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1.
Mixtures of tri-S-butyl phosphorotrithioate (DEF) emulsion and the potassium salt of picloram were strongly synergistic when applied as foliar sprays to pot-grown privet, poplar, guava and Eucalyptus plants. A similar but less marked effect was observed in privet, using mixtures of DEF and a water-soluble amine formulation of 2,4,5-T. By contrast, mixtures of an oil-soluble ester formulation of 2,4,5-T with DEF were antagonistic with privet. 相似文献
2.
D. J. Turner 《Pest management science》1972,3(3):323-331
The possibilities are demonstrated of increasing the activity of foliar applied growth regulator herbicides by mixing them with chemicals which injure the cuticle or epidermis. S, S, S-Tributyl phosphorotrithioate (“DEF”) increases the effects of picloram, 2,4,5-T and mecoprop salts on four woody species, privet (Ligustrum ovalifolium Hassk.), poplar (× Populus gelrica Ait.), bluegum (Eucalyptus globulus Labill.) and guava (Psidium guajava L.). Mixtures with esters of the herbicides are not synergistic and often antagonistic. DEF, tributyl phosphorotrithioite, a number of alkyl and aryl phosphates and phosphites and potassium ethyl xanthate enhance the phytotoxicity of picloram solution on dwarf bean (Phaseolus vulgaris L.). Mixtures of picloram with tributyl phosphorotrithioite, tributyl phosphate, mixed acid butyl phosphates, trimethyl phosphate and mixed isomers of tritolyl phosphate are synergistic when applied to guava foliage. Tributyl phosphate and mixed acid butyl phosphates interact similarly with picloram on privet and tributyl phosphate increases the effects of foliar applied mecoprop salt on guava. The mode of action of the additives is not fully understood but there is evidence that DEF facilitates the entry of water soluble growth regulator herbicides into leaves and has little effect on the rate at which the herbicides move through the plant. Tributyl phosphate and mixed acid butyl phosphates are suggested for practical use in herbicide formulations to control woody plants, as they are relatively cheap and non-toxic. 相似文献
3.
The effectiveness of‘Tordon 50-d’(5% a.i. picloram plus 20% a.i. 2,4-D both as the triisopropanolamine salts) and various mixtures of 2,4,5-T and picloram were tested for the control of blackberry (Rubus fruticosus L. agg.) in Victoria, Australia. A high correlation was obtained between the % reduction in live canes and the % kill of crowns 13 months after Rubus procerus P.J. Muell. thickets were sprayed with 2,4,5-T or‘Tordon 50-d'. Counting the number of live canes is, therefore, a convenient method of comparing the efficacy of these herbicides for the control of blackberry. ‘Tordon 50-d’was generally more effective than 2,4,5-T but stimulation of suckering from roots was recorded at one site when low rates of‘Tordon 50-d’were used. It was necessary to add high dose rates of‘Tordon 50-d’to 2,4,5-T before there were worthwhile improvements in weed control.‘Tordon 5–20’(5% a.i. picloram as triisopropanolamine salt plus 20% 2,4,5-T as the ethyl hexyl ester) was only slightly more effective in controlling blackberry than‘Tordon 50-d'. The cost and soil residue problems associated with picloram should limit its use as an additive to 2,4,5-T for the control of blackberry in Australia. 相似文献
4.
A method is described for the analysis of mixtures of picloram with 2,4-D or 2,4,5-T in commercial formulations. The method involves the esterification of the acids in sealed tubes at 105°C using boron trifiuoride-methanol reagent, followed by extraction, and then estimation by gas chromatography using flame ionisation detection. 相似文献
5.
The uptake of 2,4,5-T by spines of gorse (Ulex europaeus L.) was limited and not enhanced when picloram was added to the application solution. Translocation of 2,4,5-T in 6-month-old cuttings after treatment of a single spine or lateral branch was poor. The most significant accumulation of translocated herbicide occurred in stem tissue, with lesser amounts detected in root tissues, root nodules, stem apices and flowers. Untreated lateral branches or spines accumulated minimal amounts of herbicide. The pattern and extent of distribution of 2,4,5-T was not increased by addition of picloram. The lack of efficient control of gorse by 2,4,5-T can largely be attributed to its inadequate uptake and lack of true systemic translocation. 相似文献
6.
