Resistance to Aryloxyphenoxypropionate Herbicides in Two Wild Oat Species (Avena fatuaandAvena sterilisssp.ludoviciana)

Weed Science ◽  
1992 ◽  
Vol 40 (4) ◽  
pp. 599-605 ◽  
Author(s):  
Ali M. Mansooji ◽  
Joseph A. Holtum ◽  
Peter Boutsalis ◽  
John M. Matthews ◽  
Stephen B. Powles
Keyword(s):  
Methyl Ester ◽  
Western Australia ◽  
South Australia ◽  
Avena Fatua ◽  
Wild Oat ◽  
Avena Sterilis ◽  
Susceptible Control ◽  
Low Levels ◽  
Marked Resistance

Resistance to the methyl ester of diclofop, an aryloxyphenoxypropionate graminicide, was shown for a wild oat (Avena fatua) population from Western Australia, and marked resistance to a range of aryloxyphenoxypropionate and cyclohexanedione graminicides was detected in a winter wild oat (Avena sterilisssp.ludoviciana) population from South Australia. TheA. sterilisbiotype exhibited high levels of resistance to the aryloxyphenoxypropionate herbicides diclofop, fluazifop, haloxyfop, fenoxaprop, quizalofop, propaquizafop, and quinfurop and low levels of resistance to the cyclohexanedione herbicides sethoxydim, tralkoxydim, and cycloxydim. Ratios of LD50values for responses of resistant and susceptibleA. sterilisto the aryloxyphenoxypropionate herbicides were between 20 for propaquizafop and > 1,000 for fluazifop, and were between 2.5 and 3 for the cyclohexanedione herbicides. The LD50value for diclofop for theA. fatuabiotype was 442 g ai ha-1which was 2.7-fold that of a susceptible control. Thirty-three percent of the plants survived at the registered rate of application.

Wild Oat (Avena fatua) andAvena sterilisMorphological Characteristics and Response to Herbicides

Weed Science ◽  
1984 ◽  
Vol 32 (3) ◽  
pp. 353-359 ◽  
Author(s):  
Carol N. Somody ◽  
John D. Nalewaja ◽  
Stephen D. Miller
Keyword(s):  
United States ◽  
Surface Area ◽  
Southern California ◽  
Leaf Surface ◽  
The United States ◽  
Avena Fatua ◽  
Propanoic Acid ◽  
Wild Oat ◽  
Avena Sterilis ◽  
Leaf Surface Area

Wild oat (Avena fatuaL. ♯3AVEFA) andAvena sterilisL. ♯ AVEST accessions from the United States were screened for tolerance to diallate [S-(2,3-dichloroallyl) diisopropylthiocarbamate], triallate [S-(2,3,3-trichloroallyl) diisopropylthiocarbamate], barban (4-chloro-2-butynylm-chlorocarbanilate), diclofop {2-[4-(2,4-dichlorophenoxy) phenoxy] propanoic acid}, difenzoquat (1,2-dimethyl-3,5-diphenyl-1H-pyrazolium), flamprop [N-benzoyl-N-(3-chloro-4-fluorophenyl)-DL-alanine], and MSMA (monosodium methanearsonate). Some accessions were tolerant to more than one herbicide but none were tolerant to all herbicides. Tolerance to a herbicide was not restricted to certain areas of origin of the accessions, and tolerant accessions occurred even in locations that had not been treated previously with the herbicide. In general, accessions from Southern California and Arizona were shorter, produced more tillers, and required the least number of days to panicle emergence. However, accessions from within individual areas were nearly as variable in these characteristics as the entire 1200 accessions. Tolerance of accessions to flamprop, difenzoquat, MSMA, and diclofop was not due to low leaf surface area, since the tolerant accessions usually had the most leaf surface area. All the accessions tolerant to difenzoquat, MSMA, and flamprop, and three of the four accessions tolerant to diclofop, tillered less than the susceptible accessions.

