bluuebunny/crossref_metadata_2025 huggingface dataset:
Potato Yield and Quality Not Changed by Foliar-applied Methanol
Authors: Feibert E.B.G. , James S.R. , Rykbost K.A. , Mitchell A.R. , Shock C.C.
Published: February 2019

Previously published research suggests that the yield and water-use efficiency of C-3 plants can be enhanced through foliar-applied methanol. Potatoes (Solanum tuberosum L. cv. Russet Burbank) grown in Oregon at Klamath Falls, Madras, and Ontario were subjected to repeated foliar methanol treatments during the 1993 season. Methanol was applied at 20%, 40%, and 80% concentration with Triton X-100 sticker-spreader at 0.1%, and methanol was applied at 20% and 40% without Triton X-100. Methanol had no effect on tuber yield, size distribution, grade, or specific gravity at any location. Tuber stem-end fry color showed no methanol response at the two locations where it was measured. Soil water potential (measured at Madras and Ontario) showed no difference in water-use efficiency between methanol-treated and nontreated potato plants.
Ammonium and Nitrate Uptake throughout Development in Dendranthema ×grandiflorum
Authors: King Joseph J. , Peterson Lloyd A. , Stimart Dennis P.
Published: February 2019

Ammonium and NO3 uptake from hydroponic solutions containing 1 mm each of (NH4)2SO4 and Ca(NO3)2 were measured during development of Dendranthema ×grandiflorum (Ramat.) Kitamura `Iridon', `Sequoia', and `Sequest'. Nitrogen depletion from solutions approximated a 1 NH4: 1 NO3 ratio throughout a 90-day growth cycle (r = 0.96). Although harvest date cultivar interactions were significant for both forms of N, overall patterns of N uptake were similar among cultivars. Nitrogen removal from hydroponic solutions (milligrams per plant) was greatest from days 40 to 60; however, N removal (milligrams per gram of tissue dry weight) was greatest in the first month of development and decreased steadily until day 90. From day 40 to 60, new leaf development ceased while inflorescence buds developed to ≈1.0 cm in diameter. After this time, N uptake decreased rapidly as inflorescences expanded. Correlations between morphological changes and N demand could maximize the efficiency of applied N by matching form and application timing with plant needs.
Nitrogen Accumulation and Fertilizer Use Efficiency by Grapevines in Short-season Growing Areas
Authors: Hanson Eric J. , Howell G. Stanley
Published: February 2019

Mature `Concord' vines (Vitis labrusca L.) were excavated at 2- to 4-week intervals through the season to study seasonal changes in vine N concentration. Vine N content began increasing 2 weeks after budbreak, increased most rapidly from mid-May to mid-July, and declined between fruit maturation and the beginning of leaf senescence. Vine N content was lowest at budbreak (18 g) and maximum at fruit maturity (75 g). This change represented a net accumulation of 57 g N/vine or 77 kg N/ha. In a separate study, `Seyval blanc' vines were treated with double 15N-labeled ammonium nitrate at either budbreak or bloom. Labeled N was applied as a spray beneath vines to simulate a broadcast vineyard application. Vines were excavated when leaves began to senesce in October, partitioned into various components, and analyzed by mass spectrophotometry to determine fertilizer-derived N content. Vines had recovered statistically similar percentages of fertilizer N applied at budbreak (7.1%) and bloom (10.6%). The low recovery of fertilizer N likely resulted from the method of fertilizer application, the presence of a competitive grass sod between the rows, and relatively high native soil N levels.
Scion Inclination in Malus domestica Borkh. and Prunus spp. Influences Root Growth and Distribution
Authors: Bargioni Giorgio , Baroni Giorgio , Tonutti Pietro , Pitacco Andrea , Ramina Angelo
Published: February 2019

Effects of scion inclination on root growth and distribution were studied on INRA GF 677 (Prunus persica × Prunus amygdalus) and apple/M.9 trees. At planting, central leaders were positioned vertically (0°) or inclined 45° or 60° to the north and south. Three years after planting, root total dry weight of inclined trees was lower than that of the control (0°, vertical central leader). Five years after planting, the isotropic distribution of the normal root systems was distorted by inclination in both species. Roots were more numerous and more elongated in the direction of inclination. Statistical analysis of root density data, using a polar coordinate system, confirmed that the trunk inclination reduced root development and redirected root distribution. The major effect was induced on GF 677 by 60° inclinations. Tree orientation did not seem to influence root distribution.
A Modified Stimpmeter for Small-plot Turfgrass Research
Authors: Gaussoin Roch , Nus Jeff , Leuthold Larry
Published: February 2019

Golf ball roll is measured with a United States Golf Association (USGA) Stimpmeter. Three Stimpmeters were fabricated identically to the USGA Stimpmeter, except for the location of the ball release notch. The modified Stimpmeters had ball release notches located at 57, 38, and 19 cm, rather than at 76 cm from the beveled end. The modified Stimpmeters were tested on a creeping bentgrass green located at Mead, Neb., at three mowing heights (4.8, 4.0, and 3.2 mm). The Stimpmeters were effective in measuring golf ball roll distance and provided reasonable and consistent estimates of friction. Modified Stimpmeters are relatively inexpensive to construct and can be used on small turfgrass research plots.
Caladium Height Control with Paclobutrazol Drench Applications
Authors: Barrett James E. , Bartuska Carolyn A. , Nell Terril A.
Published: February 2019

