity. After onions were cured for various lengths of time, a random sample of onions was marked for individual measurement. All onions were placed into either low or high humidity A/C controlled storage for up to 30 weeks. Onions were removed as they showed signs of being rotten. Initially, and every 2 weeks thereafter, weight and grade data were collected from individual onions and in bulk from other onions. There were up to 96 treatment combinations each year. Using individual onion data, simulation of the weight loss of the bulked onions was done. Although over 5,000 onions were involved, individual measurements were taken on only 1,920 onions over the 3 years. Five simulations were conducted using parameters derived from individual onion data. Results of the simulations resembled the actual weight loss trends within the specified 90% confidence range.
Development of Bell Peppers with Resistance to the Southern Root-knot Nematode
Authors: Fery R.L. , Dukes P.D. , Thies J.A.
Published: February 2019

The southern root-knot nematode (Meloidogyne incognita) is a major pest of bell peppers (Capsicum annuum) in the United States. Since none of the leading bell pepper cultivars grown in the U.S. exhibit adequate levels of resistance, a breeding program was initiated to incorporate the N root-knot nematode resistance gene into commercial bell pepper germplasm. A backcross breeding procedure was used. The donor parent of the N gene was the open-pollinated, pimiento pepper cultivar Mississippi Nemaheart, and the recurrent parents were the open-pollinated bell pepper cultivars Keystone Resistant Giant and Yolo Wonder. A large number of homozygous resistant BC6 populations were evaluated in field tests in 1995, and two lines (PA-440, an isoline of `Keystone Resistant Giant', and PA-453, an isoline of `Yolo Wonder') were selected for further field evaluation and seed multiplication in 1996. Results of replicated field and greenhouse tests conducted in 1996 indicate that root-knot nematode resistance has been incorporated successfully in `Keystone Resistant Giant' and `Yolo Wonder' backgrounds.
Salinity Tolerance of Tamarind, Barbados Cherry, and Zapote Seedlings
Authors: Santos Bielinski M. , Morales-Payan Jose P.
Published: February 2019

Nursery experiments were conducted in the Dominican Republic to determine the tolerance of tamarind (Tamarindus indica), acerola or Barbados cherry (Malpighia punicifolia), and zapote (Calocarpum sapota) irrigation with saline water (0, 2, 4, 6, and 8 dS/m) at different frequencies (every 24, 48, and 72 hours) during 60 days. Results indicate that tamarind was the less salt-sensitive and zapote the less salt-tolerant of the three species. Linear relationships were found between salt concentration and growth, with biomass accumulation decreasing as salinity and irrigation frequency increased.
Influence of Calcium, Magnesium, Boron, and Molybdenum Fertilization Rates on the Growth of Young Papaya Plants
Authors: Santos Bielinski M. , Morales-Payan Jose P.
Published: February 2019

The effect of varying calcium (Ca), magnesium (Mg), boron (B), and molybdenum (Mo) rates on the growth of young `Cartagena Ombligua' papaya (Carica papaya) plants was studied in experiments conducted in the Dominican Republic. Rates of 0, 3, 6, 9, and 12 g Ca; 0, 0.85, 1.7, 2.55, and 3.4 g Mg; 0, 20, 40, 60, and 80 mg B; and 0, 0.05 0.1,0.15 and 0.2 mg Mo per plant were applied to the soil 20 days after transplanting. Ca did not stimulate plant growth, but instead was toxic at rates of 9-12 g per plant. Mg fertilization significantly stimulated root growth (Y = 2.35 + 0.48X, r2 = 0.95), but not shoot growth. Mo applications decreased plant growth, whereas B enhanced overall plant growth (Y = 10.64 + 70.5X, r2 = 0.96).
Potential of Cool-Season Legumes for Removing Excess P From Poultry Litter Application
Authors: Earhart D.R. , Baker M.L. , Haby V.A.
Published: February 2019

Phosphorus (P) concentration in surface waters from non-point agricultural sources is an increasing resource management concern. This study was conducted at Overton, Texas, on a Bowie fine sandy loam (fine-loamy, siliceous, thermic, Plinthic Paleudults) to evaluate cool-season legumes for P uptake following poultry litter (PL) application rates on spring vegetables. Treatments were PL rate (0, 1X, 2X, 4X) and a commercial blend (CB) for comparison. Cool-season legumes, consisting of crimson clover, berseem clover, hairy vetch, and red clover, were the subplots. The vegetable crop in Spring 1995 was watermelon. The 1X PL rate was 2.2 t·ha-1 and the CB was 44.8N-0P-32.5K kg·ha-1. Dry matter yield was decreased by the 4X PL rate. Plant P concentration increased linearly as PL rate was increased. The greatest P uptake (4.1 kg·ha-1) was at the 2X rate. Hairy vetch had the greatest yield (1,875 kg·ha-1), plant P concentration (0.53%), and P uptake (9.6 kg·ha-1). PL rate increased soil P concentration at all depths. The least amount of P accumulation was from CB and was equal to the control. Hairy vetch appears to have the capability of removing a greater amount of P and reducing soil concentration when compared to the other legume species tested.
Spatial and Temporal Factors in Weed Interference with Newly Planted Apple Trees
Authors: Merwin Ian A , Ray John A.
Published: February 2019

