Differences in the Phytotoxic Response of Wild Oats(Avena fatua)to Triallate and Trifluralin

Weed Science ◽  
1978 ◽  
Vol 26 (3) ◽  
pp. 273-276 ◽  
Author(s):  
D. Billett ◽  
R. Ashford

Several differences between the mode of action of trifluralin (α,α,α-trifluoro-2,6-dinitro-N,N-dipropyl-p-toluidine) and triallate [S-(2,3,3-trichloroallyl)diisopropylthiocarbamate] were observed on wild oats(Avena fatuaL.) in growth chamber experiments. Trifluralin exhibited little or no postemergence effect when applied to the soil surface. Surface applications of triallate interfered with deposition of epicuticular wax on leaf surfaces, and caused necrotic lesions, leaf break, and the abortion of the first leaf through the coleoptile. Trifuralin, but not triallate, incorporated in the soil reduced extension of the wild oat coleoptile. Soil-incorporated treatments involving trifluralin induced more extensive swelling of the mesocotyl, coleoptile node, and and coleoptile than triallate applied similarly. Triallate appeared to exert its major effect on cell elongation of the wild oat foliar material enclosed in the coleoptile. Trifluralin caused its greatest phytotoxic effect on the meristematic tissue at the region of the coleoptile node.

1985 ◽  
Vol 63 (10) ◽  
pp. 1789-1793 ◽  
Author(s):  
D. V. Rao ◽  
M. V. S. Raju

The radial elongation of epidermal cells of the scutellum of wild oat (Avena fatua L.) embryos was studied quantitatively. In the nondormant embryos, the length of these cells, both on the adaxial and abaxial sides of the scutellum, was doubled in 10 days after the beginning of the imbibition of caryopses in water; no such elongation of cells was observed in the dormant embryos. The epidermal cells elongated to form papillae only after the primary root had emerged from the caryopsis. The length of the entire scutellum and that of its epidermal cells increased significantly in the presence of gibberellic acid and glucose or sucrose. It is suggested that the epidermal cell elongation is a postgermination phenomenon involving absorption and transport of the products of starchy endosperm hydrolysis, thus promoting further growth in the germinated embryo of the wild oat.


Weed Science ◽  
1970 ◽  
Vol 18 (1) ◽  
pp. 80-84 ◽  
Author(s):  
J. D. Banting

After 3 days or more germination in 5-(2,3-dichloroallyl) diisopropylthiocarbamate (diallate) or S-(2,3,3-trichloroallyl)diisopropylthiocarbamate (triallate) vapor, shoots and roots of wild oat (Avena fatua L.) and spring wheat (Triticum aestivum L.) were measured, sectioned, stained, and squashed for comparison of growth and mitotic activity. Shoot tissue of wild oat was damaged more readily than root tissue by diallate vapor. The meristematic tissue at the base of the first leaf was apparently more vulnerable than stem apex tissue since it exhibited more divisions and a greater number of abnormalities. The effect of triallate was similar but less pronounced. Shoot tissue of wheat also was more sensitive to diallate than root tissue. This was indicated by reduced mitotic activity and by shoot inhibition. Few abnormalities were observed in wheat even at high concentrations. Results were similar with triallate. Root and shoot measurements indicated that wheat was more tolerant to triallate than to diallate. Shoot inhibition occurred in both wild oat and wheat at concentrations that did not affect mitosis. Mitotic damage from the use of either diallate or triallate thus appeared to be of secondary importance, the major effect being on some phase of cell elongation or expansion.


Weed Science ◽  
1974 ◽  
Vol 22 (5) ◽  
pp. 476-480 ◽  
Author(s):  
Robert W. Neidermyer ◽  
John D. Nalewaja

The response of wheat (Triticum aestivum L.) and wild oat (Avena fatua L.) to barban (4-chloro-2-butynyl-m-chlorocarbanilate) was studied as influenced by plant morphology and air temperature after application. Growth of wheat and wild oat seedlings was reduced by barban at 0.3 μg and 0.6 μg applied to the first node, respectively. Barban application to the base and midpoint of the first leaf blade required a lower dose to reduce wild oat growth than wheat growth. Increased tillering occurred from barban injury to the main culm in wheat. Wheat and wild oat susceptibility to barban increased as the post-treatment temperature decreased from 32 to 10 C. Barban selectivity for wild oats in wheat was greater at 27 and 21 C than at 16 and 10 C.


1979 ◽  
Vol 59 (1) ◽  
pp. 93-98 ◽  
Author(s):  
F. A. QURESHI ◽  
W. H. VANDEN BORN

Uptake of 14C-diclofop-methyl {methyl 2-[4-(2,4-dichlorophenoxy)phenoxy propanoate]} by leaves of wild oats (Avena fatua L.) was reduced significantly in the presence of MCPA {[(4-chloro-o-tolyl)oxy]acetic acid]}, especially the dimethylamine formulation. If the herbicides were applied separately, the degree of interference with uptake depended on the extent of overlap of droplets of the two spray preparations on the leaf surface. Spray volume and direction of spray application were important factors in minimizing the mixing of spray droplets on the leaves if the two herbicides were applied separately with a tandem arrangement of two sprayers. Such a sequential application of MCPA ester and diclofop-methyl in a field experiment provided significantly greater wild oat control than could be obtained with a tank mix of the same two herbicides, but the results were not consistent enough to recommend the procedure for practical use.