A gas chromatographic method for the determination of 2,3,7,8-tetrachloro-dibenzo-1,4-dioxin in 2,4,5-trichlorophenoxyacetic acid and 2,4,5-T alkyl ester herbicides is described. Of 80 samples of 100% 2,4,5-trichlorophenoxyacetic acid alkyl ester herbicides 25 contained less than 0.05 part/million and 75 less than 0.5 part/million 2,3,7,8-tetrachlDrodiben2o-1,4-dioxin. Of 32 samples of 50% formulations of 2,4,5-T alkyl esters in mineral oil, 8 contained less than 0.05 part/million and 18 less than 0.5 part/million tetrachlorodioxin. The maximum found was 28.3 part/ million. 相似文献
7.
The formation of roots and shoots on root segments of Rubus procerus P.J. Muell was prevented by soaking the segments for 24 h in a 10?4M solution of 2,4,5-T or a 10?5M solution of picloram. Shoot numbers were significantly increased after treatment with 10?9M and 10?10M 2,4,5-T, but picloram did not cause a significant increase in shoot numbers. Measurement of the concentration of 2,4,5-T in the extracambial tissue showed that roots treated with 10?4M 2,4,5-T contained 5× 10?8 mmole 2,4,5-T per mg dry weight, and by extrapolation, roots treated with 10?9M 2,4,5-T contained 2× 10?10 mmole/mg dry weight. Action du 2,4,5-T et du piclorame sur la régénération de la ronce (Rubus procerus P.J. Muell) è partir de fragments de racines La formation de racines et de tiges è partir de fragments de racines dc Ruhus procerus P.J. Muell a été supprimée par trempage des fragmenls pendant 24 heures dans une solution a 10?4M et de 2.4,5-T, ou dans une solution 10?5M de piclorame. Le nombre de pousses s'est accru significativement après traitement avec le 2,4,5.-T è 10?9M et 10?10M, mais le piclorame n'a pas provoqué d'accroissemcnt significatif du nombre de pousses. La mesure de la concentration de 2,4,5-T dans le tissu extra-cambial a montré que les racines trailées avec du 2,4,5-T è 10?4M contenaient 5×10?8 mmole de 2.4,5-T par mg de poids sec et par extrapolation, quc les racines traitées avec du 2,4,5-T k 10?9M devaient contenir 2 × 10?12 mmole/mg de poids sec. Die Wirkiing von 2,4,5-T und Picloram auf den Wuchs der Wurzehegmenten von Bromheeren (Rubus procerus P.J. Muell). Die Bildung von Wurzeln und Sprossen aus Wurzelsegmen-ten von Ruhu.i procerus P.J. Muell wurde durch 24-stündiges Einlegen der Wurzelstücke in 10?4M 2,4,5-T bzw 10?5M Picloram verhindert. Die Anzahl neugebiideter Sprosse wurde nach Einlegen in 10?9M und 10?10M 2,4,5-T, nicht jedoch durch Picloram, signifikant erhöht. Im extracambialen Gewebe von Wurzeln, die mit 10?4M 2,4,5-T behand-elt worden waren, wurden 5×10?8mMol 2,4,5-T je mg Trockengewiclu bestimmt. Durch Extrapolation wurde ermittclt. dass mit 10?9M 2,4,5-T behandelte Wurzeln 2× 10?12mMol/mg Trockengewicht cnthielten. 相似文献
8.