Temporal and spatial combinations of tree-row weed suppression treatments were evaluated during 5 years in a New York apple (Malus domestica Borkh. cv. Imperial Gala on Malling 26 rootstocks) orchard planted in Apr. 1991, and provided with trickle irrigation. Twenty-eight factorial treatment combinations [0, 2, 4, and 6 m2 weed-free areas (WFAs); and May, June, July, August, May + June, June + July, May + June + July, and June + July + August weed-free times (WFTs)] were maintained from 1991 to 1995 by postemergence paraquat herbicide applications in tree-row strips. Trunk cross-sectional area (TCA) growth and yield were monitored annually, and few differences were observed as WFA increased from 2 to 4 to 6 m2 per tree. However, WFT substantially influenced TCA, fruit production, and yield efficiency. Early summer WFTs increased TCA during the first two growing seasons, compared with late summer treatments. When trees came into production in 1993-94, yields increased as the duration of WFT increased, but where similar periods of WFT had been established later during the growing season, annual yield, cumulative yield efficiency, and the ratio of crop value to weed-control costs were all reduced. Groundcover species distribution was evaluated each year in September, and graminaceous weeds were more prevalent in the early and midsummer WFTs, while herbaceous broadleaf weeds dominated in the August treatments. A quadratic model regressing cumulative yield efficiency on WFTs grouped into 30-, 60-, and 90-day categories showed that efficiency peaked between 60 and 90 days of WFT. It appeared that timing of weed suppression may be as important as the area of suppression beneath trees in comparable apple orchards, that early summer weed control was especially important for newly planted trees, and that drip irrigation allowed reductions in the area and amount of tree-row herbicide applications, without significant losses in apple tree growth or crop value.
Comparative Evaluation of Nitrogen Release Patterns from Controlled-release Fertilizers by Nitrogen Leaching Analysis
Authors: Cabrera Raul I.
Published: February 2019

Seven nursery grade (8-9 month duration), polymer-coated, controlled-release fertilizers (CRF) were topdressed or incorporated into a 2 peat: 1 vermiculite: 1 sand (by volume) medium to yield the same amount of N per container. The pots (0.5 L) were uniformly irrigated with DI water every week to produce a target leaching fraction of 25%. Leachate N contents (ammonium plus nitrate), employed as indicators of N release, allowed for comparison of CRF performance as a function of temperature changes over a season. Two distinct N leaching (i.e., release) patterns were observed over the 180-day experimental period. The fertilizers Osmocote 18-6-12FS (Fast Start: OSM-FS), Prokote Plus 20-3-10 (PROK), Osmocote 24-4-8HN (High N: OSM-HN) and Polyon 25-4-12 (POLY) exhibited a N leaching pattern that closely followed changes in average daily ambient temperatures (Tavg) over the season. This relationship was curvilinear, with N leaching rates per pot (NLR) being highly responsive to Tavg changes between 20 and 25 °C. Temperatures above 25 °C produced an average maximum NLR of 1.27 mg·d-1 for these fertilizers. OSM-FS, PROK, and OSM-HN had the highest cumulative N losses over the experimental period. In contrast, the CRF group formed by Nutricote 18-6-8 (270: NUTR), Woodace 20-4-12 (WDC), and Osmocote 18-6-12 (OSM) showed a more stable N leaching pattern over a wider range of temperatures, with rates about 30% to 40% lower than those in the temperature-responsive CRF, and averaging a maximum NLR of 0.79 mg·d-1 for Tavg >25 °C. NUTR and WDC had the lowest cumulative N losses over the season. Soluble salt readings paralleled N leaching for each CRF, indicating similar leaching patterns for other nutrients. Incorporation produced significantly higher cumulative N losses than topdressing, but without effect on the actual N leaching pattern over the season. Regardless of the N formulation in the CRF, over 85% of the N recovered in the leachates was in the nitrate form.
Vegetative Growth Responses of Florist Azaleas to Dikegulac, GA4+7, and 6-Benzylamino Purine
Authors: Bell Michelle L. , Larson Roy A. , Bailey Douglas A.
Published: February 2019

Dikegulac, dikegulac + GA4+7, BA, and Promalin (GA4+7 + BA) were evaluated as lateral shoot-inducing agents on greenhouse forcing azalea, Rhododendron cultivars Gloria and Prize. The addition of GA4+7 (1000 or 2000 mg.L-1) to a commercial rate of dikegulac (3900 mg.L-1) did not effectively increase plant diameter or leaf width compared to plants sprayed with dikegulac alone. The combination of dikegulac and GA4+7 (3900 + 2000 mg.L-1, respectively) was more phytotoxic than dikegulac alone. Foliar sprays of BA and Promalin at 1000 and 2000 mg.L-1 and 1000 and 1816 mg.L-1, respectively, did not increase lateral shoot count. Neither the addition of GA4+7 to dikegulac nor the use of Promalin is a viable alternative to dikegulac application for inducing lateral branch development of dikegulac-sensitive cultivars. Chemical names used: Na 2,3:4,6-Bis-0-(l-methylethylidene)-α-L-xylo-2-hexulofuranosonic acid (dikegulac), (lα,2β,4aα,4bβ,10β)-2,4a,7-trihydroxy-l-methyl-8-methylenegibb-3-ene-l,10-dicarboxylic acid l,4a-lactone (GA4+7),N-(phenylmethyl)-lH-purin-6-amine (BA), and Promalin [1:1 (wt/wt) GA4+7 and BA].
Exothermic Characteristics of Dormant Buds of Persimmon (Diospyros kaki Thunb.) in Relation to Cold Hardiness
Authors: Kang S.K. , Motosugi H. , Yonemori K. , Sugiura A.
Published: February 2019