Paclobutrazol drench treatments were evaluated for efficacy on Caladium ×hortulanum (Birdsey) cultivars Aaron, White Christmas, and Carolyn Wharton. Drenches at 2.0 mg/pot did not reduce height of `Aaron' and `White Christmas' plants when applied 1 week after planting, but 2.0 mg applied at 3 weeks after planting did result in shorter plants. The difference for time of application may be due to the amount of roots present to take up paclobutrazol when applied. In two factorial experiments, there were no interactions between cultivar and time of application or amount of chemical. Paclobutrazol at 0.5 mg/pot resulted in plants that were shorter than the controls. Higher amounts of paclobutrazol provided additional reductions in height, but there was variation between the experiments for degree of effect with amounts >1 mg. Generally, commercially acceptable height control was provided by paclobutrazol drench treatments at 0.5 and 1.0 mg/pot applied 3 weeks after planting. Chemical names used: (2RS,3RS)-1-(4-chlorophenyl)-4,4-dimethyl-2-1,2,4-triazol-1-yl-pentan-3-ol (paclobutrazol).
Photoperiod Sometimes Influences Common Bacterial Blight Disease of Common Beans
Authors: Mohamed Mohamed F. , Coyne Dermot P.
Published: February 2019

Common bacterial blight, incited by Xanthomonas campestris pv. phaseoli (Smith) Dye (Xcp), is a serious disease of common beans (Phaseolus vulgaris L.). Three experiments were conducted twice in growth chambers at 26 ± 1C under short (10 hours light/14 hours dark) and long (16 hours light/8 hours dark) photoperiods to determine the influence of these photoperiods, flower bud removal, pod development, and pre- and post-inoculation photoperiods on the reaction of common beans to Xcp. In one test, `PC-50' (susceptible; S) flowered earlier and was more susceptible to Xcp under the short photoperiod than under the long photoperiod. BAC-6 (resistant; R) flowered at the same time under both photoperiods but developed rapid leaf chlorosis (RLC) (hypersensitive reaction) under long photoperiods. Flowering and disease reactions to Xcp by XAN-159 (R) were similar under both photoperiods. In a second test, daily removal of flower buds of `PC-50' decreased its susceptibility to Xcp under the short photoperiod. RLC of inoculated leaves of BAC-6 occurred during flowering and pod development under both photoperiods. XAN-159 expressed a high level of resistance to Xcp but showed RLC at later pod development stages. In a third test, the disease reaction of `PC-50' was affected by the particular photoperiod applied post-inoculation but was not influenced by the photoperiod applied before inoculation with Xcp. The implications of these results in breeding beans for resistance to Xcp are discussed.
Effectiveness of Selected Fungicides in Controlling Foliar Diseases of Common Periwinkle (Vinca minor L.)
Authors: Koelsch Mary C. , Cole Janet C. , von Broembsen Sharon L.
Published: February 2019

Common periwinkle and `Bowles' periwinkle production has declined in the southern United States due to foliar diseases caused by Colletotrichum gloeosporioides (Penz.) Penz. & Sacc. in Penz. and Phoma exigua Desmaz. var. inoxydabilis Boerema & Vegh in Vegh et al. Our study determined whether several labeled and experimental fungicides could control pathogens causing foliar diseases in common periwinkle in vitro and outdoors during two consecutive summers. Five concentrations of each of eight fungicides were used to test inhibition of mycelial growth of P. exigua var. inoxydabilis and two isolates of C. gloeosporioides on fungicide-amended agar. All concentrations of propiconazole inhibited growth of P. exigua var. inoxydabilis (100%) and both isolates of C. gloeosporioides (>96%). Cyproconazole completely inhibited mycelial growth of P. exigua var. inoxydabilis. Thiophanate methyl/mancozeb partially inhibited growth of C. gloeosporioides (50%). In outdoor trials, plants were sprayed weekly with the following fungicides and rates (in g a.i./liter): thiophanate methyl/mancozeb, 1.35; propiconazole, 0.14; thiophanate methyl, 0.84; triforine, 0.27; cyproconazole, 0.08; triforine–CC 17461, 0.27; or CGA 173506, 0.90. Thiophanate methyl/mancozeb was most effective at reducing foliar necrosis during both seasons. Shoot dry weights of plants treated with thiophanate methyl/mancozeb were significantly higher at the end of each growing season than those of plants treated with the other fungicides or the nontreated control plants. Chemical names used: dimethyl [(1,2-phenylene)-bis (iminocarbonothioyl)] bis [carbamate] and a combination of zinc ion and manganese ethylenebisdithiocarbamate (thiophanate methyl/mancozeb); 1-[2-(2′,4′-dichlorophenyl)-4-propyl-1,3-dioxolan-2-yl-methyl]-1H-1,2,4-triazole (propiconazole); dimethyl [(1,2-phenylene)-bis (iminocarbonothioyl)] bis [carbamate] (thiophanate methyl); N,N′-[1,4-piperazinediylbis (2,2,2-trichloroethylidene)] bis [formamide] (triforine); 2-(4-chlorophenyl)-1-(1H-1,2,4-triazol-l-yl)-butan-2-ol (cyproconazole); N,N′-[1,4-piperazinediylbis (2,2,2-trichloroethylidene)] bis [formamide] with micro emulsion (triforine–CC 17461); 4-(2-2-difluoro-1,3-benzodioxol-4-yl) pyrrole-3-carbonitrile (CGA 173506).
Age of Plant Material Influences Resistance of Some Prunus Rootstocks to Meloidogyne incognita
Authors: Fernández Carolina , Pinochet Jorge , Esmenjaud Daniel , Gravato-Nobre Maria Joao , Felipe Antonio
Published: February 2019

