bluuebunny/crossref_metadata_2025 huggingface dataset:
The Use of RAPD Markers to Determine Parentage in Mangifera indica L.
Authors: Schnell R.J. , Ronningl C.M. , Degani C
Published: February 2019

To investigate the usefulness of RAPDs for determining parentage in mango, progeny arising from caged trees of the cultivars Keitt (FS1) and Kent (FS2) were analyzed. In the FS1, 110 bands were generated, of which 78 (70.2%) were repeatable. Of these 78 loci, 23 were variable and segregated 3:1 as expected. In the FS2, 142 bands were generated, of which 57 (40%) were not repeatable, 6 (4.2%) were present in the progeny but not in the parent, and 79 (56%) were repeatable. Thirty-nine of these loci were variable; however, only 21 segregated as expected. Apparently, the progeny arising from the caging of `Keitt' are the result of self-pollination, while those arising from caged `Kent' are not. The six bands found in the FS2 but not in `Kent' are reproducible and, along with the 46% anomalous segregation, indicate that cross-pollination did occur. The implications for mango breeding efforts are discussed.
Comparison of Four Pistachio Rootstocks in California
Authors: Ferguson Louise , Beede Robert
Published: February 2019

Currently, the California pistachio industry relies on four rootstocks: two species and two interspecific hybrids—P. atlantica, P. integerrima, P. integerrima × P. atlantica, and P. atlantica × P. integerrima. The first three are open-pollinated, the last is the result of a closed pollination. The objective of these long-term trials is to compare rootstock behavior in the three major pistachio-producing regions of California. Three trials of 100 replications consisting of one of each of the four rootstocks were established in the three major growing regions of California in 1988. All the rootstocks in all three locations were budded with buds from the same female and male trees. Thus, all differences in performance are the result of rootstock or local climate. Results thus far demonstrate that rootstocks with P. atlantica as the maternal parent are more cold tolerant; more efficient in boron, zinc, and copper uptake; less vigorous; less precocious; and more susceptible to V. dahliae than rootstocks with P. integerrima as the maternal parent. The results also demonstrate that pistachios in California's southern San Joaquin Valley will bear 1 year ahead of pistachios in the central San Joaquin Valley or the northern Sacramento Valley. Trees on rootstocks with P. integerrima parentage also bear earlier than trees on P. atlantica and have higher yield efficiencies. All are colonized by vesicular–arbuscular mycorrhizae.
A Comparison of Fatty Acids of Cultivated Opuntia Species
Authors: Kuti J.O.
Published: February 2019

Seeds and cladodes (stems) of cultivated Opuntia species were analyzed for fatty acids using gas chromatography. The major fatty acids found in the cladode tissues were myristic (14:0), palmitic (16:0), stearic (18:0), arachidic (20:0), and behenic (22:0). The seeds contained predominantly palmitic, stearic, and behenic acids. Significant differences, both in content and composition of fatty acids, exist among the species so that fatty acid profiles may be useful as taxonomic markers for the differentiation of cultivated Opuntia species.
Isozyme Polymorphism and Inheritance in Rhipsalidopsis and Schlumbergera (Cactaceae)
Authors: O'Leary Maureen C. , Boyle Thomas H.
Published: February 2019

Cultivars and seedlings of Rhipsalidopsis and Schlumbergera were subjected to isozyme analysis using seven enzyme systems [aspartate aminotransferase (AAT), aminopeptidase (AMP), glucose-6-phosphate isomerase (GPI), malate dehydrogenase (MDH), phosphoglucomutase (PGM), shikimate dehydrogenase (SKD), and triose phosphate isomerase (TPI)]. Isozymes were extracted from phylloclades and roots, and were separated by polyacrylamide gel electrophoresis (PAGE) using single percentage (5% to 10%) gels. Six enzymes exhibited polymorphism in Rhipsalidopsis, whereas all seven enzymes were polymorphic in Schlumbergera. Inheritance studies were performed on AAT, GPI, MDH, PGM, and TPI for Rhipsalidopsis and on AMP, PGM, and SKD for Schlumbergera. Significant segregation distortion was observed in some families. Polymorphic isozymes are potentially useful markers for cultivar identification and for genetic and breeding studies.
Nutrient Uptake and Growth of Roses in Recirculating and Nonrecirculating Systems
Authors: Tsujita Masaru J. , Roberts G.L.
Published: February 2019

This study compared the growth and nutritional status of three rose cultivars (`Jacaranda', `Osiana', `Kardinal') in recycled and non-recycled nutrient systems. The recycled treatment was maintained at an electrical conductivity of 1.8 mS·cm–1 throughout the three crop cycle experiment, whereas the non-recycled treatment allowed the 1.8 mS·cm–1 solution to drain off the troughs. All plants were grown using hydrokorn substrate in 12-liter pots at a temperature of 18C night and 22C day under 24 h supplemental lighting. The first crop cycle showed very little difference in plant growth parameters and foliar nutrient content between the two nutrient delivery methods. By the end of the second crop cycle, foliar N and P were lower in the recycled treatment. Foliar macronutrient concentration was lower in the recycled treatment. By the end of the third crop cycle, plants were visually less vigorous in the recycled treatments. Chloride accumulated in the recycled solution and reached 17 mg·liter–1 by the third crop cycle. Flower yields were lower for `Jacaranda' and `Osiana' in the recycled treatment. Vase life and water uptake of the cut flowers did not differ between the two treatments.
An Indication for Suitability of Bark for Use in Potting Mixes
Authors: Reddy Shiv K.
Published: February 2019

