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1.
D. V. CLAY 《Weed Research》1980,20(2):97-102
The tolerance of strawberries to herbicides was tested by applications to the roots of plants growing in sand and by foliage applications to plants grown in compost, and compared with tolerance in the field. Dimefuron was safe as a foliar application but much more toxic than simazine when applied in sand or in the field. Metamitron caused slight injury as a foliar spray; in sand and in the field it was intermediate in toxicity between simazine and lenacil. At normal rates propachlor was safe as a foliar spray and much safer than lenacil when applied in sand. High rates had no adverse effect in the field. Ethofumesate and pendimethalin caused some temporary stunting when applied to foliage, but were less toxic than lenacil when applied to roots in sand. Field applications of both herbicides at 1–1.5 kg/ha were safe. Foliage sprays of bentazone, oxadiazon and oxyfluorfen severely damaged the sprayed leaves, but these herbicides were less active than lenacil when applied to the roots. In the field they caused severe leaf damage, but by the end of the growing season the plants had recovered. The experiments demonstrated the value of separate root and shoot activity tests for indicating which herbicides merit further field testing. 相似文献
2.
The relative phytotoxicity of four soil-applied herbicides, benzthiazuron, cycloate, delachlor, and pyrazon, used for sugar beet (Beta vulgaris L.), was tested on a dilution series of peat, Newe Ya’ar clay soil and Hamadia calcareous clay soil mixed with sand, and of Newe Ya’ar clay soil mixed with lime. The phytotoxicity was assessed with oats (Avena sativa L. cv. Mulga). Cycloate was the most potent herbicide of the four, except in soils with high organic matter ( ?11%), where delachlor was more active. Benzthiazuron was the least phytotoxic herbicide in the peat + sand mixtures, but it was more active than pyrazon in lighter soils of the Newe Ya’ar series. The addition of sand to the peat and the soils increased the phytotoxicity of all herbicides. The addition of lime to Newe Ya’ar clay soil decreased the phytotoxicity of benzthiazuron and pyrazon but not of delachlor. 相似文献
3.
Soil persistence of selected sugar-beet herbicides and their combinations with lenacil 总被引：1，自引：0，他引：1
Laboratory studies on the degradation of several sugar-beet herbicides both singly and in combination with lenacil were conducted in four soils. First-order kinetics were used to describe the breakdown rates of lenacil, benzthiazuron, carbetamide, propham and phenmedipham, and their combinations with lenacil. Mean half-lives of the herbicides ranged from 14 days for propham to 191 days for benzthiazuron. There were no significant differences between the herbicides applied singly or in combination. Persistance dans le sol de plusieurs herbicides de la betterave et leurs combinaisons avec le lenacil Pour quatre types de sols, nous avons étudié, au laboratoire, la dégradation de plusieurs herbicides de la betterave appliqués seuls ou avec du lenacil. Des cinétiques de première ordre ont été utilisées pour calculer les taux de dégradation des herbicides suivants: lenacil, benzthiazuron, carbetamide, prophame, phenmediphame et de leurs combinaisons avec du lenacil. Les temps moyens de rémanence des herbicides se situaient entre 14 jours pour le prophame et 191 pour le benzthiazuron. Nous n'avons trouvé aucune difference significative entre les herbicides appliqués seuls et avec du lenacil. 相似文献
4.
