Plant Growth Response to Several Allelopathic Chemicals

Weed Science ◽  
1983 ◽  
Vol 31 (3) ◽  
pp. 293-298 ◽  
Author(s):  
Nancy L. Shettel ◽  
Nelson E. Balke
Keyword(s):  
Growth Response ◽  
Shoot Growth ◽  
Dry Weight ◽  
Amaranthus Retroflexus ◽  
Panicum Miliaceum ◽  
Weed Species ◽  
Crop Species ◽  
Proso Millet ◽  
Redroot Pigweed ◽  
Shoot Dry Weight

Salicylic acid,p-hydroxybenzoic acid, caffeine, hydroquinone, and umbelliferone were evaluated in the greenhouse for their effects on shoot dry-weight accumulation of several crop and weed species. With the exception of caffeine, all the chemicals reduced shoot growth in oats (Avena sativaL. ‘Goodfield’). Chemicals applied preplant incorporated, preemergence, or postemergence were effective, depending upon the rate of chemical. When applied preplant incorporated at rates as high as 56.0 kg/ha, most of the chemicals reduced growth of corn (Zea maysL. ‘B73 × Mo17′), soybean [Glycine max(L.) Merr. ‘Corsoy’], velvetleaf (Abutilon theophrastiMedic.), redroot pigweed (Amaranthus retroflexusL.), and wild proso millet (Panicum miliaceumL.). Exceptions were caffeine on corn and soybean and hydroquinone on soybean. At 11.2 kg/ha the chemicals inhibited the weed species more than the crop species. Postemergence applications of caffeine and hydroquinone inhibited growth of the weed species more than the crop species. Hydroquinone at 1.1 kg/ha inhibited redroot pigweed, but rates as high as 11.2 kg/ha did not inhibit soybean. These experiments show that growth of agronomically important crops and weeds can be inhibited differentially by allelopathic chemicals.

The Interaction of Soybean (Glycine max) and Five Weed Species in the Greenhouse

Weed Science ◽  
1985 ◽  
Vol 33 (5) ◽  
pp. 669-672 ◽  
Author(s):  
Janet L. Shurtleff ◽  
Harold D. Coble
Keyword(s):  
Glycine Max ◽  
Dry Matter ◽  
Dry Weight ◽  
Amaranthus Retroflexus ◽  
Matter Content ◽  
Dry Matter Content ◽  
Weed Species ◽  
Common Ragweed ◽  
Common Lambsquarters ◽  
Redroot Pigweed

The influence of relative planting date on the growth of common cocklebur (Xanthium pensylvanicumWallr. ♯ XANST), common ragweed (Ambrosia artemesiifoliaL. ♯ AMBEL), sicklepod (Cassia obtusifoliaL. ♯ CASOB), and redroot pigweed (Amaranthus retroflexusL. ♯ AMARE) grown in competition with soybean [Glycine max(L.) Merr. ‘Bragg’] was studied in the greenhouse. Increases in dry matter and height were slower for the five weed species than for soybean throughout the period of the study. The root: shoot ratio of soybean was the highest of any plant in the study, while common ragweed, common cocklebur, common lambsquarters, and sicklepod were intermediate, and redroot pigweed was the lowest. Soybean dry weight was always reduced when grown in competition with a weed. Soybean dry-matter production was reduced most when weeds were planted 2 weeks before soybean, especially with common cocklebur and common lambsquarters. Weed dry-matter content was severely reduced when the weed seed were planted simultaneously with or following soybean. Soybean height was usually reduced by competition with the weeds. The height of common ragweed was increased, however, when planted simultaneously with soybean. Common lambsquarters, redroot pigweed, and common ragweed heights were increased when planted 2 weeks prior to soybean.

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.

scholarly journals Pre-Emergence Herbicides and Mulches for Weed Control in Cutting Propagation

Agronomy ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1249
Author(s):  
Anthony L. Witcher ◽  
Isha Poudel
Keyword(s):  
Weed Control ◽  
Crop Production ◽  
Dry Weight ◽  
Stem Cuttings ◽  
Weed Species ◽  
Crop Species ◽  
Cutting Propagation ◽  
Shoot Dry Weight ◽  
Cost Efficient ◽  
Hand Weeding

Weed control is critical in cutting propagation to maximize root growth and liner quality, but hand weeding is time consuming and not cost efficient. Pre-emergence herbicides are widely used in container-grown nursery crop production, but concerns of potential phytotoxicity have limited widespread use in propagation. Mulches are a viable alternative for weed control but few products have been evaluated in propagation. Five pre-emergence herbicides and five mulches were evaluated for rooting stem cuttings of three nursery crop species and for control of four weed species. Mulches were applied (0.8 cm depth) prior to sticking cuttings while pre-emergence herbicides were applied (low labeled rate) two weeks after sticking cuttings. Rooting percentage, root dry weight, and shoot dry weight were not affected by pre-emergence herbicide or mulch, except for butterfly bush (Buddleja davidii ‘Nanho Blue’) which was severely injured when treated with the pre-emergence herbicide isoxaben. Oxyfluorfen + oxadiazon provided excellent control of all tested weed species and has potential to be used in propagation of a number of crops. Mulches did not provide adequate weed control, but increased application depth may enhance efficacy and should be further evaluated.

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.

