bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of Root-media pH on Impatiens Shoot Micronutrient Concentrations
Authors: Biernbaum John A. , Argo William R.
Published: February 2019

Impatiens were planted in media containing either hydrated or carbonate dolomitic lime and subirrigated for 17 weeks using four irrigation water qualities (IWQ) and three water-soluble fertilizers (WSF). Micronutrients (Fe, Mn, Zn, Cu, B, and Mo) were incorporated into all root media at planting with fritted trace elements (FTE 555) at 0.07 kg·m–3 and were added to all WSF treatments with a commercially available chelated material (Compound 111) at a constant 50 mg·liter–1. Root-medium pH obtained from the various IWQ/WSF solutions at 4, 8, 12, and 17 weeks after planting were used to determine relationships with shoot tissue micronutrient concentrations. Tissue Fe concentrations decreased linearly as root-media pH increased from 5.0 to 8.5. Below pH 5.0, the tissue Fe concentration increased at a rate indicating greater nutrient availability in the root medium. However, between pH 4.0 and 7.5, tissue Fe was within acceptable levels. A linear relationship also was found with tissue Zn and B, but without the rate increase below a pH of 5.0. Tissue Mn decreased to a minimum as the rootmedium pH increased from 4.0 to 6.0 and increased again as the root medium pH increased from 6.0 to 8.5. Tissue Mo concentrations increased as root medium pH increased. Tissue Cu concentrations were unaffected by medium pH.
Nitrogen Fertilizer-use Efficiency in Two Woody Ornamentals
Authors: Devereaux Diana , Cabrera Raul I.
Published: February 2019

High levels of N are often used to produce a vigorous plant that is also aesthetically pleasing to the purchaser. Environmental concerns with the overuse of N raise the need to find the minimum N requirements necessary to produce a salable plant. Ilex opaca and Lagerstroemia indica plants growing in 1.5-gal containers were irrigated with nutrient solutions containing N concentrations of: 15, 30, 60, 120, 210, and 300 mg N/liter. After 4 months, data indicate that using solutions >60 mg N/liter for both plant species results in leachates with N concentrations higher than those in the applied solutions. Nitrogen leaching losses increased with applied N, ranging from ≈15% to 50% for the low and high treatments, respectively. Chlorophyll readings of leaf tissue were not significantly different for plants of both species receiving N solutions higher than 60 mg·liter–1. These results indicate that N levels lower than those typically used for production of these woody ornamentals will still produce salable plants while increasing N fertilizer-use efficiency.
Container Size Affects Ligustrum Growth and Nitrogen Use
Authors: Yeager Thomas H.
Published: February 2019

Three-month-old rooted cuttings of Ligustrum japonicum Thunb. were planted in a 2 pine bark: 1 Canadian peat: 1 sand substrate (by volume) in either 0.75- or 2.2-liter containers and grown for 17 weeks in a greenhouse. One-half of the plants grown in 0.75-liter containers were transplanted to 2.2-liter containers after 11 weeks and grown for 6 weeks in 2.2-liter containers. Shoot dry weights were highest for plants grown 17 weeks in 2.2-liter containers and smallest for plants grown 17 weeks in 0.75-liter containers. Root dry weights were similar for plants grown 17 weeks in 0.75-liter containers. The percentage of applied N used by shoots and roots (44% and 8%, respectively) was highest for plants grown 17 weeks in 2.2-liter containers and smallest (30% and 5%, respectively) for plants grown 17 weeks in 0.75-liter containers.
Physiological Responses of Intsia bijuga Trees to Drought Stress
Authors: Marler Thomas E. , Guzman Louann C.
Published: February 2019

Intsia bijuga is an important native tree on Guam, and is being promoted as an urban forestry tree. Container-grown I. bijuga trees were subjected to a drying cycle (50% of mean water loss replaced daily) to determine physiological responses to drought. Early to mid-morning gas exchange began to decline compared to well-watered plants on day 12, and quickly declined thereafter. Net CO2 assimilation (A) was close to zero by day 29 and became negative by day 36. Chlorophyll fluorescence of drought-stressed trees was not different from that of well-watered trees on numerous days of measurement throughout the drying cycle. Unlike leaflets of well-watered trees, leaflets of the stressed trees exhibited heliotropic movement to avoid direct exposure to the sun. The stressed trees did not respond with any change in osmotic potential of leaflets following rehydration. Carbon dioxide-use efficiency of stressed trees was reduced to 66% of well-watered trees. The most profound response following rewatering (day 37) was leaf shedding. All trees shed some leaves, and 33% of the trees shed the entire canopy. On the trees that retained some leaves, A returned to that of the control trees by day 13 of recovery.
Light Quality Initiating or Ending the Day Affects Internode Length in Petunia
Authors: Karlssonl Meriam , Nilsen Jarle
Published: February 2019

`Ultra Rose Star' petunia plants were germinated and grown at 21C. The study was initiated 26 days after seeding and the photoperiod was 15 h of light and 9 h of darkness. During the initial or ending 90 min of the light period, the plants were exposed to a light quality of a higher (≈2.0) or lower (≈0.8) red (R, 660 nm) to far red (FR, 730 nm) ratio than daylight (R: FR, ≈1.1). Flowering occurred within 65 days from seeding for plants in all treatments. Plants receiving a low R: FR during the initial 90 min of the day had similar internode lengths as those plants receiving a high R: FR at the end of the day. The average internode length of the main stem at flowering was 0.6 ± 0.08 cm for plants receiving a low R: FR in the morning or a high R: FR at the end of the day. In addition, the internodes of those plants exposed to a low R: FR in the morning were longer than on plants receiving a low R: FR at night or a high R: FR in the morning. The average internode length at flowering was 0.4 ± 0.08 cm for plants with an ending low R: FR or a beginning high R: FR light quality of the day.
Influence of Day and Night Temperature on Development of Sweet Pepper Seedlings
Authors: Si Yaping , Heins Royal D.
Published: February 2019

