Growth and Development of Bigroot Morningglory (Ipomoea pandurata)

Growth and development of bigroot morningglory was observed and quantified. Emergence occurred 75 ± 5 growing degree days (GDD) after seeding. Flower and seed production began 630 ± 20 GDD after emergence and continued until the first frost killed the shoots. Seedlings needed approximately 460 GDD of growth to become perennial. In the second year of growth, plants emerged in early May and flowered within 425 ± 50 GDD. Shoot dry weight accumulation in first-year plants was 3.5 g for the first 600 GDD after which a fifteenfold increase in dry weight occurred. Root growth followed the same pattern, however the large increase in dry weight occurred approximately 300 GDD later than that of the shoots. The root:shoot ratio was 0.2 to 0.3 for the first 900 GDD and increased to greater than 1.0 by the final harvest.

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

Journal of Environmental Horticulture ◽

10.24266/0738-2898-33.3.137 ◽

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.

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Effect of Transplanting and Paclobutrazol on Root Growth of ‘Green Column’ Black Maple and ‘Summit’ Green Ash

Journal of Environmental Horticulture ◽

10.24266/0738-2898-22.4.209 ◽

2004 ◽

Vol 22 (4) ◽

pp. 209-212 ◽

Cited By ~ 5

Author(s):

Gray Watson

Keyword(s):

Root Growth ◽

Growth Regulation ◽

Dry Weight ◽

Extension Growth ◽

First Year ◽

Fraxinus Pennsylvanica ◽

Green Ash ◽

Root Extension ◽

Root Dry Weight ◽

Second Year

Abstract ‘Summit’ green ash (Fraxinus pennsylvanica ‘Summit’) and ‘Green Column’ black maples (Acer nigrum ‘Green Column’) were transplanted and treated with paclobutrazol (PBZ) to study its effect on root growth after transplanting. PBZ increased root extension growth of transplanted ‘Green Column’ maples in the first year after treatment, prior to the onset of above-ground growth regulation. Root growth of transplanted ‘Summit’ ash was not affected by PBZ. Transplanting reduced extension growth of regenerated roots in the first year for ‘Green Column’ maples with no effect on root dry weight. In ‘Summit’ green ash transplanting increased root extension growth in the second year, and root dry weight in both years.

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Influence of Various Polyethylene Mulch Colors on Growth and Development of `Vates' Collards

HortScience ◽

10.21273/hortsci.32.4.600d ◽

1997 ◽

Vol 32 (4) ◽

pp. 600D-600

Author(s):

J.M Kemble ◽

J. Brown ◽

E. Simonne

Keyword(s):

Growth And Development ◽

Soil Depth ◽

Dry Weight ◽

Base Temperature ◽

Fresh Weight ◽

Degree Days ◽

Marketable Yield ◽

Soil Temperatures ◽

Polyethylene Mulch ◽

Final Harvest

The effect of various mulch colors (black, yellow, red, blue, white, and aluminum) on growth and development of `Vates' collards was evaluated in Fall 1996 at the E.V. Smith Research Center in Shorter, Ala. Black polyethylene mulch was installed onto raised, fumigated beds, then sprayed with a 1: 2 (v/v) mixture of exterior oil-based enamel paint to paint thinner with one of the five mulch colors listed. Five-week-old plants were transplanted into beds. Beginning two weeks after transplanting and continuing every other week thereafter, heads were harvested to determine head fresh weight and dry weight. Hourly soil temperatures at 10 cm soil depth were recorded and growing degree days (GDDs) with a base temperature of 4.4 °C were calculated. At two weeks after transplanting, average head fresh and dry weight were highest for the aluminum-colored treatment with head fresh (24.7 and 12.3 g, respectively) and dry weights (2.7 and 1.3 g, respectively) twice that of the yellow treatment (P ≤ 0.05). By four weeks after transplanting and up through the final harvest, marketable yield and average head fresh weights did not differ among the treatments (17,900 kg/ha, 1.4 kg per head, respectively). The red and black mulch treatments accumulated more GDDs than the other treatments, but total marketable yields did not differ among any treatments.

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Growth and Development of Purple Nutsedge Based on Days or Thermal Units

Planta Daninha ◽

10.1590/0100-83582015000200001 ◽

2015 ◽

Vol 33 (2) ◽

pp. 165-173 ◽

Cited By ~ 1

Author(s):

R.S.O. Lima ◽

E.C.R. Machado ◽

A.P.P. Silva ◽

B.S. Marques ◽

M.F. Gonçalves ◽

...

