scholarly journals Dormancy Release of Purple Nutsedge Tuber Buds by a Single Thermal Pulse

1997 ◽  
Vol 122 (3) ◽  
pp. 306-309 ◽  
Author(s):  
Wen-Hao Sun ◽  
Roy K. Nishimoto
Keyword(s):  
High Temperature ◽  
Cyperus Rotundus ◽  
Dormancy Release ◽  
Heat Unit ◽  
Fluctuating Temperature ◽  
Purple Nutsedge ◽  
Temperature Pulse ◽  
Thermal Pulse ◽  
Single Temperature ◽  
Rapid Shift

The effect of single and daily fluctuating temperature cycles on budbreak of purple nutsedge (Cyperus rotundus L.) tubers was characterized to determine whether the budbreak response was a trigger or rhythmic action. Glasshouse-grown tubers were incubated at 20 °C for 2 weeks, and the nonsprouted tubers were used in experiments. A single 30-minute temperature pulse from 20 to 35 °C caused 80% budbreak, while tubers without the thermal pulse had only 25% budbreak. Increasing the duration of the single 35 °C temperature pulse from 30 minutes to 12 hours did not increase budbreak. Even a 3-minute 35 °C pulse caused 63% budbreak. A single gradual shift (0.02 °C per minute) from 20 to 35 °C was as effective as a rapid shift (0.5 °C per minute) in stimulating budbreak. Nonsprouted tubers preincubated at 25 °C were stimulated to cause budbreak by exposure at 35 °C for 12 hours, but not at 15 °C for 12 hours. A single temperature pulse of at least 10 °C differential (from 20 to 30, 35, or 40 °C) stimulated budbreak, while a 5 °C differential (from 20 to 25 °C) did not; all pulses had the same heat unit (°C > 20 °C × time (minutes) = 3600 °C/minute). These results suggest that budbreak of purple nutsedge tubers responds to high temperature as a trigger action.

Diurnally Alternating Temperatures Stimulate Sprouting of Purple Nutsedge (Cyperus rotundus) Tubers

Weed Science ◽  
1996 ◽  
Vol 44 (1) ◽  
pp. 122-125 ◽  
Author(s):  
Joel E. Miles ◽  
Roy K. Nishimoto ◽  
Osamu Kawabata
Keyword(s):  
High Temperature ◽  
Cyperus Rotundus ◽  
Maximum Temperature ◽  
Temperature Cycle ◽  
Purple Nutsedge ◽  
Tuber Temperature ◽  
Tuber Sprouting ◽  
Alternating Temperature ◽  
Increasing Temperature ◽  
Temperature Responses

Experiments were conducted to determine the response of purple nutsedge tuber sprouting to diurnally alternating temperature. These experiments compared the response to alternating and constant temperatures and determined the effect of the amplitude of alternation and time of exposure to the maximum temperature. Tuber sprouting was more rapid and complete with alternating temperatures than with constant temperatures. Increasing temperature fluctuation from 0 to 6 C for 12 h daily linearly increased total tuber sprouting. As little as 30 min exposure to high temperature per day provided nearly the same level of sprouting as a 12 h alternating temperature cycle. This phenomenon should be considered when conducting studies to describe tuber temperature responses or when predicting tuber sprouting and emergence.

Enhancement of Herbicide Activity with an Isoparaffinic Oil Carrier

Weed Science ◽  
1971 ◽  
Vol 19 (6) ◽  
pp. 701-705 ◽  
Author(s):  
R. J. Burr ◽  
G. F. Warren
Keyword(s):  
Acetic Acid ◽  
Cyperus Rotundus ◽  
Setaria Viridis ◽  
Ipomoea Hederacea ◽  
Purple Nutsedge ◽  
Green Foxtail ◽  
Herbicide Activity ◽  
Dichlorophenoxy Acetic Acid ◽  
Agropyron Repens

Several herbicides were tested in the greenhouse on ivyleaf morningglory (Ipomoea hederacea(L.) Jacq.), green foxtail (Setaria viridis(L.) Beauv.), purple nutsedge (Cyperus rotundusL.), and quackgrass (Agropyron repens(L.) Beauv.) to determine the degree of enhancement in activity that could be obtained with an isoparaffinic oil carrier applied at 140 L/ha. The enhancement varied with the herbicide and with the species, ranging from 16-fold enhancement with 2-chloro-4-(ethylamino)-6-(isopropylamino)-s-triazine (atrazine) and 2-sec-butyl-4,6-dinitrophenol (dinoseb) on ivyleaf morningglory to no enhancement of atrazine activity on purple nutsedge and quackgrass or (2,4-dichlorophenoxy)acetic acid (2,4-D) activity on quackgrass and ivyleaf morningglory. An oil adjuvant was less effective in enhancing dinoseb and 3-(3,4-dichlorophenyl)-1-methoxy-1-methylurea (linuron) activity than was the isoparaffinic oil carrier. Also, the isoparaffinic oil carrier emulsified in water was less effective than the undiluted oil in enhancing dinoseb activity on green foxtail, even though equal volumes of the isoparaffinic oil were applied.