Sweet pepper (Capsicum annuum `Resistant Giant #4') seedlings were grown in 128-cell plug trays under 16 day/night temperature (DT/NT) regimes from 14 to 26C. In this temperature range, plant stem height, leaf unfolding rate, plant volume, internode length, stem diameter, leaf area, and shoot dry weight were primarily functions of average daily temperature (ADT). Internode length increased as ADT or the difference between day and night temperature (DIF) increased. The root-to-shoot ratio decreased linearly as DT increased and was not significantly affected by NT. Leaves were darker green under positive DIF than negative DIF temperature regimes. Increasing NT from 14 to 26C reduced the node at which the first flower appeared by an average of 1.2 nodes. Percent abortion of the first flower increased as DT increased. Plant quality, as defined by seedling index [(dry weight × stem diameter)/internode length], increased as DIF became more negative.
Compositional Nutrient Diagnosis of the P Status in Potato Crops
Authors: Assimiou Adou Rahim Alimi , Parent Léon E.
Published: February 2019

In Quebec, potato crops are largely grown on light acid soils altered by podzolization. In the plow layer, abundance of sesquioxides, low pH and low organic matter content produce high P-fixing capacity. Liming to pH not exceeding 5.6, organic matter additions and banding of P fertilizers are practices to improve the P status in the soil–plant system. Plant response to treatments could be diagnosed by yield evaluation and foliar analysis. Agricultural lime, dolomitic limestone and basalt were applied to an acid soil (pH 4.6). Ordinary superphosphate, biosuperphosphate, triple superphosphate, and diammonium phosphate impregnated with humic peat were banded at two rates. Highest tuber yield was 40 t·ha–1. There was no response to liming materials as pH did not exceed 4.9. There was a significant response to P fertilizers. Nutrient balance assessment of the foliage by Compositional Nutrient Diagnosis indicated a critical “d” value of 1.5 and a critical P index of 0.8.
Development of DRIS Nutrient Norms for Processing Tomato
Authors: Hartz T.K. , Miyao E. , Valencia J. , Mullen R.
Published: February 2019

Nearly 100 commercial processing tomato fields in California were sampled during 1993–94 with the objective of developing DRIS (Diagnosis and Recommendation Integrated System) nutrient norms. More than 30 farming operations and a wide range of soil types and conditions were included in the survey. Whole, recently mature compound leaves (blade + petiole) were collected at three growth stages: first bloom, main fruit set, and 10% to 30% red fruit. Fields were classified by fruit yield as high (>90 MT/ha) or low yield (<78 MT/ha); mean yield for these groups was 58 and 103 MT/ha, respectively. DRIS nutrient norms and nutrient ratios were calculated, by growth stage, for N, P, K, Ca, Mg, and S. Tissue concentrations of Zn, Mn, and Fe were so highly variable that meaningful ratios could not be achieved. DRIS norms varied substantially among growth stages, with K concentration declining precipitously, N and P declining modestly, and Ca, Mg, and S remaining relatively stable over the season. Evaluation of DRIS indices showed that ≈25% of low-yield fields exhibited serious nutrient imbalance. K was implicated as the most-frequently limiting nutrient.
Induced Iron Toxicity in Chinese Cabbage and Leaf Lettuce
Authors: Lee Kyu-Min , Lee Chiwon W. , Duysen Murray E.
Published: February 2019

The influences of elevated nutrient solution Fe++ concentrations on tissue iron contents and toxicity symptom development in Chinese cabbage and leaf lettuce were investigated. Seedling plants established in peat-lite mix in 15-cm plastic pots were fertilized with nutrient solutions containing 0 to 10 mM Fe++ for 6 weeks. Both Chinese cabbage and leaf lettuce produced dark leaf spots on plants grown with 5 mM or higher Fe++ concentrations. Biomass yields were reduced when leaf tissue iron contents in Chinese cabbage and leaf lettuce, respectively, were 551 mg·kg–1 and 379 mg·kg–1 or higher on a dry matter basis. In both species, tissue iron contents increased as the nutrient Fe++ concentration increased. Tissue iron contents in both species may be greatly enhanced to a certain level without causing plant toxicity by micronutrient fertilization.
The Effect of Liquid Nitrogen and Sulfuric Acid on Several Rubus Species
Authors: Peacock Derek N. , Hummer Kim E.
Published: February 2019

Many Rubus species have a seedcoat imposed exogenous dormancy. Our objective was to contrast the effect of liquid nitrogen (LN2), sulfuric acid (H2SO4), and an untreated control on seed germination of R. multibracteatus A. Leveille & Vaniot and R. parviflorus Nutt. and to determine if LN2 could be used as a mechanical scarifying agent for these species. Three replicates of 100 seeds of each species were treated with either three 3-min dips in LN2 with corresponding 10 min thaws or for 30 min with H2SO4 or were left untreated. The LN2 pretreatment did not significantly reduce the viability of R. multibracteatus or R. parviflorus as compared to the control. A random sample of germinated R. multibracteatus from the LN2 pretreatment showed normal seedling development upon planting. The H2SO4 pretreatment significantly increased germination percentages as compared to the control or LN2 pretreatment as well as for R. ursinus Cham. & Schldl. and R. eustephanus Focke ex Diels. The LN2 treatment did not significantly improve germination over the control group and therefore was not an effective scarifying agent as applied to R. multibracteatus or R. parviflorus. However, these two Rubus species were not damaged by repeated dips in LN2. Alternative LN2 pretreatments are being examined for their potential to improve Rubus germination further.
Effects of Salinity, Temperature, and pH on Germination of Echinacea angustifolia Seeds
Authors: Lee Kyu-Min , Hussaini Qudsia , Ke Shanqiang , Lee Chiwon W.
Published: February 2019