Various barks, aged and composted to different degrees, are used in potting mixes. These differences have different effects on plant growth. It was observed that electrical conductivities (ECs) of the bark mixes that reduced plant growth were lower when compared to the ECs of the mixes that did not reduce growth, despite the same fertilization. This difference in EC diminished over time, differently for different barks. The decrease in EC was mainly due to a decrease in N. Apparently, nutrients were adsorbed or immobilized, which decreased their availability to the plants. This observation may be used to assess the suitability of a bark. The relative decrease in EC or N of similarly fertilized bark mix vs. no bark, peat mix (that does not reduce EC) may indicate the relative unsuitability of the bark, as related to nutrition. The amount of decrease in EC may also indicate the amount of additional fertilization to be provided to the bark mix during its use. The same method may also be applicable to other wood wastes, such as kenaf, sawdust, etc.
Timing is Crucial for Plug Seedling Soil Testing
Authors: Compton Amy J. , Nelson Paul V.
Published: February 2019

Soil and tissue standards and procedures have not been developed for plug seedlings. Turn-around time for foliar analysis is often adversely long for timely crop corrections. Visual assessment occurs after damage has occurred. Many plug growers have tried but abandoned soil testing due to erratic results. Of the three monitoring systems, soil testing offers the best potential, but can it be effectively refined for plugs? Petunias were grown in 288-plug trays under six fertilizer regimes. Fertilization or waterings were applied at 9:00 am, and 1 hour later, soil solutions were squeezed out and analyzed. Soil levels after fertilization and watering were too variable to inscribe a curve, while levels after fertilization formed a curve consistent with growth of the seedlings. Twice, soil samples were taken 1, 4, 8, and 24 hours after a fertilizer application. Some soil solution concentrations 1 and 4 hours after fertilization were 51 and 36 ppm for NH4-N, 46 and 32 ppm for PO4-P, and 147 and 84 ppm for NO3-N, respectively. Soil testing can be used for plug production, but samples must be taken after a fertilizer application and at a specified length after the application.
Nitrogen Nutrition of New Guinea Impatiens and Spathiphyllum in a Subirrigation System
Authors: Kent Matthew W. , Reed David Wm.
Published: February 2019

Greenhouse cultural methods must change rapidly to minimize runoff and to keep pace with environmental regulation aimed at protecting water resources. Two experiments were designed to investigate the effect of N fertilization rate on New Guinea impatiens (Impatiens ×hawkeri) and peace lily (Spathiphyllum Schott) in an ebb-and-flow subirrigation system. Maximum growth response for impatiens was centered around 8-mM N levels as measured by root and shoot fresh and dry weight, height, leaf number, leaf area, and chlorophyll concentration. For peace lily, growth peaked around 10 mM N. Growing medium was divided into three equal layers: top, middle, and bottom. Root distribution favored the middle and bottom layers, and the relative distribution of roots was consistent as N level increased. Soluble salts remained low in middle and bottom layers at N concentrations below 10 mM, but increased significantly for all soil layers at levels above 10 mM. The top layer contained two to five times higher soluble salt levels than in the middle or bottom layers at all N levels. Increased nitrate concentration mimicked increases in soluble salts, while pH decreased as N concentration increased for both impatiens and peace lily.
Nitrogen Uptake and Growth Response to Short Periods of Low Nitrogen by Two Bedding Plants
Authors: Cox Douglas A.
Published: February 2019

`First Lady' marigold (Tagetes erecta L.) and `Selenia' New Guinea impatiens (NGI; Impatiens sp. hyb.) were grown in solution culture for 60 days. At 10-day intervals, plants received low N for 10 days (marigold) or 20 days (NGI). Low-N treatment was 5% and 10% of the control, respectively, for marigold and NGI. After each low-N period, FW of treated and control plants was measured and N uptake by the controls was determined by solution depletion. Nitrogen uptake by marigold reached a peak 40 days after planting, and then decreased somewhat during the final 20 days of the experiment. In contrast, N uptake by NGI increased gradually after planting, reaching its highest level at the end of the experiment (60 days). Low-N periods 10 to 20 and 20 to 30 days after planting reduced the FW of marigold about 35% vs. control. FW reductions resulting from earlier or later low-N periods were much smaller or did not occur. Reductions in NGI FW resulted from low-N periods 20 to 40, 30 to 50, and 50 to 60 days after planting. While short periods of low N reduced the growth of both species, these reductions were desirable and not excessive, and no foliar symptoms of N deficiency were apparent at any time. Results of these experiments have implications for efficient fertilizer use and growth suppression using short periods of low nutrition.
Effect of Selected Iron Sources on Chlorosis of Pin Oak
Authors: Husain Javed , Khatamian Houchang , Long C.E.
Published: February 2019

One-year-old, nursery-grown pin oak seedlings were planted in 25 × 10-cm plastic containers filled with silica sand. Plants were placed under greenhouse environment and fed every 3 days with 10, 20, and 30 ppm elemental Fe from FeEDTA, FeDTPA, FeEDDHMA, and FeSO4. Two other treatments were Hoagland solution at normal pH and at pH 8.5. The control consisted of Hoagland solution without Fe. The pH of the nutrient solutions was maintained at 8.5 throughout the experiment. At the end of the growing season, leaves were visually rated (VR) for Fe chlorosis and saved for foliar Fe, Ca, and Mg analysis. There was no correlation between leaf Fe content and degree of chlorosis. FeEDDHMA at 10, 20, and 30 ppm; FeSO4 at 10 ppm; FeEDTA at 20 and 30 ppm; FeDTPA at 30 ppm; and Hoagland solution at pH 8.5 resulted in lower leaf chlorosis than the control. There was no difference in foliar VR among the Fe sources.
Is the DIF Technique Suitable for the Italian Climate
Authors: D'Angelo Giovanni , Frangi Piero , Verga Pierluigi
Published: February 2019