The Basis for Synergism between Barban and Flamprop on Wild Oat (Avena fatua)

Weed Science ◽  
1982 ◽  
Vol 30 (2) ◽  
pp. 147-152 ◽  
Author(s):  
Mahendra P. Sharma ◽  
Fayaz A. Qureshi ◽  
William H. Vanden Born
Keyword(s):  
Methyl Ester ◽  
Nonionic Surfactant ◽  
Avena Fatua ◽  
Synergistic Interaction ◽  
Wild Oat ◽  
Commercial Formulation ◽  
Leaf Stage

Absorption, translocation, and metabolism of the methyl ester of14C-flamprop [N-benzoyl-N-(3-chloro-4-fluorophenyl)-DL-alanine] (hereafter referred to as flamprop-methyl) and14C-barban (4-chloro-2-butynyl-m-chloro carbanilate) in wild oat (Avena fatuaL.) were investigated to determine the basis of the synergistic interaction between the two herbicides. The mutual effects of the two herbicides were studied when they were applied together to wild oat at the two- and four-leaf stage. The addition of the commercial formulation of barban, barban formulation additives, technical barban, or the nonionic surfactant polyoxyethylene-6-tridecylether resulted in varying degrees of increase in the absorption of14C-flamprop-methyl. Translocation of14C-flamprop-methyl following leaf application in wild oat was mainly acropetal. The addition of commercial barban to14C-flamprop-methyl did not influence the pattern of14C translocation. Metabolism of flamprop-methyl by wild oat at either leaf stage was not influenced by barban. Absorption of14C-barban was increased by the addition of the commercial formulation of flamprop-methyl and by polyoxyethylene-6-tridecylether. The addition of flamprop-methyl did not influence the pattern of translocation and metabolism of14C-barban in wild oat at either leaf stage. It is concluded that increased absorption of flamprop-methyl and barban by wild oat at the two- and four-leaf stages is the most important factor in the synergistic interaction between these herbicides. Translocation and metabolism of the herbicides do not seem to be important factors in the synergism observed.

Effect of Moisture Stress on Wild Oat (Avena fatua) Response to Diclofop

Weed Science ◽  
1983 ◽  
Vol 31 (2) ◽  
pp. 247-253 ◽  
Author(s):  
William C. Akey ◽  
Ian N. Morrison
Keyword(s):  
Methyl Ester ◽  
Soil Moisture Content ◽  
Sandy Loam ◽  
Moisture Stress ◽  
Avena Fatua ◽  
Propanoic Acid ◽  
Wild Oat ◽  
Physiological Factors ◽  
Growth Room ◽  
Reduced Activity

The effect of moderate moisture stress on the activity of the methyl ester of diclofop {2-[4-(2,4-dichlorophenoxy)phenoxy] propanoic acid} applied to wild oat (Avena fatuaL.) and the influence of morphological and physiological factors on the activity of the herbicide on stressed plants were investigated in growth-room experiments. Wild oat was grown in very fine sandy loam brought to a gravimetric soil moisture content (SMC) of 20% (water potential of -0.3 bars) or 10% (-6.5 bars) prior to herbicide treatment. The activity of diclofop on wild oat was slightly, but significantly, reduced when the SMC was increased from 10 to 20% immediately after spraying. Maintaining the SMC at 10% after spraying further reduced the activity of the herbicide. Wild oat plants grown at 20% SMC had 22% greater leaf area and retained 23% more herbicide than plants grown at 10% SMC. Penetration of the methyl ester of14C-diclofop into wild oat grown at 20 or 10% SMC did not differ significantly 12, 24, or 48 h after application. Stressed and unstressed plants did not differ significantly in the metabolism of the methyl ester of14C-diclofop. However, growth at a low SMC prior to treatment decreased the proportion of the radiolabeled herbicide recovered in the apex, third leaf, and tillers of wild oat. This may partially account for the reduced activity of this herbicide on wild oat subjected to moisture stress.