The influences of NaCl concentration, incubation temperature, and pH on the germination of Echinacea angustifolia seeds were investigated. Dehulled, surface-disinfected seeds were germinated in petri dishes containing 0, 0.5, 1, 1.5, 2.0, 2.5, 3.0, 3.5, or 4.0 g–liter–1 NaCl at 12, 17, 22, or 27C for 10 days. Percent seed germination was the highest at 0 ppm NaCl and was progressively reduced as NaCI concentrations increased to 4 g–liter–1 at all temperatures. The NaCI suppression of germination was most severe when seeds were incubated at 27C. No germination occurred at 12C. When seeds were germinated over a pH range from 4 to 11, the highest percent germination occurred at pHs between 6 and 8 at 25C.
In Vitro Regeneration of Trichosanthes from Shoot Tips
Authors: Yadava U.L. , Dhir S.K.
Published: February 2019

The morphogenetic potential of parval or pointed gourd (Trichosanthes dioica Roxb.) shoot-tip explants was investigated to establish this species as a model tissue culture system. An effective multiple-shoot propagation method is described. Ten-millimeter shoot tips from young branches of greehouse-grown plants served as explants. They were initiated on a MS basal medium. Multiple shoots were encouraged by transferring established explants to a proliferation medium consisting of MSB + 1 mg BAP/liter, because lower concentrations of BAP (0.1 to 0.5 mg–liter–1) inhibited multiple shoot formation; however, the same concentrations promoted rooting in explants. Medium supplemented with 1 mg BAP/liter and 100 mg PVP/liter caused the best proliferation of shoot tips. Upon transferring to fresh medium of the same composition, these shoot tips elongated 24 cm with three to five nodes in 4 weeks of culturing. Shoot multiplication cultures were maintained by transferring segments of multiple-shoot clusters to medium containing 1 mg BAP/liter and 0.5 mg GA3/liter. Medium supplemented with TDZ inhibited the number of regenerating explants but enhanced the number of shoot buds. Eighty percent of these plantlets were successfully rooted on MS medium supplemented with 1 mg NAA/liter. Plantlets survived in potting soil and exhibited normal growth under mist in the greenhouse.
Variation of Chromosome Numbers in Easter Lily Regenerated from Ovary Tissues
Authors: Ramsay Jodie L. , Galitz Donald S. , Lee Chiwon W.
Published: February 2019

Easter lily (Lilium longiflorum L.) cultivars Ace and Nellie White were regenerated through the culture of immature ovary tissues. Shoot initiation and proliferation were most efficient when a modified Murashige and Skoog (MS) medium containing 5% sucrose, 1 mg 2,4-D/liter, and 2 mg benzylamino purine (BAP)/liter was used. The shoots, when divided and subcultured on the same medium, formed roots within 4 weeks. The rooted plants were transferred to soil in a greenhouse. Root-tip smears made from the regenerated plants showed a range of variation in chromosome numbers from 10 to 25 per cell, in contrast to the bulb-grown plants, which had 2x = 24 chromosomes per cell. The mixoploid condition existed in many regenerants exhibiting chromosome number variation in different root cells of the same plant.
Variation in Micropropagated Trees of `Redspur Delicious' Apple
Authors: Zimmerman Richard H.
Published: February 2019

Small actively growing micropropagated trees of `Redspur Delicious' apple (Malus xdomestica Borkh.) were planted in an orchard at the end of May 1982. By Spring 1986, a lack of uniformity in tree size, appearance, and flowering was obvious. Only four of the 18 trees had a typical spur-type growth habit. These four trees had significantly more spurs per unit of shoot length, flowered sooner, had higher early fruit yields, and remained significantly smaller after 13 years in the orchard, but had significantly less cumulative yield than the nonspur types. Shoots from the spur-type trees were recultured in 1988 and the resulting trees planted in an orchard in 1990. These latter trees were uniform in appearance and all had typical spur-type growth with ≈30% more spurs per meter of shoot growth than the original trees from which they were propagated.
In Vitro Responses of Tissues from Rhododendron Plants With and Without Tissue Proliferation
Authors: Ruan Yiqin , Brand Mark H.
Published: February 2019

Rhododendron `Montego' shoot cultures initiated from plants with and without tissue proliferation (TP and NTP) served as explant sources for all studies (Note: in vitro TP shoot cultures produce primarily dwarf shoots, some long shoots, and stem tumors). Calli induced from TP leaves and tumors and NTP leaves were cultured on woody plant (WP) medium containing NAA and 2-iP. During the first 4 weeks of culture, calli from NTP leaves had higher relative growth rates than calli from TP leaves or tumors. However, calli from TP leaves and tumors grew faster than calli from NTP leaves for all subculture periods that followed. Shoot tips (5 mm) were excised from TP dwarf shoots, TP long shoots, and NTP shoots and were cultured on WP medium with or without 15 μM 2-iP. Shoot tips from TP dwarf and long shoots multiplied on medium without 2-iP, averaging 18.4 and 1.7 shoots per shoot tip in 12 weeks, respectively. Shoot tips from NTP shoots only multiplied when maintained on 2-iP-containing medium. When placed on 2-iP-containing medium, both types of TP shoot tips produced clusters of callus-like nodules that gave rise to highly tumorized, short shoots or leafy meristems.
Improved Adventitious Shoot Production in White Ash
Authors: Bates Sharon A. , Preece John E. , Yopp John H.
Published: February 2019