The influence of salinity and plant age on nematode reproduction was determined on two susceptible and six root-knot-nematode-resistant Prunus rootstocks inoculated with Meloidogyne incognita (Kofoid and White). Experiments were conducted under greenhouse conditions over 120 (plant age study) and 75 (salinity study) days. Following inoculation with 4000 nematodes per plant, susceptible 2-month-old GF-677 (Prunus persica L. Batsch. × P. dulcis Mill. Webb) and Montclar (P. persica) were affected significantly more than 1-year-old plants. Barrier (P. persica × P. davidiana Carr. Franch.) plantlets showed a partial loss of resistance in relation to older plants, suggesting that a root tissue maturation period is required for expression of full resistance. Nemared (P. persica); G × N No 22 (P. persica × P. dulcis); and the plums GF 8-1 (P. cerasifera Ehrh. × P. munsoniana Wight and Hedrick), PSM 101 (P. insititia L.), and P 2980 (P. cerasifera) maintained their high level of resistance or immunity, regardless of plant age. Nematode reproduction was higher in GF-677 rootstock in saline soil. Nemared and Barrier showed similar low galling and nematode reproduction in nonsaline and saline soil. PSM 101 immunity to M. incognita was not affected by soil condition.
Multiple Regression Models for the Analysis of Potential Cultivation Areas for Japanese Plums
Authors: Rumayor-Rodríguez Agustín
Published: February 2019

The annual yield variation in a Japanese plum (Prunus salicina Lindl.) germplasm collection [with 32 cultivars (cv)] was used to generate regression models to describe fruit yields in terms of climate. A Geographic Information System (GIS) combined with generated regression models was used for a regional analysis of potential areas for growing plums in Zacatecas, Mexico. Three distinct cv groups were obtained by principal component analysis and were included in the study: a) `Frontier'–`Santa Rosa', b) `Ozark Premier'–`Burbank', and c) `Shiro'. The amount of winter chilling and temperatures during bloom time were the climatic conditions most related to yield. `Frontier'–'Santa Rosa' had relatively low chilling requirements (700 chill units) compared to `Ozark Premier'–`Burbank', which required the most chilling (900 chill units). `Shiro' yields were more consistent than those of the other two groups, suggesting that it has less strict requirements and received sufficient chilling every year. High temperatures at bloom reduced fruit yield in all cultivars; however, the dependence of yield on temperatures during bloom in `Shiro' was modified by summer temperatures the previous year, suggesting that temperatures at the floral induction and formation stages affect flower primordia development. Using GIS, three potential areas for growing plums in the region were defined on maps, and the differences in potential yield between the cultivar groups were determined. `Frontier'–`Santa Rosa' may be good choices as plum cultivars for the region because they were the cultivars with the highest potential yield in the largest area; however, the flexibility of the method used allows the user to get a regional gradient of the expected yields with several plum cultivars. Using experimental information and a GIS can extend the applicability of germplasm collection data to regional planning in the establishment of orchards and new fruit industries.
Inheritance of the Cutleaf Trait in Hazelnut
Authors: Mehlenbacher Shawn A. , Smith David C.
Published: February 2019

The cutleaf hazelnut [Corylus avellana L. f. heterophylla (Loud.) Rehder] is grown as an ornamental for its distinct leaf shape. Its leaves are slightly smaller, more deeply lobed, and more sharply toothed than those of standard hazelnut cultivars. When the cutleaf hazelnut was crossed with cultivars with normal leaves, all seedlings had normal leaves. When seedlings were backcrossed to their cutleaf parent, half of the seedlings expressed the cutleaf trait, and when crossed with each other in pairs, 25% of the seedlings were cutleaf. These segregation ratios indicate that the cutleaf trait is conferred by a single recessive gene for which the symbol cf is proposed. Progenies segregating simultaneously for leaf shape and color indicate that the cutleaf locus is independent of the locus controlling red leaf color and of the locus controlling a chlorophyll deficiency, which appears to be identical to that previously observed in seedlings of `Barcelona'.
Change in Tissue Mineral Elemental Concentration during Root Initiation and Development of Poinsettia Cuttings
Authors: Svenson Sven E. , Davies Fred T.
Published: February 2019

Variation in tissue elemental concentration in apical stem cuttings of `Lilo' and `V-10 Amy' poinsettia (Euphorbia pulcherrima Willd. ex. Klotzch) were studied during the initiation and development of adventitious roots. Changes in selected macro- and micro-element concentrations coincided with root initiation (i.e., Fe, Cu, and Mo accumulated in the basal portions of stem cuttings during early root initiation before root primordia elongation); P, K, Ca, and Mg concentrations declined. During root primordia elongation and root emergence, Fe, Cu, and Mo and Mg, Mn, B, and Zn concentrations continued to increase at the cutting bases, but P and K concentrations remained low compared to when cuttings were initially inserted in the propagation medium. When all cutting of both cultivars had rooted, foliar N, Fe, and Mo concentrations declined, but Cu increased compared to when cuttings were initially propagated.
A Model for Estimating Area of Muskmelon Leaves
Authors: Panta G.R. , NeSmith D.S.
Published: February 2019

Eight muskmelon (Cucumis melo reticulatus L.) cultivars were selected to test whether a model could be developed to estimate leaf area across cultivars. Regression analyses of leaf area vs. leaf width and length revealed several models that could be used for estimating the area of individual muskmelon leaves. A linear model using leaf width squared was the best overall, yielding the equation A = 3.3 + 0.63 (W2), where A is area of an individual leaf lamina (square centimeter) and W is leaf width (centimeter) at the widest point perpendicular to the leaf midrib. Forcing the intercept through the origin did not significantly alter prediction capability and resulted in a simple model of the form A = 0.64 (W2) that was applicable to all eight cultivars.
The Response of Stem Girdling and Covering Material on Air-layering Propagation of Rubber Plants
Authors: Herrin B. Bejie , Carter Johnny
Published: February 2019

A greenhouse study was conducted to determine the influence of four stem girdling methods and the use of three covering materials on air-layering propagation of rubber plants (Ficus elastica L.). Stem girdling methods consisted of a control, slit, copper wire, and debarking. Black plastic, clear plastic, and aluminum foil were the covering materials used. Results from this study showed that all of the covering materials responded similarly when compared to the control. All of the stem girdling treatments stimulate the number of roots, root growth, and root fresh weight when compared to the control. However, the debarking treatment produced the greatest number of roots, root length, and root fresh weight.
Supraoptimal Root-zone Temperature Influences the Medium Solution and Growth of `Helleri' Holly
Authors: Walden Ronald F. , Wright Robert D.
Published: February 2019