Endogenous hormones in afterripening wild oat (Avena fatua) seed

1980 ◽  
Vol 58 (9) ◽  
pp. 1016-1024 ◽  
Author(s):  
J. S. Taylor ◽  
G. M. Simpson
Keyword(s):  
Thin Layer ◽  
Zeatin Riboside ◽  
Avena Fatua ◽  
Enzyme Hydrolysis ◽  
Cytokinin Activity ◽  
Endogenous Hormones ◽  
Wild Oat ◽  
Dormant Seed ◽  
Gibberellin Activity ◽  
Low Levels

Levels of gibberellins and cytokinins in dormant Avena fatua L. seeds were measured by bioassay during the afterripening process. Little change in the level of either hormone was detected in the dry seed. Following imbibition of fully afterripened seed, however, gibberellin levels increased while cytokinin levels declined. Seed strains varying in their degree of dormancy were also analysed for hormone levels; a significantly higher level of cytokinin activity was found in the most dormant strain compared with the least dormant strain. Low levels of bound hormones, including cytokinin ribotides and gibberellin glucose conjugates, were detected following enzyme hydrolysis but neither class of compounds varied greatly in level during afterripening.The major cytokinins detected in Avena fatua seeds cochromatographed with zeatin-9-glucoside, zeatin riboside, and zeatin on both HPLC columns and chromatography paper. The major gibberellin activity cochromatographed with GA4/GA7 on silica gel partition columns and thin-layer plates.Germination studies demonstrated that GA4/7 is significantly more active than GA3 in promoting the germination of dormant Avena fatua seeds. External applications of cytokinins were not found to affect the germination of dormant seed, but did promote germination in partially afterripened material.

The Response of Wild Oat (Avena fatua) andAvena sterilisAccessions to Photoperiod and Temperature

Weed Science ◽  
1984 ◽  
Vol 32 (2) ◽  
pp. 206-213 ◽  
Author(s):  
Carol N. Somody ◽  
John D. Nalewaja ◽  
Stephen D. Miller
Keyword(s):  
Growth Rate ◽  
Gibberellic Acid ◽  
Relative Growth Rate ◽  
Morphological Characteristics ◽  
Avena Fatua ◽  
Growth Characteristics ◽  
Day Length ◽  
Wild Oat ◽  
Avena Sterilis ◽  
Relative Growth

Twenty-nine wild oat (Avena fatuaL. ♯3AVEFA) andAvena sterilisL. ♯ AVEST accessions having various areas of origin and/or growth characteristics were grown to maturity in controlled environmental chambers. The four environments consisted of a 16-h photoperiod until 3 weeks after emergence, when the photoperiod was decreased (DP) 1 h per week for 8 weeks at a constant 14, 20, or 26 C (DP 14, DP 20, or DP 26); and an 8-h photoperiod until 3 weeks after emergence, when the photoperiod was increased (IP) 1 h per week for 8 weeks at a constant 20 C (IP 20). The relative growth rate of the accessions was similar in each environment. The length of the second leaf was up to 15 cm greater under 8- than 16-h day length at 20 C for some accessions, but was similar under both day lengths for other accessions. The width of the second leaf was greater under 14 than 20 C and was narrower with a 16-h than an 8-h photoperiod. Tiller initiation was slower in the DP 14 and IP 20 than in the DP 20 and DP 26 environments. Days to panicle emergence for individual accessions ranged from 10 to 57 days higher in the DP 14 than in the DP 20 environment. Seed produced on plants grown at 14 C had lower germination in water and 1500 ppm gibberellic acid than seed from plants grown at 20 C. Wild oat accessions varied in morphological characteristics, days to panicle emergence, and dormancy, and responded differently to changes in photoperiod and temperature. Wild oat morphological characteristics, days to panicle emergence, and dormancy did not consistently relate to species or area of origin.

