Vernalization affects absorption and translocation of clopyralid and aminopyralid in rush skeletonweed (Chondrilla juncea)

Weed Science ◽  
2020 ◽  
Vol 68 (5) ◽  
pp. 445-450
Author(s):  
Tara L. Burke ◽  
Ian C. Burke

AbstractThe developmental status of perennial weeds such as rush skeletonweed (Chondrilla juncea L.) can influence herbicide absorption and translocation. Differential efficacy between fall and spring applications suggests vernalization impacts herbicide absorption and translocation in other perennial asters. Clopyralid and aminopyralid absorption and translocation were quantified in nonvernalized and vernalized plants following application of 14C-labeled herbicides 2, 4, 8, 24, and 72 h after treatment. Less 14C clopyralid was absorbed, and at a slower rate, in vernalized plants. Movement out of the treated leaf was slower, with 14C clopyralid translocating more rapidly than 14C aminopyralid. More 14C moved to the roots in nonvernalized plants compared with vernalized plants, regardless of herbicide. Increased translocation to belowground survival structures is needed for effective control of C. juncea.

Weed Science ◽  
1986 ◽  
Vol 34 (S1) ◽  
pp. 2-6 ◽  
Author(s):  
Gary A. Lee

Rush skeletonweed (Chondrilla junceaL. CHOJU) infestations occur along the eastern seaboard and in several western states of the United States. This Eurasian species was inadvertently introduced prior to 1870, with established stands first reported in Maryland and West Virginia (16). These infestations (16) were assessed as lacking aggressive characteristics and posed little threat as a problem weed. Although rush skeletonweed was discovered in the Pacific Northwest as early as 1938, the species was not recognized as a potential weed problem until nearly three decades later (27). Subsequent surveys revealed that infestations occupied over 2.3 million ha in California, Idaho, Oregon, and Washington (6). Attempts to generate support for an organized control program in Idaho were met with little enthusiasm during the 1960's.


Weed Science ◽  
1999 ◽  
Vol 47 (6) ◽  
pp. 636-643 ◽  
Author(s):  
Wendy A. Pline ◽  
Jingrui Wu ◽  
Kriton K. Hatzios

Absorption, translocation, and metabolism of14C-glufosinate were studied in three annual and two perennial weed species. Young seedlings ofSetaria faberi, Chenopodium album, Cassia obtusifolia, Solanum carolinense, andAsclepias syriacawere treated with foliar-applied14C-glufosinate, and plant tissues were harvested 12, 48, and 72 h after treatment (HAT). Absorption of14C-glufosinate was initially rapid, but increased only slightly after 12 h in all species. Glufosinate absorption was highest inS. carolinense(73% of applied radioactivity), followed byS. faberi(54%),C. obtusifolia(44%),C. album(41%), andA. syriaca(37%) 72 HAT. Translocation of radioactivity out of the treated leaf was species dependent and did not increase much with time in all weed species.S. carolinenseandS. faberitranslocated the highest amounts of absorbed radioactivity out of the treated leaf with 49 to 59% moving to the upper foliage.S. faberitranslocated the highest amount of absorbed radioactivity to the roots (12 to 14%), whileC. albumtranslocated the least (2 to 3%). TLC analysis of plant extracts showed that14C-glufosinate was not metabolized inS. faberi, C. obtusifolia, S. carolinense, andA. syriaca. A glufosinate metabolite with an Rf value matching that of methyl-phosphinico propionate was detected inC. album. Treatment with ammonium sulfate (AMS) increased glufosinate absorption inS. faberiandC. obtusifolia12 HAT, but decreased absorption inC. album. Treatment with pelargonic acid (PA) did not affect glufosinate absorption in any of the species tested. Treatment with AMS and PA did not affect glufosinate translocation in any of the five weed species. Treatment with AMS and PA did not influence the metabolism of glufosinate in any of the five weed species studied. These results show that differential absorption and translocation seem to explain the greater sensitivity of the annual and perennial weeds to glufosinate. Treatment with ammonium sulfate may increase the efficacy of glufosinate in perennial weeds.


2021 ◽  
Vol 12 ◽  
Author(s):  
Jiayi Li ◽  
Wenping Zhang ◽  
Ziqiu Lin ◽  
Yaohua Huang ◽  
Pankaj Bhatt ◽  
...  

