Effects of the fungal protein Nep1 and Pseudomonas syringae on growth of Canada thistle (Cirsium arvense), common ragweed (Ambrosia artemisiifolia), and common dandelion (Taraxacum officinale)

Weed Science ◽  
2004 ◽  
Vol 52 (1) ◽  
pp. 98-104 ◽  
Author(s):  
John W. Gronwald ◽  
Kathryn L. Plaisance ◽  
Bryan A. Bailey
Keyword(s):  
Pseudomonas Syringae ◽  
Shoot Growth ◽  
Foliar Application ◽  
Dry Weight ◽  
Ambrosia Artemisiifolia ◽  
Canada Thistle ◽  
Common Ragweed ◽  
Fungal Protein ◽  
Shoot Dry Weight ◽  
Common Dandelion

The effects of the fungal protein Nep1 and Pseudomonas syringae pv. tagetis (Pst) applied separately or in combination on Canada thistle, common ragweed, and common dandelion were examined in growth chamber experiments. Experiments examined five treatments: (1) untreated control, (2) Silwet L-77 (0.3%, v/v) control, (3) Nep1 (5 μg ml−1) plus Silwet L-77 (0.3%, v/v), (4) Pst (109 colony-forming units [cfu] ml−1) plus Silwet L-77 (0.3%, v/v), and (5) Pst (109 cfu ml−1) and Nep1 (5 μg ml−1) plus Silwet L-77 (0.3%, v/v). Foliar treatments were applied at 28, 26, and 21 d after planting for Canada thistle, common dandelion, and common ragweed, respectively. For all three species, foliar application of Nep1 alone or in combination with Pst caused rapid desiccation and necrosis of leaves, with the greatest effect on recent, fully expanded (RFE) leaves. Within 4 to 8 h after treatment (HAT), 60 to 80% of RFE leaves of all three species were necrotic. Measured 72 HAT, Pst populations in Canada thistle leaves treated with Nep1 plus Pst were approximately 105 cfu cm−2 compared with 107 cfu cm−2 for leaves treated with Pst alone. Measured 2 wk after treatment, foliar application of Nep1 reduced shoot dry weight of the three weeds by 30 to 41%. Treatment with Pst reduced shoot growth of common ragweed, Canada thistle, and common dandelion by 82, 31, and 41%, respectively. The large suppression of common ragweed shoot growth caused by Pst treatment was associated with a high percentage (60%) of leaf area exhibiting chlorosis. Treatment with Pst plus Nep1 did not result in significant decreases in shoot dry weight for Canada thistle and common dandelion compared with either treatment alone. For common ragweed, shoot growth reduction caused by applying Pst and Nep1 together was not greater than that caused by Pst alone.

scholarly journals Growth Response of 13 Container-Grown Landscape Plants to Uniconazole

1990 ◽  
Vol 8 (3) ◽  
pp. 151-153
Author(s):  
Stuart L. Warren
Keyword(s):  
Growth Response ◽  
Shoot Growth ◽  
Foliar Application ◽  
Foliar Spray ◽  
Dry Weight ◽  
Experimental Plant ◽  
Growth Reduction ◽  
Ligustrum Lucidum ◽  
Shoot Dry Weight ◽  
Landscape Plants

Abstract Uniconazole, an experimental plant growth regulator, was applied as a foliar spray and a medium drench to 13 and 7 species, resp. Shoot dry weight was determined at 60, 90, and 120 days after treatment. Sixty days after treatment, shoot dry weight of no species was affected by uniconazole. At 90 and 120 days, shoot dry weight of all species, except golden privet (Ligustrum × vicaryi), Russian-olive (Elaeagnus angustifolia), and waxleaf privet (Ligustrum lucidum), decreased with increasing rates of uniconazole, regardless of method of application. Degree of growth reduction varied by species, rate, and method of application. For most species, uniconazole was effective in suppressing growth for 120 days. Generally greater reduction of shoot growth resulted from drench application compared to foliar application.