In Northern Italy, two trials have been performed on Lilium and poinsettia cultivars to control plant height by day–night temperature regimes. Two identical glasshouse compartments have been used for the experiments: one maintained at standard conditions (the same minimum and ventilation temperatures during day and night), the other with minimum day temperature lower than night. Cultivations of lilies and poinsettias started in Winter and Summer 1993, respectively, with different climate conditions (cold in winter and hot in summer). Results on Lilium indicated that a good control of greenhouse temperature can be achieved in Italy's winter climate, even on sunny days; the best height reduction (30%) was obtained on Lilium longiflorum cv. `White American', compared to other Lilium species. Test on poinsettia have been based mainly on controlling ventilation of the glasshouse to raise temperature in the first part of the night and to lower it during the first daytime hours.
The Effect of Cold–Warm (5 to 20C) Stratification and Light on Germination and Cotyledon Emergence in Trillium grandiflorum (Michx.) Salisb.
Authors: Solt Stephanie , Pellett Norman
Published: February 2019

In nature, Trillium seeds are reported to take 2 years to germinate, the radicle emerging the first year and the cotyledon the second year. The accepted stratification treatment has been a sequence of cold–warm–cold–warm. Our objective was to determine the temperature sequence and length of cold needed for optimum germination and the effect of light on cotyledon emergence. In the initial experiment, the seeds were subjected to either a warm–cold–warm–cold or a cold–warm–cold–warm regimen in a moist environment. Germination occurred after the first cold period and cotyledons emerged 7 weeks later. In a second experiment, seeds were subjected to various lengths of cold and the presence or absence of light during the following warm period. An 83-day cold period resulted in 79% germination and a 76-day cold period resulted in 53% germination. Light had little or no effect on cotyledon emergence.
Determining the Critical Photoperiod for Flowering of Several Herbaceous Perennial Species
Authors: Runkle Erik S. , Heins Royal D. , Cameron Arthur C. , Carlson William H.
Published: February 2019

Twenty-four herbaceous perennial species were treated at 5C for 0 or 15 weeks. Critical photoperiods for flower initiation and development with and without a cold treatment were determined. Photoperiods were 10, 12, 14, 16, and 24 h of continuous light and 9 h plus a 4-h night interruption. Continuous photoperiodic treatments consisted of 9-h natural days extended with light from incandescent lamps. Response to cold and photoperiod varied by species; Scabiosa caucasica `Butterfly Blue' flowered without a cold treatment under all photoperiods after 8 to 10 weeks of forcing, but plant height increased from 14 to 62 cm as daylength increased. Rudbeckia fulgida `Goldsturm' flowered without cold after 13 to 15 weeks of forcing, but only under 16 hours of continuous light and night interruption treatments. Heuchera sanguinea `Bressingham Hybrids' did not flower without cold under any photoperiod but did flower under all photoperiods with cold. The only Lavendula angustifolia `Munstead Dwarf' plants that flowered without cold were those under 24-h continuous light; ≈60% flowered. After cold, some lavender plants flowered under all photoperiods, and the flowering percentage increased with increasing daylength.
The Shoot Apex (Vegetative or Generative) of Heliconia bihai and H. latispatha in Relation to Growth
Authors: Maciel Norberto , Rojas Eybar
Published: February 2019

The shoot apex from plants of Heliconia bihai (L.) L. and H. latispatha Benth. growing under natural inductive conditions, and two shade-loving (60% and 0%) at different growth stages (one to six or eight expanded leaves) was studied. Observations were made using a light microscope, in 15-μm-thick sections. The analysis included changes in 1) size and shape of the meristem, 2) shape, ubication of new leaves, spathes, and flowers in the apex, and 3) relation between these characteristics, the condition of the apex (vegetative, transitional, and generative), and the plant growth stages. The anatomical structures of the shoot apex (meristem, leaves, and flowers primordias) are illustrated by photomicrographs. The meristem change in size and shape with grow up expanded leaf number. The condition of the apex was related to the total leaf number. The total leaf number was five or six in H. bihai under 60% and 0 % shade levels and 8 in H. latispatha at both shade levels. The apex reaches the generative stage when the plant has a minimum expanded leaf number of four (at 60 % shade) and five (0 %) in H. bihai and five in both shade conditions in H. latispatha. After this, the inflorescence started progressively to raise above the rest of rhizome.
Influence of Daylength Delivery on Flowering in Several Herbaceous Perennial Species
Authors: Hamaker Cheryl , Carlson William H. , Heins Royal D. , Cameron Arthur C.
Published: February 2019

To determine the most effective lighting strategies for flower induction of long-day (LD) plants, 10 species of herbaceous perennials were chilled at 5C for 0 or 12 weeks and then forced at 20C under the following photoperiods: short day, 4-h night interruption (4-h NI), 7-h night interruption (7-h NI), 7-h day extension, 7-h predawn (7-h PD), and 24-h continuous light (24-h). All treatments consisted of a 9-h photoperiod of sunlight supplemented with 90 μmol·m–2 from HPS lamps. LD treatments were delivered by incandescent lights and induced flowering in obligate LD plants. Rate of flowering, height, and bud number at first flower varied among species and LD treatments. Although flowering was accelerated under 24-h and 7-h NI for most species, it was delayed under 24 h for Coreopsis verticillata `Moonbeam' and Campanula carpatica. For unchilled plants of most species, flowering was delayed under 7-h PD compared to other LD treatments. Chilling decreased time to flower and reduced differences between LD treatments. Coreopsis `Moonbeam' and C. Ianceolata `Early Sunrise' were shorter when grown under 4-h NI.
Comparison of Nine Native Grasses Grown on Sludge Applied Soil
Authors: Kocsis Erika N. , Hooks Ronald F. , McCrimmon James N.
Published: February 2019