Rooted cuttings of Ilex crenata Thunb. `Helleri' were grown for 12 weeks in pine bark with two root-zone temperature treatments (unheated or heated to 40C for 6 hours·day–1), two rates of limestone addition (0 or 6 kg·m–3), and three weekly N application rates (200, 400, or 600 mg·liter–1 as urea ammonium nitrate) in a factorial combination. Decreases in shoot and root dry weights due to root-zone heating (69% and 75%, respectively) or limestone addition (41% and 42%, respectively) were not influenced by N application rate. Effects of root-zone heating on medium solution characteristics, which differed in response to limestone addition, were similar for all N application levels. In unlimed pine bark at 400 mg N/liter, the pH and the NH4-N: NO3-N ratio were higher in the heated medium (5.5 and 1.15, respectively) than in the unheated medium (3.9 and 0.64, respectively) after 80 days, suggesting that 6 hours of daily exposure to 40C inhibited nitrification. The higher medium solution pH due to root-zone heating resulted in lower medium solution and shoot tissue Mn concentrations.
Interactions of High Temperature and Exposure Time Influence Nitrification in a Pine Bark Medium
Authors: Walden Ronald F. , Wright Robert D.
Published: February 2019

Pine bark-filled containers periodically fertilized with NH4-N were heated from 21C to 28, 34, 40, 46, or 52C for daily exposures of 1, 2, 4, 6, or 24 hours over 20 days. Concentrations of NH4-N and NO3-N in medium solution extracts were determined every 5 days. Medium solution NH4-N concentration was higher at constant (24 hours) exposure to 40C than at lower temperatures or exposure times. There was a similar increase in NH4-N concentration for a 2-hour·day–1 exposure to 46C, with further increases in NH4-N for longer exposure times. By day 10, NH4-N concentration was highest after 1 hour·day–1 exposure to 52C. Decreases in medium solution NO3-N concentration generally coincided with the increases in NH4-N. These results indicate that container medium thermal periods, similar to those observed in nurseries of the southern United States, may inhibit nitrification, thereby influencing NH4-N: NO3-N ratios in the medium solution of plants fertilized with predominantly ammoniacal N sources.
Differential Occurrence of Bacterial Wilt in Muskmelon Due to Preferential Striped Cucumber Beetle Feeding
Authors: Brust Gerald E. , Rane Karen K.
Published: February 2019

Ten muskmelon (Cucumis melo L.) cultivars were tested for their susceptibility to bacterial wilt, caused by Erwinia trucheiphila (Smith) Bergey, Harrison, Breed, Hammer and Huntoon and vectored by the striped cucumber beetle Acalymma vittatum (F). `Superstar', `Rising Star', `Pulsar', `Caravelle', `Cordele', `Legend', `Makdimon', `Galia', `Rocky Sweet', and `Passport' were used in field studies to determine the number of striped cucumber beetles, feeding damage, and incidence of bacterial wilt. `Makdimon' and `Rocky Sweet' hosted significantly more beetles than the other cultivars. These two cultivars and `Legend' and `Cordele' had much more feeding damage and a significantly higher incidence of bacterial wilt than the others. A greenhouse experiment was conducted with seven of the cultivars to test their susceptibility to bacterial wilt when directly inoculated with the causal agent. All cultivars were equally susceptible to the disease when it was introduced directly into the plant. Selective feeding by striped cucumber beetles was probably most responsible for `Makdimon', `Rocky Sweet', `Legend', and `Cordele' having greater incidences of bacterial wilt than the other cultivars.
Pest Evaluation in Sustainable Cabbage Production Systems
Authors: Hoyt G.D. , Walgenbach J.F.
Published: February 2019

Conservation tillage systems provide optimum conditions to reduce soil erosion and increase surface soil organic matter. This experiment was established with the long-term goal of developing conservation tillage systems that use either chemical inputs to produce vegetables and control pests, or legume cover crops, biological pesticides, and tillage to provide plant nutrition and control pests. The experiment consisted of cabbage (Brassica oleracea var. L. Capitata Group) grown by traditional-tillage (TT) or strip-tillage (ST) culture using either chemical or organic production methods for pest control. Cabbage heads were heavier with TT than with ST for the chemical production system. Although weed biomass was significantly higher with organic methods, there was a poor relationship between weed biomass at harvest and cabbage head weight. The lack of differences in lepidopterous pest damage suggests that the conservation tillage systems examined likely would not affect lepidopterous pest management systems using biological insecticides. Within tillage treatments, the organic production system resulted in less Alternaria infection than did the chemical production system. Since no fungicides were applied on any treatment, lower disease ratings in the organic production system may have been the result of reduced soil contact of the cabbage leaves from the increased soil coverage by the weed and intercropped legume canopy.
Hot-water Dips Extend the Shelf Life of Fresh Broccoli
Authors: Forney Charles F.
Published: February 2019