Root and shoot development in Corymbia calophylla and Banksia brownii after the application of the fungicide phosphite

2002 ◽  
Vol 50 (2) ◽  
pp. 155 ◽  
Author(s):  
S. R. Barrett ◽  
B. L. Shearer ◽  
G. E. St J. Hardy
Keyword(s):  
Root Development ◽  
Root Length ◽  
Native Species ◽  
Shoot Growth ◽  
Foliar Application ◽  
Leaf Size ◽  
Dry Weight ◽  
Shoot Development ◽  
Shoot Dry Weight ◽  
Growth Abnormalities

The effects of low-volume foliar application (24, 48, 96 kg ha–1) of phosphite on root and shoot development in Corymbia calophylla Lindley and Banksia brownii ex R.Br. were investigated in a glasshouse study. Shoot growth, root and shoot dry weight and root length were not significantly reduced by phosphite application in C. calophylla 2 weeks and 4 months after phosphite application. Shoot growth, shoot dry weight and root length were not significantly reduced in the non-mycorrhizal B. brownii. However, in plants treated with 24 and 96 kg ha–1, root dry weight was significantly reduced 4 months but not 2 weeks after spray. A discoloration of the root stele was also observed in phosphite-treated plants of this species. At 2 weeks after spray, root concentrations of phosphite in C. calophylla were up to five times higher than shoot concentrations. At 4 months after application, growth abnormalities were observed in B. brownii and these included spindly new shoot growth with rosetted foliage of reduced leaf size. The results of this study, which assessed one mycorrhizal and one non-mycorrhizal native species, suggest that species may vary in their response to phosphite in terms of root development and phosphite applied at rates of 24 kg ha–1 or higher may result in reduced root growth, particularly in non-mycorrhizal species. Further studies on root development in a wider range of species are needed to validate these findings.

scholarly journals Effect of Repeated Short Interval Flooding Events on Root and Shoot Growth of Four Landscape Shrub Taxa

2011 ◽  
Vol 29 (4) ◽  
pp. 220-222
Author(s):  
Kathryne J. Jernigan ◽  
Amy N. Wright
Keyword(s):  
Shoot Growth ◽  
No Reduction ◽  
Southeastern United States ◽  
Short Interval ◽  
Dry Weight ◽  
Shoot Dry Weight ◽  
Flooding Event ◽  
Root And Shoot Growth ◽  
Size Index ◽  
Flooding Events

Abstract Research was conducted to screen four landscape shrub taxa for tolerance to repeated flooding events. Plants of Fothergilla × intermedia ‘Mt. Airy’ (dwarf witchalder), Ilex verticillata ‘Winter Red’ (winterberry), Clethra alnifolia ‘Ruby Spice’ (summersweet), and Viburnum nudum Brandywine™ (possumhaw) were flooded repeatedly over six weeks for 0 (non-flooded), 3, or 6 days with a draining period of 6 days between each flooding event. The experiment was repeated for a total of two runs. With the exception of F. × intermedia ‘Mt. Airy’, all taxa showed good visual quality and no reduction in root growth in either run, and effects on shoot growth were minimal. Size index of Clethra alnifolia ‘Ruby Spice’ was 27% higher in plants flooded for 0 or 3 days than in plants flooded for 6 days in run 1 only. Shoot dry weight of Ilex verticillata ‘Winter Red’ was actually 11% higher in plants flooded 6 days days than in plants flooded for 0 or 3 days in run 2. Size index of Viburnum nudum Brandywine™ increased with increasing flood length, and plants flooded for 6 days had a 9% higher SI than plants flooded for 0 days in run 1. With the exception of Fothergilla × intermedia L. ‘Mt. Airy’, all taxa appeared tolerant of and even thrived during flooding and would be appropriate shrub selections for a southeastern United States rain garden.

scholarly journals Emergence and Shoot Growth of Cosmos and Marigold from Paclobutrazol-treated Seed

2001 ◽  
Vol 19 (1) ◽  
pp. 11-14 ◽  
Author(s):  
Wallace G. Pill ◽  
James A. Gunter
Keyword(s):  
Growth Medium ◽  
Shoot Growth ◽  
Dry Weight ◽  
Tagetes Patula ◽  
Shoot Height ◽  
Shoot Dry Weight ◽  
Grade 5 ◽  
Treated Seed ◽  
Emergence Percentage ◽  
And Control