The use of grasses native to New Mexico are preferred for revegetating Albuquerque's sewage sludge disposal site. A greenhouse study was conducted to determine the most appropriate grass species that could be used in revegetation. Nine grasses grown in soil collected at Albuquerque's sludge disposal site were compared based on germination measurements, including plant height and density. Final shoot and root weights also were taken for comparison. Plant tissue was analyzed for the accumulation of metals and salts. With 200 ml of water applied weekly, plant height was greatest in spike dropseed (Sporobolus contractus A. S. Hitchc.) at 33.86 cm; plant density was greatest in alkali sacaton (Sporobolus airoides Torr.). Results indicate the grasses that have the best potential for use in revegetation are blue grama [Bouteloua gracilis (H.B.K.) Lag. ex Griffiths], sideoats grama [Bouteloua curtipendula (Michx.) Torr.], and alkali sacaton.
Branching Architecture of 3-year-old Plantation-grown Micropropagated Silver Maple
Authors: Preece J.E. , Huetteman C.A. , Adams R.G. , Ashby W.C. , Roth P.L.
Published: February 2019

Whole-tree branch architecture was quantified by counting and measuring the lengths of main stems, basal branches, and all primary (1°), secondary (2°), and tertiary (3°) branches. Trees were grown in replicated clonal plantations established in 1991 on a southern Illinois lowland and an upland site. Fifty-two clones in each of five complete blocks were measured from each plantation. Number of primary branches that formed in 1991, 1992, and 1993, and the number of nodes in the terminal meter of growth were highly significant for silver maple provenance and for clones (four clones for each of 13 provenances), except that clonal differences were nonsignificant for the number of 1° branches on 1991 wood. There were significant effects of provenance and clone on total number and the various sizes of 2° and 3° branches. Generally, a greater number and longer length of 2° and 3° branches formed on trees from the more rapidly growing southern provenances.
Expression of Soluble and Wall-bound Acid Invertases in Different Tissue of Lilium longiflorum Flower Buds
Authors: Ranwala Anil P. , Miller William B.
Published: February 2019

In mature Lilium longiflorum flower buds, anther and stigma had the highest soluble acid invertase activity [3.29 and 2.31 μmol of reducing sugars (RS)/min per gram of fresh weight (FW), respectively] compared to style, ovary, petal, and filament with activities of 1.52, 1.08, 0.99 and 0.98 μmol RS/min per gram of FW, respectively. DEAE-sephacel chromatography revealed that invertase activity in petal, ovary, style, and stigma was composed exclusively of invertase II and III isoforms. Anther invertase was mainly invertase I with small amounts of invertase II and III. Filament tissue mainly had invertase II and III isoforms with a small amount of invertase I. Wall-bound invertases were extracted with 1.0 m NaCl. Anthers had the highest wall-bound invertase activity (4.42 μmol RS/min per gram of FW) followed by stigma (0.42 μmol RS/min per gram of FW). Other tissues had low wall-bound invertase activity (<0.1 μmol RS/min per gram FW). For further purification, the binding of soluble invertases to nine different reactive dyes was investigated. Invertase I was bound to Reactive Green 5, Reactive Green 19, and Reactive Red 120 columns and was eluted with 0.5 m NaCl, resulting in increase in specific activity ≈10-fold with ≈70% recovery. Invertase II and III bound only to Reactive Red 120. Elution with 0.5 m NaCl resulted in an ≈6-fold increase in specific activity.
Fertility Studies on Brassicas Grown in Acid Soils
Authors: Lee Gail S. , Teague Tina G.
Published: February 2019

In soils that can range in pH from the low 4's to 7, depending on the location and liming history, deficiency of Zn, B, and Mo coupled with the soil acidity complex of Mn toxicity had been previously identified as severe limiting factors in producing quality Brassica crops. Fertility studies on fall and spring planted Brassicas focused on the effect of including/not including micronutrients during various phases of growth when NPK preplant fertilizer was reduced. Differential responses to reduction in preplant NPK and applications of micronutrients was found to be dependent on planting time (fall or spring), species of Brassica planted and cultivar. Nutrient uptake in leaf blades and petioles was followed. In broccoli timing of micronutrient applications significantly affected the harvest period length. Broccoli final yields of the B, Zn and Mg treatments were found to contribute ≈75% to 80% of the final yield of a full range micronutrient solution.
Effect of Composts and Synthetic Nitrogen Fertilizer on Growth and Nematode Infestation in Lettuce and Basil
Authors: Valenzuela Hector R. , Hamasaki Randall
Published: February 2019

Experiments were conducted to evaluate the effect of two different compost materials and several compost: synthetic N fertilizer ratios on the growth, yields, and nematode infestations in head and semi-head lettuce, and basil. Treatments were homemade compost at 25 MT/ha, Amend compost at 25 MT/ha, N alone at 150 kg·ha–1, and Amend compost at 25 MT/ha plus 0, 100, 200 or 300 kg N/ha. The basil trial followed the lettuce experiment on the same treatment beds to evaluate the long-term effects of compost applications. Compost plus 100 kg N/ha resulted in the greatest yields of 12 to 24 MT/ha for the semi-head and head lettuce trials, respectively. Basil was harvested for 6 months during a 10-month growth cycle. Highest basil yields of 64 MT/ha and canopy growth were obtained with a combination of compost plus synthetic N fertilizer, with 300 kg N/ha required for maximum yields during the 6-month harvesting period. By the last sampling date nematode counts were lowest for plots that received compost treatment alone and highest for the controls and for plants receiving synthetic N fertilizer alone.
In Situ Chlorophyll Fluorescence Determinations on Vegetable Crops in the Tropics
Authors: Valenzuela Hector , Riede Stacy , Yamamoto Harry
Published: February 2019