Freshly harvested heads of `Cruiser' or `Paragon' broccoli (Brassica oleracea L. Italica group) were heated by immersing in water at 42, 45, 48, 50, or 52C. Immersion times were decreased as treatment temperatures were increased and ranged from 20 to 40 minutes at 42C to 1 to 3 minutes at 52C. Control heads, dipped in 25C water for 0, 10, or 40 minutes, began to turn yellow after ≈3 days storage at 20C and 80% to 90% relative humidity. Immersion in 42C water delayed yellowing by 1 or 2 days; immersion in 45, 48, 50, or 52C prevented yellowing for ≤7 days. Water loss of broccoli during storage at 20C increased by ≤1% per day by some hot-water treatments. Immersion in hot water decreased the incidence of decay during storage at 20C. Immersion in 50 or 52C water for 2 minutes was most effective in controlling decay development. Broccoli immersed in 52C water for 3 minutes had a distinct off-odor. Control and treated broccoli held at 0C for 8 days following hot-water dips were similar in quality. Yellowing of heat-treated broccoli was inhibited when broccoli was warmed to 20C following storage at 0C. Hot-water treatments also delayed senescence at 20C when broccoli was treated following 3 weeks of storage at 0C. Immersion of broccoli in 50C water for 2 minutes was the most effective treatment for reducing yellowing and decay while not inducing off-odors or accelerating weight loss.
Orchard Floor Crops Reduce Growth of Young Pecan Trees
Authors: Foshee Wheeler G. , Goff William D. , Patterson Michael G. , Ball Donald M.
Published: February 2019

Hairy vetch (Vicia villosa Roth), common vetch (V. sativa L. `Cahaba White'), arrowleaf clover (Trifolium vesiculosum Savi `Yuchi'), crimson clover (T. incarnatum L. `Tibbee'), red clover (T. pratense L. `Redland II'), yellow nutsedge (Cyperus esculentus L.), buckwheat (Fagopyrum sagittatum Gilbert), hairy indigo (Indigofera hirsuta L.), bahiagrass (Paspalum notatum Flugge `Pensacola'), common bermudagrass [Cynodon dactylon (L.) Pers.], and centipedegrass [Eremochloa ophiuroides (Munro) Hack] were grown for 3 years in a 3 × 3-m spacing around young pecan [Carya illinoinensis (Wangenh.) K. Koch] trees. Compared to weed-free plots, all cover crops suppressed tree growth substantially, and there were no differences among cover crops in the degree of suppression. Mean trunk cross-sectional area of weed-free trees increased 26-fold by the end of the third growing season but increased only 13-fold for trees grown with any cover crop. These results suggest that cover crops, if grown in young pecan orchards to promote beneficial insects, should be excluded from the immediate area around the young trees.
Ideal Pear Sensory Attributes and Fruit Characteristics
Authors: Kappel Frank , Fisher-Fleming Robert , Hogue Eugene J.
Published: February 2019

The relationship between the objective assessment of sensory attributes or fruit characteristics of pear (Pyrus communis L.) fruit and the corresponding consumer or sensory panel rating was studied. Optimum fruit diameter was between 6 and 7.5 cm. Some fruit were judged to be too large. Fruit with a bright yellow skin were rated ideal, whereas green or red skin was rated less favorably. A pyriform shape with a length: diameter ratio range of 1.44 to 1.48 was optimum. Round fruit or very elongated fruit were considered undesirable. Perceived firmness increased linearly as the measured firmness increased, with the optimum firmness at 27 to 30 N (using an 11.1-mm penetrometer tip). Perceived juiciness was negatively, linearly related to measured firmness. Ideal firmness for an ideal juiciness rating was 18 to 22 N. Acceptable soluble solids concentrations (SSC) varied with the study year, but ranged between 13.6% and 17.2%. The sweet/sour balance (ratio of SSC: titratable acidity) was a useful indicator of fruit quality.
Adaptability and Reliability of Yield for Four Bell Pepper Cultivars Across Three Southeastern States
Authors: Hodges Laurie , Sanders Douglas C. , Perry Katharine B. , Eskridge Kent M. , Batal K.M. `Dean' , Granberry Darbie M. , McLaurin Wayne J. , Decoteau Dennis , Dufault Robert J. , Garrett J. Thomas , Nagata Russell
Published: February 2019

Four bell pepper (Capsicum annuum L.) cultivars were evaluated for yield (total weight of marketable fruit) performance over 41 environments as combinations of 3 years, three planting dates, and seven locations across North Carolina, South Carolina, and Georgia. Cultural practices, including trickle irrigation and double rows planted on black-plastic-covered beds, were uniform across all environments, except for fertilization, which was adjusted at each location based on soil tests. Comparing production over 3 years between the mountain location and the Coastal Plain location in North Carolina, yields were lower on the Coastal Plain. Spring plantings provided higher yields than summer plantings at both locations. Yield increases were obtained from hybrid cultivars over that of the open-pollinated (OP) standard [`Keystone Resistant Giant #3' (KRG#3)] in the summer planting in the mountains compared to the Tidewater Coastal Plain. Across the three-state region, hybrid cultivar yields were higher than those of the OP cultivar for the second spring planting date in 1986 and 1987. Although the hybrid yields were higher than that of the OP standard, the hybrid `Skipper' yielded less than the other hybrids (`Gator Belle' and `Hybelle'). `Gator Belle' generally out-yielded `Hybelle' at all locations, except in Fletcher, N.C. This difference may be related to the relative sensitivity of these two cultivars to temperature extremes, rather than soil or geographic factors, because there was a tendency for `Hybelle' yields to exceed `Gator Belle' in the earliest planting date. Based on the reliability index, the chance of outperforming KRG#3 (the standard) was 85% for `Hybelle', 80% for `Gator Belle', but only 67% for `Skipper'.
Field Tests of Methanol as a Crop Yield Enhancer
Authors: McGiffen Milton E. , Green Robert L. , Manthey John A. , Faber Ben A. , Downer A. James , Sakovich Nicholas J. , Aguiar Jose
Published: February 2019

To test the usefulness of methanol treatments in enhancing yield and drought tolerance, we applied methanol with and without nutrients to a wide range of crops across California: lemon (Citrus limon L.), creeping bentgrass (Agrotis palustris Huds.), romaine lettuce (Lactuca sativa L.), carrot (Daucus carota L.), corn (Zea mays L.), wheat (Triticum aestivum L.), pea (Pisum sativum L.), and radish (Raphanus sativus L.). Environments included greenhouse and field tests in coastal, inland-valley, and desert locations. Methanol did not increase the yield or growth of any crop. In some cases, methanol caused significant injury and decreased yield.
Nitrogen and Water Rates for Subsurface Trickle-irrigated Romaine Lettuce
Authors: Thompson Thomas L. , Doerge Thomas A.
Published: February 2019