To increase adventitious shoot formation, we investigated the effects of the number of weeks on medium with high levels of plant growth regulators and seedcoat removal. Dissected white ash seeds were placed on a solidified MS medium containing 10 μM TDZ and 1 μM 2,4-D (shoot initiation medium). After 2, 3, or 4 weeks in vitro, explants were transferred to shoot elongation medium (3 μM TDZ, 1 μM BA, and 1 μM IBA). After 12 weeks, the greatest number (1.8) and longest shoots (18.7 mm) were in cultures incubated on the shoot formation medium for 3 weeks. In a separate experiment, dissected seeds were placed on shoot formation medium. Seedcoats were removed after 10 days in vitro. Explants were transferred to shoot elongation medium after 4 weeks in vitro. There were more shoots (2.5) on 12-week-old explants without seedcoats than on explants with seedcoats (0.9). This result may be related to inhibitors in the testa.
The Influence of the Physical State of the Nutrient Media on the Growth of Excised Date Palm (Phoenix dactylifera L.) Roots
Authors: Dlaigan Yousef I. , Said A.E. , El-Hamady M.A.
Published: February 2019

The effects of the physical state of nutrient media on the growth and elongation of excised date palm roots were investigated. Roots were cultured in a nutrient medium containing MS salts mixture, 1/2 modified White's organics, and (in mg–liter–1): NaH2PO4–H2O, 170; sucrose, 60,000; inositol, 40; adenine sulfate, 240; activated charcoal, 4000; 2,4-D, 1; kinetin, 2. pH was adjusted at 5.7 ± 0.1. Both agar and Gelrite were singly used as solidifying agents. Liquid media were either stationary or rotated on gyratory shakers at 70 to 80 rpm. The effects of incubation of cultured roots under light or dark conditions were also studied. Media pH and its effects on growth and elongation of cultured roots were tested at various ranges (3, 4, 5, 6, 7, 8, 9, 10). Trials were also made to determine the passage length for transfer and subculture of cultured roots to a newly prepared medium. Liquid media highly supported better growth and elongation of cultured roots compared to solidified media. There was no significant difference in growth or elongation between agar or Gelrite media. Shaking liquid medium resulted in significantly better growth and elongation compared to stationary medium. No difference was observed between dark- and light-incubated cultured roots. Cultured roots grew and elongated better at pH 7.0–8.0. No growth or elongation occurred at pH 9.0. Roots continued to grow and elongate even after 12 weeks in culture. Therefore, 10 to 12 weeks after culture was determined to be the optimum passage length for date palm root culture.
Optimizing RAPD Markers for Onion Genomic DNA Analysis
Authors: Wettasinghe Ruwanthi C. , Peffley Ellen B.
Published: February 2019

Random amplified polymorphic DNA (RAPD) have potential as genetic markers that may facilitate selection in plant improvement. To obtain clear, reproducible, and repeatable RAPD bands, four DNA extraction protocols and two Taq polymerases were compared. DNA extraction followed modified Tai and Tanksley (PMBR), Dellaporta et al. (PMBR), and Guilllemant et al. (PMBR) protocols, and a plant tissue DNA isolation kit from Gentra Systems was used. The modified Guillemant protocol was selected because of ease of extraction and cost effectiveness. Genotypes studied were TG1015Y (Allium cepa). Polymerases compared were Taq and Taq Stoffel fragment. Results are based on separate amplifications and electrophoretic assays. PCR amplifications of Stoffel fragment produced more scorable and reproducible RAPD bands compared to bands produced using Taq polymerase.
Molecular Characterization of a cDNA that Encodes Glutamate-1-semialdehyde-2,1-aminomutase in Tomato
Authors: Polking Gary F. , Hannapel David J. , Gladon Richard J.
Published: February 2019

Our recent research has focused on the control of genes and enzymes involved with the synthesis of chlorophyll, especially as it relates to tomato fruit development and ripening. Glutamate-1-semialdehyde-2,1-aminomutase (GSAAM) is one of the first committed enzymes in the chlorophyll biosynthetic pathway, and it is one of three enzymes that catalyze the conversion of glutamate into 5-aminolevulinic acid. We have isolated a full-length cDNA clone of GSAAM from a tomato fruit library. The tomato primary sequence shows extensive homology to GSAAM sequences found in other plant species. The primary structure also predicts a 46.7-kDa, 437-amino acid, mature protein and a transit peptide of 44 amino acids. Southern analysis indicated that GSAAM was present as a single copy. Northern blot analysis showed that GSAAM was expressed differentially in various tomato organs and that GSAAM transcripts decreased with increased fruit age. Immunoblot analysis also indicated that GSAAM protein decreased dramatically with increased fruit age. These results show that there is developmental regulation of the expression of GSAAM in tomato fruits.
RAPD Variation among Salt-selected and Nonselected Buffalograss [Buchloë dactyloides (Nutt.) Engelm.] Clones
Authors: Reid S.D. , Ali-Ahmad M. , Hughes H.G.
Published: February 2019