Keyword(s):

Plant Growth ◽

Mathematical Models ◽

Growth And Development ◽

Dry Matter ◽

Cyperus Rotundus ◽

Growing Degree Days ◽

Plant Growth And Development ◽

Degree Days ◽

Purple Nutsedge ◽

Independent Trials

This work was carried out with the objective of elaborating mathematical models to predict growth and development of purple nutsedge (Cyperus rotundus) based on days or accumulated thermal units (growing degree days). Thus, two independent trials were developed, the first with a decreasing photoperiod (March to July) and the second with an increasing photoperiod (August to November). In each trial, ten assessments of plant growth and development were performed, quantifying total dry matter and the species phenology. After that, phenology was fit to first degree equations, considering individual trials or their grouping. In the same way, the total dry matter was fit to logistic-type models. In all regressions four temporal scales possibilities were assessed for the x axis: accumulated days or growing degree days (GDD) with base temperatures (Tb) of 10, 12 and 15 oC. For both photoperiod conditions, growth and development of purple nutsedge were adequately fit to prediction mathematical models based on accumulated thermal units, highlighting Tb = 12 oC. Considering GDD calculated with Tb = 12 oC, purple nutsedge phenology may be predicted by y = 0.113x, while species growth may be predicted by y = 37.678/(1+(x/509.353)-7.047).

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Root Microbiome Modulates Plant Growth Promotion Induced by Low Doses of Glyphosate

mSphere ◽

10.1128/msphere.00484-20 ◽

2020 ◽

Vol 5 (4) ◽

Author(s):

Dario X. Ramirez-Villacis ◽

Omri M. Finkel ◽

Isai Salas-González ◽

Connor R. Fitzpatrick ◽

Jeffery L. Dangl ◽

...

Keyword(s):

Plant Growth ◽

Root Growth ◽

Growth Inhibition ◽

Growth Promotion ◽

Action Spectrum ◽

Dry Weight ◽

Agricultural Fields ◽

Low Doses ◽

Shoot Dry Weight ◽

Root Microbiome

ABSTRACT Glyphosate is a commonly used herbicide with a broad action spectrum. However, at sublethal doses, glyphosate can induce plant growth, a phenomenon known as hormesis. Most glyphosate hormesis studies have been performed under microbe-free or reduced-microbial-diversity conditions; only a few were performed in open systems or agricultural fields, which include a higher diversity of soil microorganisms. Here, we investigated how microbes affect the hormesis induced by low doses of glyphosate. To this end, we used Arabidopsis thaliana and a well-characterized synthetic bacterial community of 185 strains (SynCom) that mimics the root-associated microbiome of Arabidopsis. We found that a dose of 3.6 × 10−6 g acid equivalent/liter (low dose of glyphosate, or LDG) produced an ∼14% increase in the shoot dry weight (i.e., hormesis) of uninoculated plants. Unexpectedly, in plants inoculated with the SynCom, LDG reduced shoot dry weight by ∼17%. We found that LDG enriched two Firmicutes and two Burkholderia strains in the roots. These specific strains are known to act as root growth inhibitors (RGI) in monoassociation assays. We tested the link between RGI and shoot dry weight reduction in LDG by assembling a new synthetic community lacking RGI strains. Dropping RGI strains out of the community restored growth induction by LDG. Finally, we showed that individual RGI strains from a few specific phyla were sufficient to switch the response to LDG from growth promotion to growth inhibition. Our results indicate that glyphosate hormesis was completely dependent on the root microbiome composition, specifically on the presence of root growth inhibitor strains. IMPORTANCE Since the introduction of glyphosate-resistant crops, glyphosate has become the most common and widely used herbicide around the world. Due to its intensive use and ability to bind to soil particles, it can be found at low concentrations in the environment. The effect of these remnants of glyphosate in plants has not been broadly studied; however, glyphosate 1,000 to 100,000 times less concentrated than the recommended field dose promoted growth in several species in laboratory and greenhouse experiments. However, this effect is rarely observed in agricultural fields, where complex communities of microbes have a central role in the way plants respond to external cues. Our study reveals how root-associated bacteria modulate the responses of Arabidopsis to low doses of glyphosate, shifting between growth promotion and growth inhibition.