Experiments were conducted in a controlled environment growth room to compare the phytotoxicity of five formulations of clopyralid and to determine the effect of post-treatment simulated rainfall applications on the efficacy of these formulations. Clopyralid, formulated as the acid, monoethanolamine salt, potassium salt, 2-ethylhexyl ester or 1-decyl ester was applied to Cirsium arvense or Polygonum convolvulus at the 8–10 and 4–6 leaf stage of development, respectively. Based on the shoot and root dry weight data from both species, the 2-ethylhexyl ester was consistently less phytotoxic than the other four formulations. With respect to Cirsium arvense shoot and root dry weight, there was no difference in efficacy between the acid, monoethanolamine salt, potassium salt and 1-decyl ester. Root dry weight changes of Polygonum convolvulus did not correlate well with an increase in dose of the five formulations. Maximum increase in stem diameter of Polygonum convolvulus occurred after application of 100 g a.e. ha?1 of the acid, monoethanolamine salt, potassium salt and 1-decyl ester whereas with the 2-ethylhexyl ester, the maximum increase occurred after application of 200 g a.e. ha?1. Simulated rainfall was applied 3, 6, 9 or 12 h after application of 200 g a.e. ha?1 of the five clopyralid formulations to both species. Rainfall reduced the efficacy of clopyralid, regardless of the formulation or species. The 2-ethylhexyl ester was less efficacious than the other four formulations, irrespective of the timing of simulated rainfall. 相似文献
9.
D. J. TURNER 《Weed Research》1985,25(4):289-299
In pot experiments, mixtures of ammonium sulphate with surfactants or oil additives increased the phytotoxicity of commercially formulated bentazone (‘Basagran’) to Stellaria media (chickweed). Ammonium sulphate with a proprietary oil adjuvant Actipron had similar effects with benazolin potassium salt, but not with an ethyl ester formulation of benazolin. The phytotoxicity of bentazone and benazolin salts to Trifolium repens (white clover) and Lolium perenne (perennial ryegrass) was almost unaffected by these additives. In a field experiment, a mixture of ammonium sulphate with Actipron improved the control of S. media by bentazone and benazolin salts. Oils and surfactants markedly increased rates of entry of 14C bentazone into leaves of S. media, white clover and Chrysanthemum segetum. Ammonium sulphate sometimes had similar effects but on other occasions reduced uptake. In some circumstances the additives apparently interacted synergistically, to increase uptake of labelled herbicide into the leaf or to enhance its transport within the plant. In these test species, differential absorption of bentazone could not explain differences in species susceptibility, suggesting that the main cause of resistance was the ability of plants to degrade the herbicide. 相似文献
10.
A model system consisting of chemically isolated cuticular membranes placed on agar was used to study the penetration of various formulations of 14C-labelled clopyralid, fluroxypyr, triclopyr, picloram, and 2,4-D into and through cuticular membranes. Clopyralid, commercially formulated as the acid, or 1-decyl ester was rapidly absorbed after 12 h by isolated cuticles of Euonymus fortunei. There was less absorption of the monoethanolamine and potassium salt formulations when compared to the acid and 1-decyl ester. However, in terms of the absorbed 14C-activity that partitioned into the agar, there was no difference between the acid and salt formulations with approximately 90% being partitioned after 48 h. Conversely, the 1-decyl ester formulation of clopyralid was retained in the cuticle; less than 5% of the absorbed fraction was recovered in the agar after 48 h. When the acid forms of clopyralid, fluroxypyr, triclopyr, picloram, and 2,4-D were compared, there was little or no difference in absorption among the herbicides. However, the 14C-activity from clopyralid partitioned the most (90%) and triclopyr the least (50%) into the agar. When ester formulations of clopyralid, fluroxypyr, and triclopyr were compared, at least 95% of the 14C-activity was absorbed 24 h after application. However, of the amount absorbed, significantly more of the butoxyethyl ester of triclopyr (36%) partitioned into the agar than did the 1-decyl ester of clopyralid (6%) or the 1-methylheptyl ester of fluroxypyr (5%). Differential retention of various herbicide formulations in this model system may explain, in part, the differences in absorption and translocation among radiolabelled clopyralid formulations observed in previous research (Kloppenburg & Hall, 1990). 相似文献
11.