The use of random amplified polymorphic DNA (RAPD) markers has been shown to be a potentially useful technique for identifying buffalograss breeding lines. Analysis of RAPD markers has also revealed considerable variation within, as well as among, each of four natural buffalograss populations surveyed. Identification of genetic markers for quantitative traits, such as physiological components of tolerance to salt stress, can provide important information for plant improvement programs. The objectives of this study were to develop DNA fingerprints for buffalograss clones selected from an in vitro seedling screening program for survival at high NaCI (200–250 mM) levels, identify markers for future analysis, and assess the variability among the lines. DNA was extracted from leaves of 10 salt-selected and 15 non-selected buffalograss clones. Fifty-two 10-mer primers were screened for ability to produce bands with DNA from four clones as visualized on ethidium-stained agarose gels. Bands were most reproducible with a genomic template DNA concentration of 1 ng–μl–1 reaction volume. Primers selected for ability to produce a moderate number of clear bands were used to produce RAPD profiles of the 25 clones. Abundant polymorphism to distinguish among clones was found. Four primers produced a total of 45 polymorphic markers. The primer 5′-CGGAGAGCCC-3′ produced 11 readily scored markers, allowing identification in 94.67% of pair-wise comparisons. As a group, RAPD profiles of salt-selected clones are more variable than non-selected clones from the same population; however, no unique pattern of markers generated by primers screened to date differentiates all salt-selected clones from the non-selected group.
Effect of Defoliation on the Translocation and Use of Photosynthates in Grapevine
Authors: Ahmedullah M. Ahmed
Published: February 2019

On potted Carignane grapevines, the following three leaf removal treatments were used: 1) six basal leaves allowed; 2) all leaves left on the vine; and 3) all leaves left on the vine except shoot tip, darkened by covering the leaves with aluminum-coated paper bags. Translocation and use of photosynthates was studied using C14 in the season of application and in the following year. In the season of C14 application, the roots and trunk were the major sinks. Reserve photosynthates were used to support current-season growth following budbreak in all three treatments. Treatments 1 and 2 showed similar trends in use of reserves; in treatment 3, however, reserves continued to be used until harvest at full maturity. Defoliated vines used more stored reserves than nondefoliated vines. Defoliated vines used more reserve carbohydrates, leaving little C14 reserves in old roots compared to nondefoliated vines.
Plastic Mulch Enhances and Conserves N03-N in Bell Pepper
Authors: Wells Otho S. , Mitchell James R.
Published: February 2019

N03-N is readily leached from mineral soils with rain or overhead irrigation. To determine the amount of N03-N conserved with plastic mulch, `Northstar' bell pepper was grown with and without 2-mil black plastic mulch, with 0, 80, and 160 lbs/acre of preplant N. One treatment consisted of unplanted rows. At 1, 2, 3, and 5 months after planting on 26 May 1994, soil samples for N03-N analyses were taken at 0–6” and 6–12”. Not only was N03-N conserved under the mulch, but it was also enhanced. N03-N levels increased up to 595 ppm in plots with mulch, no crop, and 160 lbs N/acre. The pepper crop utilized about one-third of the nitrogen under the mulch. After 5 months, nitrate levels averaged about 6 ppm in all plots without mulch, whereas, in plots with mulch, nitrate levels averaged about 97 ppm. For most of the season nitrate were higher at 0–6 inches than at 6–12 inches, but, nearer the end of the season, nitrates in plots without mulch were nearly the same or greater at 6–12 inches than at 0–6 inches. Yields were highest with mulch and 80 lbs N/acre.
Influence of Growing Media Amended with Compost and the Electrical Conductivity of Nutrient Solution on Three Medicinal Plants Grown in Multicompartment Trays
Authors: Herrera Elizabeth , Tremblay Nicolas , Gosselin André
Published: February 2019

Transplants of angelica (Angelica archangelica L.), horehound (Marrubium vulgare L.), and thyme (Thymus vulgaris L.) were grown in multicompartment trays with five proportions of compost (0%, 15%, 30%, 45%, 60%) mixed to peatmoss and perlite. Plants were fertilized with different electrical conductivity (EC) levels of the nutrient solution (0, 1, and 2 mmho/cm). Horehound and thyme plants were transplanted in the field to measure the residual effects of treatments on dry matter yields and level of active substances. The three medicinal plants showed increased shoot and root dry weights as well as leaf mineral content (some nutrients) when proportion of compost and EC of nutrient solution were higher. The optimal combinations of compost and fertilization treatments on plants growth varied between species. Residual effects of treatments applied in greenhouse on shoot dry matter weight of horehound and thyme plants were observed until the 9th and 12th week, respectively, after transplantation. Treatments also affected active substance levels in horehound plants in field. Organic fertilization management influenced growth, yield in the field and level of certain active substances of the harvested parts of medicinal plants.
Fish Culture Water and Sludge Applied Via Drip Irrigation Improves Yield of Pak Choi (Brassica rapa L. Chinensis)
Authors: Palada M.C. , Cole W. M. , Crossman S.M.A , Rakocy J.E. , Kowalski J.A.
Published: February 2019