1988 ◽  
Vol 2 (4) ◽  
pp. 495-498 ◽  
Author(s):  
John T. O'Donovan

In continuous wheat or barley or in a canola/barley rotation, wild oat control every year over 4 yr maintained wild oat seedling populations at 3 plants/m2 or less. Failure to control wild oats annually increased wild oat populations (>200 plants/m2 by the fourth year) in continuous wheat dramatically, while in the other two cropping systems, populations increased to only 40 plants/m2 or less by the fourth year. In the continuous wheat and in the canola/barley rotation, wild oat control every year generally provided the best economic returns when prices and costs were averaged over 4 yr; in continuous barley, the average return was better when wild oats was controlled only in the second or third years rather than every year.


1957 ◽  
Vol 49 (3) ◽  
pp. 259-274 ◽  
Author(s):  
Joan M. Thurston

In samples of wild-oat panicles collected in England and Wales in 1951 only two species, Avena fatua L. and Avena ludoviciana Dur., occurred; both were very variable in grain characters but most plants bred true. Plants of all except one type of A. fatua were upright in habit with few tillers and averaged 95% dormant grains at harvest; plants of A. ludoviciana were procumbent or prostrate at the maximum tillering stage with numerous tillers and the percentage dormant grains was lower than in A. fatua.The taxonomy of wild oats is discussed. Chromosome counts on eleven selections showed that 2n = 42.Types intermediate between wild and cultivated oats were compared with wild oats.


Weed Science ◽  
1987 ◽  
Vol 35 (5) ◽  
pp. 669-672 ◽  
Author(s):  
William S. Curran ◽  
Larry A. Morrow ◽  
Ralph E. Whitesides

Studies were conducted to evaluate the effect of wild oat (Avena fatua L. # AVEFA) interference in lentils (Lens culinaris Medik). An infestation of 32 and 65 wild oats/m2 maintained up to 5 weeks in the field did not reduce lentil grain yield. However, 32 wild oats/m2 reduced yields 32% when allowed to remain for 7 weeks and 49% if they remained until harvest time (11 weeks). Sixty-five wild oats/m2 reduced grain yield 42 and 61% for the same time periods, respectively. In the growth chamber, 69 wild oats/m2 reduced lentil plant dry weight 29% if allowed to remain for 3 weeks, 61% for 5 weeks, and 72% for 7 weeks (harvest time). The field data suggest that wild oat control measures may be delayed for several weeks after lentil emergence without reducing crop yield.


1984 ◽  
Vol 62 (11) ◽  
pp. 2469-2471 ◽  
Author(s):  
William A. Quick ◽  
Andrew I. Hsiao

The period of afterripening required by dormant seeds of wild oat (Avena fatua L.) depends upon their genetic and environmental history. A steady increase was found in the level of inorganic phosphate (Pi) and germinability of dry mature caryopses of genetically dormant wild oat lines as afterripening progressed. There were no appreciable changes in Pi or in germinability of the companion seeds stored at −15 °C over the period of study. Secondary seeds were more dormant and had lower levels of Pi during afterripening than was the case with primary seeds. Storage at room temperature had little effect on Pi level of nondormant seed line. Results support the hypothesis that levels of endogenous Pi within the seed influence germinability.


1985 ◽  
Vol 63 (12) ◽  
pp. 2187-2195 ◽  
Author(s):  
M. V. S. Raju ◽  
G. J. Jones ◽  
G. F. Ledingham

Avena fatua L. (wild oats), an introduced annual, is a successful weed in the cultivated fields of the Canadian prairies. Its inflorescence is a determinate panicle consisting of many spikelets, each of which contains two or three florets. During anthesis, the lodicules in each floret swell after water uptake and cause the lemma to diverge and to establish a wide angle between it and the palea. The essential organs in the floret are exposed to the environment and subsequently the anthers dehisce releasing pollen. The pollen grains are dropped on the stigmatic branches, thus effecting self-pollination. Following pollination, the floret closes because of the collapsing of lodicules. The pollen on the stigma germinates after the floret has closed. Anthesis, both in the field and in the growth cabinet, shows a daily rhythm and occurs in the afternoon. This rhythmic floret opening seems to be temperature sensitive. The ambient temperature range for anthesis in the field is 25–28 °C. The wild oat is primarily a chasmogamous species and enforced cleistogamy in the florets can be induced experimentally.


Weed Science ◽  
1994 ◽  
Vol 42 (3) ◽  
pp. 353-357 ◽  
Author(s):  
Stephen W. Adkins ◽  
Andrea L. Adkins

A study under glasshouse conditions determined the effect of germination stimulants, potassium nitrate and ethephon, on emergence of several pure lines of wild oat from soil. Effect of the two chemicals on stimulating emergence was variable and no synergism noted when used together. Examination of exhumed seed showed that these treatments reduced seed viability. By counting the number of dead and adding to those that emerged, total seed removed from the soil was obtained. All treatments removed seed from the soil seedbank, especially when seed was old, near the soil surface, was primary seed, or from low or intermediate dormancy lines. However, because of the insensitivity of a large proportion of the seed and the high rates required it is unlikely that either potassium nitrate or ethephon has practical use for field application.


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