Portable chlorophyll fluorometers have made it possible to evaluate the photosynthetic efficiency of photosystem 11 for vegetable crops under ambient conditions. A sampling protocol was first established to eliminate variability due to positioning of the fiber optics in relation to the leaf, leaf selection, and natural environmental variability. Fluorescence parameters of the quantum yield of noncyclic electron transport (DF/Fm') and electron transport rate (ETR) were taken from several economically important vegetables under ambient conditions between 11 and 14 h. The objective of the second part of the study was to conduct in situ chlorophyll fluorescence and biomass determinations as affected by salt stress and N deficiency. DF/Fm' and ETR were studied in rhizobium inoculated, noninoculated and inorganic N-fed soybean and differences in fluorescence were related to yield. The influence that salt stress, and several N rates have on fluorescence photochemical quenching (qP) and nonphotochemical quenching (qN), NPQ ([Fm-Fm']/Fm'), DF/Fm' and ETR for hydroponically grown lettuce will also be presented.
Influence of Phosphorus on Gas Exchange and Plant Development and Nutrient Uptake of Chile Ancho and Bell Pepper Plants
Authors: Davies Fred T. , Duray Sharon A. , Phavaphutanon Lop , Stahl Randy
Published: February 2019

In two separate experiments, the influence of phosphorus nutrition on gas exchange, plant development, and nutrient uptake of Capsicum annuum chile ancho `San Luis' and bell pepper `Jupiter' plants were studied. Plants were fertilized weekly using 250 ml of a modified Long–Ashton solution (LANS) containing 0, 11, 22, 44, 66, or 88 μg P/ml. Phosphorus stress was evident with both pepper cultivars at 0 and 11 μg P/ml, with reduced plant growth and development: leaf number and area, fruit, leaf, stem, root, shoot, and total plant dry weight. The root: shoot ratio was greatest at 0 μg P/ml, reflecting greater dry matter partitioning to the root system. Greater phosphorus stress occurred at 0 μg P/ml in `San Luis' compared to `Jupiter' (88% vs. 58% reduction in total plant dry weight compared to optimum P response). `San Luis' was also more sensitive to phosphorus stress at 11 μg P/ml than `Jupiter' as indicated by the greater reduction in growth responses. With increasing P nutrition, leaf tissue P increased in both cultivars with maximum leaf tissue P at 88 μg P/ml. In `San Luis', there were no differences in tissue P between 0 and 11 μg P/ml plants, whereas 0 μg P/ml `Jupiter' plants had the lowest tissue P. Low P plants generally had the highest tissue N and lowest S, Fe, Mn, Zn B, Mo, and Al. With both cultivars, gas exchange was lowest at 0 μg P/ml, as indicated by low transpiration (E), stomatal conductance (gs), and net photosynthesis (A). Internal CO2 (Ci) and vapor pressure deficit were generally highest at 0 μg P/ml, indicating that Ci was accumulating with lower gs, E, and A in these phosphorus-stressed plants. Generally, no P treatments exceeded the gas exchange levels obtained by 44 μg P/ml (full strength LANS) plants.
Shredded Tire Rubber as a Medium Amendment for Container-grown Greenhouse Plants
Authors: Zhao Xiaomei , Kingery William L. , Newman Steven E.
Published: February 2019

Media blends containing 25%, 40%, and 50% shredded tire rubber were compared to two commercial media, Baccto Grower's Mix and Ball Peat-Lite Mix, to evaluate its potential as a container medium amendment for container-grown greenhouse plants. Salvia splendens `Red Hot Sally' and Vinca rosea `Cooler Peppermint' grown in 25% rubber were marketable with growth similar to or superior to those grown in the commercial media. Exacum affine `Little Champ', Vinca rosea `Cooler Grape', Tagetes erecta `Discovery Yellow', and Begonia semperflorens `Vodka' grown in 25% rubber were of marginally acceptable quality. Plants grown in 40% or more rubber were shorter and chlorotic compared to those in the commercial media. Exacum affine grown in 40% or more rubber contained high levels of zinc, which may have been linked to the chlorosis and growth reduction. Rubber reduced media water-holding capacity, while cation exchange capacity and pH were not affected.
Rose Response to Nutrient Recirculation and High-pressure Sodium (HPS) Radiation
Authors: Moodv D. Sean , Hopper Douglas A.
Published: February 2019

Four cut rose cultivars (`Royalty', `Samantha', `Sonia', and `Gabriella') were exposed to supplemental radiation for 2 years of production at the W.D. Holley Plant Environmental Research Center (PERC) at Colorado State Univ. and 1 year at Jordan's Greenhouse (cultivars Royalty and Kardinal). At PERC the house was divided into two treatments: l) natural light, and 2) supplemental radiation at ≈100 μmol·m–2·s–1 (750 fc) from 1000-W high-pressure sodium (HPS) lamps for 10 h each night. Jordan's had a third treatment of supplemental radiation at ≈50 μmol·m–2·s–1 (400 fc). Nutrient solution recirculation was tested with one bench in each of the treatments. Each rose was counted and measured for stem length and fresh weight. At PERC, all the cultivars showed no significant differences in the weekly number of flowers produced or the total flower fresh weight when grown under nonrecirculation vs. recirculation of nutrient solution. From 1993 results, grade A production for 60 `Royalty' plants increased from 455 flowers under natural conditions to 522 flowers under lighted conditions over 7 months, a 97-flower increase (21%) due to lighting.
Source Variation in Chemical Characteristics of Coconut Coir Dust
Authors: Konduru Sreenivas , Evans Michael R. , Stamps Robert H.
Published: February 2019