Microcomputer-based thermal analysis (TA) was conducted on dormant mixed buds of Japanese persimmon (`Hiratanenashi'). The exotherms of buds were detected by thermoelectric modules. Flower buds of peach (Prunus persica Batsch cv. Shimizuhakuto) were also analyzed. When TA was used on a whole excised bud, including bud scales, the persimmon buds had only one exotherm at –14.3 °C, while the peach buds had high and low exotherms at –8.4 °C and –14.1 °C, respectively. However, when the exotherm was measured for the primordium, with the bud scales and transitional leaves removed, each primordium showed only one exotherm at –20.7 °C in persimmon and –11 °C in peach. Determination of killing temperature by visual observation, electrolyte leakage method, and triphenyltetrazolium chloride test revealed that the primordium of the persimmon bud was killed at about –14 °C as the excised whole bud or as the whole bud attached to the branch segment. Using the same method, the naked primordium was killed between –22 °C and –25 °C as the primordium was cooled. The peach primordium was killed at –14 °C when examined as a whole bud and at –11 °C as a naked primordium. Furthermore, the exotherm temperatures of persimmon buds and stem segments were measured at appropriate intervals during the two winter seasons 1993–95. Exotherm temperatures of persimmon buds were always higher than the low-temperature exotherm (LTE) temperatures of the stem segments and lower than the high-temperature exotherm (HTE) temperatures of the stem segments. LT50 of persimmon buds almost coincided with the exotherm temperatures of buds. A postulated role of bud scales in supercooling is discussed.
Evaluation of Cover Crop Mixtures for Use in Vegetable Production Systems
Authors: Creamer Nancy G. , Bennett Mark A. , Stinner Benjamin R.
Published: February 2019

Planting polyculture mixtures of cover crops can optimize the benefits of their use. Thirteen polyculture mixtures of cover crops were evaluated in Columbus and Fremont, Ohio, to find a species mix that would establish quickly for erosion control, overwinter in Ohio, contribute sufficient N and have a C : N ratio between 20:1 and 30:1 to optimize N availability for subsequent crops, be killable by mechanical methods, and have high weed control potential. All of the mixtures in Columbus had achieved 30% ground cover 1 month after planting, but only four of the mixtures achieved this in Fremont due to poor conditions at planting. Above-ground biomass (AGB) accumulation in the mixtures ranged from 3631 to 13,642 kg·ha-1 in Columbus, and 449 to 12,478 kg·ha-1 in Fremont. Nitrogen in the AGB ranged from 74 to 269 kg·ha-1 in Columbus, and 10 to 170 kg·ha-1 in Fremont. Weed cover in the cover crop plots ranged from 1% to 91% eight weeks after cover crop kill in Columbus, and 12% to 90% seven weeks after cover crop kill in Fremont. Because one or more species in each screened mixture was determined not to be suitable, none of the mixtures was optimum. However, information gained about performance of individual species within the mixtures is also useful. `Nitro' alfalfa (Medicago sativa L.), ladino clover (Trifolium repense L.), subterranean clover (Trifolium subterraneum L.), Austrian winter peas [Pisum sativum ssp. Arvense (L.) Poir], and annual ryegrass (Lolium multiflorum Lam.) did not overwinter dependably in Ohio. Tall fescue (Festuca arundinacea L.), perennial ryegrass (Lolium perenne L.), and orchardgrass (Dactylis glomerata L.) did not compete well with taller, more vigorous species, and were not persistent in the mixtures. Medium and mammoth red clover (Trifolium pratense L.), annual and perennial ryegrass, and white and yellow blossom sweetclover [Melilotus alba Desr., and Melilotus officianalis (L). Desr.], were not killable by mechanical methods. Individual species that established quickly, were competitive in the mixtures, overwintered dependably, and were killed by mechanical methods were rye (Secale cereale L.), barley (Hordeum vulgare L.), crimson clover (Trifolium incarnatum L.), and hairy vetch (Vicia villosa Roth.)
Orchard Floor Practices Affect Soil Compaction around Young Pecan Trees
Authors: Foshee Wheeler G. , Raper Randy L. , Goff William D. , Patterson Michael G.
Published: February 2019

Orchard floor treatments of total weed control with herbicides, disking, mowing, grass control only with herbicides, and no control of vegetation were maintained in a 3 × 3-m area underneath young pecan [Carya illinoinensis (Wangehn.) K. Koch] trees. Soil compaction in treated areas was compared to heavily trafficked row middles. Mean cone index (CI) readings obtained from a cone penetrometer for the heavily trafficked areas were higher, indicating greater compaction than all other treatments in the 4.7- to 11.8-cm soil depth range. Heavily trafficked areas had severe compaction (>2.0 MPa) at the 9.5- to 22.9-cm soil depths. Mowed plots had similar CI readings at 14.2- to 54.3-cm depth as those heavily trafficked. The mowed areas had severe compaction at the 14.2- to 22.9-cm depth range. Grass control only with herbicides and plots with no control of vegetation had low CI throughout the soil profile. Disking, grass control, and no control treatments had similar effects, except at the 4.7-cm depth, where disking reduced compaction. An orchard floor management practice that minimized traffic near young trees, but also reduced weed competition, appears to be the best choice.
In Vitro Plant Regeneration of Mexican Lime and Mandarin by Direct Organogenesis
Authors: Pérez-Molphe-Balch Eugenio , Ochoa-Alejo Neftalí
Published: February 2019