Summary. Pyrazon (5-amino-4-chloro-2-phenylpyridazin-3(2H)-one) and benzthiazuron (N-(2-benzothiazolyl)-N′-methylurea) were compared in respect to their effects on photosynthesis and growth of sugar beet, and to their movement in soil. Benzthiazuron had a five-fold greater inhibitory effect than pyrazon on photosynthesis, and a ten-fold greater inhibitory effect on the growth of sugar beet grown in treated culture solution. On the other hand, sugar beet was more tolerant to benzthiazuron than to pyrazon when grown in soil treated pre-emergence with the herbicides. Leaching of pyrazon in clay soil appeared to be greater than that of benzthiazuron. Both herbicides entered the emerging seedlings through their roots, and hence movement of the compounds to the root zone by excess irrigation might be injurious to sugar beet. This was found to be more likely to occur with pyrazon than with benzthiazuron. Sélectivité du PCA et du benzthiazuron pour la betterave sucrière Résumé. Le PCA (5-amino-4-chloro-2-phénylpyridazine-3(2H)-one) et le benz-thiazuron (N-(2-benzothiazolyl)-N′-méthylurée) ont été compareés en ce qui concerne leurs effets sur la Photosynthèse et la croissance de la betterave sucrière et leur migration dans le sol. Le benzthiazuron manifesta un effet inhibiteur cinq fois plus grand sur la croissance de la betterave sucrière cultivée en solution traitée. En revanche, la betterave sucrière fut plus résistante au benzthiazuron qu'au PCA quand elle fut cultivée dans un sol traité en pré-levée avec ces herbicides. Le lessivage du PCA dans un sol argileux apparut plus important que celui du benzthiazuron. II a été constaté que les deux herbicides pénétraient dans les plantules, après la Ievée, par les racines et que la migration des produits dans la zone des racines sous I'effet d'une irrigation excessive pouvait provoquer des dégâts sur la betterave à sucre. II fut constaté que ce phénomène était plus probable avec le PCA qu'avec le benthiazuron. Selektivität von Pyrazon und Benzthiazuron in Zuckerrüben Zusammenfassung. Pyrazon (5-Amino-4-chlor-2-Phenylpyridazin-3(2H)-one) und Benzthiazuron (N-(2-Benzothiazolyl)-N′-methyl-harnstoff) wurden in ihrer Wirkung auf die Photosynthese und das Wachstum von Zuckerrüben sowie auf ihre Beweglichkeit im Boden verglichen. Das Herbizid Benzthiazuron hatte einen fünffach grösseren Hemmeffekt auf das Wachstum von Zuckerrüben, die in einer behandelten Nährlösung wuchsen. Andererseits waren Zuckerrüben toleranter gegenüber Benzthiazuron als gegenüber Pyrazon, wenn sie in Boden wuchsen, der im Vorauflauf mit diesen Herbiziden behandelt worden war. Die Einwaschung von Pyrazon in Tonboden war offensichtlich grösser als diejenige von Benzthiazuron. Es konnte festgestellt werden, dass beide Herbizide in die auflaufenden Keimpflanzen durch deren Wurzel eindrangen. Daher könnte die Verlagerung der Herbizide in die Wurzelzone durch Überschussbewässerung die Zuckerrüben schädigen. Dies ist bei Pyrazon offensichtlich eher zu erwarten als bei Benzthiazuron. 相似文献
5.
Summary. The effects of several herbicides on the rates of CO2 uptake and transpiration of intact plants were measured. A simple technique is described which reveals whether photosynthesis-inhibiting herbicides are inactivated by plants. By this method, the inactivation of simazine by maize could be confirmed. Evidence is presented for physiological inactivation of monuron by Plantago lanceolata , of cycluron (OMU) and pyrazon by sugar beet, of N'-(4-butoxyphenyl)-NN-dimethylurea by of 5-bromo-6-methyl-3-phenyluracil by flax. Certain plant species showed different reactions to some other new herbicides. The effect of herbicides in the culture solution on CO2 uptake by the leaves is probably largely determined by the rate of transpiration of the plants. Assuming that uptake in proportional to transpiration rate, estimates of the concentration of the herbicides inside the plant were made.
L'inactivation physiologique de quelques herbicides produisant une inhibition de la photosynthèse 相似文献
L'inactivation physiologique de quelques herbicides produisant une inhibition de la photosynthèse 相似文献
6.