Chemical characteristics of saturated media extracts of coconut (Cocos nuc L.) coir dust were determined from material from different sources (producers and countries) and were found to be source-dependent. For all samples tested, the pH was between 5.5 and 6.6, and the electrical conductivity ranged from 0.2 to 2.4 cm–1. Nitrate-N levels were between 0.3 and 8 ppm, and ammoniacal-N levels were 0.2 ppm or less. Calcium and Mg levels ranged from 1 to 24 and 1 to 3 ppm, respectively. Potassium and Cl levels ranged widely from 16 to 686 and 24 to 600 ppm, respectively. Sodium levels were between 28 and 53 ppm. The levels of B, Cu, Fe, Mn, and Zn were <1 ppm. Although there were significant differences between producers within a country, sources originating from different countries were found to have the greatest differences in chemical characteristics.
Effect of Iron Concentration on Growth and Phylloclade Edge Yellowing of Holiday Cactus.
Authors: Ramirez Dario , Lang Harvey J.
Published: February 2019

Production of holiday cactus has been limited by the common occurrence of marginal chlorosis of the phylloclades, which can lead to losses in crop quality. This work was conducted to determine if poor growth and phylloclade yellowing could be correlated to applied Fe concentration. Rooted cuttings of Schlumbergera truncata `White Christmas', `Twilight Tangerine', 'Christmas Charm', and `Lavender Doll' were transplanted into a modified Hoagland's solution, adjusted to a pH of 6.3, containing Fe-EDTA at either 0,10,20,30, or 40 mg·liter–1 Fe. Plants were grown in a controlled environmental chamber under 16 h daylength for 16 weeks at 22/18C day/night temperature. Plants grown under 0 and 10 mg·liter–1 Fe had significantly greater fresh weight, height, and root length than plants grown under higher Fe concentrations for all cultivars. Comparison of tissue analysis results revealed a direct correlation between poor growth and levels of Fe within the tissue. There was no correlation, however, between Fe concentration and phylloclade edge yellowing, as yellowing occurred sporadically in all treatments. Comparison studies in the greenhouse of plants grown in peat: perlite medium showed similar trends.
ROSESIM Restructured To Accept Full Quadratic Polynomial Coefficients and Daily Step Input
Authors: Hopper Douglas A. , Cifelli Kevin
Published: February 2019

An interactive simulation model of plant growth must be flexible to accept specific crop equations from the user. ROSESIM functions as a dynamic plant growth model based on `Royalty' rose (Rosa hybrida L) response to 15 unique treatment combinations of photosynthetic photon flux (PPF), day temperature (DT), and night temperature (NT) under constant growth chamber conditions. Environmental factors are assumed constant over an entire day. Coefficients are read from an external ASCII file, thus permitting coefficients from any linear, quadratic, or interaction terms to be input into ROSESIM up to a full quadratic model form. Nonsignificant terms are given a coefficient of zero. ROSESIM has been restructured into Borland C++ object oriented program (OOP) code to execute in the Microsoft Windows 3.1 operating environment. This enables ease of operation in the user friendly graphical user interface (GUI) provided with most IBM personal computers (PC). The user chooses a set of environmental conditions which can be altered after any selected number of days, allowing conditions to be changed and modeled daily for interactive comparison studies.
Alternative Means of Thrips Control in Greenhouse Crops
Authors: McIntyre Julie A. , Hopper Douglas A. , Cranshaw Whitney
Published: February 2019

Various cultural, biological, and low toxicity methods of pest control that can be used as part of an Integrated Pest Management program for greenhouse growers were tested. Experiments were conducted to analyze alternative methods to control western flower thrips (Frankliniella occidentalis) on greenhouse crops, including an insect growth regulator (IGR), aluminized mulches, medial surface treatments involving irrigation, and predaceous nematodes. Persistence of thrips was determined by immersing excised flowers in 70% ethanol solution and pouring the extract through filter paper; thrips on the filter paper were counted. Various experiments were conducted over a 4-month period to determine which means provided the best control. The repeated use of an IGR was effective in reducing thrips populations. Preliminary evaluations indicate nematodes may provide better control than soil treatments.
`Annette Hegg Dark Red' Rootstock Reduces the Incidence of Poinsettia Bract Edge Burn on `Supjibi' Scions
Authors: McAvoy Richard , Bible Bernard , Singha Suman
Published: February 2019

The poinsettia cultivar Annette Hegg Dark Red (AHDR) is resistant to bract edge burn (BEB), while `Supjibi' readily develops BEB. In 1993, scions of both `Supjibi' and AHDR were grafted onto either `Supjibi' or AHDR rootstock (RS) prior to bract initiation. At anthesis, BEB symptoms were more prevalent on `Supjibi'/`Supjibi' than on `Supjibi'/AHDR. Four weeks postanthesis, 26.4% of the bracts on `Supjibi'/`Supjibi' developed BEB, and 10% of the bracts had severe symptoms (based on number and size of necrotic spots), while only 13.8% of the bracts on `Supjibi'/AHDR developed BEB, with 1.7% having severe symptoms. Calcium levels in `Supjibi' bracts averaged 0.41% for scions on `Supjibi' RS and 0.39% on AHDR RS. AHDR scions failed to develop BEB regardless of RS. In 1994, plants with a `Supjibi' scion on a dual RS (`Supjibi' + `Supjibi', or `Supjibi' + AHDR) were formed using an approach graft technique and the following treatments were applied: one RS severed before bract initiation to produce plants with just a `Supjibi' or AHDR RS, AHDR + `Supjibi' RS intact until anthesis then either the `Supjibi' or AHDR RS severed, or both RS remained intact until termination of the study. Scions with only AHDR RS during bract development or only AHDR RS after anthesis developed a lower incidence of BEB than bracts on `Supjibi' scions that were on just `Supjibi' RS during bract development, or just `Supjibi' RS after anthesis, or on both RS during the entire study.
Container Volume and Height Affect Shoot and Root Development in Marigold Seedlings
Authors: Marohnic Jennifer , Geneve Robert L.
Published: February 2019

