Response of ‘TifEagle’ Bermudagrass (Cynodon dactylon × Cynodon transvaalensis) to Ethephon and Trinexapac-ethyl

2005 ◽  
Vol 19 (2) ◽  
pp. 251-254 ◽  
Author(s):  
Patrick E. McCullough ◽  
Lambert B. McCarty ◽  
Haibo Liu ◽  
Ted Whitwell
Keyword(s):  
Root Length ◽  
Cynodon Dactylon ◽  
Peat Moss ◽  
Root Mass ◽  
Negative Effects ◽  
Clemson University ◽  
Soil Medium ◽  
The Third ◽  
Surface Areas ◽  
Turf Quality

Turf managers combine ethephon with trinexapac-ethyl (TE) on bentgrass greens to suppress annual bluegrass, inhibit turf growth, and enhance turf quality; however, effects of this growth regulator combination have not been reported on bermudagrass greens. Two experiments were conducted at the Clemson University Greenhouse Complex to investigate the response of ‘TifEagle’ bermudagrass to ethephon and TE. TifEagle bermudagrass plugs were placed in pots with 23-cm depths, 324-cm2 total surface areas, and a soil medium of an 85:15 (v/v) sand and peat moss mix. Ethephon was applied at 0, 3.8 (EP1), and 7.6 (EP2) kg ai/ha/3 wk with TE at 0 and 0.04 kg ai/ha/ 3 wk over a 9-wk period. Initial responses of bermudagrass to ethephon included chlorotic leaves and severe thinning. Bermudagrass treated with ethephon had quality reduced as much as 33% from nontreated turf. TE enhanced turf quality 4 to 22% from 4 to 9 wk after initial treatment. TE helped mask ethephon-induced quality decline after the third application. In the presence of TE, bermudagrass clipping yield was reduced from nontreated turf by 57, 70, and 72% when ethephon was applied at 0, 3.8, and 7.6 kg/ha/3 wk. Ethephon linearly reduced root mass after 9 wk from nontreated turf by 20 and 33% at 3.8 and 7.6 kg/ha/3 wk, respectively. Compared with respective ethephon rates alone, bermudagrass treated with TE and ethephon at 0, 3.8, and 7.6 kg/ha/3 wk, averaged 28, 8, and 15% more root mass. Ethephon at 3.8 and 7.6 kg/ha/3 wk without TE reduced TifEagle bermudagrass root length 14 and 16%, respectively, compared with untreated turf. Bermudagrass treated with ethephon at 0, 3.8, and 7.6 kg/ha/3 wk with TE averaged 3, 11, and 17% higher root length compared with respective ethephon rates after 9 wk. Overall, ethephon may have negative effects on TifEagle root mass, root length, and turf quality. However, combining ethephon with TE may help reduce these deleterious effects.

scholarly journals Physiological Response of `TifEagle' Bermudagrass to Paclobutrazol

HortScience ◽  
2005 ◽  
Vol 40 (1) ◽  
pp. 224-226 ◽  
Author(s):  
Patrick E. McCullough ◽  
Haibo Liu ◽  
Lambert B. McCarty ◽  
Ted Whitwell
Keyword(s):  
Root Length ◽  
Physiological Response ◽  
Cynodon Dactylon ◽  
Root Mass ◽  
Clemson University ◽  
Turf Quality