Abstract This study was conducted to determine whether treating seeds of ‘Sensation Mixed’ cosmos (Cosmos bipinnatus Cav.) and ‘Bonanza Gold’ marigold (Tagetes patula L.) with paclobutrazol (PB) could suppress seedling growth. Seeds were soaked in solutions of 0, 500 or 1000 mg PB/liter (ppm PB) for 16 hours at 25C (77F) or they were primed [−0.5 MPa (−5 bars) for 7 days at 20C (68F)] in Grade 5 exfoliated vermiculite moistened with 0, 500 or 1000 ppm PB solltuions. Soaked and primed seeds were dried for 1 day at 19C (65F) and 25% relative humidity. These seeds and control (non-treated) seeds were sown into plug cells containing peat-lite. Increasing PB concentration decreased cosmos shoot height at 32 days after planting (DAP), but decreased emergence percentage, responses that were more pronounced with priming than with soaking. A 1 ppm PB growth medium drench [30 ml/cell(0.2 mg PB/cell)] and, to a greater extent a 10 mg PB/liter (ppm PB) shoot spray [2 ml/shoot (0.02 mg PB/shoot)], both applied at 10 DAP, resulted in greater cosmos shoot height suppression at 32 DAP than treatment of seeds with 1000 ppm PB. Soaking marigold seeds in 1000 ppm PB failed to decrease shoot height below those of plants from non-treated seeds at 32 DAP. However, exposure to 1000 ppm PB during priming of marigold seeds resulted in a similar shoot height suppression (13%) as the growth medium drench, and similar shoot dry weight reduction (21%) as the shoot spray. Suppression of shoot growth by this seed treatment was short-term since by five weeks after transplanting into 15 cm (6 in) pots, only marigold plants that had received the growth medium drench or shoot spray were smaller than those of control plants. Treating marigold seeds with 1000 mg ppm PB used about one-fifth the PB used to drench the growth medium.

scholarly journals Evaluation of a Substrate-applied Humectant to Mitigate Drought Stress in Young, Container-grown Plants

2015 ◽  
Vol 33 (3) ◽  
pp. 137-141
Author(s):  
Bruce R. Roberts ◽  
Chris Wolverton ◽  
Samantha West
Keyword(s):  
Drought Stress ◽  
Root Growth ◽  
Shoot Growth ◽  
Dry Weight ◽  
Root:Shoot Ratio ◽  
Xylem Water Potential ◽  
Bedding Plants ◽  
Shoot Dry Weight ◽  
Soilless Substrate ◽  
Absorbing Roots

The efficacy of treating soilless substrate with a commercial humectant was tested as a means of suppressing drought stress in 4-week-old container-grown Zinnia elegans Jacq. ‘Thumbelina’. The humectant was applied as a substrate amendment at concentrations of 0.0, 0.8, 1.6 and 3.2% by volume prior to withholding irrigation. An untreated, well-watered control was also included. The substrate of treated plants was allowed to dry until the foliage wilted, at which time the plants were harvested and the following measurements taken: number of days to wilt (DTW), xylem water potential (ψx), shoot growth (shoot dry weight, leaf area) and root growth (length, diameter, surface area, volume, dry weight). For drought-stressed plants grown in humectant-treated substrate at concentrations of 1.6 and 3.2%, DTW increased 25 and 33%, respectively. A linear decrease in ψx was observed as the concentration of humectant increased from 0.0 to 3.2%. Linear trends were also noted for both volumetric moisture content (positive) and evapotranspiration (negative) as the concentration of humectant increased. For non-irrigated, untreated plants, stress inhibited shoot growth more than root growth, resulting in a lower root:shoot ratio. For non-irrigated, humectant-treated plants, the length of fine, water-absorbing roots increased linearly as humectant concentration increased from 0.0 to 3.2%. Using humectant-amended substrates may be a management option for mitigating the symptoms of drought stress during the production of container-grown bedding plants such as Z. elegans.