J. C. STREIBIG 《Weed Research》1986,26(3):207-214
In growth chambers the phytotoxicity of binary mixtures of four herbicides was compared using an Additive Dose Model as reference. Of the four herbicides used, lenacil was the most potent whereas ethofumesate was the least potent herbicide; chloridazon and metamitron were equally potent. The Additive Dose Model implicitly presupposes that at any one response level the herbicides of a mixture can replace each other in proportion to their relative potency when applied separately. Metamitron and chloridazon mixtures appeared to follow the reference model. The efficacy of mixtures of lenacil and chloridazon or lenacil and metamitron, however, were increased in comparison with the herbicides applied separately. On the other hand, lenacil and ethofumesate or metamitron and ethofumesate were less phytotoxic than expected from the Additive Dose Model. The results are discussed in relation to the mode of action of the compounds. Action combinée de certains herbicides absorbés par les racines en culture d'avoine Avena sativa L. La phytotoxicité de mélanges binaires de quatre herbicides a fait l'objet d'une comparaison en phytotron, utilisant comme témoin un Modèle Dose Additive. Parmi les quatre herbicides utilisés, le lénacile s'est révélé le plus et l'éthofumésate le moins actif; le chloridazone et le métamitrone ont fait preuve d'une activitéégale. Le Modèle Dose Additive présuppose qu'à tout niveau d'activité chaque herbicide faisant partie d'un mélange puisse se substituer à l'autre en fonction de son efficacité relative en traitement simple. Les mélanges métamitrone–chloridazone semblent s'accorder au modèle de référence. Cependant, l'efficacité des mélanges chloridazone–lénacile et lénacile–métamitrone a augmenté par rapport à l'application de chaque élément séparément. D'autre part, les mélanges lénacile–éthofumesate et métamitrone–éthofumesate ont fait preuve d'une phytotoxicité moindre que celle qu'annonçait le modèle. Ces résultats sont discutés par rapport au mode d'action des composés. Kombinierte Wirkung verschiedener wurzelwirksamer Herbizide auf Avena sativa L. In Klimakammern wurde die Phytotoxizität von Zweier-Mischungen von vier Herbiziden untersucht und mit einem Modell additiver Dosierungen verglichen. Von den vier untersuchten Herbiziden war Lenacil das wirksamste und Ethofumesat das schwächste; Chloridazon und Metamitron wirkten gleich stark. Das Modell additiver Dosierungen setzt stillschweigend voraus, dass auf jedem Wirkungsniveau die Herbizide einer Mischung einander im Verhältnis ihrer relativen Wirksamkeiten, wenn allein appliziert, ersetzen können. Metamitron + Chloridazon Mischungen scheinen dem Vergleichsmodell zu folgen. Die Wirkungen der Mischungen von Lenacil + Chloridazon oder Lenacil + Metamitron, hingegen, waren im Vergleich zu den Effekten der einzeln applizierten Komponenten gesteigert. Andrerseits waren Lenacil + Ethofumesat oder Metamitron + Ethofumesat weniger phytotoxisch, als das Modell hätte erwarten lassen. Die Resultate werden mit Bezug auf die Wirkungsmechanismen der Komponenten diskutiert. 相似文献
7.
Differential sensitivity of Atriplex patula and Chenopodium album to sugar beet herbicides: a possible cause for the upsurge of A. patula in sugar beet fields 
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下载免费PDF全文 In the last decade, the prevalence of Atriplex patula as a weed in the Belgian sugar beet area has increased. Possible reasons for its expansion in sugar beet fields, besides a poor implementation of the low‐dose phenmedipham/activator/soil‐acting herbicide (FAR) system, might be low sensitivity or evolved resistance to one or more herbicides used in sugar beet. Dose – response pot bioassays were conducted in the glasshouse to evaluate the effectiveness of five foliar‐applied sugar beet herbicides (metamitron, phenmedipham, desmedipham, ethofumesate and triallate) and three pre‐plant‐incorporated herbicides (metamitron, lenacil, dimethenamid‐P) for controlling five Belgian A. patula populations. Local metamitron‐susceptible and metamitron‐resistant populations of Chenopodium album were used as reference populations. Effective dosages and resistance indices were calculated. DNA sequence analysis of the photosystem II psbA gene was performed on putative resistant A. patula populations. Overall, A. patula exhibited large intraspecific variation in herbicide sensitivity. In general, A. patula populations were less susceptible to phenmedipham, desmedipham, ethofumesate and triallate relative to C. album populations. Two A. patula populations bear the leucine‐218 to valine mutation on the chloroplast psbA gene conferring low level to high level cross‐resistance to the photosystem II inhibitors phenmedipham, desmedipham, metamitron and lenacil. In order to avoid insufficient A. patula control and further spread, seedlings should preferentially be treated with FAR mixtures containing higher‐than‐standard doses of metamitron and phenmedipham/desmedipham and no later than the cotyledon stage. 相似文献
8.