An efficient system for in vitro regeneration by organogenesis starting from internodal stem segments from seedlings of Mexican lime (Citrus aurantifolia Christm. Swing.) and mandarin (C. reticulata Blanco cv. Monica) was developed. The best results were obtained when the wounded edges of internodal stem segments cut longitudinally were placed downward on the surface of the culture medium. The optimal culture medium from both species was Murashige and Skoog with vitamins from B5 medium, 5% sucrose, 33.3 μm BA and 5.4 μm NAA. The best response was obtained when the segments were incubated at 25 ± 2 °C for 21 d in darkness, followed by 29 d on a 16/8-h light/dark cycle (fluorescent light, 54 μmol·m-2·s-1). The best regeneration system tested allowed the attainment of adventitious shoots from 96% and 88% of the explants in Mexican lime and mandarin, respectively. In Mexican lime an average of 7.8 well-differentiated shoots per explant was obtained, and in mandarin the yield was 5.1. Rooting of 70% of the shoots was achieved in culture medium with NAA (2.7–5.4 μm) or IBA (2.5–4.9 μm). Of the rooted plants, 85% adapted well to soil conditions. Chemical names used: 6-benzylaminopurine (BA), α-naphthaleneacetic acid (NAA), indole-3-butyric acid (IBA).
Plant Spacing and Variety Affect Pumpkin Yield and Fruit Size, but Supplemental Nitrogen Does Not
Authors: Reiners Stephen , Riggs Dale I.M.
Published: February 2019

Field studies were conducted at two locations in 1995 to determine the effect of spacing, nitrogen application, and variety on pumpkin (Cucurbita pepo L.) marketable yield. Pumpkin yield was unaffected by three rates of applied N (67, 112, or 157 kg N·ha-1). Marketable fruit number per hectare increased with both 'Howden' and 'Wizard' pumpkins as in-row plant spacing decreased from 1.2 to 0.3 m. Average fruit size significantly decreased at the closer spacing, but the decline in mass was much greater in nonirrigated as compared to irrigated plots. This resulted in a significantly greater yield in the irrigated plots at the closer spacing, while there was no significant increase in yield without irrigation. The results demonstrate that growers may increase the number of fruit per unit area with closer spacing but optimal soil moisture may be a prerequisite for the increase.
Characterization of the Pecan Industry in North America with Emphasis in the Southwest
Authors: Kilby Michael W.
Published: February 2019

The pecan is native to North America and is cultured as a major crop in both the United States and Mexico. In the early part of this century, pecans were thought of as a secondary crop grown in the southern geographic section of the United States. Increased demand for use as a nutritious food has resulted in expansion of the industry into the desert Southwest and California. Adaptive cultivars and irrigation coupled with the lack of diseases and insects has been instrumental in industry development in the West. As the industry has matured during the latter part of the century, pecan culture has improved into a strong crop enterprise business. Orchard management technique and orchard development concepts have been refined, resulting in increased production and awareness. In recent years, production in Mexico has impacted the U.S. price structure and pecan industry economy. The alternate-bearing nature of pecans also impacts prices received by growers. The aging of pecan trees has resulted in serious dilemmas, such as increased tree size and shading. This situation requires techniques such as tree thinning or hedge pruning to enhance annual production and improve nut quality. Various ramifications and parameters of these management practices will be discussed.
Carbohydrate and Nitrogen Partitioning within One-year Shoots of Young Peach Trees Grown with Grass Competition
Authors: Tworkoski T.J. , Glenn D.M. , Welker W.V.
Published: February 2019

Carbohydrate and nitrogen were measured during 1992 and 1993 in shoots of peach [Prunus persica (L.) Batsch.] trees that were planted in 1989 and grown in three vegetation-free areas contained within plots planted to tall fescue (Festuca arundinacea Schreber), orchardgrass (Dactylis glomerata L.), or a mixture of Lolium perenne L. and Festuca rubra L. Trees grown in 9.3-, 3.3-, and 1.5-m2 vegetation-free areas had the greatest to the least fruit yield, respectively. Fruit number and mass were negatively correlated with stem mass. Grass type had little effect on mass, carbohydrate, or N partitioning within the tree. Individual sugars and carbohydrate partitioning were not affected by grass competition. In contrast, the proportion of shoot N partitioning into stem and leaves declined markedly as the size of the vegetation-free area increased. Proximity of peach trees to grass may have limited N uptake, which, in turn, reduced fruit yield but not stem and leaf growth.
Snap Bean Production in Conventional Tillage and in No-till Hairy Vetch Mulch
Authors: Abdul-Baki Aref A. , Teasdale John R.
Published: February 2019

A 3-year study was conducted at the Beltsville Agricultural Research Center, Beltsville, Md., to evaluate plant stand, growth, and yield of snap bean (Phaseolus vulgaris L.) cultivars Carlo and Matador grown with conventional tillage (CT) or with no-tillage hairy vetch (Vicia villosa Roth) (HV) mulch. Plant stand and dry mass of both cultivars in CT were similar to those in no-till HV. However, leaf area and yield with no-till HV were significantly higher than those with CT.
Fumigant Alternatives to Methyl Bromide for Polyethylene-mulched
Authors: Locascio Salvadore J. , Gilreath James P. , Dickson D.W. , Kucharek Thomas A. , Jones J.P. , Noling J.W.
Published: February 2019