Summary. Studies of the influence of formulation, degree of chlorination of the benzene ring and structure of the side chain of some phenoxyalkyl acid herbicides on absorption and translocation were made in a woody plant, Acer macrophyllum Pursh. In an experiment in which the leaves were treated with 2,4-D or 2,4,5-T as the acid, triethanolamine salt or 2-ethylhexyl ester formulations, it was found that absorption increased with decreasing polarity of the molecule. The lower relative mobility of the ester formulations was offset by their greater absorption which resulted in greater accumulation in the roots when compared with the other herbicides. In treatments where dichlorprop or fenoprop formulated as the 2-ethylhexyl esters were applied, a definite effect of chemical structure was observed on both absorption and translocation. The results of these tests and their implications in the response of big leaf maple are discussed. Caractères de l'absorption et de la migration de quelques herbicides du groupe des acides phénoxyalkyles dans l'érable a grandes feuilles Acer macrophyllum Pursh. 相似文献
12.
The effects of lenacil, terbacil, chlorthiamid and 2,4,5-T at 100 ppm on carbon dioxide evolution, oxygen uptake and nitrogen transformation in two soils have been investigated for several months in the laboratory. The herbicides had no effect on CO2 output from either Boddington Barn soil (organic carbon content 1.6%, pH 6.1) or Triangle soil (organic carbon content 3.7%, pH 4.8) apart from 2,4,5-T which reduced it sometimes. All the herbicides caused temporary reductions in O2. uptake, but in Triangle soil treated with 2,4,5-T a significant reduction was observed during the second half of the incubation. 2,4,5-T and to a lesser extent chlorthiamid, reduced nitrification in Triangle soil. All the herbicides slightly increased mineralization of nitrogen except 2,4,5-T which had variable effects in Triangle soil. 相似文献
13.
R. L. AMOR 《Weed Research》1975,15(1):39-45
On 3-year-old thickets of Rubus procerus sprays of 0·067% 2,4,5-T reduced the density of live canes most when sprayed from the commencement of flowering in early summer through to autumn. However, on 7-year-old thickets the time of spraying had no significant effect. Sprays of 0·067% picloram were most effective on 3-year-old thickets when applied just before and during flowering. Generally 2,4,5-T was more effective when sprayed twice a year, but some live plants remained after this was carried out for 2 years. Because of the higher density of plants in thickets of R. ulmifolius hybrid, this taxon is more difficult to eradicate than thickets of R. procerus. Although picloram was the most effective herbicide tested, picloram and activated aminotriazole have a more limited potential usage than 2,4,5-T on blackberry. Ecologie et destruction des ronces (Rubus fruticosus L. agg) IV. Effets d'applications uniques ou répétées de 2,4,5-T, de piclorame et d'aminotriazole. Des traitements au 2,4,5-T à 0·067% sur des buissons de Rubus procerusâgés de trois ans ont réduit la densité des tiges vivantes, surtout lorsque le traitement a été fait depuis le commencement de la floraison, au début de l'été, jusquà l'automne. Toutefois, sur des buissons âgés de sept ans, l'époque du traitement n'a pas eu d'effet significatif. Ce sont les traitements avec le piclorame à 0,067% qui furent les plus efficaces sur des ronces de trois ans, lorsqu'ils furent appliqués juste avant et pendant la floraison. En général, le 2,4,5-T a été plus efficace lorsqu'il a été appliqué deux fois dans l'année, mais quelques plantes sont restées vivantes après que ce traitement ait été réalisé deux annees de suite. En raison de la forte densite des plantes dans les buissons de l'hybride R. ulmifolius, ce taxon est plus difficile a détruire que R. procerus. Bien que le plclorame ait été le plus efficace des herbicides essayés, le piclorame et l'aminotriazole activé sont d'un usage potentiel plus limité que le 2,4,5-T sur les ronces. Ökologie und Bekämpfung der Brombeere (Rubus fruticosus L. agg.) IV. Die Wirkung einmaliger und wiederholter Anwendungen von 2,4,5-T, Picloram und Aminotriazol Bei dreijährigen Rubus procerus-Dickichten wurde die Dichte der lebenden Ruten am stärksten verringert, wenn zu Beginn der Blüte im Frühsommer, bis zum Herbst hindurch 2,4,5-T (0,067%) gespritzt wurde. Bei siebenhährigen Dickichten hatte der Spritzzeitpunkt keinen gesicherten Einfluss, Spritzungen mit Picloram (0,067%) zeigten bei dreijaärigen Beständen die beste Wirkung, wenn sie kurz vor und während der Blüte durchgeführt wurden. Im allgemeinen war 2,4,5-T, zweimal jährlich angewandt, am wirkungsvollsten, Wenn diese Massnahme zwei Jahre lang durchgeführt wurde, blieben aber einige intakte Pflanzen übrig. Wegen der höheren Pflanzendichte in Dickichten von Hybrid-R. ulmifolius, ist dieses Taxon schwieriger zu vernichten als Bestände von R. procerus. Wenngleich Picloram unter den geprüften Herbiziden das wirksamste war, so wird doch Picloram und Aminotriazol weniger gegen die Brombeere eingesetzt als 2,4,5-T. 相似文献
14.