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Copper nutrition of subterranean clover (Trifolium subterraneum L. cv. Seaton Park). I. Effects of copper supply on growth and development

Australian Journal of Agricultural Research ◽

10.1071/ar9810257 ◽

1981 ◽

Vol 32 (2) ◽

pp. 257 ◽

Cited By ~ 3

Author(s):

DJ Reuter ◽

AD Robson ◽

JF Loneragan ◽

DJ Tranthim-Fryer

Keyword(s):

Root Growth ◽

Growth And Development ◽

Copper Deficiency ◽

Subterranean Clover ◽

Trifolium Subterraneum ◽

Dry Weight ◽

Growing Season ◽

Internode Elongation ◽

Plant Parts ◽

Lateral Branches

Effects of severe and moderate copper deficiency on the development of leaves and lateral branches, on the distribution of dry weight within the plant, and on seed yield of Seaton Park subterranean clover were assessed as part of three glasshouse experiments. Copper deficiency markedly depressed top and root growth without producing any distinctive symptoms. It retarded phasic development by delaying development of leaves and lateral branches, senescence of plant parts, and flowering: it also depressed the proportion of stem plus petiole in plant tops and decreased internode elongation, pollen fertility and the number of burrs and seeds formed. As a result of its effect in delaying flowering, copper deficiency would depress seed production particularly strongly when low soil water supply shortens the growing season. The need for suitable procedures for diagnosing copper deficiency is emphasized by the lack of specific plant symptoms in this species.

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Effects of subsoil calcium on the root growth of some lucerne genotypes (Medicago sativa L.) in acidic soil profiles

Australian Journal of Agricultural Research ◽

10.1071/ar9770629 ◽

1977 ◽

Vol 28 (4) ◽

pp. 629 ◽

Cited By ~ 15

Author(s):

JR Simpson ◽

A Pinkerton ◽

J Lazdovskis

Keyword(s):

Root Growth ◽

Lower Layer ◽

Dry Weight ◽

Solution Culture ◽

Acidic Soil ◽

Root Penetration ◽

Soil Calcium ◽

Medicago Sativa L ◽

Total Dry Weight ◽

Final Harvest

The root growth of lucerne was examined in an acidic soil profile modified by varying additions of calcium carbonate to different layers of the subsoil. Root growth responded strongly to changes in the concentration of exchangeable soil calcium. Symptoms of thickening, distortion and poor lateral formation occurred under low calcium treatments. The results were in agreement with the interacting effects of calcium (at 0.5–5.0mM) and aluminium ions (at 0–20,µM) on lucerne in separate solution culture experiments. Differences in root penetration were observed between three lucerne clones selected from the cultivars Hunter River and Siro Peruvian. At the first harvest, the magnitude of these differences was increased by the addition of lime to the profiles. The three genotypes produced similar total dry weight yields, but differed in their distribution of growth between shoots and roots. This distribution was not affected by the addition of lime to the subsoil. However, the length of roots in the lower layer of the profile ( > 60 cm depth) was more responsive to subsoil treatment than was total dry weight. At the final harvest, the shoot yields of two genotypes were affected by lime treatments, but that of the deepest-rooted genotype was not. The results suggest that improved genotypes could be selected from Australian lucernes for establishment in areas with acidic subsoils, but that selection on root penetration alone would not necessarily lead to increased shoot yields.

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Dog mustard (Erucastrum gallicum) response to crop competition

Weed Science ◽

10.1017/s0043174500093048 ◽

1997 ◽

Vol 45 (3) ◽

pp. 397-403

Author(s):

David A. Wall

Keyword(s):

Interspecific Competition ◽

Leaf Area ◽

Seed Production ◽

Growth And Development ◽

Dry Weight ◽

Field Studies ◽

Limiting Factor ◽

Shoot Dry Weight ◽

Summer Fallow ◽

Crop Competition

Greenhouse studies suggested that dog mustard was less competitive than wheat, but of similar competitiveness to flax. In field studies, dog mustard growth and development were markedly affected by crop competition. Competition from flax and wheat reduced dog mustard leaf area, shoot dry weight, plant height, and seed production compared with the weed grown on summer-fallow. Dog mustard was a prolific seed producer when grown in the absence of interspecific competition. On summer-fallow, dog mustard produced as many as 79,100 seeds plant−1when moisture was not a limiting factor. However, average seed production was 19,400 and 8000 seeds plant−1in 1994 and 1995, respectively.