Tomato (Lycopersicon esculentum Mill.) was grown to evaluate various chemicals as possible alternatives to methyl bromide soil fumigation. Due to a combination of weeds, nematodes, and soil fungi, the use of a broad-spectrum fumigant has been essential for economical tomato production in Florida. Methyl bromide (MBr) and combinations of MBr with chloropicrin (Pic) are the fumigants of choice for most growers using polyethylene mulch culture. In 1991, MBr was allegedly associated with stratospheric ozone depletion. The U.S. Environmental Protection Agency has since mandated a phaseout of MBr for soil fumigation in the United States by the year 2001. At three locations in Florida, alternative soil fumigants were evaluated, including soil injected 98% MBr—2% Pic at 450 kg·ha-1, 67% MBr—33% Pic (390 kg·ha-1), Pic (390 kg·ha-1), dichloropropene + 17% Pic (1,3-D + Pic) at 327 L·ha-1, and metam-sodium (935 L·ha-1). Also, metam-sodium and tetrathiocarbonate (1870 L·ha-1) were applied by drip irrigation. Dazomet (450 kg·ha-1) was surface applied and soil incorporated. Pebulate (4.5 kg·ha-1) was soil incorporated with some treatments. Pic and 1,3-D + Pic treatments provided good to moderate control of nematodes and soil fungi except in one of the six studies, in which nematode control with 1,3-D was moderate to poor. Nutsedge densities were suppressed by addition of pebulate. Tomato fruit yields with 1,3-D + Pic + pebulate and with Pic + pebulate at the three sites ranged from 85% to 114%, 60% to 95%, and l01% to 119%, respectively, of that obtained with MBr treatments. Pest control and crop yield were lower with treatments other than the above pebulate-containing or MBr-containing treatments. These studies indicate that no one alternative pesticide can provide the consistent broad-spectrum control provided by MBr. Chemical names used: trichloronitromethane (chloropicrin); 1,3-dichloropropene (1,3-D); sodium N-methyldithiocarbamate (metam-sodium); sodium tetrathiocarbonate (tetrathiocarbonate); 3,5-dimethyl-(2H)-tetrahydro-l,3,5-thiadiazine-2-thione (dazomet); S-propyl butyl(ethyl)thiocarbamate (pebulate).
Production and Rooting of Shoots Generated from Dormant Stem Sections of Maple Species
Authors: Henry Paul H. , Preece John E.
Published: February 2019

Vegetative shoots were forced in the greenhouse from excised stem (branch) sections of dormant Japanese maple (Acer palmatum Thunb.), red maple (Acer rubrum L.), and sugar maple (Acer saccharum Marsh.). Softwood shoots generated in this way were used as stem cuttings in a subsequent adventitious rooting study. Data indicate that maple shoots can be forced using this technique, but that both the percentage of stem sections forming shoots and the number of shoots produced are highly variable among both species and clones. Whereas Japanese and red maple formed shoots on >50% of stem sections, shoots were generated on only 20% of sugar maple stem sections. Significant variability was also observed in rooting response, with red maple shoots rooting at much higher percentages (60%) than either Japanese maple (26%) or sugar maple (15%).
Influence of DB-cAMP, Adenosine, Forskolin, and Traumatic Acid on in Vitro Bulbing of Lilium longiflorum
Authors: Marinangeli Pablo , Delmastro Silvia , Curvetto Néstor
Published: February 2019

Both dibutyryl-cAMP and forskolin, with and without a pretreatment with traumatic acid, stimulated bulbing in vitro of Lilium longiflorum Thunb. by up to 65% over the controls. Dibutyryl-cAMP, forskolin, their combinations with traumatic acid, and adenosine significantly increased the micropropagation yield. Traumatic acid alone produced similar results on bulblet number per explant, but with increased fresh mass per bulblet. Chemical names used: 9-ß-D-ribofuranosyladenine (adenosine); adenosine 3′, 5′ - cyclic monophosphate (cAMP); dibutyryl adenosine 3′, 5′ - cyclic monophosphate (DB-cAMP); 9-ß-L (+) adenosine or 9-ß-L (+) ribofuranosyladenine; forskolin; 10(E) dodeca-1,12-dicarboxylic acid (traumatic acid).
Preharvest Calcium Applications Have Little Effect on Mineral Distribution in Ripe Strawberry Fruit
Authors: Makus D.J. , Morris J.R.
Published: February 2019

Supplemental Ca was supplied to `Cardinal' and `Fern' strawberry (Fragaria ×ananassa Duch.) plants grown in an Enders clayey silt loam soil as a foliar spray of Ca glutarate, as soil incorporated gypsum, as fertigated calcium nitrate (CaNO3), or as a combination of the above. Controls received no Ca. Individual fruits were partitioned into six parts: proximal, distal, inner and outer receptacle, and proximal and distal achenes. Mineral nutrient concentrations (dry mass basis) found in the inner and outer receptacle, and in achenes were, in descending order, K, P, Ca, Mg, Al, Na, Fe, Mn, Zn, B, and Cu; K, P, Ca, Mg, Na, Mn, Fe, Zn, Al, B, and Cu; and Ca, P, Mg, K, Na, Fe, Mn, Zn, Al, Cu, and B, respectively. Many nutrients, including Ca, tended to occur in greater concentrations in the proximal portion of the fruit than in the distal part. With the exception of Al, nutrient concentration gradients were lowest in the inner receptacle. Fruit Ca concentrations were highest in achenes and lowest in inner receptacle tissue. Differences among cultivars in Ca concentration were found in achenes but not in receptacle tissue. Calcium treatment had no effect on receptacle tissue Ca concentrations, regardless of cultivar, but CaNO3 and combination treatments increased Ca concentrations in the achenes in the proximal half of `Cardinal' fruit. Concentrations of all other nutrients except Mn were unaffected by supplemental Ca treatments.
Effect of Uniconazole on Shoot Growth and Budset of Containerized Fraser Fir
Authors: Hinesley L. Eric , Warren Stuart L. , Snelling Layne K.
Published: February 2019