Using fish culture water and sludge may benefit vegetable production by reducing the need for high-quality irrigation water in areas where water is a limiting resource for agriculture. Fish water and sludge contains nutrients, thereby reducing the need for chemical fertilizers. A study was conducted to integrate fish (tilapia) culture with field production of Pak choi (Brassica rapa L. Chinensis). Water from tilapia culture tanks from which solids were removed (SR) and from tanks with no solid removal (NR) were applied to pak choi 2 to 3 times weekly through a drip system. These treatments were compared with sludge (FS) removed from culture tanks using three methods of irrigation. Conventional methods of fertigation (F) and band fertilizer (B) application were included as control treatments. The trial was conducted for 2 seasons. In the first season, pak choi applied with (FS) produced total yields ranging from 21 to 26 t·ha–l. Pak choi applied with fish water from tanks with (SR) and (NR) produced yields of 19 and 20 t·ha–l, respectively. Pak choi grown with (F) and (B) applications yielded 21 and 20 t·ha–l, respectively. There were no significant yield differences between the (FS) treated and (F) plots. Yield from (FS) treatment was significantly higher than all other treatments except (F). Similar results were obtained during the second season, but total yields from various treatments were 50% higher than the first season. Fish culture water and sludge are therefore good alternative sources of irrigation and fertilizer for pak choi.
Root System Activity of Fruit Trees in Response to Shoot Pruning, High Temperature, and Excess Water
Authors: Morinaga Kunihisa
Published: February 2019

Relationship between root system and shoot pruning was studied by three different pruning times (February, June, and August) and intensity (heavy, medium, and light) using satsuma mandarin trees (Citrus unshiu Marc.). Root weight, respiratory rate of fine root, and CO2 concentration in root zone were measured on the 90th day after starting each pruning treatment. The weight of fine root was more severely influenced by pruning intensity than by pruning time. Fine root of heavy pruned trees showed lower respiratory rate than those of medium- and light-pruned trees. Heavy-pruned trees showed the highest CO2 concentration level in root zone. Influence of high root temperature on root respiration was investigated using `Kyoho' grape (Vitis vinifera L. × V. Iabrusca L.), kiwifruit (Actinidia deliciosa), and satsuma mandarin trees. Respiratory rate of grape root increased more rapidly than those of mandarin and kiwifruit under high root temperature. Respiratory rate of mandarin root given immersion treatment in stagnated water began to decrease significantly at the 70th hour after starting the treatment. Photosynthesis of the trees decreased by 85% at the same time.
Artemisinin (Qinghaosu) Production in Artemisia annua
Authors: Ferreira Jorge F.S. , Simon James E. , Janick Jules
Published: February 2019

Artemisinin (qinghaosu), an endoperoxide sesquiterpene lactone with antimalarial activity and little human toxicity, is produced in A. annua L., a short-day plant with the critical photoperiod of 13.5 h. Artemisinin peaks at full flowering when it is 11 times higher in inflorescences than in leaves. Supplementation of MS medium with BA, kinetin, CCC, or daminozide decreased content in shoot cultures as compared to the control, with the exception of CCC at 6.3 μM. Artemisinin content (percent dry weight) in this experiment did not correlate with shoot number (r = –0.198) but was highly correlated (r = 0.775**) with root number, indicating that although roots do not produce artemisinin, they may be involved in its synthesis. Maximum artemisinin was produced in hormone-free medium. Friable calli were obtained with a combination of BA (4.4 μM) and 2,4-D (4.5 μM), but artemisinin was absent from calli, cells, and cell culture media. Biseriate glandular trichomes are present in leaves and flowers from the earliest developmental stages. Artemisinin was extracted by a 1-min dip in organic solvents from flowers and leaves, indicating that the biseriate glandular trichomes of A. annua are the probable site of accumulation or sequestration of artemisinin.
Controlling Citrus Rootstock Sprouting in the Nursery Using Commercially Available NAA
Authors: Rouse Robert E.
Published: February 2019

Tre-Hold, a commercially available sprout inhibitor containing ethylnaphthaleneacetate (NAA) for newly planted citrus trees in orchards was effective to prevent axillary bud growth on rootstock seedlings in the nursery. Tre-Hold applied at formulated concentration (1×), three-fourths (3/4×), and one-half (1/2×) to field-grown and container-grown greenhouse seedlings prevented sprouting. It was possible to control dormancy of individual buds without affecting adjacent buds. When applied to green citrus tissue, no phytotoxicity occurred. Full concentration of Tre-Hold was found to prevent scion bud healing of container-grown trees when the seedling was treated before budding. Application a few days before unwrapping and after the scion bud had healed did not affect bud healing or budling growth.
Inhibition of Polygalacturonase in Tomato Pericarp Tissue by Lysophosphatidylethanolamine: Implications in Fruit Shelf-life
Authors: Mangat Navjot K. , Palta Jiwan P.
Published: February 2019

The pericarp tissue of red mature tomato (Lycopersicon esculentum cv. Gagliano) was used to exctract polygalacturonase (PG) enzyme. The technique for assaying PG activity involves measurement of released reducing groups that were linked together in pectin. Since the crude extract of PG from pericarp will contain considerable reducing groups, we found that repeated washings of the cell wall pulp removed much of the sugars and thus minimized the background absorbance without loss of PG activity. There is an inherent perplexity concerning the selection of blank for PG assay. This is because (i) the enzyme extract contains both the substrate (pectin) and product (free reducing groups) involved in the reaction; (ii) the color development with cyanoacetamide requires heating for 10 min. Thus, even though the reaction is terminated with borate buffer (pH 9.0) the breakdown of pectin continues chemically by heat; (iii) the absorbance from both pectin and enzyme together at zero time termination was always lower than the sum of absorbances from pectin alone and enzyme alone. This suggests that when together in the same tube, the enzyme appears to protect the pectin from physical breakdown during the period of 10 min. boil needed to develop color using the cyanoacetamide. Thus, the most appropriate blank is processing separately the solutions of enzyme alone and substrate pectin alone for color development and then adding the two absorbances. Using this improved assay we found that lysophosphatidylethanolamine (LPE) inhibited tomato PG activity. This inhibition appears to depend on the ripening stage of the fruit. Our results suggest that LPE is able to impart firmness to tomato fruit by reducing the PG activity, which in turn could protect the pectin/middle lamellae from enzymic breakdown. The effects of LPE on PG activity are distinct from those of Triton X-100 and lysophosphatidylcholine.
Inhibitory Effect of Fresh-cut Spinach on Listeria monocytogenes
Authors: Babic Isabelle , Watada Alley E.
Published: February 2019