Marigold seedlings were grown in four containers that differed in both volume and shape. Seedlings grown in 1.5-gal containers showed the greatest potential for shoot and root development 20 days after sowing. These seedlings had greater leaf area, shoot and root dry weight, and total root number and length compared to seedlings grown in 406 plug trays, 72-cell packs, or 6-inch containers. There was a positive correlation (r2 = 0.81) between cell volume and seedling growth as well as a positive correlation (r2 = 0.89) between container height with seedling growth. An attempt was made to separate the impact of container volume vs. container height on seedling growth. Containers were designed using acrylics to vary the container height while keeping the volume constant at 1500 cm3. There was a positive correlation (r2 = 0.87) between shoot and root dry weight with container height. The data suggest that both container volume and height contribute to overall seedling growth in marigold, but when container volume is not limiting, container height has a large impact on seedling development.
A “New” Method of Installing Prairie Forb Transplants
Authors: Kemery Ricky D. , Dana Michael N.
Published: February 2019

Fir seedling transplant containers were used as an alternative to conventional plug containers (72 per tray) in a system to grow seedlings of native prairie perennials and install them on a highway site in central Indiana. Plants grown in deep-tube fir-seedling containers exhibited greater fresh and dry weights than conventional plug transplants with no root circling. Results from survival data indicate that plants grown in fir seedling containers offer better chances of success on highway sites with low soil fertility and poor soil structure. A chronology of installation methods, tools, and mechanization possibilities is presented.
Effect of Hydration and Dehydration on Corn Seed Germination and Vigor
Authors: Fana Jian , Roos E.E. , Vertucci C.W. , Moore F.D.
Published: February 2019

Seed water content has been considered the most important factor controlling various physiological reactions in seeds. Hydration/dehydration affects many physiological reactions, including the “priming effect” and “accelerated aging,” depending on time and level of hydration. Corn seeds (11% mc) were subjected to six cycles of hydration (2 h) and dryback or one hydration of 12 h and dryback. Following soaking, seeds were dried quickly by using a fan to remove moisture and then equilibrated to their initial mc. Seeds were evaluated for germination and vigor (root length and leachate conductivity). Percent germination of seeds treated with either continuous or intermittent hydration and dehydration was >90%. Vigor of seeds hydrated for successive 2-h cycles initially increased (priming effect); however, after the sixth cycle, vigor was equal to the nontreated control seeds. One cycle of hydration for 12 h then dryback had no effect on germination but did increase vigor. We are now extending the number of 2-h hydration periods to 10 to determine when damage occurs from these cycles. Our objective is to better understand the relationship between seed hydration and physiological changes associated with seed priming, accelerated aging, and imbibition damage.
Establishment of Hawthorn Seedlings as Affected by Site of Antidessicant Application
Authors: Remmick Michael D. , Fuchigami Leslie H.
Published: February 2019

A film-forming antidesiccant (Moisturin-4; Burke's Protective Coatings, Washougal, Wash.), 1:1 (v/v) with water, was applied to dormant, bare-root, 2-year seedlings of Washington hawthorn (Crataegus phaenopyrum), a difficult-to-establish species. Antidesiccant applications were made to nonstressed controls or to stressed plants (13 h air-drying at 19C and 20% RH) either before or after drying. Antidesiccant was applied to stems only (SO), roots and stems (RS), or not at all (stressed controls). Three subgroups of treated plants were measured to assess changes in fresh weight (FW), xylem water potential (XWP), or specific conductivity (ks) of stems before stress, after stress, or 2 to 3 weeks following planting in the greenhouse. Applications of antidesiccant to SO allowed stressed plants to recover prestress levels of FW after 2 to 3 weeks, whereas stressed plants receiving the RS treatment did not fully recover prestress levels of FW. XWP of stressed SO plants tended to increase following outplanting. ks was highly variable, but tended to be higher in nonstressed plants. Nonstressed and SO seedlings had higher percentages of budbreak.
Effect of Different Levels of Blue-green Algal Extract on Somatic Embryo Elongation, Shoot Proliferation, and Root Formation of Five Pecan Cultivars
Authors: Allam Aida M.
Published: February 2019

Attempts to improve somatic embryogenesis of five pecan (Carya illinoinensis L.) cultivars using different levels of blue-green aIgal extract added to the media proved effective. WPM4-pecan media, containing 1.0 g malic hydrozide/liter and 30 g sucrose/liter, for embryo enlargement showed that the higher the extract concentration the longer the embryo harvested after 7 to 8 weeks of incubation at 22 to 25C. `Desirable' responded the best to the algal extract, where the percent elongation recorded was 129.1, 177.3, 174.2, and 200.6 for 0%, 1%, 2%, and 4%, respectively. Dessicating the embryos at 5C for 5 days enhanced the conversion on WPM4 conversion media containing silver nitrate and GA3. The number of normal shoots and roots was higher at 1% extract in cultivars Muhan, Elliot, and S-17, while the 4% algal extract was more effective for `Desirable' and `Shawnee'. Algal extract had no effect on media pH. Survival of converted embryos in the greenhouse was promising.
Factors Affecting the In Vitro Storage of Strawberry
Authors: Reed Barbara M.
Published: February 2019