Diuron (DUR) is a phenylurea herbicide widely used for the effective control of most annual and perennial weeds in farming areas. The extensive use of DUR has led to its widespread presence in soil, sediment, and aquatic environments, which poses a threat to non-target crops, animals, humans, and ecosystems. Therefore, the removal of DUR from contaminated environments has been a hot topic for researchers in recent decades. Bioremediation seldom leaves harmful intermediate metabolites and is emerging as the most effective and eco-friendly strategy for removing DUR from the environment. Microorganisms, such as bacteria, fungi, and actinomycetes, can use DUR as their sole source of carbon. Some of them have been isolated, including organisms from the bacterial genera Arthrobacter, Bacillus, Vagococcus, Burkholderia, Micrococcus, Stenotrophomonas, and Pseudomonas and fungal genera Aspergillus, Pycnoporus, Pluteus, Trametes, Neurospora, Cunninghamella, and Mortierella. A number of studies have investigated the toxicity and fate of DUR, its degradation pathways and metabolites, and DUR-degrading hydrolases and related genes. However, few reviews have focused on the microbial degradation and biochemical mechanisms of DUR. The common microbial degradation pathway for DUR is via transformation to 3,4-dichloroaniline, which is then metabolized through two different metabolic pathways: dehalogenation and hydroxylation, the products of which are further degraded via cooperative metabolism. Microbial degradation hydrolases, including PuhA, PuhB, LibA, HylA, Phh, Mhh, and LahB, provide new knowledge about the underlying pathways governing DUR metabolism. The present review summarizes the state-of-the-art knowledge regarding (1) the environmental occurrence and toxicity of DUR, (2) newly isolated and identified DUR-degrading microbes and their enzymes/genes, and (3) the bioremediation of DUR in soil and water environments. This review further updates the recent knowledge on bioremediation strategies with a focus on the metabolic pathways and molecular mechanisms involved in the bioremediation of DUR.


Weed Science ◽  
2017 ◽  
Vol 66 (1) ◽  
pp. 4-14 ◽  
Author(s):  
Christopher R. Johnston ◽  
Peter M. Eure ◽  
Timothy L. Grey ◽  
A. Stanley Culpepper ◽  
William K. Vencill

The efficacy of WSSA Group 4 herbicides has been reported to vary with dependence on the time of day the application is made, which may affect the value of this mechanism of action as a control option and resistance management tool for Palmer amaranth. The objectives of this research were to evaluate the effect of time of day for application on 2,4-D and dicamba translocation and whether or not altering translocation affected any existing variation in phytotoxicity seen across application time of day. Maximum translocation (Tmax) of [14C]2,4-D and [14C]dicamba out of the treated leaf was significantly increased 52% and 29% to 34% in one of two repeated experiments for each herbicide, respectively, with application at 7:00 AM compared with applications at 2:00 PM and/or 12:00 AM. Applications at 7:00 AM increased [14C]2,4-D distribution to roots and increased [14C]dicamba distribution above the treated leaf compared with other application timings. In phytotoxicity experiments, dicamba application at 8 h after exposure to darkness (HAED) resulted in significantly lower dry root biomass than dicamba application at 8 h after exposure to light (HAEL). Contrasts indicated that injury resulting from dicamba application at 8 HAEL, corresponding to midday, was significantly reduced with a root treatment of 5-[N-(3,4-dimethoxyphenylethyl)methylamino]-2-(3,4-dimethoxyphenyl)-2-isopropylvaleronitrile hydrochloride (verapamil) compared with injury observed with dicamba application and a root treatment of verapamil at 8 HAED, which corresponded to dawn. Overall, time of application appears to potentially influence translocation of 2,4-D and dicamba. Furthermore, inhibition of translocation appears to somewhat influence variation in phytotoxicity across times of application. Therefore, translocation may be involved in the varying efficacy of WSSA Group 4 herbicides due to application time of day, which has implications for the use of this mechanism of action for effective control and resistance management of Palmer amaranth.


Weed Science ◽  
1983 ◽  
Vol 31 (6) ◽  
pp. 819-825 ◽  
Author(s):  
Baruch Rubin ◽  
Abraham Benjamin