Two field experiments were conducted with subsurface trickle-irrigated romaine lettuce (Lactuca sativa L. cv. Parris Island Cos) during the 1990–92 winter growing seasons in southern Arizona. The objectives were to determine 1) yield and quality response to varying combinations of soil water tension (SWT) and N fertilizer, 2) seasonal patterns of N uptake, and 3) unutilized fertilizer N. During 1990–91, N rates were 35, 120, and 205 kg·ha–1. During 1991–92, the experiment was factorial with N levels from 50 to 300 kg·ha–1 and target SWT levels of 7.0 and 4.0 kPa. Unutilized fertilizer N was the difference between fertilized and nonfertilized plots in total N inputs not harvested in the crop. When excessive irrigation was not applied (SWT between 6.5 and 7.4 kPa), 95% of the maximum crop yield and yield quality (head length and fresh mass) response occurred at N rates of 156 to 193 kg·ha–1, with unutilized fertilizer N <60 kg·ha–1. Excessive irrigation (4.6 kPa) resulted in lower yields and yield quality and higher unutilized fertilizer N. Romaine accumulated >74% of its total N uptake in the 38 days before harvest. Unutilized fertilizer N increased sharply when adequate N and water rates were exceeded. These results suggest that a target SWT of no wetter than 6.5 kPa is appropriate for subsurface trickle-irrigated romaine lettuce.
Thidiazuron Effects on Fruit Set, Fruit Quality, and Return Bloom of Apples
Authors: Greene Duane W.
Published: February 2019

Thidiazuron (THI) applied at full bloom (FB) at 10 or 50 mg·liter–1 thinned `McIntosh' apples (Malus domestica Borkh.) and reduced return bloom. The same concentrations applied at 22 days after FB (DAFB) thinned excessively and inhibited return bloom even more. THI at 1, 5, or 15 mg·liter–1 did not thin `Empire' at FB, but when applied 18 DAFB, these concentrations achieved thinning, with 5 mg·liter–1 reducing crop load to near ideal commercial levels. Return bloom of `Empire' was not influenced by THI at these concentrations. THI increased fruit weight, flesh firmness, soluble solids concentration, and fruit asymmetry on `McIntosh' and `Empire' and reduced red pigmentation and seed count on `McIntosh', especially when applied 22 DAFB. A FB application of CPPU and THI, each at 5 or 10 mg·liter–1, on `Delicious' increased the fruit length: diameter (L: D) ratio and flesh firmness (at harvest and following 26 weeks of refrigerated storage and reduced return bloom). CPPU at either 5 or 10 mg·liter–1 increased the fruit L: D ratio more than 25 mg Promalin/liter. Chemical names used: N-phenyl-N′-1,2,3-thiadiazol-5-ylurea (thidiazuron); N-(2-chloro-4-pyridyl)-N′-phenylurea (CPPU); N-(phenylmethyl)-1H-purine-6-amine plus gibberellins A4+7 (Promalin).
Role of Growth Regulators in In Vitro Rhizome Growth of Potato
Authors: Escalante B.Z. , Langille Alan R.
Published: February 2019

Disinfested, etiolated medial segments of potato (Solanum tuberosum L.) sprouts cv. Katahdin with two axillary buds were placed on Murashige and Skoog (MS) medium in clear plastic culture boxes. Basal ends of explants were inserted into MS medium containing BA at 2 mg·liter–1. Nine treatments, composed of factorial combinations of GA3 at 0, 0.2, and 2 mg·liter–1 and IAA at 0, 0.3, and 3 mg·liter–1, were imposed. These were applied via small agar cylinders placed on the apical cut surface of each segment. Regardless of the presence of cytokinin and auxin, no rhizomes developed after 3 weeks in culture without a supply of GA3. Number and length of primary and secondary rhizomes increased with an increase in GA3 concentration in the agar cylinder from 0 to 2 mg·liter–1. Rhizome initiation and development appear to be controlled by coordinated participation of endogenous plant hormones during the early events leading to tuber development. Chemical names used: 2,4a,7-trihydroxy-1-methyl-8-methylenegibb-3-ene-1,10-carboxylic acid 1->4 lactone (GA3); indole-3-acetic acid (IAA); N-(phenylmethyl)-1H-purin-6-amine (BA).
Field and Laboratory Resistance of St. Augustinegrass Germplasm to the Southern Chinch Bug
Authors: Busey Philip
Published: February 2019

St. Augustinegrass [Stenotaphrum secundatum (Walt.) Kuntze] is host to the southern chinch bug (SCB) (Blissus insularis Barber). This study evaluated and compared field and laboratory resistance of St. Augustinegrass germplasm to the SCB. Turf field plots of 20 St. Augustinegrass genotypes were monitored monthly for 2 years for damage by the SCB. After each occurrence of damage, plots were treated individually with an insecticide and allowed to become damaged again. Genotypes differed in frequency of damage, which varied from 1.02 occurrences per year for FX-22 and FX-338 to zero occurrences per year for `Floratam'. During the next 2 years when no insecticide was applied, the portion of dead canopy varied from 86% for FX-313 to 0% for `Floratam'. In a second field experiment, SCB damage was evaluated in 10 polyploid St. Augustinegrass genotypes. Damage varied from 90% for `Bitterblue' to 0% for `FX-10'. Oviposition rate was determined from SCB confined in the laboratory on genotypes from both field experiments. Oviposition rate differed among genotypes and predicted (P < 0.01; r2 = 0.67 to 0.79) field damage. To my knowledge, this paper is the first to report field resistance to the SCB in St. Augustinegrass, validating the use of laboratory bioassays.
Evaluation of an Enzyme-linked Immunosorbent Assay Method for Predicting Brown Patch Infection in Turf
Authors: Fidanza Michael A. , Dernoeden Peter H.
Published: February 2019