Research was conducted in two studies at the Clemson University Greenhouse Complex, Clemson, S.C., with the objective of evaluating `TifEagle' bermudagrass (Cynodon dactylon × C. transvaalensis) response to paclobutrazol. TifEagle bermudagrass plugs were placed in 40 cm polyvinylchloride containers, with 20.3-cm-diameters and built to U.S. Golf Association specifications with 85 sand: 15 peatmoss (by volume) rootzone mix. Paclobutrazol was applied to separate containers at 0, 0.14, 0.28, and 0.42 kg·ha-1 (a.i.) per 6 weeks. Minor phytotoxicity occurred with 0.14 kg·ha-1 applications, but turf quality was unaffected. Severe bermudagrass phytotoxicity occurred from paclobutrazol at 0.28 and 0.42 kg·ha-1. Total clipping yield from 12 sampling dates was reduced 65%, 84%, and 92% from 0.14, 0.28, and 0.42 kg·ha-1, respectively. Root mass after 12 weeks was reduced 28%, 45%, and 61% for turf treated 0.14, 0.28, and 0.42 kg·ha-1, respectively. Paclobutrazol reduced root length 13%, 19%, and 19% by 0.14, 0.28, and 0.42 kg·ha-1, respectively. Turf discoloration and negative rooting responses advocate caution when using paclobutrazol on `TifEagle' bermudagrass. Chemical names used: (+/-)-(R*,R*)-ß-[(4-chlorophenyl) methyl]-alpha-(1, 1-dimethyl)-1H-1,2,4,-triazole-1-ethanol (paclobutrazol).

scholarly journals Preemergence Herbicide Effects on Hybrid Bermudagrass Root Architecture and Establishment

HortScience ◽  
2018 ◽  
Vol 53 (4) ◽  
pp. 567-572 ◽  
Author(s):  
Erick G. Begitschke ◽  
James D. McCurdy ◽  
Te-Ming Tseng ◽  
T. Casey Barickman ◽  
Barry R. Stewart ◽  
...  
Keyword(s):  
Root Length ◽  
Root Architecture ◽  
Cynodon Dactylon ◽  
Future Research ◽  
Root Mass ◽  
Randomized Design ◽  
Herbicide Treatments ◽  
Negative Effect ◽  
Herbicide Effects ◽  
Preemergence Herbicides

Preemergence herbicides generally have a negative effect on hybrid bermudagrass [Cynodon dactylon (L.) Pers. × C. transvaalensis Burtt-Davy] establishment. However, little is known about the effect they have on root architecture and development. Research was conducted to determine the effects of commonly used preemergence herbicides on ‘Latitude 36’ hybrid bermudagrass root architecture and establishment. The experiment was conducted in a climate-controlled greenhouse maintained at 26 °C day/night temperature at Mississippi State University in Starkville, MS, from Apr. 2016 to June 2016 and repeated from July 2016 to Sept. 2016. Hybrid bermudagrass plugs (31.6 cm2) were planted in 126-cm2 pots (1120 cm3) and preemergence herbicide treatments were applied 1 d after planting at the recommended labeled rate for each herbicide. Preemergence herbicide treatments included atrazine, atrazine + S-metolachlor, dithiopyr, flumioxazin, indaziflam, liquid and granular applied oxadiazon, S-metolachlor, pendimethalin, prodiamine, and simazine. Treatments were arranged in a completely randomized design with four replications. Plugs treated with indaziflam and liquid applied oxadiazon failed to achieve 50% hybrid bermudagrass cover by the end of the experiment. Of the remaining herbicide treatments, all herbicides other than granular applied oxadiazon and atrazine increased the number of days required to reach 50% cover (Days50). In addition, all herbicide treatments reduced root mass when harvested 6 weeks after treatment (WAT) relative to the nontreated. By 10 WAT, all treatments reduced root mass in run 1, but during run 2, only prodiamine, pendimethalin, simazine, atrazine + S-metolachlor, liquid applied oxadiazon, and indaziflam reduced dry root mass compared with the nontreated. At 4 WAT, all treatments other than simazine and granular applied oxadiazon reduced root length when compared with the nontreated. By 10 WAT, only dithiopyr, S-metolachlor alone, and indaziflam reduced root length when compared with the nontreated. No differences were detected in the total amounts of nonstarch nonstructural carbohydrates (TNSC) within the roots in either run of the experiment. Results suggest that indaziflam, dithiopyr, and S-metolachlor are not safe on newly established hybrid bermudagrass and should be avoided during establishment. For all other treatments, hybrid bermudagrass roots were able to recover from initial herbicidal injury by 10 WAT; however, future research should evaluate tensile strength of treated sod.