Seed Longevity and Seedling Emergence Behavior of Wild Oat (Avena fatua) and Sterile Oat (Avena sterilis ssp. ludoviciana) in Response to Burial Depth in Eastern Australia

Weed Science ◽  
2021 ◽  
pp. 1-28
Author(s):  
Gulshan Mahajan ◽  
Bhagirath S. Chauhan
Keyword(s):  
Weed Control ◽  
Cover Crops ◽  
Avena Fatua ◽  
Seed Longevity ◽  
Burial Depth ◽  
Wild Oat ◽  
Avena Sterilis ◽  
Complete Control ◽  
Emergence Pattern ◽  
Eastern Australia

Abstract Weed emergence time and the longevity of weed seeds within the soil play an important role in implementing a timely and effective weed control program. In this study, the seed longevity and emergence pattern of wild oat (Avena fatua L.) and sterile oat [Avena sterilis ssp. ludoviciana (Durieu) Gillet & Magne] were monitored in field conditions. Fresh seeds of A. fatua and A. ludoviciana were placed into nylon bags (50 seeds per bag in three replications for three locations in Southeast Australia: Gatton, Narrabri, and St. George) and buried at depths of 0, 2, and 10 cm in November 2017. Bags were exhumed at 6-mo intervals over 30-mo to evaluate seed germination, viability, and decay components. The seed decay component of A. fatua and A. ludoviciana followed an exponential pattern. On both the surface and at the 10 cm burial depth, 50% of the seeds of A. fatua and A. ludoviciana had decayed by 6-mo. The seeds of A. fatua persisted longer at 2 cm depth than at other depths, particularly at St. George where 90% of the seeds decayed after the 30-mo study. However, at Gatton and Narrabri, 90% of the seeds of A. fatua at this depth had decayed after 18-mo of seed placement in the soil. In the emergence pattern experiment, the emergence of A. fatua and A. ludoviciana from different burial depths was also studied (2017-2019). The emergence of A. fatua and A. ludoviciana was greater from 2 cm (29-36%) and 5 cm (18-43%) soil depths compared to the surface (5-10%) and 10 cm (3-9%) soil depth. A. ludoviciana emerged earlier (2253 growing degree days, GDD; March 14, 2018) than A. fatua (3364 GDD; May 23, 2018). Both species exhibited high emergence between May to June 2018, and the last cohort of each species was observed in October 2018. The highest seedlings emergence occurred at the start of the winter season (May), which emphasizes the need for early PRE weed control such as tillage, herbicide application, and cover crops to ensure crops are planted in a clean seedbed. The continued emergence of these weeds into the spring season (October) emphasizes the need for extended periods of A. fatua and A. ludoviciana management. The results also suggest that management strategies that can control all emerged seedlings over two years and restrict seed rain in the field could lead to complete control of Avena spp. in the field.

Effects of Diclofop on Growth, Mitotic Index, and Structure of Wheat (Triticum aestivum) and Wild Oat (Avena fatua) Adventitious Roots

Weed Science ◽  
1981 ◽  
Vol 29 (4) ◽  
pp. 426-432 ◽  
Author(s):  
I. N. Morrison ◽  
M. G. Owino ◽  
E. H. Stobbe
Keyword(s):  
Triticum Aestivum ◽  
Methyl Ester ◽  
Mitotic Index ◽  
Adventitious Root ◽  
Adventitious Roots ◽  
Avena Fatua ◽  
Root Tip ◽  
Wild Oat ◽  
Root Tips ◽  
Wheat Roots

Methyl ester of diclofop {2-[4-(2,4-dichlorophenoxy) phenoxy] propanoic acid} (diclofop as used herein refers to the methyl ester) added to nutrient solution inhibited adventitious root development and reduced the mitotic index in adventitious root tips of wheat (Triticum aestivumL. ‘Neepawa’) and wild oat (Avena fatuaL.). Elongation of wild oat roots was significantly inhibited by 0.15 μM diclofop 24 h after treatment; whereas, wheat roots were unaffected at concentrations less than 1.5 μM even at 12 days, indicating at least a 10-fold difference in sensitivity. Initiation of new adventitious roots was reduced in both species by 0.30 μM diclofop. Mitotic index was more severely reduced at lower concentrations and after a shorter exposure in wild oat than in wheat. Histological studies showed that 24 h after wild oat roots were treated with 0.30 μM diclofop for 24 h, severe damage occurred to tissues within the developing central cylinder, close to the root apex. Disruption of cortical and epidermal cells generally was not as severe until 4 to 7 days after treatment. By 12 days the entire root tip was almost completely obliterated, with only the epidermal cell walls remaining intact.