A field investigation was conducted during 1991 and 1992 to determine the effectiveness of enzyme-linked immunosorbent assay (ELISA) to predict brown patch (Rhizoctonia solani Kühn) infection events in `Caravelle' perennial ryegrass (Lolium perenne L.). Turfgrass samples were collected either between 7:00 and 8:00 am or 4:00 and 5:00 pm, and from plots mowed to a height of either 1.7 or 4.5 cm. Pathogen detection levels were generally higher in am-sampled turf and in plots mowed to a height of 4.5 cm. During 2 years, only 7 of 15 infection events were predicted from samples collected from high-cut turf and only three from samples collected from low-cut turf. While this technology is useful for confirming the presence of R. solani, it was unreliable for predicting infection events.
Sampling and Treatment Thresholds for Spider Mite Management in Field-grown Rose Plants
Authors: Karlik J.F. , Goodell P.B. , Osteen G.W.
Published: February 2019

Spider mites [including Tetranychus pacificus McGregor (Pacific mite) and T. turkestani Ugarov & Nikolski (strawberry mite)] are the most important invertebrate pests of the roses (Rosa hybrida) grown in Kern County, Calif. (the major production area in the United States). However, sampling methods and treatment thresholds have been subjective. A rapid presence–absence field sampling method has been developed, and treatment thresholds for mites have been evaluated based on the method. Roses exhibit a higher tolerance for spider mite populations than previously thought.
Floral Biology and Embryo Development in Chestnut (Castanea sativa Mill.)
Authors: Botta Roberto , Vergano Grazia , Me Giovanni , Vallania Rosalina
Published: February 2019

Floral biology of chestnut, from sporogenesis to mature embryo, is described. Microsporogenesis in flowers of unisexual catkins occurred in the first week of June 1991. Anthesis started in mid-June (≈70 days after budbreak) and lasted 2 weeks. In mid-June, in each pistillate flower, six to eight styles began to emerge, and 4 to 7 days later, they were extended fully (i.e., full bloom). In each flower, 10 to 16 anatropous ovules developed from the ovary axis. The megaspore mother cell had formed by the end of bloom. The mature ovule consisted of two integuments and a long, narrow nucellus with a small embryo sac of the Polygonum type. Zygotes were found 15 to 20 days after pistillate flower full bloom. Embryo development followed the Onagrad type, Trifolium variation. Seeds attained full size in mid-September, and fruit were mature in early November. The embryonal axis averaged 4.5 mm long × 2.1 mm wide. An apical meristem and the radicle were evident at opposite ends of the axis.
Variation for Black Rot Resistance in Tronchuda Regenerated from Epicotyl Segments
Authors: Msikita W. , Wilkinson H.T. , Dias J.C. Silva
Published: February 2019

Tronchuda (Brassica oleracea var. tronchuda Bailey syn. costata) regenerants with resistance to Xanthomonas campestris pathovar campestris Pammel (Dawson) were produced by culturing epicotyl segments of 3-week-old seedlings on Murashige and Skoog medium supplemented with 2 mg BAP and NAA at 0.1 mg·liter–1. Cultures were placed in darkness (1, 2, or 3 weeks) or in a 16-hour·day–1 light regime. Seedlings of all four cultivars were more susceptible (mean disease severity rating of 3.8 to 4.0; where 1 = trace and 4 = more than 2 cm2 diseased leaf tissue) than the respective regenerants. There were significant differences in disease severity of regenerants among and within the four cultivars. Dark incubation of cultured explants generated plants with higher disease resistance than evident with control plants. One week of dark incubation resulted in increased resistance in regenerants of `Penca de Chaves', `Portuguesa', and `Vilinda' (2.1, 2.3, and 2.7 mean disease severity, respectively), whereas 2 weeks of dark incubation increased resistance in regenerants of `Ana Maria' and `Vilinda' (2.1 and 2.7 mean disease severity, respectively). The genotype×plant treatment interaction was significant. Chemical names used: 6-benzylaminopurine (BAP); a-naphthaleneacetic acid (NAA).
Plant Regeneration from Petioles of Kiwifruit Microshoots
Authors: González María Victoria , Rey Manuel , Rodríguez Roberto
Published: February 2019

A simple and reliable protocol for plant regeneration from petioles of micropropagated plants of kiwifruit [Actinidia deliciosa (A. Chev) Liang and Ferguson, var. deliciosa `Hayward'] is described. Morphogenic callus was initiated by culturing petioles taken from in vitro-propagated plants. From the media tested, Cheng's K(h) medium plus 0.1 μm IAA, 4.5 μm zeatin, and 2% sucrose was the best for callus induction, maintenance, and shoot bud formation and development. Bases of developed shoots were immersed in 5 mm IBA for 15 seconds; subsequent culture in half-strength K(h) basal medium achieved 82% rooting. Regenerated plantlets were successfully transplanted to soil with 97% survival. Chemical names used: indole-3-acetic acid (IAA); indole-3-butyric acid (IBA); 2-methyl-4-(1H-purin-6-ylamino)-2-buten-1-ol (zeatin).
In Vitro Rooting and Greenhouse Acclimatization of Lachenalia Shoots
Authors: Ault James R.
Published: February 2019