Ten herbicides, bromacil, chlorthal-dimethyl, diphenamid, diuron, fluometuron, neburon, prometryne, pyrazon, simazine and trifluralin at two doses were repeatedly sprayed, in autumn and in spring, for 4 consecutive years on non-cultivated, sprinkler-irrigated field plots. Herbicidal effect was assessed at 1–2 month intervals on the natural weed population and after each observation a paraquat + diquat spray destroyed emerged weeds. The response of various weed species to herbicides varied markedly but a herbicide-induced shift in the composition of weed population did not occur, presumably because of the paraquat treatment. The overall phytotoxicity to weeds present was, in decreasing order: diuron, bromacil, simazine, trifluralin, prometryne, neburon, fluometuron, pyrazon, diphenamid, chlorthal-dimethyl. Persistence of herbicides was in decreasing order: diuron = bromacil, simazine, neburon (at higher rate), fluometuron, trifluralin, prometryne. Control produced by pyrazon improved with the number of applications, but that of diphenamid and chlorthal-dimethyl remained weak and short. After repeated applications, the activity of these herbicides increased or remained at similar level, but in no case decreased. Soil samples were taken 5 months after each application and bioassayed. Phytotoxic residues were detected beneath the disturbed top-soil from bromacil, diuron, fluometuron and simazine after the first application, and from neburon after the second application; residues from trifluralin were found in the top soil only after the fifth application. After the seventh spraying, residues of bromacil were found in the 45–60-cm soil layer. Ammonia content in soil samples taken from treated plots after the fourth, sixth and seventh application was generally similar to the untreated control. In these samples, nitrate content appeared to be correlated negatively with remaining weed number; the control thus contained less nitrate than efficient herbicidal treatments. Soil samples taken after the seventh application of bromacil, diuron, fluometuron, neburon and simazine, which contained appreciable residual concentrations, did not show significant differences from control, in an in vitro nitrification test. 相似文献
9.
Selectivity of foramsulfuron + thiencarbazone‐methyl and classic herbicides in sensitive and non‐sensitive sugar beet genotypes 下载免费PDF全文
下载免费PDF全文 A new herbicide for sugar beet cultivation using the ALS‐inhibiting active ingredients foramsulfuron and thiencarbazone‐methyl is under approval in the EU member states. Sugar beet genotypes that are non‐sensitive to this herbicide are currently under development. Selectivity of the ALS‐inhibiting herbicide and yield response of the non‐sensitive genotypes might be relevant to meet the requirements for variety registration. To evaluate these issues, six field trials were conducted in Germany in 2013 and 2014. Classic herbicides and the ALS‐inhibitor herbicide were applied in dosages of up to fourfold the authorised (or applied for) application rates. The ALS‐inhibitor herbicide did not cause any significant phytotoxicity and had no effect on leaf area index at a single, double or fourfold dosage. By contrast, classic herbicides had significant negative effects at the single dosage. At fourfold dosage, they caused 41% phytotoxicity and reduced leaf area index by 35%. The relative yield difference between ALS‐inhibitor and classic herbicide treatments was 8.6% and 17.4% of white sugar yield at double and fourfold dosage respectively. The ALS‐inhibitor herbicide thus showed higher selectivity than the classic herbicides. In the registration process, the resulting yield advantage could balance a possible yield penalty of non‐sensitive genotypes. The introduction of a new system for weed control could improve application flexibility and control of troublesome weeds in sugar beet. 相似文献
10.
Summary. The phytotoxicities in a number of soils of lenacil, linuron, prometryne and simazine to two indicator plants were determined in field and glasshouse experiments. The results were compared with estimates of the adsorption capacity of the soils obtained by two methods using dimethylaminobenzaldehyde as a model adsorbate. The possible influence of other soil properties was also considered.
One of the adsorption measurements had some predictive value for glasshouse behaviour but was not markedly superior to soil organic carbon content for this purpose. None of the factors studied was usefully correlated with field performance. Results from field experiments in spring were poorly correlated with those from similar experiments in autumn. Neither set of field results related closely to those obtained in the glasshouse. It is concluded that the influence of climate was more important than that of soil type.
La phytotoxiciti de quelquts herbicides dans des experiences en pots et en plein champ, en relation avec les propriétés du sol 相似文献
One of the adsorption measurements had some predictive value for glasshouse behaviour but was not markedly superior to soil organic carbon content for this purpose. None of the factors studied was usefully correlated with field performance. Results from field experiments in spring were poorly correlated with those from similar experiments in autumn. Neither set of field results related closely to those obtained in the glasshouse. It is concluded that the influence of climate was more important than that of soil type.
La phytotoxiciti de quelquts herbicides dans des experiences en pots et en plein champ, en relation avec les propriétés du sol 相似文献
11.