Studies. were undertaken to investigate the cause of the bacteriostatic activity of spinach leaves against Listeria monocytogenes. Listeria monocytogenes was inoculated at the concentration 104 cells/ml in raw, autoclaved and vacuum filtration sterilized spinach macerates as well as in tryptic soy broth used as control. The concentrations after 24 h at 28C were 105, 5 × l06 and 105 cells/ml in respective spinach macerates and 4 × l08 cells/ml in tryptic soy broth. The anti-Listeria activity was still present in spinach macerates sterilized by vacuum filtration but strongly reduced in autoclaved macerates. Serial dilutions of freeze-dried spinach were tested on the growth of Listeria monocytogenes in tryptic soy broth. The minimum concentration for maximum inhibition was 10 mg·ml–1. The growth of Listeria monocytogenes in tryptic soy broth in mixed cultures with different microbial species isolated from spinach was not inhibited. In conclusion, the bacteriostatic activity against Listeria monocytogenes might be due to antimicrobial compounds present in spinach leaves.
Economic Analysis of Low-input and Conventional Vegetable Production Systems in Southern Georgia
Authors: Brunson Kathryn E. , Stark C. Robert , Phatak Sharad C. , Wetzstein Michael E.
Published: February 2019

Research results are presented from a multi-year study on vegetable production in southern Georgia that compared two low-input production systems to the conventional rye cover crop technology. The low-input systems use beneficial insect principles as a substitute for conventional pesticide controls, but pesticides are used if needed. Preliminary results from the low-input systems using crimson and subterranean clovers indicate that crimson clover produces better yields and can “catch up” to the conventional rye system. The higher yields of the rye technology can be offset by the cost reductions associated with the low-input technologies. Production budgets were developed for 3 years of eggplant and 2 years of fresh-market tomato and bell pepper to reveal expected net returns under the low-input and conventional systems.
Alternative Strategies for Small Fruit Production: A Summary of a Northeast SARE Project
Authors: Handley David , Goulart Barbara
Published: February 2019

Fourteen cooperators representing four universities and the USDA/ARS developed a 5-year program of research and education for small fruit production in the northeastern United States. The objectives were to develop and test alternative production practices for strawberries and raspberries, to analyze the economic feasibility of sustainable production practices, to evaluate grower acceptance of sustainable technology, and to deliver the knowledge based on this research to the farming public. Specific research efforts determined strawberry and raspberry cultivar susceptibility to insects and disease and the influence of various cultural practices on crop susceptibility to disease, insects, and weed competition. Farmers indicated a willingness to adopt new sustainable technologies, even if profits might be reduced. However, they were not willing to commit more management time to such technology. Information delivery channels included a newsletter, more than 150 public presentations, and more than 100 publications.
Cotton Gin Trash, Rice Hulls, and Poultry Litter as Soil Amendments in Mid-south Vegetables
Authors: Teague Tina Gray , Lee Gail S.
Published: February 2019

Soil fertility studies conducted in commercial vegetable fields to examine alternative uses of mid-south agricultural wastes as soil amendments included work with poultry litter, cotton gin trash, and rice hulls. Poultry litter applications ranging from 0.3 to 0.9 Mg·ha–1 resulted in significant increases in spinach, cabbage, turnip greens, and collard yields grown in soils damaged by precision leveling or in sandy soils with low organic matter; however, positive yield response to litter applied to undamaged soils was variable. Raw rice hulls applied at rates ranging from 2 to 44 Mg·ha–1 resulted in reduced cabbage yield. Trials with cotton gin trash and cover crops on yield of cabbage, broccoli, southern pea, snap bean, and cucumber indicate significant problems with weeds following use of raw gin trash. Composting alleviated most weed problems, but no yield response was apparent at composted gin trash rates ≤9.6 Mg·ha–1. High rates (60 Mg·ha–1) of composted gin trash on damaged soil significantly improved cabbage yield. There were increases in soil pH and Ca levels. Research was supported by a SAREIACE grant.
Soil Nutrient Dynamics following Composted De-inked Paper Sludges and Municipal Waste Compost Applications in Sod Production
Authors: Lecomte P. , Laganière M. , Desjardins Y.
Published: February 2019

Increasing costs associated with the disposal of industrial and urban wastes necessitate the development of alternatives which are economical and environmentally safe. With >3000 ha in Quebec, sod production represents an interesting alternative for the use of new amendments, such as composted de-inked paper sludges and municipal waste compost. The objective of this trial was to evaluate the potential benefits of these amendments (nutrient retention in the root zone and chemical and physical soil benefits) and question potential environmental hazards. Chemical dynamics of N, P, K, micronutrients and heavy metals were examined over four soil layers (0 to 15, 15 to 30, 30 to 60, an >60 cm) on sandy and clay soil. Preliminary results for 1993 and 1994 indicate that nutrient concentrations in water extract are high following the establishment of sites. When sod is absent, high concentrations of lead (500 mg·kg–1 in urban compost) show only a slight trend to accumulate. Nevertheless, this new approach toward using industrial and urban composts seems to be adequate and economically attractive.
Post-transplant Effects of Mechanical and Chemical Correction of Circling Roots on Shumard Oak
Authors: Arnold Michael A.
Published: February 2019