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Pot-In-Pot Production and Cyclic Irrigation Influence Growth and Irrigation Efficiency of ‘Okame’ Cherries

Journal of Environmental Horticulture ◽

10.24266/0738-2898-16.3.159 ◽

1998 ◽

Vol 16 (3) ◽

pp. 159-162 ◽

Cited By ~ 1

Author(s):

John M. Ruter

Keyword(s):

Water Loss ◽

Production System ◽

Dry Weight ◽

Stem Diameter ◽

Total Biomass ◽

Root:Shoot Ratio ◽

Irrigation Application ◽

Application Efficiency ◽

Shoot Dry Weight ◽

Daily Water

Abstract A study was conducted with Prunus x incamp ‘Okame’ to evaluate the effects of a pot-in-pot production system (PIP) compared to a conventional above-ground system (CAG) and cyclic irrigation on plant growth and water loss. Plants were grown in #7 (26 liter) containers with a pinebark: sand (8:1 by vol) substrate. Cyclic irrigation provided the same total volume of water, but was applied one, three, or four times per day. Final plant height and stem diameter, shoot and root dry weight, total biomass, and root:shoot ratio all increased for plants grown pot-in-pot compared to above-ground. Multiple irrigation cycles increased stem diameter, shoot dry weight and total biomass compared to a single irrigation application. Multiple irrigation cycles also decreased the root:shoot ratio. Mean daily water loss (plant transpiration + evaporative loss from the substrate) was influenced by production system, irrigation, and date. Mean daily water loss was 30% higher for pot-in-pot grown plants compared to above-ground. Cyclic irrigation resulted in a two-fold decrease in average leachate volume and a 27% increase in overall irrigation application efficiency compared to a single application. Production system had no affect on leachate volume or irrigation application efficiency. Substrate pH increased when cyclic irrigation was used. Production system and irrigation had no affect on soluble salts. Nitrate-N concentrations were less in the leachate of plants grown pot-in-pot compared to above-ground.

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Zoysiagrass Establishment from Sprigs following Application of Herbicides, Nitrogen, and a Biostimulator

HortScience ◽

10.21273/hortsci.31.6.972 ◽

1996 ◽

Vol 31 (6) ◽

pp. 972-975 ◽

Cited By ~ 11

Author(s):

M.J. Carroll ◽

P.H. Dernoeden ◽

J.M. Krouse

Keyword(s):

Root Growth ◽

Dimethyl Ester ◽

Growing Season ◽

Field Studies ◽

First Year ◽

Zoysia Japonica ◽

Second Year ◽

Herbicide Use ◽

Preemergence Herbicides ◽

Postemergence Herbicides

Sprigs of `Meyer' zoysiagrass (Zoysia japonica Steud.) were treated with urea nitrogen, a biostimulator, and one of three preemergence herbicides or one of two postemergence herbicides to hasten establishment in two field studies. Monthly application of N at 48 kg·ha–1 during the growing season had no influence on sprig establishment the first year, but slightly increased (+5%) zoysiagrass cover the second year. Presoaking sprigs in a solution containing (mg·L–1) 173 auxin and 81 cytokinin, and iron at 1.25 g·L–1 before broadcasting of sprigs, and biweekly sprays (g·ha–1) of 53 auxin and 24 cytokinin, and iron at 0.2 g·L–1 or (g·ha–1) 68 auxin and 36 cytokinin, and iron at 1.45 g·L–1 after broadcasting sprigs had no effect on zoysiagrass cover or rooting. Preemergence and postemergence herbicide use generally enhanced zoysiagrass cover by reducing smooth crabgrass competition [Digitaria ischaemum (Schreb. ex Schweig) Schreb. ex Muhl]. Oxadiazon enhanced zoysiagrass coverage more than dithiopyr, pendimethalin, quinclorac, or fenoxaprop. Oxadiazon and dithiopyr provided similar levels of crabgrass control, but dithiopyr reduced `Meyer' zoysiagrass midsummer root growth. Chemical names used: 3,5,-pyridinedicarbothioic acid, 2-[difluromethyl]-4-[2-methyl-propyl]-6-(trifluoromethyl)-S,S-dimethyl ester (dithiopyr); [±]-ethyl 2-[4-[(6-chloro-2-benzoxazolyl)oxy]phenoxy] propanoate (fenoxaprop); 3-[2,4-dichloro-5-(1-methylethoxy)phenyl]-5-(1,1-dimethylethyl)-1,3,4-oxadiazol-2-(3H)-one (oxadiazon); N-(1-ethylpropyl)-3,4-dimethyl-2,6-dinitrobenzenamine (pendimethalin); 3,7-dichloro-8-quin-olinecarboxylic acid (quinclorac).

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