R. J. MARTIN 《Weed Research》1983,23(2):77-83
An experiment was done to determine the effect of spring and autumn application of asulam and dalapon, nitrogen fertilizer and oversown white clover (Trifolium repens L.) on the productivity of subtropical pasture dominated by carpet grass (Axonopus affinis Chase). Assessments were made of pasture yield, botanical composition, weed invasion and recolonization by pasture species during the 12-month period following herbicide application. Both herbicides decreased the yield of carpet grass and increased that of the more productive paspalum (Paspalum dilatatum Poir.) except after autumn application when the yield of paspalum was greatly reduced by dalapon. White clover became established only on plots treated with herbicide and only after autumn application. Clover yields were greatest on plots treated with dalapon. Asulam was considered to be the most suitable herbicide for altering the balance between carpet grass and paspalum because dalapon initially reduced paspalum yield after autumn application and delayed recovery of total pasture. In addition, dalapon permitted greater invasion by broadleaf weeds. This work showed that herbicides have a potential role for speeding up botanical changes in unproductive carpet grass pasture and further refinement of the technique might provide a useful tool for increasing pasture productivity. 相似文献
12.
Summary. Pyrazon (5-amino-4-chIoro-2-phenyl-3(2H)-pyridazinonc) labelled with tritium in the phenyl ring, was applied to both the root and shoot of seedlings of red beet (Beta vulgaris L., cultivar Detroit Dark Red I, German millet (Setatra italica J.), and tomato (Lycopersicon esculentum Mill., cultivar Heinz 1350). Of these species, red best is tolerant, millet is moderately tolerant, and tomato is susceptible to pyrazon. When the roots were exposed to 1–325 ppm 3H-pyrazon in the nutrient solution, the greatest root absorption and transiocation to the shoot was observed in tomato and the least in red beet, while millet was intermediate. Applications to the first true leaf indicated that pyrazon was absorbed by the foliage of all three but that it was not transported basipetally. The absorption and translocation studies indicated that pyrazon mi transported primarily in the xylem. A radioactive metabolite of 3H-pyrazon was detected in the shoots of red beet, but there was no evidence for its presence in the shoots of the other two species. Since this metabolite is radioactive, its structure must contain at least some altered form of the phenyl ring which contained the tritium in the parent molecule. This differentiates it from 5-amino-4-chloro-pyridazinone, the previously proposed degradation product of pyrazon, since this compound lacks the phenyl ring. On the bash of these results, it is hypothesized that pyrazon will be phytotoxic if a suffic inn mm entration of the unaltered chemical reaches the site of herbicidal action in the shoot. Migration et métabolisme de la pyrazone dans les espéces rislstantes et sensibles 相似文献
13.
The effects of dalapon, pyrazone and trifluralin at 100 ppm on carbon dioxide evolution and nitrogen transformation in two soils have been investigated in the laboratory. None of the herbicides had any adverse effects on carbon dioxide evolution or mineralisation of nitrogen. In Triangle soil (organic carbon 3.9%, pH 5.4) dalapon and pyrazone inhibited nitrification for at least 3 weeks. In Boddington Barn soil (organiccarbon 1.5%, pH 6.6) this effect was not observed. Dalapon degraded rapidly during the first 6 weeks, but pyrazone and trifluralin were more persistent. 相似文献
14.
Y. ESHEL 《Weed Research》1969,9(3):167-172
Summary. Studies were conducted to determine the influence of pyrazon (5-amino-4-chloio-2-phenyl-3(2H)-pyridazinone) on photosynthesis. A strong inhibiting effect on O2 evolution from leaf discs of several species was recorded. For most species a concentration of 5 × 10−5 M caused a reduction of about 50% in the rate of photosynthesis. Photosynthesis of sugar beet, highly resbtant to pyrazon, was reduced to 50% by a concentration of 7–5 × 10−5 M. Since these differences cannot account for the great divergence in susceptibility to pyrazon, it is suggested that the selectivity of this herbicide results from degradation and differential accumulation in the foliage.
Pyrazon was phytotoxic to plants of tomato and pigweed (Amaranthus retrofiexus L.) kept in the light but not when kept in the dark, after foliage application. The conclusion that pyrazon inhibits the mechanism of photosynthesis and causes starvation for carbohydrates, was strengthened by the fact that external feeding of glucose overcame the toxicity of the compound in tomato plants. These results and a possible mode of selectivity are discussed. 相似文献
Pyrazon was phytotoxic to plants of tomato and pigweed (Amaranthus retrofiexus L.) kept in the light but not when kept in the dark, after foliage application. The conclusion that pyrazon inhibits the mechanism of photosynthesis and causes starvation for carbohydrates, was strengthened by the fact that external feeding of glucose overcame the toxicity of the compound in tomato plants. These results and a possible mode of selectivity are discussed. 相似文献
15.
