Absorption, Translocation, and Toxicity of Foliar-Applied Imazaquin in Yellow and Purple Nutsedge (Cyperus esculentusandC. rotundus)

Weed Science ◽  
1988 ◽  
Vol 36 (3) ◽  
pp. 313-317 ◽  
Author(s):  
Ujjanagouda B. Nandihalli ◽  
Leo E. Bendixen

Imazaquin {2-[4,5-dihydro-4-methyl-4-(1-methylethyl)-5-oxo-1H-imidazol-2-yl]-3-quinolinecarboxylic acid} absorption, translocation, and toxicity were investigated in yellow nutsedge (Cyperus esculentusL. # CYPES) and purple nutsedge (C. rotundusL. # CYPRO) after foliar treatment. Imazaquin rates from 0.125 to 0.375 kg ai/ha were sprayed on nutsedge plants at the four-leaf stage. Compared to untreated plants, these rates reduced the main shoot growth of yellow nutsedge by 70 to 86% and that of purple nutsedge by 80 to 92% at 28 days after application (DAA). However, the regrowth as measured by tiller production was significantly greater at 0.125 and 0.188 kg/ha rates than at higher rates. The plants treated with 0.313 and 0.375 rates had no rhizomes or tubers at the 28 DAA sampling. In yellow nutsedge, absorption of14C-imazaquin increased from 36% at 1 DAA to 57% at 8 DAA. of the total absorbed14C, 12% translocated from the treated area by 8 DAA. Roots and rhizomes accumulated equal amounts of radioactivity. In purple nutsedge, the absorption of imazaquin increased from 17% at 1 DAA to 53% at 8 DAA. Translocation of absorbed14C in purple nutsedge at 8 DAA was 21%. Rhizomes accumulated significantly greater amounts of14C than the roots.

Weed Science ◽  
1988 ◽  
Vol 36 (4) ◽  
pp. 411-416 ◽  
Author(s):  
Ujjanagouda B. Nandihalli ◽  
Leo E. Bendixen

Imazaquin {2-(4,5-dihydro-4-methyl-4-(1-methylethyl)-5-oxo-1H-imidazol-2-yl)-3-quinolinecarboxylic acid} site of uptake and toxicity from soil application were investigated in yellow nutsedge (Cyperus esculentusL. #3CYPES) and purple nutsedge (C. rotundusL. # CYPRO). Imazaquin concentrations of 0.1 to 0.5 ppmw inhibited yellow nutsedge shoot emergence completely, while purple nutsedge shoots emerged at the lower concentrations. Herbicide placement above the tuber reduced shoot emergence and shoot and root dry weights of both species more than did placement below the tuber. Increasing herbicide rate increased the number of tuber buds that sprouted. Three-day-old nutsedge propagules absorbed14C-imazaquin from both rhizome shoots and roots and the herbicide moved both acropetally and basipetally in nutsedge propagules.


Plant Disease ◽  
2004 ◽  
Vol 88 (7) ◽  
pp. 771-771 ◽  
Author(s):  
N. Martínez-Ochoa ◽  
S. W. Mullis ◽  
A. S. Csinos ◽  
T. M. Webster