In two experiments, uniconazole (0.25 to 16 mg·L-1 a.i.) was applied as a root drench to containerized Fraser fir [Abies fraseri (Pursh) Poir.] at various times of the year. Leader length, stem diameter, length of laterals, and number of subterminal buds were reduced the following growing season. Treatment during the 1994 growing season reduced lateral bud formation on the leader in 1995, whereas treatment with 8 or 16 mg·L-1 in Mar. 1995 (prior to budbreak) increased it. Uniconazole caused needle discoloration and abscission at concentrations ≥4 mg·L-1. Leader growth was reduced more than branch elongation, which tended to make plants more decurrent. The utility of uniconazole in production of tabletop Fraser fir Christmas trees was unclear; reduced shoot elongation was often accompanied by fewer lateral buds and needle discoloration and/or abscission. Chemical name used: E-1-(p-Chlorophenyl)-4,4-dimethyl-2-(1,2,4-triazole-1-penten-3-ol) (uniconazole).
Components of Partial Resistance to Black Spot Disease (Diplocarpon rosae Wolf) in Garden Roses
Authors: Xue A.G. , Davidson C.G.
Published: February 2019

Eleven rose (Rosa spp.) cultivars and advanced lines from the Morden rose breeding program were tested in controlled conditions for five components of partial resistance to two isolates of Diplocarpon rosae Wolf, the causal agent of black spot. The isolates were collected from diseased rose leaves in 1995 at Morden, Man., and in Ottawa, Ont. The components examined include incubation period (IP), leaf area with symptoms (LAS), number of lesions (NL), lesion length (LL), and sporulation capacity (SC). Differences in cultivar responses were found for all components. Of the 11 rose genotypes, no visible symptoms developed on line 91V8T201 even at 14 days after inoculation. This line was considered completely resistant to the two isolates tested. X6, T5, and `Prairie Joy' had a high level of partial resistance. N3 and `Cuthbert Grant' were intermediate. The remaining five cultivars or lines exhibited a low level of partial resistance. Linear correlations among LAS, IP, NL, and LL were high. Correlations between SC with IP, NL, or LL were nonsignificant. Although each of the five components can be used in selection for partial resistance, any one component may not represent the complete potential for a particular rose genotype. Results of this study suggest that LAS and SC are preferable as criteria for resistance to minimize the labor requirement when evaluating large numbers of rose genotypes in the greenhouse.
Development and Correction of K-deficiency in Drip-irrigated Apple
Authors: Neilsen Gerry , Parchomchuk Peter , Meheriuk Michael , Neilsen Denise
Published: February 2019

Various schedules of 40 g N and 17.5 g P/tree per year were applied with irrigation water (fertigation) to `Summerland McIntosh' apple (Malus ×domestica Borkh.) trees on M.9 rootstock commencing the year of planting. Leaf K concentrations averaged 0.82% dry mass, indicating deficiency, by the third growing season. This coincided with extractable soil K concentrations of 50-60 μg·g-1 soil in a narrow volume of the coarse-textured soil located within 0.3 m of the emitters. The decline in leaf K concentration was reversed and fruit K concentration increased by additions of K at 15-30 g/tree applied either as granular KCl directly beneath the emitters in spring or as KCl applied as a fertigant in the irrigation water. K-fertilization increased fruit red color, size, and titratable acidity only when leaf K concentration was <1%. Fruit Ca concentration and incidence of bitter pit or coreflush were unaffected by K application. NPK-fertigation commencing upon tree establishment is recommended for high-density apple orchards planted on similar coarse-textured soils.
Lupine (Lupinus polyphyllus) Flowering Response to Photoperiod and Hosta Response to Florel Growth Regulator
Authors: Hopper Douglas A. , Drew Danelle E. , Hudachek Catherine E. , Rudolph Lori C.
Published: February 2019

Seeds of `Russell hybrid' and `Minarette' mix lupines were sown in three experiments on 3 Sept., 10 Nov., and 2 Mar. under long-day (LD). Seedlings were transplanted on 27 Jan., 11 Mar., and 16 Apr. and moved to natural-day (ND) or LD (1500 to 0200 hr). Plants were either placed in a 17/13C day/night (DT/NT) temperature or 22/18 °C DT/NT greenhouse, and moved monthly to ND or LD for 32 treatment combinations. Days until visible bud, flowering, and vegetative heights were analyzed. `Minarette' formed flowers more consistently than did `Russell hybrids', indicating that `Minarette' populations tend to flower earlier. Young lupines did not respond to photoperiod, but facultative flowering was observed. Foliage height was greater under LD. One-year-old Hosta sieboldiana and H. `Francis William' were transplanted with one crown and placed in two temperatures as with lupines. Expt. H1 hostas were placed under LD/ND with no spray, 500 ppm, or 1000 ppm Florel; Expt. H2 hostas were placed under LD with no spray, 250 ppm Florel monthly, 500 ppm Florel at 4-, 6-, or 8-week intervals, or 2500 ppm benzyladenine (BA) sprays monthly (Dec. 1996 to July 1997). H. sieboldiana had more offsets than H. `Francis William', but the latter had increased offsets with Florel sprays. Both cultivars were shorter with 1000 ppm Florel treatments. BA-treated plants were shorter with more offsets than Florel-treated plants.
Effect of Temperature on Cutting Production of 10 Hanging-Basket Crops
Authors: Wang Shi-Ying , Carlson William H. , Heins Royal D.
Published: February 2019