Jing Chang 《Pesticide biochemistry and physiology》2010,98(2):296-299
The synergism of S,S,S-tributyl phosphorotrithioate (DEF) and its effect on carboxylesterase activity were investigated in deltamethrin-selected resistant (DRR) and susceptible (DSS) strains of cotton aphids, Aphis gossypii (Glover). Compared to the DSS strain, the DRR strain showed 23,900-fold resistance to deltamethrin, and 7560- and 99-fold cross-resistance to bifenthrin and ethofenprox, respectively. The synergist, DEF, increased the toxicity of both deltamethrin and bifenthrin, but not of ethofenprox when DEF was pretreated of 15 h. DEF exhibited significant inhibition on the carboxylesterase activity in the DRR strain, but no significant effect on that of the DSS strain in vitro. After the cotton aphids exposing to DEF, the carboxylesterase activity decreased gradually until 15 h and then gradually recovered until 24 h in the DRR strain, which fluctuated according to the effect of DEF on the deltamethrin toxicity detected using DEF pretreatment in the DRR strain. Therefore, our studies suggested that the effect of DEF on carboxylesterase was associated with deltamethrin resistance in the DRR strain. 相似文献
15.
G. W. IVENS 《Weed Research》1971,11(2-3):150-158
Summary. In a series of foliar spray treatments on the deciduous Acacia drepanolobium Sjöstedt, a mixture of picloram+2,4-D lulled a large proportion of the trees in May, the latter part of the principal rainy season, moderate numbers in November-December, the subsidiary rains, and small numbers during the two intervening dry seasons. An ester formulation of 2,4,5-T was generally less effective, but similar seasonal variations in kill occurred. At the time of maximum susceptibility, the rate of shoot extension growth was declining and new leaves were fully extended, but still succulent.
With the evergreen Tarchonanthus camphoratus L., the effectiveness of spraying was related directly to the growth rate of the shoots. The percentage kill was highest following application of picloram+2,4-D in May-July, the late long rains and first half of the long dry season, but low during the November-December rains and short dry season. T. camphoratus is susceptible to foliar herbicide treatment over a longer period than A. drepanolobium , presumably because of its different seasonal growth characteristics. 相似文献
With the evergreen Tarchonanthus camphoratus L., the effectiveness of spraying was related directly to the growth rate of the shoots. The percentage kill was highest following application of picloram+2,4-D in May-July, the late long rains and first half of the long dry season, but low during the November-December rains and short dry season. T. camphoratus is susceptible to foliar herbicide treatment over a longer period than A. drepanolobium , presumably because of its different seasonal growth characteristics. 相似文献
16.