Impatiens necrotic spot virus (INSV), family Bunyaviridae, genus Tospovirus, is an emerging virus found mostly in ornamentals under greenhouse production. INSV has been detected in peanut (Arachis hypogaea L.) in Georgia and Texas (3) and recently in tobacco (Nicotiana tabacum L.) in the southeastern United States (2) but little is known about INSV distribution and impact on these crops. Noncrop plant hosts are likely to contribute to disease spread by serving as reservoirs for the virus and reproductive hosts for thrips (Frankliniella occidentalis Pergande), which transmit the virus. Yellow nutsedge, a native of North America, and purple nutsedge introduced from Eurasia, are considered serious weed problems in the southeastern United States. To date, there are no reports of natural INSV infections in these weeds. A survey was conducted at two research farms in Tift County, Georgia to determine if yellow and purple nutsedge plants were naturally infected with Tomato spotted wilt virus (TSWV) and INSV. The first field at the Black Shank Farm had been planted with flue-cured tobacco K-326 earlier in the year and fallow at the time of sampling. The second field at the Ponder Farm was planted at the time of sampling with yellow squash (Cucurbita pepo L.) and cabbage (Brassica oleracea L.). In early October 2002, 90 nutsedge plants were taken at random from each site. Leaf and root tissues of each of the nutsedge plants were tested for TSWV and INSV using double-antibody sandwich enzyme-linked immunosorbent assay (DAS-ELISA) alkaline phosphatase antisera kits (Agdia Inc., Elkhart, IN). No visible symptoms of INSV or TSWV were observed. Samples from the field at the Black Shank Farm resulted in 2 of 26 positive for INSV in purple nutsedge plants and 6 of 64 in yellow nutsedge plants. At the Ponder Farm, 3 of 12 were positive for INSV in purple nutsedge plants and 14 of 78 in yellow nutsedge plants. None of the samples in either site tested positive for TSWV. The DAS-ELISA positive samples were verified for INSV using reverse transcription-polymerase chain reaction (RT-PCR) as previously described by Dewey et al. (1). Total RNA extracts were obtained from the DAS-ELISA positive nutsedge samples using RNeasy extraction kits (Qiagen Inc., Valencia, CA). The RT-PCR was carried out with primer 1F: 5′-TCAAG(C/T) CTTC(G/T)GAA(A/G)GTGAT 3′ (1) and primer 2R: 5′-ATGAACAAAGCAAAGATTACC 3′ specific to the 3′ end of the INSV N gene open reading frame (GenBank Accession No. NC003624). DAS-ELISA negative tissues of Cyperus esculentus L. and Emilia sonchifolia (L.) DC and an E. sonchifolia DAS-ELISA positive for INSV were included in the reactions as controls. All of the DAS-ELISA positive nutsedge samples yielded an amplification product with the expected size of 298 bp when PCR products were resolved by agarose (0.7%) gel electrophoresis. The relatively high occurrence of INSV found in the sampled fields may explain the recent increase in incidence of INSV in susceptible field crops. Although yellow nutsedge is more common than purple nutsedge in North America, the potential for dispersal of INSV in both species could be significant because of the nature of nutsedge tuber survival and spreading capabilities. References: (1) R. A. Dewey et al. J. Virol. Methods 56:19, 1996. (2) N. Martínez-Ochoa et al. On-line publication. doi:10.1094/PHP-2003-0417-01-HN. Plant Health Progress, 2003. (3) S. S. Pappu et al. Plant Dis. 83:966,1999.


Weed Science ◽  
1968 ◽  
Vol 16 (3) ◽  
pp. 339-340 ◽  
Author(s):  
W. S. Hardcastle ◽  
R. E. Wilkinson

Purple nutsedge (Cyperus rotundus L.) and yellow nutsedge (Cyperus esculentus L.) tubers were stored at 5 C in soil treated at 0, 2, 3, 4, 6, 8, or 10 lb/A 2,6-dichlorobenzontrile (dichlobenil) for 2, 4, 6, 8, 10, or 12 weeks. Respiration of dormant tubers differed with species, unaffected by period of storage or dichlobenil concentration. Sprouting of untreated tubers decreased from 90% after 2 weeks storage to 43% after 12 weeks. Yellow nutsedge sprout production was uniform in time; purple nutsedge sprouting progressed to an 8-week high. Increased concentrations of dichlobenil progressively inhibited sprouting.