Response of ‘TifEagle’ Bermudagrass (Cynodon dactylon×C. transvaalensis) to Fenarimol and Trinexapac-Ethyl

2006 ◽  
Vol 20 (1) ◽  
pp. 1-5 ◽  
Author(s):  
Patrick E. McCullough ◽  
Lambert B. McCarty ◽  
Haibo Liu
Keyword(s):  
Root Growth ◽  
Root Length ◽  
Initial Treatment ◽  
Cynodon Dactylon ◽  
Poa Annua ◽  
Root Mass ◽  
Minor Injury ◽  
Repeated Applications ◽  
Growth Restrictions

Fall applications of fenarimol on hybrid Bermudagrass (Cynodon dactylon×C. transvaalensis) provide effective preemergencePoa annua(L.) control and suppressOphiosphaerellaspp. pathogens; however, concerns exist for turf injury and root growth restrictions. Two 60-d greenhouse studies were conducted to evaluate the effects of fenarimol at 0, 1.6, and 3.2 kg ai/ha per 30 d with and without trinexapac-ethyl (TE) at 0.017 kg ai ha/15 d on ‘TifEagle’ Bermudagrass. Turf color was enhanced by TE 14 d after initial treatment (DAIT) and was continually superior throughout the experiment. Fenarimol at 3.2 kg/ha per 30 d decreased turf color 14 DAIT, but was similar to nontreated turf on all other observation dates. Increased fenarimol rates applied twice caused approximately 10% injury at 42, 49, and 56 d after treatment; however, injury was acceptable after initial and repeat applications. TE reduced clipping yield an average 39% from six sampling dates. Initial fenarimol applications (without TE) reduced clippings by 37% 20 DAIT and repeated applications reduced clippings 40, 50, and 60 DAIT. Increased fenarimol rate linearly decreased root mass for turf treated with and without TE; however, Bermudagrass receiving TE averaged 23% enhanced root mass 60 DAIT over all fenarimol rates. Bermudagrass receiving fenarimol at 0, 1.6, and 3.2 kg/ ha per 30 d with TE averaged 27, 24, and 16% higher root mass, respectively, compared to turf receiving fenarimol without TE. Treatments had no influence on root length. Results indicate that two consecutive fenarimol applications at 1.6 and 3.2 kg/ha per 30 d may cause minor injury to TifEagle Bermudagrass and restrict root growth. Repeated TE applications, however, could decrease injury from fenarimol and enhance rooting relative to fenarimol applied exclusively.

scholarly journals Response of Six Dwarf-type Bermudagrasses to Trinexapac-ethyl

HortScience ◽  
2005 ◽  
Vol 40 (2) ◽  
pp. 460-462 ◽  
Author(s):  
Patrick E. McCullough ◽  
Haibo Liu ◽  
Lambert B. McCarty
Keyword(s):  
Root Length ◽  
Acid Ethyl Ester ◽  
Visual Quality ◽  
Growth Retardant ◽  
Root Mass ◽  
Growth Responses ◽  
Turf Quality ◽  
Research Complex ◽  
Cyclohexane Carboxylic Acid ◽  
Dwarf Type