O. R. SOUTHWOOD 《Weed Research》1971,11(4):231-239
In a field trial, different doses of five herbicides applied in autumn and late winder were compared for the control of barley grass (Hordeum leporium Link) in dryland Lucerne. Diuron at 1·1, 2·2, and 4·5 kg/ha and atrazine at 1·1 kg/ha were more effective in increasing Lucerne production than linuron at 4·5 kg/ha and various rates of dalapon and paraquat. Autumn application generally resulted in greater Lucerne production than late winter application. Most treatments reduced the amount of barley grass in the Lucerne. Diuron and atrazine also eliminated reduced the amount of barley grass in the Lucerne. Atrazine, diuron and linuron had a strong residual effect and reduced the density of subterranean clover and barley grass in the autumn following treatment. 相似文献
16.
John A. P. Marsh 《Pest management science》1985,16(1):93-100
The effects of seven herbicides, alone or combined with a commercial compound fertiliser, on nitrogen and phosphorus transformations in soil, were investigated in the laboratory. No significant effect was observed without the fertiliser. When the fertiliser (N:P:K ratio 20:14:14) was applied (2 gkg?1 of soil), asulam markedly reduced nitrification, while increasing the mineralisation of nitrogen; chloridazon, glyphosate, isoproturon and paraquat all prevented the reduction in available phosphate that occurred in the control soil in the first 2 weeks. The rates of degradation of dalapon and isoproturon were greatly reduced in fertilised soil. The importance of these results is discussed in the context of the requirements of registration authorities. 相似文献
17.
Summary. Pre-emergence application of 2–5 kg/ha (a.i.) of atrazine or simazine was the most effective treatment for control of broad-leaved weeds in maize. Other triazines injured maize at all rates tested. Among the crops following maize treated with atrazine or simazine at 2–5 kg/ha, sugar beet was injured whereas wheat, oats, vetch, onions and soybeans were not. Post-emergence application of triazine herbicides was not effective and did not increase maize yields significantly over those of the unweeded plots. Wheat, oats, vetch and sugar beet were injured when following maize treated with post-emergence sprays; onions and soybeans showed no visible injury except from atrazine or simazine at 5 kg/ha or more, and from mixtures of atrazine+prometryne or atrazine+ametryne at 12–5 kg/ha. Les triazines herbicides sur le mais et leurs arrière-effets sur les cultures suivantes 相似文献
18.
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
19.
Summary. Several alkylphenol ethylene oxide ether non-ionic surfactants were tested in aqueous foliar sprays with dalapon, amitrole and paraquat for (heir enhancement of phytocidal activity against Zea mays L. With three homologous series of surfactants studied (octyl-, nonyl- and laurylphenol types), the herbicide, the surfactant concentration and the hydrophilic constitution (ethylene oxide content) of the surfactant molecule all markedly influenced maximum toxicity. Smaller apparent differences in effectiveness were also attributable to the hydrophobic (alkylphenol) portion of the surfactant. The results arc discussed in relation to possible cuticle-spray solution interactions and their influence on herbicide penetration.
Relations entre la structure et l'activite de produits tensio-actifs non ionigues, a base d'éther d'oxyde éthylénique et d'alkylphénol, en présence de trois herbicides hydrosolubles 相似文献
Relations entre la structure et l'activite de produits tensio-actifs non ionigues, a base d'éther d'oxyde éthylénique et d'alkylphénol, en présence de trois herbicides hydrosolubles 相似文献
20.
A. WALKER 《Weed Research》1976,16(6):369-373
In glasshouse experiments, atrazine, simazine, lenacil and linuron applied to the soil surface were phytotoxic to turnip seedlings which had emerged from a depth of 1–5 cm when 3 mm artificial rainfall was applied at the time of seedling emergence or shortly afterwards. When rainfall was applied on 2 or 3 consecutive days, the herbicides were in general more phytotoxic. As the delay between emergence and commencement of surface watering increased, however, the response of the seedlings decreased. Studies with [14C]-atrazine showed that at emergence the seedlings contained a small amount of herbicide which increased considerably with surface watering. Relatively high concentrations were attained when rainfall was applied while the seedlings were small, but as the interval between seedling emergence and rainfall increased, the same uptake resulted in lower shoot concentrations, Atrazine extraction from the soil showed little movement from the surface 1.0 cm, suggesting uptake via the stem. The observed responses of the other three herbicides are explained by assuming the same pattern of uptake as that recorded for atrazine. 相似文献