Weed Science ◽  
1971 ◽  
Vol 19 (5) ◽  
pp. 601-606 ◽  
Author(s):  
P. E. Keeley ◽  
R. J. Thullen

Nonradioactive and14C-labeled arsenical herbicides were applied to foliage of purple nutsedge (Cyperus rotundusL.) and yellow nutsedge (Cyperus esculentusL.) grown under greenhouse and growth chamber conditions. Disodium methanearsonate (DSMA) controlled purple nutsedge better at 20 and 29 C than at 13 C. Monosodium methanearsonate (MSMA) was as effective in controlling this weed at 13 C as at 20 and 29 C. DSMA and MSMA provided 80% or greater control of yellow nutsedge grown at the three temperatures. When plants were treated with14C-DSMA and14C-MSMA, greater radioactivity was detected in yellow nutsedge than in purple nutsedge. The apparent differential herbicide penetration of purple and yellow nutsedge leaves is believed to have contributed substantially to the control of nutsedge observed in this study.


Weed Science ◽  
1982 ◽  
Vol 30 (3) ◽  
pp. 225-230 ◽  
Author(s):  
Gregg A. Dixon ◽  
E. W. Stoller

Metolachlor [2-chloro-N-(2-ethyl-6-methylphenyl)-N-(2-methoxy-1-methylethyl)acetamide] toxicity, absorption, translocation, and metabolism were investigated in corn (Zea maysL.) and yellow nutsedge (Cyperus esculentusL.). Metolachlor did not inhibit seed germination in corn or tuber germination in yellow nutsedge. It did not kill yellow nutsedge tubers that were exposed to 4 ppmw for 9 weeks. Metolachlor (10 ppmw) applied in soil above the seed significantly reduced corn shoot growth, but the same concentration around or below the seed had no effect. A soil mixture with metolachlor (1 ppmw) placed above or around yellow nutsedge tubers significantly reduced shoot growth, but placement around the tuber was the most toxic; placement below the tuber had no effect on shoot growth. The concentration of metolachlor that resulted in 50% reduction of shoot growth of 4-day-old seedlings in solution culture was > 10−4M for corn and <10−6M for yellow nutsedge. Root-applied14C-metolachlor was acropetally translocated to shoots of both species following a 7- to 13-day absorption period, with yellow nutsedge translocating the highest portion of the absorbed material to shoots. In 2-day-old seedlings with roots exposed to14C-metolachlor for up to 48 h, both species absorbed and translocated the radioactivity to shoots, but corn absorbed much more than yellow nutsedge. When the14C-metolachlor was applied to shoots of both species, the radioactivity was translocated basipetally into roots. Yellow nutsedge exuded appreciable14C-metolachlor out of the roots and absorbed more14C-metolachlor through shoot tissues than corn. Both corn and yellow nutsedge seedlings readily converted the14C-metolachlor to metabolites, but corn was able to metabolize the14C-metolachlor at a faster rate than yellow nutsedge and also produced more metabolites.


1995 ◽  
Vol 9 (2) ◽  
pp. 277-280 ◽  
Author(s):  
J. K. Peterson ◽  
H. F. Harrison

The allelopathic influence of sweet potato cultivar ‘Regal’ on purple nutsedge was compared to the influence on yellow nutsedge under controlled conditions. Purple nutsedge shoot dry weight, total shoot length and tuber numbers were significantly lower than the controls (47, 36, and 19% inhibition, respectively). The influence on the same parameters for yellow nutsedge (35, 21, and 43% inhibition, respectively) were not significantly different from purple nutsedge. Sweet potato shoot dry weight was inhibited by purple and yellow nutsedge by 42% and 45%, respectively. The major allelopathic substance from ‘Regal’ root periderm tissue was isolated and tested in vitro on the two sedges. The I50's for shoot growth, root number, and root length were 118, 62, and 44 μg/ml, respectively, for yellow nutsedge. The I50's for root number and root length were 91 and 85 μg/ml, respectively, for purple nutsedge and the I50for shoot growth could not be calculated.