Trinexapac-ethyl (TE) is an effective plant growth retardant for hybrid bermudagrass; however, growth responses of various dwarf-type bermudagrass cultivars to TE have not been reported. Two 60-day greenhouse experiments were conducted at the Clemson Greenhouse Research Complex, Clemson, S.C., to evaluate the response of `Champion', `FloraDwarf', `MiniVerde', `MS Supreme', `Tifdwarf', and `TifEagle' bermudagrass with and without TE at 0.0125 kg·ha-1 a.i. per 10 days. From 20 to 60 days after initial treatments, TE enhanced visual quality 9% to 13% for all cultivars. From four samples, TE reduced clippings 63%, 63%, 69%, 62%, 64%, and 46% for `Champion', `FloraDwarf', `MiniVerde', `Tifdwarf', and `TifEagle', respectively. Trinexapac-ethyl enhanced root mass 23% and 27% for `MiniVerde' and `FloraDwarf' bermudagrass, respectively. `Champion', `MS Supreme', `Tifdwarf', and `TifEagle' bermudagrass treated with TE had similar root mass to the untreated respective cultivars. Among untreated cultivars, `FloraDwarf', `MiniVerde', `MS Supreme', and `Tifdwarf' had similar root masses; however compared to these cultivars, `Champion' and `TifEagle' had 33% and 81% less root mass, respectively. Root length was unaffected by TE; however, `Champion' and `TifEagle' averaged 20% and 36% less root length compared to `Tifdwarf' bermudagrass, respectively, while `FloraDwarf', `MiniVerde', and `MS Supreme' had similar root length to `Tifdwarf'. Trinexapac-ethyl safely enhanced turf quality and reduced clipping yield at 0.0125 kg·ha-1 per 10 days without inhibiting root growth of six dwarf-type bermudagrasses. Chemical name used: [4-(cyclopropyl-[α]-hydroxymethylene)-3,5-dioxo-cyclohexane carboxylic acid ethyl ester] (trinexapac-ethyl).

scholarly journals Drought Avoidance Mechanisms of Selected Bermudagrass Genotypes

HortScience ◽  
1991 ◽  
Vol 26 (2) ◽  
pp. 180-182 ◽  
Author(s):  
K.L. Hays ◽  
J.F. Barber ◽  
M.P. Kenna ◽  
T.G. McCollum
Keyword(s):  
Drought Stress ◽  
Root Distribution ◽  
Cynodon Dactylon ◽  
Carbohydrate Content ◽  
Root Mass ◽  
Greenhouse Study ◽  
Drought Avoidance ◽  
Turf Quality ◽  
Simulated Drought ◽  
And Performance

This study was conducted to determine rooting characteristics, root carbohydrate content, and performance of 10 bermudagrass [Cynodon dactylon (L.) Pers.] genotypes exposed to drought. A greenhouse study was conducted twice to determine root distribution and carbohydrate content throughout the soil profile during simulated drought stress. Root distribution among genotypes and accumulation of total nonstructural carbohydrate within roots differed with depths. Root mass at 30, 60, 90, and 150 cm was significantly correlated with turf quality during drought stress (r = 0.72, 0.86, 0.80, and 0.81, respectively) only for one of the two tests. Root carbohydrate distribution was not significantly correlated with turf quality for the selected bermudagrass genotypes.

scholarly journals Causes of Regionalism. How ASEAN-China FTA Fits the (New) Wave of Regionalism?

2017 ◽  
Vol 17 (1) ◽  
pp. 66-94
Author(s):  
Ivana Miková
Keyword(s):  
Common Mechanism ◽  
Third Wave ◽  
New Wave ◽  
Negative Effects ◽  
Regional Trade ◽  
Multilateral Trade ◽  
The Third ◽  
Alternative Approach ◽  
General Logic ◽  
Balance Mechanism

AbstractThe main aim of this paper is to discuss standard explanations of the causes respective to each wave of economic regionalism and to introduce an alternative approach suggesting the existence of a common mechanism driving all three periods of intensified economic integration. This study argues for the general logic to economic regionalism based on the balance mechanism. Proposed mechanism embraces standard theoretical explanations and places them into a broader context of general encompassing logic common to all three occurrences of economic regionalism. For acquiring empirical evidence of this mechanism, all three waves of regionalism and their causes are analysed as well as on one particular case of the third wave of regionalism - ASEAN-China FTA. Central motivation is the existence of plethora of factors leading to the preference of the regional trade strategies in particular time periods without offering explanation common to all three main occurrences of regionalism. However, this study argues that every instance of economic turmoil leads to protectionist tendencies in the form of economic regionalism followed by the multilateral trade liberalisation mitigating negative effects of protectionist tendencies.

