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

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).

2005 ◽  
Vol 19 (2) ◽  
pp. 251-254 ◽  
Author(s):  
Patrick E. McCullough ◽  
Lambert B. McCarty ◽  
Haibo Liu ◽  
Ted Whitwell

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.


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 ◽  
...  

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.


2006 ◽  
Vol 20 (1) ◽  
pp. 1-5 ◽  
Author(s):  
Patrick E. McCullough ◽  
Lambert B. McCarty ◽  
Haibo Liu

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.


HortScience ◽  
2005 ◽  
Vol 40 (2) ◽  
pp. 460-462 ◽  
Author(s):  
Patrick E. McCullough ◽  
Haibo Liu ◽  
Lambert B. McCarty

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).


HortScience ◽  
1991 ◽  
Vol 26 (2) ◽  
pp. 180-182 ◽  
Author(s):  
K.L. Hays ◽  
J.F. Barber ◽  
M.P. Kenna ◽  
T.G. McCollum

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.


HortScience ◽  
2000 ◽  
Vol 35 (2) ◽  
pp. 213-216 ◽  
Author(s):  
Grady L. Miller

The effects of several soil amendments, following a single filling of core aerification holes, on growth and transpiration of `Tifdwarf' bermudagrass [Cynodon dactylon (L.) Pers. × C. transvaalensis Burtt Davy] were examined during drought stress. Soil amendments had variable effects on turf quality. In general, turf grown in ZeoPro®- and Profile®-amended sand had the highest quality. Data indicated that the evaluated soil amendments have the potential to influence soil water content, ultimately influencing transpirational response to drought stress. Amended sand contained 1% to 16% more transpirable water compared with non-amended sand. Turfgrass grown in Axis®- and Isolite®-amended sand required 0.4 to 1.4 days longer to reach the endpoint (transpiration rate of drought stressed plants <12% of well-watered plants) during a period of rapid water depletion. Data from this study suggest that the total volume these amendments occupied in the root zone, following a single filling of core aerification holes in sand, may positively influence soil moisture status, resulting in an increase in drought avoidance.


2014 ◽  
Vol 38 (4) ◽  
pp. 1170-1180 ◽  
Author(s):  
Roberto dos Santos Trindade ◽  
Adelson Paulo Araújo

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.


2020 ◽  
Vol 38 (1) ◽  
pp. 29-36
Author(s):  
Travis Culpepper ◽  
Joseph Young ◽  
David T. Montague ◽  
Manish Sapkota ◽  
Eduardo Escamilla ◽  
...  

Abstract Urban soils may restrict turfgrass rooting depth with shallow soil layers in high sand content soils, which may influence water conservation. A greenhouse study sought to quantify water usage and determine the physiological response of turfgrasses at four irrigation levels. ‘ATF-1434′ tall fescue (Schedonorus arundinaceus (Schreb.) Dumort. nom. cons.; syn. Festuca arundinacea Schreb.), ‘Jamur' Japanese lawngrass (Zoysia japonica Steud.), and ‘Zeon' Manilagrass [Zoysia matrella (L.) Merr.] were established in 10 cm (4 in) diameter by 17.8 cm (7 in) tall containers. Each species was irrigated with 16.5, 21.9, 27.3, or 32.7 mm.wk−1 (0.65, 0.86, 1.1, or 1.3 in.wk−1). Gravimetric water loss was determined by pre- and post-irrigation pot weights. Turf quality, leaf discoloration, percent green cover, and gross photosynthesis were evaluated weekly and root parameters were measured at the conclusion of each trial. Although root mass was similar among species, water deficit stress and leaf discoloration occurred sooner in tall fescue than the two Zoysia species, reducing turf quality and green cover. Japanese lawngrass and Manilagrass had greater stomatal conductance, resulting in 109 and 89% higher gross photosynthesis relative to tall fescue. Both zoysiagrasses maintained acceptable turf quality with 27.3 mm water.wk−1. However, tall fescue quality was not acceptable at any irrigation level. Index words: Photosynthesis, gravimetric water loss, tall fescue, Japanese lawngrass, Manilagrass. Species used in this study: Tall fescue (Schedonorus arundinaceus (Schreb.) Dumort. nom. cons.; syn. Festuca arundinacea Schreb.); Japanese lawngrass (Zoysia japonica Steud.); Manilagrass [Zoysia matrella (L.) Merr.].


1988 ◽  
Vol 2 (1) ◽  
pp. 53-58 ◽  
Author(s):  
Billy J. Johnson

Vegetative growth of ‘Tifway’ African bermudagrass (Cynodon transvaalensisBurtt-Davy # CYNTR) x bermudagrass [C. dactylon(L.) Pers. # CYNDA] treated with flurprimidol {α-(1-methylethyl)-α-[4-trifluoromethoxy)phenyl]-5-pyrimidinemethanol} at 0.2 kg/ha and repeated at 3-week intervals for a total rate of 0.8 kg/ha was suppressed for 6 weeks compared to growth of nontreated grass. A single application of flurprimidol at 0.8 kg/ha in late May suppressed growth for 4 weeks. When the single 0.8 kg/ha application was delayed until mid-July, bermudagrass growth was suppressed for only 2 weeks. Applications of nitrogen (N) at 25 and 50 kg/ha did not influence flurprimidol's suppression of bermudagrass growth. Turf quality in some instances was lower when treated with 50 kg N/ha or the turfgrass required a longer recovery period than when treated with 25 kg N/ha following flurprimidol treatment. Although single or multiple applications of flurprimidol, each totaling 0.8 kg/ha, injured bermudagrass in some instances, the injury was not severe and the turfgrass fully recovered.


Weed Science ◽  
1984 ◽  
Vol 32 (6) ◽  
pp. 819-823 ◽  
Author(s):  
B. Jack Johnson

Bermudagrass [Cynodon dactylon(L.) Pers. ‘Tifway’] injured by MSMA (monosodium methanearsonate) plus metribuzin [4-amino-6-tert-butyl-3-(methylthio)-as-triazin-5(4H)-one] or 2,4-D [(2,4-dichlorophenoxy)acetic acid] plus mecoprop {2-[(4-chloro-o-tolyl)oxy] propionic acid} plus dicamba (3,6-dichloro-o-anisic acid) recovered more rapidly when nitrogen (N) was applied in sequence with the herbicides than when no N was applied. Bermudagrass recovery was faster with less injury within 2 weeks after herbicide treatment when N was applied at the first MSMA plus metribuzin treatment or when N was applied at 2 weeks after the first 2,4-D plus mecoprop plus dicamba treatment. Turf quality at 4 weeks or later was consistently as good or better in plots where N was applied at 2 weeks after the first application of either herbicide combination than when N was applied earlier.


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