Stock plants of Argeranthemum frutescens `Butterfly' and `Sugar Baby', Brachycome hybrid `Ultra', Helichrysum bracteatum `Golden Beauty', Scaevola aemula `New Wonder', Petunia axillaris hybrids `Purple Sunsport' and `Blue Vein', Sutera cordata `Mauve Mist' and `Snowflake', and Verbena hybrid `Blue' were grown in glass greenhouses under five different temperatures (17, 20, 23, 26, or 29 °C) and a 13-h photoperiod. Cuttings were taken two to three times per week. Total cutting production increased as temperature increased. However, different varieties showed different temperature response patterns. Cutting production in Argeranthmum and Brachycome was relatively insensitive to temperature. For Brachycome, Helichrysum, Scaevola, Petunia, Sutera, and Verbena, cutting production in the 29 °C treatment was double or triple that in the 17 °C treatment. For all tested species, the highest cutting production was in the 29 °C treatment. Although cuttings produced in the 29 °C treatment tended to have a soft stem, rooting was not affected by temperature under which stock plants were grown.
Winter Survival Evaluation of 172 Groundcovers in Northern Illinois
Authors: Shirazi A.M. , HedBorn E.A. , Mehaffey S.A. , Merritt A.S.
Published: February 2019

The winter hardiness of many groundcover cultivars in northern Illinois is not well-known. This study was designed to evaluate the survival of 172 plants used in the groundcover path at The Morton Arboretum. Once a month, from Sept.1997 to Jan. 1998, the plants chosen for this study were visually evaluated and their vitality rated on a scale of 1 to 5 (1 = alive, 5 = dead). All nine cultivars of Euonymus fortunei remained virtually unchanged throughout the study period. Among six cultivars of Hedera helix, only `Gold Heart' showed minor damage in November. Nine Heuchera were evaluated and all exhibited excellent resistance to cold temperatures. While all the Pulmonarias studied showed some cold damage by November, `Bielefeld Pink', `Little Blue', `Roy Davidson', Pulmonaria longifolia var. cevennensis, and Pulmonaria officinalis `Sissinghurst White' fared the best for the longest period of time. Five cultivars of Pachysandra terminalis were included in this study. None had significant damage until November, and then only rated a “2.” Of the eight Ajuga evaluated, Ajuga pyramidalis `Metallica Crispa', and Ajuga reptans `Braunherz', `Catlin's Giant', and `Gaiety', exhibited the best cold resistance. Four Polygonums varied widely in their response to cold temperatures, but all showed signs of severe damage in November. Polygonum `Border Jewel' exhibited the best tolerance, rating a “1” in October, but in November it was given a rating of “4.” Their recovery in spring will be compared.
Cowpea Seedling Response to Chilling Levels
Authors: Marsh Lurline
Published: February 2019

Controlled environment was used to simulate three chilling levels to assess differences in seedling growth of four cowpeas (Vigna unguiculata L.Walp), IT82E-18, IT82E-16, Pinkeye Purple Hull and MN13. Genotypes chilled at 14/10 °C, 15/10 °C, and 16/10 °C, (day/night) for 7 days after planting (DAP) did not differ in percent seedling emergence, which showed a maximum of 6%. At 14 DAP, genotypes differed in percent emergence at the 15/10 °C and 16/10 °C temperatures, with ranges of 34% to 51% and 61% to 86%, respectively. By 21 DAP, cowpeas at these two chilling levels had ranges of 57% to 90% and 79% to 94% emergence, respectively, and showed significant differences. At the two lower chilling regimes, the radicles failed to develop secondary roots and the seed coats remained attached to some of the primary leaves. These were generally chlorotic except for IT82E-16 at 15/10 °C. Genotypes at the highest chilling level developed secondary roots and green primary leaves, which were twice the size of those at 15/10 °C. When plants from the three chilling regimes were removed to a warm greenhouse, the leaves became green and secondary roots developed within a week. These results indicate that root development was more sensitive to the chilling temperatures than seedling emergence.
Microscopic Examination of Chilling Injury Symptoms in Ethanol-treated Cucumber Seedling Roots
Authors: Boyd Windy A. , Jennings Paul H.
Published: February 2019

Cucumber seedlings were germinated for 24 h at 25 °C and half were immersed in a 500 mM ethanol solution for 2 h. After rinsing, seedlings were chilled for 96 h at 2 °C. Control and ethanol-treated samples were taken for light and electron microscopy immediately before and after chilling, and after re-warming for 24 and 72 h. Preliminary experiments revealed visual chilling symptoms such as pinching of the root in a region just above the root tip. This region was excised under a microscope, fixed, and mounted for microscopic observations. The cortical cells of ethanol-treated seedlings before chilling appeared to be irregular in shape with irregular edges, and some epidermal damage was evident. Chilling caused much more epidermal damage in the control seedlings when compared to the ethanol-treated seedlings. After chilling, cortical cells in the control seedlings were observed to be irregularly shaped while those treated with ethanol had round cells. Upon re-warming, control seedlings exhibited increasing epidermal damage with broken cell walls, while ethanol-treated seedlings exhibited more differentiation in the stele.
Jasmonic Acid and Environments Increase Steroidal Glycoalkaloid Biosynthesis in Solanum chacoense
Authors: Chen Zhenbang , Flickinger N. Jean , Miller A. Raymond
Published: February 2019