scholarly journals Variability of root traits in common bean genotypes at different levels of phosphorus supply and ontogenetic stages

2014 ◽  
Vol 38 (4) ◽  
pp. 1170-1180 ◽  
Author(s):  
Roberto dos Santos Trindade ◽  
Adelson Paulo Araújo
Keyword(s):  
Common Bean ◽  
Root Length ◽  
Root Traits ◽  
Growth Stages ◽  
Phenotypic Variance ◽  
Root Mass ◽  
Root Area ◽  
Ontogenetic Stages ◽  
Growth Habits ◽  
Selection Of

Selection of common bean (Phaseolus vulgaris L.) cultivars with enhanced root growth would be a strategy for increasing P uptake and grain yield in tropical soils, but the strong plasticity of root traits may compromise their inclusion in breeding programs. The aim of this study was to evaluate the magnitude of the genotypic variability of root traits in common bean plants at two ontogenetic stages and two soil P levels. Twenty-four common bean genotypes, comprising the four growth habits that exist in the species and two wild genotypes, were grown in 4 kg pots at two levels of applied P (20 and 80 mg kg-1) and harvested at the stages of pod setting and early pod filling. Root area and root length were measured by digital image analysis. Significant genotype × P level and genotype × harvest interactions in analysis of variance indicate that the genotypic variation of root traits depended on soil nutrient availability and the stage at which evaluation was made. Genotypes differed for taproot mass, basal and lateral root mass, root area and root length at both P levels and growth stages; differences in specific root area and length were small. Genotypes with growth habits II (upright indeterminate) and III (prostrate indeterminate) showed better adaptation to limited P supply than genotypes of groups I (determinate) and IV (indeterminate climbing). Between the two harvests, genotypes of groups II and III increased the mass of basal and lateral roots by 40 and 50 %, respectively, whereas genotypes of groups I and IV by only 7 and 19 %. Values of the genotypic coefficient of determination, which estimates the proportion of phenotypic variance resulting from genetic effects, were higher at early pod filling than at pod setting. Correlations between shoot mass and root mass, which could indicate indirect selection of root systems via aboveground biomass, were higher at early pod filling than at pod setting. The results indicate that selection for root traits in common bean genotypes should preferentially be performed at the early pod-filling stage.

scholarly journals The influence of cetane-detergent additives into diesel fuel increased to 10% (V/V) of RME content on energy parameters and exhaust gas composition of a diesel engine

2019 ◽  
Vol 179 (4) ◽  
pp. 204-209
Author(s):  
Winicjusz STANIK ◽  
Jerzy CISEK
Keyword(s):  
Diesel Fuel ◽  
Cetane Number ◽  
The Other ◽  
Exhaust Gas ◽  
Gas Composition ◽  
Slight Effect ◽  
Negative Effects ◽  
Exhaust Gases ◽  
The Third ◽  
Reduction Of Nox

To avoid the negative effects of increasing the amount of RME in the diesel fuel (to 10%), three different additive packages were used: stabilising, cleaning, and increasing the cetane number with different concentrations. The tests were carried out using a 4-cylinder, turbocharged 1.9 TDI engine from VW. The tests were carried out for 4 fuels (comparative fuel with a content of 7% RME and 3 test fuels with a content of 10% RME, differing in the content of the additive package.It was found that each of the 3 additive packages used does not have a significant impact on fuel consumption. However, a different effect of the tested additives on the composition of exhaust gases was observed. The first package had a slight effect on reducing the NOx concentration in the exhaust, but only for small engine loads. On the other hand, the second additive pack worked more effectively only at higher engine loads (in relation to the reduction of NOx concentration in the exhaust gases). In the third packet, the amount of the cetane additive was doubled (compared to the second packet). Then, the reduction in the NOx concentration in the exhaust gas by 3–8% was obtained with reference to the comparative fuel.