Joint action of amino acid biosynthesis-inhibiting herbicides 总被引：1，自引：0，他引：1
The joint action of binary mixtures of the amino acid biosynthesis‐inhibiting herbicides glyphosate, glufosinate‐ammonium, metsulfuron‐methyl and imazapyr was assessed in pot experiments applying the Additive Dose Model (ADM). Plants of Sinapis arvensis or S. alba were sprayed with seven doses of the herbicides alone and binary fixed‐ratio mixtures of the four herbicides. In total, 73 binary mixtures were studied in six separate experiments. Mixtures of glyphosate and glufosinate‐ammonium were less phytotoxic than predicted by ADM whether commercial formulations or technical grade products were applied. In contrast, mixtures of glyphosate and metsulfuron‐methyl, glyphosate and imazapyr, glufosinate‐ammonium and metsulfuron‐methyl, glufosinate‐ammonium and imazapyr, and metsulfuron‐methyl and imazapyr either followed ADM or were synergistic. Synergism was observed most frequently for mixtures of glyphosate or glufosinate‐ammonium with metsulfuron‐methyl. Synergism was also more pronounced for commercial formulations of glyphosate and glufosinate‐ammonium than for the corresponding technical grade formulations, implying that synergism was caused by the presence of the formulation constituents of the commercial glyphosate and glufosinate‐ammonium formulations in the spray solution. 相似文献
17.
J. M. WAY 《Weed Research》1964,4(4):319-337
Summary. The effects of 2,4-D, 2,4,5-T, mecoprop and 2,3,6-TBA were compared with those of MCPA on the morphology and yield of lettuce, cabbage, cauliflower, Brussels sprout, carrot, parsnip, French and broad bean, red beet, spinach, turnip and onion. Although the relativie phytotoxicity of MCPA, 2,4-D, 2,4,5-T and mecoprop varied according to the crop, the morphological abnormalities produced by the different compounds were essentially similar, except that in lettuce and cabbage sperilic foliar symptoms appeared to be associated with 2,4-D. 2,3,6-TBA caused less epinasty and usually fewer root and stem abnormalities, but in some crops, notably French and broad bean, red beet and spinach, it produced severe injury symptoms which were different from those produced by the other compounds.
Effets de doses sub-léthales de MCPA. sur la morphologie et le rendement des cultures légumirres VI. Comparaison avec le 2,4-D, le 2,4,5-T, le micoprop et le 2,3,6-TBA 相似文献
Effets de doses sub-léthales de MCPA. sur la morphologie et le rendement des cultures légumirres VI. Comparaison avec le 2,4-D, le 2,4,5-T, le micoprop et le 2,3,6-TBA 相似文献
18.
D. R. BAILEY 《Weed Research》1969,9(1):9-19
Summary. 2,4-D-amine, 2,4-D ethyl ester, 2.4-DB-potassium. MCPA-sodium, diquat and a 1:1 mixture of 2,4,5-T butyl ester and 2,4-D ethyl ester were applied to the tropical pasture legume Centrosema pubescens Benth. (centro) grown either alone or with Panicum maximum Jacq. (guinea grass). Even at 0.5 Ib/ac (total) the 2,4,5-T/2,4-D mixture caused severe damage to seedling and mature centro. 2,4-D-amine, 2,4-D ethyl ester and 2,4-DB-potassium were less damaging and there were only slight differences in response to these. Diquat at 0.25 Ib/ac desiccated centro seedlings, but most plants survived and grew satisfactorily. There was some evidence that the growth of mature centro was depressed least when the herbicides were applied during vegetative quiescence.
Application just after the start of flowering altered the flowering pattern but did not reduce seed yields significantly. 2,4-D-amine at 0.75 and 1–5 lb/ac and 2,4-D ethyl ester at 1.5 Ib/ac decreased the percentage germination of abraded seed. Diquat 0.25 Ib/ac applied at the start of flowering caused significant increases in top growth and seed pod numbers, possibly the result of modification of the normal flowering pattern. 相似文献
Application just after the start of flowering altered the flowering pattern but did not reduce seed yields significantly. 2,4-D-amine at 0.75 and 1–5 lb/ac and 2,4-D ethyl ester at 1.5 Ib/ac decreased the percentage germination of abraded seed. Diquat 0.25 Ib/ac applied at the start of flowering caused significant increases in top growth and seed pod numbers, possibly the result of modification of the normal flowering pattern. 相似文献
19.