scholarly journals Seedling Developmental Stage at Transplanting Affects Growth and Flowering of Medallion Flower and Globe Amaranth

2015 ◽  
Vol 33 (2) ◽  
pp. 53-57 ◽  
Author(s):  
G.J. Keever ◽  
J.R. Kessler ◽  
G.B. Fain ◽  
D.C. Mitchell
Keyword(s):  
Shoot Growth ◽  
Growth Index ◽  
Dry Weight ◽  
Development Stage ◽  
Seedling Development ◽  
Bedding Plants ◽  
Shoot Dry Weight ◽  
Flower Growth ◽  
Root Restriction ◽  
Experimental Runs

A study was conducted to determine how seedling development stage at transplanting from plug flats into small pots affected growth and flowering of two commonly grown bedding plants. Seeds of Showstar® medallion flower and ‘Las Vegas Pink’ globe amaranth were sown in 392-cell flats on five dates for each of two experimental runs before transplanting into 8.9 cm (3.5 in) cubic pots. At transplanting of both species, plant height, node count and shoot dry weight increased as days from sowing to transplanting increased and there was no visible cessation in shoot growth due to root restriction. Time to first flower from transplanting decreased linearly with both species in both runs, except with medallion flower in the second run, as time from sowing to transplanting increased. In contrast, time to flower of both species from sowing increased linearly as time from sowing to transplanting increased. However, the magnitude of the increase or decrease in time to flower differed between the two runs indicating that other factors, most likely light intensity and duration, besides node counts were affecting time to flower. Globe amaranth height and growth index and medallion flower growth index at first flower decreased as time from sowing to transplanting increased, whereas medallion flower height was not affected by time from sowing to transplanting.

Uptake and Phytotoxicity of Tebuthiuron

Weed Science ◽  
1977 ◽  
Vol 25 (5) ◽  
pp. 390-395 ◽  
Author(s):  
W.G. Steinert ◽  
J.F. Stritzke
Keyword(s):  
Zea Mays ◽  
Plant Species ◽  
Nutrient Solution ◽  
Secale Cereale ◽  
Foliar Application ◽  
Gold Rush ◽  
Ambrosia Artemisiifolia ◽  
Common Ragweed ◽  
Primary Activity ◽  
Treated Leaf

Differences in the phytotoxicity of tebuthiuron (N-[5-(1,1-dimethylethyl)-1,3,4-thiadiazol-2-yl]-N,N′-dimehtylurea) to nine plant species were observed on the basis of calculated GR50values. Japanese brome (Bromus japonicusThunb.) with a GR50value of 0.016 ppmw was the most susceptible and corn (Zea maysL. ‘Gold Rush’) with a GR50value of 0.436 ppmw the least susceptible. There was some growth suppression with foliar application but primary activity on all species was attributed to root uptake. The most significant translocation of labeled tebuthiuron was to the tops of common ragweed (Ambrosia artemisiifoliaL.) plants treated through the nutrient solution where 24.5% of the total amount recovered was detected after 24 h. Only 7.3% of the total amount recovered was detected in the top of rye (Secale cerealeL. ‘Elbon’) plants with the same treatment. With both species, more than 90% of the radioactivity recovered following foliar treatments was still in the treated leaf after 24 h. Less than 5.5% of the recovered activity for both species was in the tops, less than 3% in the roots, and less than 1.5% was in the nutrient solution.

scholarly journals Cutless Controls Shoot Growth of ‘China Girl’ Holly

1994 ◽  
Vol 12 (3) ◽  
pp. 167-169
Author(s):  
G.J. Keever ◽  
C.H. Gilliam ◽  
D.J. Eakes
Keyword(s):  
Growth Inhibition ◽  
Shoot Growth ◽  
Growth Index ◽  
Dry Weight ◽  
Shoot Length ◽  
Single Application ◽  
Growing Seasons ◽  
Shoot Dry Weight ◽  
Production Growth ◽  
Container Production