Shoot formation was obtained from Lachenalia arbuthnotiae W.F. Barker, L. bulbifera (Cyrillo) Engl., and L. purpureo-coerulea Jacq. leaf tissue explants cultured on Murashige and Skoog (MS) medium supplemented with sucrose at 30 g·liter–1, 8.87 μm BA, and 0.44 μm K-NAA. Shoots of all three species rooted on subculture to MS medium supplemented with 0.0, 4.14, or 8.29 μm K-IBA or 0.0, 4.46, or 8.92 μm K-NAA. Maximum percent rooting was ≈81% from treatment with 4.14 μm K-IBA for L. arbuthnotiae and with 8.29 μm K-IBA for L. purpureo-coerulea; it was 59% from treatment with 8.92 μm K-NAA for L. bulbifera. Rooted and nonrooted shoots were acclimatized in a greenhouse. Survival of rooted plants was 93% for L. arbuthnotiae, 95% for L. bulbifera, and 94% for L. purpureo-coerulea. Survival of nonrooted shoots was 71% for L. arbuthnotiae and 91% for L. bulbifera. Chemical names used: 6-benzyladenine (BA); potassium salt of indole-3-butyric acid (K-IBA); potassium salt of 1-naphthaleneacetic acid (K-NAA).
Bud Age Affects Sprouting and Flowering in Clementine Mandarin (Citrus reticulata Blanco)
Authors: Krajewski Andrew J. , Rabe Etienne
Published: February 2019

To investigate the effects of bud age on sprouting and flowering, bearing Clementine mandarin trees were hand-pruned at monthly intervals from late spring to fall. This pruning resulted in regrowth bearing axillary buds ranging in age from 9 to 5 months. After winter rest and during the return bloom, sprouting and flowering were assessed on axils on terminally positioned stems of these ages. The proportion of axillary buds sprouting and the number of spring shoots produced by each sprouting axillary site decreased with decreasing bud age. The proportion of axils sprouting one or more inflorescences, and the average number of flowers per stem also decreased with decreasing bud age. The number of axillary sites per stem, also significantly affected sprouting and flowering. Our results demonstrate the potential of hand-pruning to manipulate sprouting and return bloom depending on when in the summer or autumn the trees are pruned.
Nitrogen and Water Rates for Subsurface Trickle-irrigated Collard, Mustard, and Spinach
Authors: Thompson Thomas L. , Doerge Thomas A.
Published: February 2019

Three field experiments using subsurface trickle irrigation with various rates of target soil water tension (SWT) and N rates were conducted in southern Arizona during 1990–93. The experiments were conducted with collard (Brassica oleracea L. Acephela Group cv. Vates), mustard [Brassica juncea (L.) Czerniak cv. Southern Giant], and spinach (Spinacea oleracea L. cv. Indian Summer). The interactive effects of water and N treatments on crop yield, N uptake, and unutilized fertilizer N were studied. In general, excessive irrigation (SWT <5.6 kPa) resulted in lower yield and N uptake and higher unutilized fertilizer N. Optimum SWTs were 9 kPa for collard, 8 kPa for spinach, and 6 to 10 kPa for mustard.
Auxins, Salt Concentrations, and Their Interactions during in Vitro Rooting of Winter-hardy and Hybrid Tea Roses
Authors: Arnold Neville P. , Binns Michael R. , Cloutier Daniel C. , Barthakur Nayana N. , Pellerin Raymond
Published: February 2019

Auxins, medium salt concentrations, and their interactive effects on rooting of two winter-hardy roses (Rosa kordesii Wulff `John Franklin' and `Champlain') and two hybrid teas (Rosa hybrida `John Paul II' and `Landora') were studied. The auxins (in mg·liter–1) IAA (0, 0.3, 1.5, 3.0, 6.0, or 15.0), IBA (0, 0.1, 0.2, 0.5, 1.0, or 3.0), and NAA (0, 0.1, 0.2, 0.5, 1.0, or 3.0) each were combined factorially with modified Murashige and Skoog (MS) medium (1/4, 1/2, 3/4, and full MS concentrations) and were tested for optimal rooting response. `John Franklin', `John Paul II', and `Landora' rooted well with low or no auxin and medium to high salt concentrations. Optimum rooting for `Champlain' was achieved with high IAA and low salts or with intermediate IBA and NAA concentrations and low to medium salts. The interactive effects of auxins and medium salts for `Champlain' showed that as salt concentration increased, the amount of IBA or NAA required for optimal rooting also increased. The effects of auxins and medium concentrations on root counts per shoot were similar to those for percent rooting. Adding auxin to the medium reduced root length for all cultivars, but salt concentration had a minimal effect. Roots generally were shortest at the highest IBA and NAA concentrations. Salt concentration had little effect on root length. Chemical names used: 1H-indole-3-acetic acid (IAA); 4-(3-indolyl)-butyric acid (IBA); α-naphthaleneacetic acid (NAA).
Characterization of the Blunt Leaf Apex (bla) Trait in Cucumber
Authors: Hokanson Stan C. , Hancock James F. , Grumet Rebecca
Published: February 2019

A further characterization of the cucumber (Cucumis sativus L.) mutant `Wisconsin SMR-18' bla (blunt leaf apex) revealed a new character associated with the previously described leaf phenotype. The attachment of the blade to the petiole of bla plants is flat across, as opposed to the cordate or indented attachment in the wild-type `Wisconsin SMR-18' plants. The new character (truncate leaf base) was easier to score and becomes distinctive earlier in development than previously described leaf apex characters. It was expressed consistently in homozygous bla plants. Segregation analysis of 1159 F2 seedlings arising from self-pollinated `Wisconsin SMR-18' × `Wisconsin SMR-18' bla F1 plants suggested that the leaf base and leaf apex character were controlled by a single locus or two tightly linked ones with a maximum distance between the two of 0.03 cM. In a field study of growth and fitness characteristics, the two genotypes did not differ significantly for flower or fruit count. The similar flowering and fruiting characteristics, along with the reliable early occurring truncate character, likely will make the two genotypes useful for pollination and gene movement studies.