Steroidal glycoalkaloids in Solanum chacoense have been found to deter feeding by herbivores, especially to Colorado potato beetle. The steroidal glycoalkaloids of S. chacoense include solanine (chaconine), leptinines, and leptines, which yield solanidine, leptinidine, and acetylleptinidine, respectively, upon acid hydrolysis. To understand the regulation of their biosynthesis, tissue culture plants were grown on MS media containing jasmonic acid, methyl jasmonate, or arachidonic acid at different levels. After 1 month in culture, 100 μM jasmonic acid stimulated solanidine, leptinidine, and acetylleptinidine accumulation 3- to 10-fold compared to control. Methyl jasmonate at 100 μM also induced solanidine accumulation, but not leptinidine and acetylleptinidine. Arachidonic acid had no effect on solanidine, leptinidine, and acetylletptinidine levels. Furthermore, leptinidine and acetylleptinidine levels increased 5-fold and 100-fold, respectively, after plants were transferred from culture in vitro to soil; meanwhile, solanidine level decreased slightly. Solanidine, leptinidine and acetylleptinidine from plants in vitro showed no changes during the same period. Our results indicated that jasmonic acid and environmental factors play important roles in the biosynthesis of steroidal glycoalkaloids in S. chacoense.
Effect of Inoculum Level on Response of Strawberry Fruit to Anthracnose Fruit Rot
Authors: Shuman Joel L. , Ballington James R.
Published: February 2019

In North Carolina, anthracnose fruit rot of strawberry (Fragaria × ananassa Duch.) is caused by the fungus Colletotrichum acutatum Simmonds. Little is known about the mechanisms of field resistance of fruits to anthracnose. It appears that resistance of various plant parts including runners, crowns, and foliage is not always correlated with resistance of fruit. Resistance of fruit may be simply overwhelmed by excessive fungal conidia. Is there a threshold level of inoculum and does this threshold vary for fruit of different cultivars? The objective of this study was to determine the effect of inoculum level on the response of seven strawberry cultivars/breeding lines to a single C. acutatum (CA-1) isolate. The experimental design was a split-plot with five levels of inoculum (0, 1 × 103, 1 × 104, 1 × 105, and 1×106 conidia/ml) as the whole plot and seven cultivars/breeding lines (`Apollo', `Chandler', `Camerosa', `Pelican', `Sweet Charley', NCH 95-173, and NCR 94-08) as the subplots with three replicates. The experiment was conducted in a growth chamber at the Southeastern Plant Evironment Laboratory at North Carolina State Univ. Mature, green fruit and fruit turning red were inoculated with conidia. Lesion diameter, percent diseased tissue, and fruit weight were determined daily. The seven cultivars/breeding lines had differing levels of fruit rot resistance and fruit firmness/skin toughness.
Influence of Stratification and Seed Age on Germination of Penstemon Seeds
Authors: Lindgren Dale T. , Schaaf Daniel M.
Published: February 2019

Seeds of eight Penstemon selections, stratified for 10, 8, 6, 4, 2, or 0 weeks in 1989 and 1990, displayed significant germination differences between species, between weeks of stratification, and between years. Germination varied from zero with P. digitalis in both 1989 and 1990 with no stratification, to 68.0% and 72.8% with P. angustifolius in 1989 and 1990, respectively, for 10 weeks of stratification. In 1991 through 1997, seeds of four of the selections were stratified for 0 or 8 weeks. Seeds that were 3 to 4 years old germinated as well as or better than seeds 1 to 2 years old. All seeds that were 9 years old had no germination, except for Penstemon `Prairie Splendor', which averaged 7% germination with no stratification. Stratification significantly increased germination of seeds up to 4 years old. Germination of Penstemon seed varied with stratification, seed age, and species/line.
Ethylene Inhibitor, 1-Methylcyclopropene, Delays Apple Softening
Authors: Blankenship Sylvia M. , Unrath C.R.
Published: February 2019

Three apple cultivars, Jonagold, Ginger Gold, and Gala, were treated at harvest with “EthylBloc,” a commercial formulation of 1-methylcyclopropene (MCP). The apples were sealed in a container and the compound entered the fruit as a gas. Apples were treated for 16 h at 22 °C. Fruit were then stored at 22 or 0 °C. In some cases fruit were retreated after 20 days. Overall MCP treated fruit showed less softening than untreated fruit. Soluble solids and starch iodine ratings were similar in all fruit. `Ginger Gold' firmness was 85 N at harvest, and after 20 days at 22 °C it was 75 N in MCP-treated fruit and 53 N in the control. In addition, there were large numbers of rotten fruit in the control, but not in the MCP treated fruit. Fruit firmness in `Gala' was ≈64 N in the control and 95 N in the MCP-treated fruit after 30 days at 22 °C. Treated and untreated fruits stored at 0 °C showed less difference in firmness than fruit stored at 22 °C. However, in `Jonagold' fruit there was a 13 N difference in firmness between treated and untreated fruit after 2 and 4 months 0 °C storage.
Assessment of Relationships between Fruit Peel Nutrient Concentrations and Storage Decay Incidence in `d'Anjou' Pear
Authors: Niederholzer F.J.A. , Spotts R.A.
Published: February 2019

Fruit were sampled from 12 mature `d'Anjou' pear trees at commercial harvest in each of two orchards in the Hood River Valley in 1996 and 1997. In 1997, separate fruit samples were obtained from the upper and lower canopy of each tree. Fruit firmness and starch index were determined for each sample in 1997. Fruit peel samples were obtained from five (1996) and 10 (1997) fruit per sample, and peel N, P, K, Mg, Ca, Mn, Zn, Fe, Cu, and B concentrations (% dry weight) determined. The remaining fruit were drenched with a dilute solution of blue mold (Penicillium expansum) and placed in cold storage. Decay incidence was evaluated after 3 and 5 months. In 1996, with the exception of Ca, fruit peel nutrient concentrations were not correlated with incidence of storage decay. A strong negative correlation between fruit peel Ca concentration and blue mold incidence was present in the samples from one orchard in 1996. Fruit peel Ca concentrations varied with year, tree, and canopy location. Results from the 1996 and 1997 seasons will be presented.