Effects of Temperature and Photoperiod on Texas Panicum (Panicum texanum) and Wild Proso Millet (Panicum miliaceum)

Weed Science ◽  
1986 ◽  
Vol 34 (6) ◽  
pp. 876-882 ◽  
Author(s):  
David T. Patterson ◽  
Ann E. Russell ◽  
David A. Mortensen ◽  
Robert D. Coffin ◽  
Elizabeth P. Flint
Keyword(s):  
United States ◽  
Vegetative Growth ◽  
Dry Matter ◽  
Dry Weight ◽  
Growing Season ◽  
Southern United States ◽  
Panicum Miliaceum ◽  
Proso Millet ◽  
Effects Of Temperature ◽  
Total Dry Weight

Texas panicum (Panicum texanumBuckl. # PANTE) is a native of the Southwest, now increasing as a weed throughout the southern United States, whereas wild proso millet (Panicum miliaceumL. # PANMI) is an introduced weed currently increasing in importance in the northern Midwest. In controlled-environment chambers, both species produced more tillers, greater leaf area, and more total dry weight at 30/24 C day/night (simulated growing season temperature in Georgia) than at 24/18 C (simulated growing season temperature in Minnesota). Texas panicum accumulated more dry matter at 30/24 C than did wild proso millet, while wild proso millet accumulated more dry matter at 24/18 C than did Texas panicum. When the two species were grown together, Texas panicum was the superior competitor at 30/24 C while wild proso millet was superior at 24/18 C. Exposure to short photoperiods at an intermediate temperature of 27/21 C accelerated flowering and limited vegetative growth in both species. In the range of photoperiods (10 to 16 h) examined, wild proso millet always flowered earlier and, consequently, produced less vegetative growth than Texas panicum. Its responses to temperature and photoperiod indicate that wild proso millet probably would be competitively inferior to Texas panicum and other adapted grass weeds in the southern United States.

The growth of Yellow Bells (Geleznowia verrucosa) seedlings in response to additions of nitrogen, potassium and phosphorus fertiliser

1998 ◽  
Vol 38 (4) ◽  
pp. 385
Author(s):  
R. F. Brennan ◽  
A. M. Crowhurst ◽  
M. G. Webb
Keyword(s):  
Plant Growth ◽  
Western Australia ◽  
Growth Response ◽  
Shoot Growth ◽  
Native Plants ◽  
Dry Weight ◽  
Critical Concentrations ◽  
Phosphorus Fertiliser ◽  
N Fertilisers ◽  
Optimum Production

Summary. Native plants are increasingly grown in Western Australia to produce flowers for export. The nitrogen (N), phosphorus (P) and potassium (K) requirements for optimum production of one of these species, Geleznowia verrucosa (Yellow Bells), was measured for 17-week-old seedlings in a glasshouse experiment reported here. There was a significant (P<0.05) growth response to all levels of N fertilisers. At all levels of P and K, except for the nil K treatments, the lowest level of applied N (20 mg N/kg soil) gave the maximum dry weight of shoots. The dry weight of shoots increased with the addition of P fertiliser to the highest level (160 mg P/kg soil), particularly for the lower levels of applied K (0 and 30 mg/kg soil) and the lowest level of applied N (20 mg/kg soil). Combinations of high levels of P (P160) and N (N80) fertiliser severely depressed shoot growth. When applied at greater than 30 mg K/kg soil, K fertiliser depressed plant growth at all levels of N and P when compared with the lower levels of applied K. At the seedling stage of growth, critical concentrations for deficiency of both N and K were 1.3% in shoots. The critical concentrations for toxicity in whole shoots of Yellow Bells appeared to be about 1.7% for N and about 2.2% for K. Adequate concentrations of N were 1.4–1.5%, while 1.7% K appeared adequate for growth of Yellow Bell shoots.

Response of Weed Seeds to Ethylene and Related Hydrocarbons

Weed Science ◽  
1979 ◽  
Vol 27 (1) ◽  
pp. 7-10 ◽  
Author(s):  
R. B. Taylorson
Keyword(s):  
Chenopodium Album ◽  
Active Form ◽  
Amaranthus Retroflexus ◽  
Weed Species ◽  
Hydrocarbon Gases ◽  
Common Lambsquarters ◽  
Setaria Faberi ◽  
Redroot Pigweed ◽  
Giant Foxtail ◽  
Common Purslane

AbstractGermination of seeds of 10 grass and 33 broadleaved weed species was examined for response to ethylene. Germination was promoted in nine species, inhibited in two, and not affected in the remainder. Of the species promoted, common purslane (Portulaca oleraceaL.), common lambsquarters (Chenopodium albumL.), and several Amaranths, including redroot pigweed (Amaranthus retroflexusL.), were affected most. Transformation of phytochrome to the active form (Pfr) gave interactions that ranged from none to syntergistic with the applied ethylene. In subsequent tests seeds of purslane, redroot pigweed, and giant foxtail (Setaria faberiHerrm.), a species not responsive to ethylene, were examined for germination response to 14 low molecular weight hydrocarbon gases other than ethylene. Some stimulation by the olefins propylene and propadiene was found for purslane and pigweed. Propionaldehyde and butyraldehyde were slightly stimulatory to purslane only.

Sign in / Sign up

Export Citation Format

Share Document