Solar heating (SH) of the soil by mulching it with transparent polyethylene (PE) during the hot season elevated the soil temperature by 10 to 18 C above that of the non-mulched soil. SH for 4 to 5 weeks resulted in effective control of most summer and winter annual weeds, the effect lasting for more than 5 months after PE removal.Melilotus sulcatusDesf.,Astragalus boeticusL. and bull mallow (Malva nicaeensisAll. # MALNI) were not controlled by SH. Perennial weeds which propagate from vegetative parts were only partially controlled with short SH, but mulching for 8 to 10 weeks improved control. Mulching the soil with perforated or shaded transparent PE or black PE resulted in a smaller increase of soil temperature and thus less efficient weed control. A combination of SH with soil-incorporated EPTC (S-ethyl dipropylthiocarbamate) or vernolate (S-propyl dipropylthiocarbamate) did not improve the weed control over SH alone, but significantly enhanced the disappearance of the herbicides from the soil. SH inhibited the disappearance of fluridone {1-methyl-3-phenyl-5-[3-(trifluoromethyl) phenyl]-4(1H)-pyridinone} but did not change the residual phytotoxicity of bromacil (5-bromo-3-sec-butyl-6-methyluracil). SH treatment improved plant growth and increased the yield of wheat (Triticum aestivumL. ‘895′) and turnip (Brassica rapaL. ‘Purple top’), but not of parsley (Petroselinum sativumHoffm.).


Weed Science ◽  
1990 ◽  
Vol 38 (1) ◽  
pp. 45-49 ◽  
Author(s):  
Timothy T. Obrigawitch ◽  
William H. Kenyon ◽  
Henry Kuratle

Field, greenhouse, and laboratory studies were conducted to examine the effect of application timing on the activity of DPX-V9360 on rhizome johnsongrass. Field and greenhouse studies indicated that johnsongrass treated with postemergence applications of DPX-V9360 at late growth stages (>5 leaves) was controlled more effectively than when treated in early growth stages (<5 leaves). Johnsongrass control was optimized with split-postemergence applications (treatments applied at early and late growth stages) in field studies compared to a single postemergence application at either early or late growth stages. The pattern of translocation of 2-14C (pyrimidine)-labeled DPX-V9360 applied to a fully expanded johnsongrass leaf did not differ significantly between three different growth stages of 10-, 30-, and 60-cm height. Over 60% of the absorbed14C remained in the treated leaf. Most of the translocated14C moved out of the treated leaf within 3 days after application and distributed to the shoot in greater quantities than to the rhizomes. About 40% of14C-DPX-V9360 applied to the leaf surfaces of a tolerant species (corn) or susceptible species (johnsongrass) was absorbed into the leaf. Corn metabolized over 90% of absorbed DPX-V9360 within 20 h, while there was no perceptible metabolism of DPX-V9360 in johnsongrass leaves after 24 h. Late growth stage and split-postemergence applications appear to provide more effective control than early growth stage applications because of better control of regrowth (new shoot emergence from rhizomes after application) and because tillering and plant emergence are more nearly complete at application time.


Weed Science ◽  
1978 ◽  
Vol 26 (6) ◽  
pp. 582-584 ◽  
Author(s):  
Roland Schirman ◽  
B. A. Zamora

No differences in the anatomy or bud pattern development were observed between young tap and lateral roots of rush skeletonweed(Chondrilla junceaL.). Shoots and lateral roots arise from meristemic zones that originate from a continuous pericyclic ring. Incubation of excised root segments resulted in rapid development of stem buds which showed geotropic response in 24 h. The development of identifiable leaf initials occurred prior to emergence through the epidermis in 8 days.


2007 ◽  
Vol 60 (4) ◽  
pp. 386-394 ◽  
Author(s):  
Cecilia Lynn Kinter ◽  
Brian A. Mealor ◽  
Nancy L. Shaw ◽  
Ann L. Hild

2016 ◽  
Vol 25 (3) ◽  
Author(s):  
Timo Lötjönen ◽  
Jukka Salonen

Perennial weeds are an increasing challenge in organic farming in the Nordic countries. The aim of this study was to compare different tillage methods in the control of Elymus repens by using two intensified bare fallow strategies. Two field experiments consisted of three ploughing methods and seven fallow methods. The experiments were carried out in organic soils in Central Finland. The methods applied in the brief fallow before cereal sowing (exp. 1) were not effective enough against E. repens. Due to wet weather conditions in the spring the fallow period was limited to two weeks in both years, which did not seem to be enough time. In the late summer fallow after ley (exp. 2), the Kvick-Finn weed-cultivator destroyed E. repens very effectively; on average 5% of E. repens remained alive in the barley crop in the autumn of the following year. After use of ordinary cultivators 10% of E. repens remained alive, after use of the spade harrow 25% and after frequent mowing over 50% remained alive, respectively. As a result of effective E. repens control, barley yield was about 1000 kg ha-1 higher than without any fallow. In conclusion, effective control of E. repens is achieved with proper machinery and repeated treatments at the optimal time.


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