Shumard oak (Quercus shumardii Buckl.) were grown in 2.3-liter (#1) containers painted on interior surfaces with Spin Out™ (100 g Cu(OH)2/liter, or not. Seedlings were transplanted to the field and root observation boxes in June and October. The effects of two mechanical root-pruning techniques, traditional (cutting roots on exterior rootball surfaces) and butterfly pruning (splitting and splaying the rootball apart), to correct circling roots were compared with Spin Out-treated seedlings. Only the Spin Out-treated seedlings and fall-transplanted nonpruned controls had a net increase in height and caliper after 2 years in the field. Few roots >1.5 mm in diameter were severed in June with mechanical pruning techniques, while butterfly pruning severed roots up to 8.5 mm in diameter in October. Root regeneration shifted from predominantly small roots ≤0.5 mm in diameter in June to roots of between 0.5 and 1.5 mm in diameter in October. Spin Out-treated seedlings regenerated substantially more roots with diameters <1.0 mm at both transplant times. While midday water potentials were similar among treatments, Spin Out-treated seedlings had the least negative predawn water potentials, suggesting better recovery from midday water stress, particularly following October transplanting.
Physiological Effects of Uniconazole, Gibberellin, and Calcium on Salt Injuries of Hibiscus syriacus and H. hamabo Seedlings
Authors: Huh Moo R. , Kwack Beyoung H. , Perry Leonard P.
Published: February 2019

Salt injury was induced by 5% (w/v) NaCl drenching on Hibiscus hamabo Sieb. & Zucc. and H. syriacus L. seedlings. Total chlorophyll content of H. hamabo was higher than that of H. syriacus. Uniconazole (0.0, 0.5, 1.0, and 5.0 mg·liter–1) treatment increased and 25- or 50-mg·liter–1 GA3 treatment decreased chlorophyll content of H. hamabo. Total chlorophyll content of H. syriacus was not affected by uniconazole or GA3. Total carbohydrate content of H. syriacus was more accumulated than that of H. homabo. Total carbohydrate content of H. hamabo was more decreased than that of H. syriacus by Ca (13.35 or 133.5 mM), uniconazole, or GA3 in relation to total carbohydrate contents. Protein contents of H. hamabo were higher than those of H. syriacus. Uniconazole or GA3 increased those of H. hamabo and decreased those of H. syriacus. Peroxidase activity of H. hamabo was higher than that of H. syriacus. Uniconazole decreased that of H. hamabo and increased that of H. syriacus. GA3 or Ca (13.35 mM) treatment increased that of both species. ATPase activity of H. hamabo was higher than that of H. syriacus. Uniconazole (5 mg·liter–1), GA3, or Ca decreased that of H. hamabo increased that of H. syriacus.
A Zinc-binding Protein in Citrus with Homology to Plant Chitinases
Authors: Taylor Kathryn C. , Ellis Danielle R.
Published: February 2019

A 5-kDa zinc-binding protein (ZBP) accumulates in the phloem above the graft union in citrus trees affected by two citrus decline disorders, citrus blight and Macrophylla decline. Citrus blight and Macrophylla decline are decline disorders of unknown etiology. Citrus blight has historically been restricted to humid production regions, and Macrophylla decline occurs in arid regions. A causal agent has not been identified for either disorder. Levels of the 5 kDa ZBP are increased 2.5- and 1.5-fold, respectively, in the phloems above the graft union in trees with citrus blight and Macrophylla decline. The protein was purified from citrus phloem and a partial N-terminal sequence was obtained. The protein has homology to the cystein-rich chitin binding domain of several plant chitinases and hevein. Hevein and class I chitinases, which have this N-terminal chitin binding domain, have antifungal activity and antibacterial activity and are induced by wounding and several other stresses. Oligonucleotides corresponding to the greatest conserved region in the N-terminal domain of the ZBP were produced. They were used as primers for PCR reactions against a citrus leaf cDNA library. Four PCR products were obtained from these reactions. The products are being subcloned and sequenced. They will be used to probe the citrus cDNA library to obtain the cDNA clone for the 5 kDa ZBP.
Student Laboratory Exercise to Understand Air and Water Relations in Container Substrates
Authors: Holcomb E. Jay , Berghage Robert , Fonteno William
Published: February 2019

The concepts of container water-holding capacity and air-filled porosity are important yet complicated for students interested in containerized crop production; however, both of these concepts can be observed and understood more completely if students develop a moisture retention curve. Our objectives were to describe an easy-to-construct and economical apparatus for creating a moisture retention curve and then to compare this curve with one generated by standard methods. The student method (column method) is constructed from plastic pipe cut into 5-cm sections. The sections of pipe are individually packed with a substrate then stacked and taped together, resulting in a 60-cm column of the substrate. The column is saturated and allowed to drain for 24 h. Then, the column is taken apart and the water content of each section determined gravimetrically. The water content of each section is graphed against height so that the result is a moisture retention curve. Data are presented to show the curve developed from the column method is similar to the curve developed by standard soil moisture tension method. The moisture retention curve can provide a better understanding of water and air holding capacities of substrates.