Abstract Ilex x meserveae ‘China Girl’ plants were sprayed with a single application of different rates of Cutless (flurprimidol) during container production. Growth index, shoot length and shoot dry weight decreased with increasing rates of Cutless. Growth index of plants treated with 500 ppm Cutless was about 17% less than that of control plants 120 days after treatment, but were similar after the spring flush the following year. Growth inhibition persisted for at least two growing seasons when plants were treated with rates of 1500 to 2500 ppm; foliage of these plants was smaller and more cupped than that of control plants. Treated plants were noticeably more compact and uniform, and foliage was darker green than that of control plants.

scholarly journals Comparing Effects of Container Treatments on Nursery Production and Field Establishment of Trees with Different Root Systems

2000 ◽  
Vol 18 (2) ◽  
pp. 83-88
Author(s):  
Ursula K. Schuch ◽  
Dennis R. Pittenger ◽  
Philip A. Barker
Keyword(s):  
Biomass Production ◽  
Shoot Growth ◽  
Dry Weight ◽  
Copper Coating ◽  
Total Biomass ◽  
Shoot Dry Weight ◽  
Nursery Production ◽  
Brazilian Pepper ◽  
Container Shape

Abstract The objectives of this study were to determine the effects of container volume, container shape, and copper-coating containers on root and shoot growth during nursery production and after establishment in the field. Liners of ficus (Ficus retusa L. ‘Nitida’), a fibrous-rooted species, and Brazilian pepper (Schinus terebinthifolius Raddi.), a coarse-rooted species, were grown in regular or tall #1 containers in a glasshouse and were subsequently transplanted to the field or into #3 or #5 regular or tall containers. During the nursery phase, copper-coated containers improved rootball quality of ficus and pepper, but biomass production was not affected consistenly by copper coating. Tall, narrow versus regular containers restricted pepper growth throughout the nursery phase and field establishment, but had little effect on ficus. Biomass production of pepper trees was greatest in regular-shaped containers, and tall containers reduced growth consistently. Container shape did not affect shoot growth of ficus. The larger container volume of the #5 yielded greater total biomass of pepper and root dry weight of ficus during nursery production than did #3 pots. In the field, shoot dry weight of ficus was greatest when previously grown in #5 containers, and total biomass of pepper was greatest in both regular #3 or #5 containers.

scholarly journals 822 PB 269 PINE BARK SOIL AMENDMENTS AND NUTRITION AFFECT GROWTH AND DROUGHT TOLERANCE OF VIBURNUM PLICATUM VAR. TOMENTOSUM `MARIESII'

HortScience ◽  
1994 ◽  
Vol 29 (5) ◽  
pp. 551b-551
Author(s):  
Carleton B Wood ◽  
Timothy J. Smalley ◽  
Mark Rieger
Keyword(s):  
Drought Tolerance ◽  
Leaf Area ◽  
Shoot Growth ◽  
Soil Amendments ◽  
Dry Weight ◽  
Pine Bark ◽  
Ammonium Toxicity ◽  
Shoot Dry Weight ◽  
Nitrogen Deficiencies ◽  
Water Contents

Container-grown Viburnum plicatum var. tomentosum `Mariesii' were planted in tilled beds and tilled beds amended with aged pine bark. After transplanting, plants were fertilized at three different rates: no fertilizer, 18.4 g of N m-2, and 36.8 g of N m-2. A 31 day drought was begun 73 days after planting. Fertilization of tilled plots induced ammonium toxicity, which caused a linear reduction in leaf area, shoot dry weight, and root dry weight. Fertilization of amended plots had no effect on shoot growth but reduced mot growth by 54%; thus, amendments ameliorated ammonium toxicity. Between 10 and 28 days after beginning the drought, plants in unfertilized-amended plots maintained higher relative leaf water contents (RLWC) and relative leaf expansion rates (RLER) than plants in unfertilized-tilled plots. Amendment induced nitrogen deficiencies contributed to the increased drought tolerance of plants from unfertilized-amended plots. Since fertilized plants developed symptoms of ammonium toxicity, we were unable to determine if increasing fertility would counteract the drought tolerance conferred by pine bark soil amendments.

Sign in / Sign up

Export Citation Format

Share Document