A Seed Bioassay to Identify Acetyl-CoA Carboxylase Inhibitor Resistant Wild Oat (Avena fatua) Populations

1996 ◽  
Vol 10 (1) ◽  
pp. 85-89 ◽  
Author(s):  
Bruce G. Murray ◽  
Lyle F. Friesen ◽  
Kelly J. Beaulieu ◽  
Ian N. Morrison
Keyword(s):  
Root Development ◽  
Filter Paper ◽  
Agar Medium ◽  
Rapid Identification ◽  
Avena Fatua ◽  
Wild Oat ◽  
Acetyl Coa Carboxylase ◽  
Acetyl Coa ◽  
Quantitative Measurements ◽  
Low Levels

A seed bioassay was developed and tested for the rapid identification of aryloxyphenoxypropionate (APP) and cyclohexanedione (CHD) resistance in wild oat. Two susceptible (S) genotypes, UM5 and Dumont, were treated with fenoxaprop-P and sethoxydim over a range of dosages on filter paper and agar. The former is a wild oat line and the latter a tame oat cultivar. Within 5 d, shoot and root development of both genotypes were completely inhibited by 10 μM fenoxaprop-P and 5 μM sethoxydim. These dosages were then tested to determine if they were suitable for distinguishing between resistant (R) and susceptible (S) plants. Agar medium was preferred over filter paper because of the ease of preparation and maintenance. Four known R wild oat populations were included in the tests. Those with high levels of resistance produced significantly longer coleoptiles and roots than S genotypes, but those with moderate or low levels of resistance could not be separated statistically from S biotypes based on quantitative measurements. However, after exposing the germinating, treated seeds to light for 24 to 48 h, all the R populations produced green coleoptiles and initiated a first leaf, unlike the S genotypes which did not turn green or produce any new growth. This procedure proved useful in discriminating between R and S genotypes and in ranking populations in terms of relative levels of resistance.

Mission Tracks in the Bush

2019 ◽  
Vol 3 (1-2) ◽  
pp. 103-124
Author(s):  
Gemma Tulud Cruz
Keyword(s):  
Nineteenth Century ◽  
Western Australia ◽  
South Australia ◽  
Nation Building ◽  
Cultural Encounters ◽  
History Of

Christian missionaries played an important role in the Australian nation building that started in the nineteenth century. This essay explores the multifaceted and complex cultural encounters in the context of two aboriginal missions in Australia in the nineteenth century. More specifically, the essay explores the New Norcia mission in Western Australia in 1846-1900 and the Lutheran mission in South Australia in 1838-1853. The essay begins with an overview of the history of the two missions followed by a discussion of the key faces of the cultural encounters that occurred in the course of the missions. This is followed by theological reflections on the encounters in dialogue with contemporary theology, particularly the works of Robert Schreiter.

In A Fix: Fixed-Term Parliaments in the Australian States

2013 ◽  
Vol 41 (2) ◽  
pp. 265-298
Author(s):  
Peter Congdon
Keyword(s):  
Western Australia ◽  
Prime Minister ◽  
New South ◽  
New South Wales ◽  
South Australia ◽  
Constitutional Amendments ◽  
South Wales

Constitutional systems of Westminster heritage are increasingly moving towards fixed-term parliaments to, amongst other things, prevent the Premier or Prime Minister opportunistically calling a ‘snap election’. Amongst the Australian states, qualified fixed-term parliaments currently exist in New South Wales, South Australia and Victoria. Queensland, Tasmania and Western Australia have also deliberated over whether to establish similar fixed-term parliaments. However, manner and form provisions in those states' constitutions entrench the Parliament's duration, Governor's Office and dissolution power. In Western Australia and Queensland, unlike Tasmania, such provisions are doubly entrenched. This article considers whether these entrenching provisions present legal obstacles to constitutional amendments establishing fixed-term parliaments in those two states. This involves examining whether laws fixing parliamentary terms fall within section 6 of the Australia Acts 1986 (Cth) & (UK). The article concludes by examining recent amendments to the Electoral Act 1907 (WA) designed to enable fixed election dates in Western Australia without requiring a successful referendum.

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