Fragaria germplasm, stored at 4C as cold-hardened in vitro plantlets, was rated for condition on a 0–5 scale at 9, 12, and 19 months. Plants with ratings ≥2 were healthy enough to remain in storage. Benzyladenine (BA) at 0, 1, 2.5, and 5 μM and storage in darkness or with a 12-h photoperiod were examined for a group of four genotypes. Means of plant condition ratings over all treatments and genotypes were best (3.4) at 9 and 12 months and declined to 2.2 at 19 months. Increasing concentrations of BA were correlated with higher condition ratings compared to those without BA, and plants stored with a 12-h photoperiod had higher ratings than those stored in the dark. At 9 and 12 months, plants grown with BA and a 12-h photoperiod had the highest ratings. Five different Fragaria genotypes were used to study the effect of photoperiod and cold-hardening on condition ratings of stored plantlets. Cold-hardened plants had higher condition ratings (2.1) than those stored without cold-hardening (1.8). Plants stored with a 12-h photoperiod had higher mean condition ratings (2.2) than those stored in the dark (1.7). Storage with cold-hardening and a 12-h photoperiod resulted in improved plant condition. The extent of improvements was genotype-dependent.
Improved Plant Regeneration from Rosa xhybrida L. Leaf Explants
Authors: Singlachar Manoj , Tripepi Robert R. , George Mary W.
Published: February 2019

Attempts to regenerate plants from leaf explants of Rosa xhybrida L. on Murashige and Skoog medium have met with limited success. We report improved regeneration of somatic embryos and adventitious shoots from leaves of `Golden Emblem' on N6 medium. Leaf explants were obtained from microshoots that had been in culture for 4 years. Leaves were placed on N6 medium containing various combinations of 0, 0.4, or 1.0 μM 2,4-D and kinetin for 20 days with an initial dark treatment of 12 days, then transferred to a medium without plant growth regulator. Adventitious shoots and somatic embryos were observed 3 weeks after transferring to medium without plant growth regulators. Leaf explants placed on media without 2,4-D failed to form embryos or shoots. The best combinations of 2,4-D and kinetin (0.4 and 0.4 μM, 0.4 and 1.0 μM, or 1.0 and 1.0 μM) induced regeneration percentages ranging from 21% to 39%. N6 appears to improve regeneration of somatic embryos and adventitious shoots from `Golden Emblem' leaf explants, but the interaction between media formulation and duration of exposure to 2,4-D and kinetin needs to be examined.
Development of a Base Collection of Malus Germplasm with Cryopreserved Dormant Buds
Authors: Forsline Philip L. , Towill Leigh E. , Waddell John , Wiesner Loren
Published: February 2019

The USDA/ARS collection of Malus is held by the Plant Genetic Resources Unit in Geneva, N.Y. The collection comprises ≈2500 accessions, most of which must be maintained as clones in the field to provide propagating material for distribution to the user community. Field maintenance of replicated accessions places the collection at risk from weather extremes, pests, diseases, etc. and is extremely costly. Cryopreservation of dormant buds in a base, or backup, collection could reduce risks and decrease maintenance costs. Since 1988, we have developed and implemented protocols to cryopreserve dormant apple buds at the National Seed Storage Laboratory, Fort Collins, Colo. More than 500 accessions have been placed in cryogenic storage. Buds have been successfully recovered by grafting from >70% of the first 250 accessions cryopreserved. These results, and those from ongoing recovery tests, indicate cryopreservation may be a safe, cost-effective approach to back up collections of tree fruit germplasm. It also may be used to enhance management of the active collections of Malus, Vitis, and Prunus at Geneva.
Shoot Differentiation and Proliferation in Echinacea purpurea through Leaf Tissue Cultures
Authors: Hussaini Qudsia , Lee Chiwon W. , Ke Shanqiang
Published: February 2019

Leaf sections of Echinacea purpurea obtained from greenhouse-grown plants were cultured on Murashige and Skoog (MS) medium supplemented with 0.5 to 4.0 μM benzyladenine (BA) and 0.1 to 10.0 μM naphthaleneacetic acid (NAA). The efficiency of adventitious shoot formation from leaf explants varied depending on growth regulator concentrations. About 90% of leaf tissues cultured with 20 μM BA and 0.1 μM NAA produced shoot differentiation. Initially, the adventitious shoot buds were purplish-red in color; they turned to green shoots as young leaves began to unfold. The individual shoots, when excised and subcultured on the MS basal medium containing 10 μM gibberellic acid (GA3), produced 15 to 20 new shoots per culture within 4 weeks.
Gelling Agents Affect Adventitious Shoot Organogenesis in White Ash
Authors: Bates Sharon A. , Preece John E. , Yopp John H.
Published: February 2019

Dissected white ash seeds were placed on an agar-solidified MS medium with 10 μM TDZ and 1 μM 2,4-D (shoot initiation medium). After 4 weeks, explants were transferred to shoot elongation medium (3 μM TDZ, 1 μM BA, and 1 μM IBA) solidified with 0.7% Sigma agar, 0.525% agar + 0.05% gelrite, 0.35% agar + 0.1% gelrite, 0.175% agar + 0.15% gelrite, 0.2% gelrite, or no gelling agent (liquid medium). After 12 weeks in vitro, shoot growth and number were suppressed in cultures containing 0.2% gelrite (9.3 mm and 0.7 shoots) and in cultures containing no gelling agent (6.9 mm and 0.7 shoots). There were no differences in shoot growth and number in cultures containing 0.7% Sigma agar (2.2 mm and 16.5 shoots), 0.525% agar + 0.05% gelrite (2.6 mm and 18.7 shoots), 0.35% agar + 0.1% gelrite (1.6 mm and 17.4 shoots), and 0.175% agar + 0.15% gelrite (2.0 mm and 20.4 shoots). The most vitrification occurred in cultures on medium with the lowest amount of agar, gelrite only, and liquid medium.