Field Efficacy ofDactylaria higginsiias a Bioherbicide for the Control of Purple Nutsedge (Cyperus rotundus)1

2000 ◽  
Vol 14 (1) ◽  
pp. 1-6 ◽  
Author(s):  
JUGAH B. KADIR ◽  
R. CHARUDATTAN ◽  
WILLIAM M. STALL ◽  
BARRY J. BRECKE
Keyword(s):  
Cyperus Rotundus ◽  
Purple Nutsedge ◽  
Field Efficacy

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

2015 ◽  
Vol 33 (2) ◽  
pp. 165-173 ◽  
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).

scholarly journals Evaluation of Allyl Isothiocyanate as a Soil Fumigant for Tomato (Lycopersicon esculentum Mill.) Production

Plant Disease ◽  
2019 ◽  
Vol 103 (11) ◽  
pp. 2764-2770 ◽  
Author(s):  
Jialin Yu ◽  
Gary E. Vallad ◽  
Nathan S. Boyd
Keyword(s):  
Lycopersicon Esculentum ◽  
Allyl Isothiocyanate ◽  
Cyperus Rotundus ◽  
Parasitic Nematodes ◽  
Tomato Production ◽  
Purple Nutsedge ◽  
Lycopersicon Esculentum Mill ◽  
Equivalent Control ◽  
Control Versus ◽  
Meloidogyne Spp

Fusarium wilt (Fusarium oxysporum f. sp. lycopersici), root-knot nematodes (Meloidogyne spp.), and purple nutsedge (Cyperus rotundus L.) are among the most damaging soilborne pests for tomato (Lycopersicon esculentum Mill.) production in the southeastern United States. Allyl isothiocyanate (allyl ITC) was evaluated as a potential fumigant alternative for control of soilborne pathogens, nematodes, and weeds. Shank- or drip-injected allyl ITC at rates ranging from 221 to 367 kg ha−1 exhibited excellent performance, reducing the recovery of total F. oxysporum from treated soils. Shank- or drip-injected allyl ITC at 367 kg ha−1 provided equivalent control of C. rotundus compared with 1,3-dichloropropene + chloropicrin and metam potassium, respectively. Totally impermeable film (TIF) did not further reduce the recovery of F. oxysporum and various nematodes from soil treated with allyl ITC compared with virtually impermeable film (VIF). However, TIF mulch significantly improved C. rotundus control versus shank- or drip-injected allyl ITC treatments under VIF mulch. Overall, allyl ITC is an effective methyl bromide alternative against F. oxysporum, C. rotundus, and plant-parasitic nematodes Criconemella spp. and Hoplolaimus spp. in plasticulture tomato production.

Propagules of Purple Nutsedge (Cyperus rotundus) in Soil

1987 ◽  
Vol 1 (3) ◽  
pp. 217-220 ◽  
Author(s):  
Gamini Siriwardana ◽  
Roy K. Nishimoto
Keyword(s):  
Dry Matter ◽  
Cyperus Rotundus ◽  
Fresh Weight ◽  
Parent Population ◽  
Purple Nutsedge ◽  
Aerial Parts

The upper 30 cm of soil in a field infested with purple nutsedge (Cyperus rotundusL. #3CYPRO) contained 4900 to 5100 corms and tubers/m26 weeks after soil rotovation and irrigation. The upper 4, 8, 12 and 16 cm of soil had 45, 79, 95 and 99%, respectively, of the corms and tubers. Lower depths of soil contained larger tubers with higher percent dry matter than the shallow depths. Of the total number of corms and tubers, 51% were from the parent population. At 6 weeks, only 15% of the total tuber and corm population were not connected to aerial parts. Tubers from the parent population had a higher fresh weight than those from the new population. Parent tubers occurred singly or in chains of up to eight tubers.

Herbicide-Crop Rotation for Johnsongrass (Sorghum halepense) Control

Weed Science ◽  
1979 ◽  
Vol 27 (5) ◽  
pp. 479-485 ◽  
Author(s):  
J. E. Dale ◽  
J. M. Chandler
Keyword(s):  
Crop Rotation ◽  
Field Experiments ◽  
Amaranthus Retroflexus ◽  
Cyperus Rotundus ◽  
Sorghum Halepense ◽  
Purple Nutsedge ◽  
Cropping Sequence ◽  
Sesbania Exaltata ◽  
Common Purslane ◽  
Sida Spinosa

The feasibility of herbicide and crop rotation for the control of johnsongrass [Sorghum halepense(L.) Pers.] in corn (Zea maysL.) was studied in field experiments. Light infestations of johnsongrass were initially present, but it became the predominant weed after 4 yr of continuous corn treated with atrazine [2-chloro-4-(ethylamino)-6-(isopropylamine)-s-triazine], cyanazine {2-[[4-chloro-6-(ethylamino)-s-triazin-2-yl]amino]-2-methylpropionitrile}, and linuron [3-(3,4-dichlorophenyl)-1-methoxy-1-methylurea], alone and in combinations at rates of 2.24, 2.24, and 0.84 kg/ha, respectively. The infestation of johnsongrass was effectively controlled by growing corn in rotation with cotton (Gossypium hirsutumL.) in a cropping sequence of corn-cotton-cotton-corn, in which trifluralin (α,α,α-trifluoro-2,6-dinitro-N,N-dipropyl-p-toluidine), fluometuron [1,1-dimethyl-3-(α,α,α-trifluoro-m-tolyl)urea] and MSMA (monosodium methanearsonate) at 0.56, 2.24, and 2.24 kg/ha respectively, were used for weed control in cotton. In the corn-cotton-cotton-corn cropping sequence, the herbicide treatments also prevented increases in the populations of other indigeneous weeds including prickly sida (Sida spinosaL.), prostrate spurge (Euphorbia supinaRaf.), spotted spurge (Euphorbia maculataL.), common purslane (Portulaca oleraceaL.), tall morningglory [Ipomoea purpurea(L.) Roth], common cocklebur (Xanthium pensylvanicumWallr.), spurred anoda[Anoda cristata(L.) Schlecht.], hemp sesbania [Sesbania exaltata(Raf.) Cory], redroot pigweed (Amaranthus retroflexusL.), goosegrass [Eleusine indica(L.) Gaertn.], junglerice [Echinochloa colonum(L.) Link], large crabgrass [Digitaria sanguinalis(L.) Scop.], and purple nutsedge (Cyperus rotundusL.).

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