Weed Science ◽  
1972 ◽  
Vol 20 (1) ◽  
pp. 71-74 ◽  
Author(s):  
P. E. Keeley ◽  
C. H. Carter ◽  
J. H. Miller

The following herbicides were evaluated for relative phytotoxicity to cotton(Gossypium hirsutumL. ‘Acala SJ-1′), purple nutsedge(Cyperus rotundusL.), and yellow nutsedge(Cyperus esculentusL.) under greenhouse conditions: 2-chloro-2′,6′-diethyl-N-(methoxymethyl)acetanilide (alachlor); 2-chloro-2′,6′-diethyl-N-(butoxymethyl)acetanilide (CP-53619); 2-(3,4-dichlorophenyl)-4-methyl-1,2,4-oxadiazolidine-3,5-dione (VCS-438); 4-chloro-5-(dimethylamino)-2-α,α,α-trifluoro-m-tolyl)-3(2H)-pyridazinone (San-6706); 2-(α naphthoxy)-N,N-diethyl-propionamide (R-7465); andS-isopropyl 5-ethyl-2-methyl-piperidine-1-carbiothioate (R-12001). Herbicides were incorporated 6.35 cm deep, at rates of 1.12, 2.24, and 4.48 kg/ha, into a fine sandy loam prior to planting. All treatments except the low rate of alachlor and VCS-438 controlled yellow nutsedge for 8 weeks. R-7465 and R-12001 at 1.12 kg/ha and San-6706 at 2.24 kg/ha controlled purple nutsedge for 8 weeks. Alachlor and CP-53619 were somewhat less effective against purple nutsedge than yellow nutsedge, but their intermediate rates suppressed purple nutsedge for 4 weeks. Even the high rate of VCS-438 was ineffective against purple nutsedge. Cotton, in terms of fresh shoot weight, exhibited considerable tolerance to 1.12 and 2.24 kg/ha of VCS-438 and CP-53619 and 1.12 kg/ha of R-7465. Applications of 2.24 kg/ha of CP-53619 and 1.12 kg/ha of R-7465, however, suppressed the development of lateral roots of cotton. Other rates of these herbicides and all rates of alachlor, R-12001, and San-6706 moderately to severely injured cotton in most of the experiments.


Weed Science ◽  
2008 ◽  
Vol 56 (5) ◽  
pp. 735-742 ◽  
Author(s):  
Theodore M. Webster ◽  
Timothy L. Grey ◽  
Jerry W. Davis ◽  
A Stanley Culpepper

The phase-out of methyl bromide requires alternative nutsedge management options in vegetable systems. Options that target tuber production, the primary means of reproduction, will be most beneficial. A study was conducted to evaluate the response of purple nutsedge and yellow nutsedge foliar growth and tuber production to a range of glyphosate rates. Glyphosate was applied at six rates between 0.41 and 2.57 kg ae ha−1to 5-wk-old nutsedge plants with multiple shoots. The rate of glyphosate needed to reduce growth 50% (I50) was similar for purple nutsedge foliar growth (0.58 kg ha−1) and tuber biomass (0.55 kg ha−1). In contrast,I50for yellow nutsedge foliar growth was 0.73 kg ha−1, which was greater than theI50for tuber biomass (0.41 kg ha−1). First-order tubers, those directly attached to the initial tuber, had anI50of 0.70 and 0.44 kg ha−1of glyphosate for purple nutsedge and yellow nutsedge tuber biomass, respectively. For all higher-order tubers,I50values ranged from 0.29 to 0.60 and 0.14 to 0.30 kg ha−1of glyphosate for purple nutsedge and yellow nutsedge tuber biomass, respectively. Glyphosate at 0.74 kg ha−1prevented fourth-order purple nutsedge and third-order yellow nutsedge tuber production (terminal tubers for yellow nutsedge). Fifth- and sixth-order purple nutsedge tuber production was eliminated by the lowest tested rate of glyphosate (0.41 kg ha−1). Effective nutsedge management options will require consistent control between spring and autumn crops. Glyphosate is economical, poses no herbicide carryover issues to vegetables, and minimizes nutsedge tuber production; therefore, it is a suitable candidate to manage nutsedges.


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