Ecology and control of blackberry (Rubus fruticosus L. agg.) 总被引：1，自引：0，他引：1
R. L. AMOR 《Weed Research》1974,14(4):239-243
Cutting off the canes, either at ground level or at a height of IS cm, stimulated the formation of suckers from lateral roots of Rubus procerus P. J. Muell. The application of 2,4,5-T or picloram sprayed on the foliage killed many plants, suppressed shoot production from the crowns of others, but stimulated sucker formation. Within age groups of from 1 to 5 years, older plants were more resistant to 2,4,5-T (0067%, 020%) and to picloram (0067%) than were younger plants. Picloram (020%) was the most effective treatment and affected plants of all ages equally. it is suggested that the age of plants may be a major source of variation in the efficacy of herbicides on other perennial weeds. Ecologie des ronces (Rubus fruticosus L. agg.) et méthodes de lutte. III-Réaction de R. procerus au fauchage et aux applications d'herbicides sur le feuillage Le fauchage des tiges, aussi bien au niveau du sol qu'a une hauteur de 15 cm, a stimuli la formation de drageons k partir des racines laterales de Rubus procerus P. J. Muell. L'application de 2,4,5-T ou de piclorame en pulvérisation sur le feuillage a tué beaucoup de plantes, a supprimé chez d'autres la production des pousses à partir des couronnes, mais a stimulé la formation de drageons. Parmi les groupes d'àge de un à cinq ans, les plantes les plus agés ont été plus riisistantes que les plus jeunes au 2,4,5-T (0,067%, 0,20%) et au piclorame (0,067%). Le piclorame (0,20%) a été le traitement le plus efficace et a affiectéégalement des plantes de tous âges. II est suggéré que l'âge des plantes peut étre une importante source de variation dans l'efficaclté des herbicides sur d'autres plantes pérennes. Ökologie und Bekämpfung der Brombeere (Rubus fruticosus L. agg.) 111. Reaktion von Rubus procerus auf meehanische Entfernung oberirdisclier Pfianienteile und auf blartapplizierte Merbizide Das Abschneiden der Ruten—entweder an der Bodenober-filiche Oder in 15 cm Höhe—fordert bei Rnbus procerus P. J. Muell. die Ausbildung von Wurzelsprossen aus Seitenwurt zeln. Die Blattbehandlung mit 2.4,5-T oder Picloram toter viele Pflanzen ab und unterdrilckt die Sprossbildung de-Seitentriebe, fordert aber die Wurzelsprossbildung. Inner-halb der Ahersgruppen von 1–5 Jahren sind Sltere Ptlanzen widerstandsfahiger gegenuber 2,4.5-T (0.067%, 0.20%) und Picloram (0.067%) als jungcre Pflanzen. Picloram (0,20%) zeigte die beste Wirkung und erfasste die Pflanzen in alien Altersstufen gleich. Es wird vermutet, dass das Alter von Pflanzen die Hauplurscahe unterschiedlicher Wirksamkeit von Herbiziden auch bei anderen mehrjflhrigen Unkrflutern ist. 相似文献
20.
ALLAN E. SMITH 《Weed Research》1976,16(1):19-22
The hydrolysis of the iso-propyl, n-butyl-and iso-octyl esters of 2,4,5-trichlorophenoxyacetic acid (2,4,5-T), the n-bytyl ester of 2,4-dichlorophenoxybutyric acid (2,4-DB) and the iso-octyl ester of 2,4-dichlorophenoxypropionic acid (2,4-DP) was studied in four prairie soils of differing textures and pH at 25±1°C. The esters were analysed using gas chromatography. After 24 h in soils at wilting point moisture, and above, less than 20% of the applied iso-propyl and n-butyl esters could be recovered from one soil type and none from the remaining three. Loss of the iso-cotyl esters was slower; however, no trace of the 2,4,5-T and 2,4-DP esters was observed in any of the moist soils after 48 and 72 h respectively. In all cases loss of all esters from air-dried soils minimal. The phenoxyalkanoic acid hydrolysis products were recovered from all soil types, treated with the various esters and identified using thin-layer chromatography. 相似文献