scholarly journals Microclimate Evaluation of the Hradec Králové City using HUMIDEX

2017 ◽  
Vol 47 (3) ◽  
pp. 231-246 ◽  
Author(s):  
Jaroslav Rožnovský ◽  
Tomáš Litschmann ◽  
Hana Středová ◽  
Tomáš Středa ◽  
Petr Salaš ◽  
...  
Keyword(s):  
Radiation Balance ◽  
Negative Effects ◽  
Environment Analysis ◽  
Surface Areas ◽  
Air Temperatures ◽  
Green Areas ◽  
Urban Heat ◽  
Surrounding Landscape ◽  
The City ◽  
Very High

Abstract Urban environment differs from the surrounding landscape in terms of the values of meteorological parameters. This is often referred to as the urban heat island (UHI), which in simple terms means higher air temperatures in cities. The cause of these changes lies in the different active surfaces in cities, which subsequently results in a different radiation balance. The higher temperatures, however, also affect the living conditions in the city and during very high temperature periods can have negative effects on the health of the city inhabitants. The results presented in this paper are based on measurements taken over several years at locations near Hradec Králové, which is surrounded by different surface areas. Environment analysis was performed using the Humidex index. The obtained results show that replacing green areas with built-up areas affects temperatures in the city, when air temperatures are very high they significantly increase the discomfort of the inhabitants. Differences in the frequency of discomfort levels are observed especially during periods of high temperatures, at lower temperatures these differences are not significant. Higher frequencies of discomfort are observed at locations with artificial surfaces (asphalt, cobblestones, concrete) and in closed spaces. In contrast, locations with lots of green areas almost always have the value of this index lower or more balanced. The results should therefore be a valid argument for maintaining and extending green areas in cities.

Posterior Cervical Keyhole Laminoforaminotomy: A Cadaveric Comparative Study to Evaluate Limits of Bony Resection

2018 ◽  
Vol 16 (5) ◽  
pp. 607-613 ◽  
Author(s):  
Ahmed B Bayoumi ◽  
Selim Berk ◽  
Ibrahim E Efe ◽  
Elif Gulsah Bas ◽  
Melissa Duran ◽  
...  
Keyword(s):  
Comparative Study ◽  
Surface Area ◽  
Nerve Root ◽  
Root Length ◽  
Maximal Length ◽  
Nerve Roots ◽  
Surface Areas ◽  
Lateral Portion ◽  
The Right ◽  
Cervical Roots

Abstract BACKGROUND The posterior cervical keyhole (KH) laminoforaminotomy has been described to involve the lateral portion of cervical laminae of the upper vertebra alone (small KH) or of both upper and lower vertebrae (large KH). OBJECTIVE To microscopically compare the two keyhole techniques in terms of their ability to expose the corresponding cervical roots. METHODS Ten cadaveric specimens were operated bilaterally from C3-4 to C6-7 level to expose a total of 80 nerve roots. The large KH was applied to the left side, the small KH to the right side. The maximal length of exposed nerve roots was measured under microscope. The virtual optimal KH surface area was determined using digital software. Each root was inspected for exposure of its root and axilla. RESULTS The maximal exposed nerve root length on the large KH side was significantly larger than on the small KH side at C3-4, C5-6, and C6-7 levels (P = .031, P = .002, P = .003). No significance was reported for C4-5 (P = .06). We could expose right axillae in (3/40) and left axillae in (33/40; P < .001). Optimal keyhole surface areas were 37.9, 38.2, 38.7, and 46.2 mm2 in craniocaudal order. CONCLUSION Large KH defects involving both upper and lower laminae and facets can expose the roots to greater extent than small KH defects at C3-4, C5-6, and C6-7 levels. Large KH defects may allow better exposure of nerve roots axillae than small KH defects.

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