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1.
Localized placement of prometryne, linuron and diuron in the soil at the first or second shoot internodes of dwarf broad bean (Vicia faba L.) equally reduced aerial plant growth, whereas simazine and atrazine had no effect. Growth reduction also occurred when the first shoot internode of scarlet runner bean (Phaseolus multiflorus L.) in the soil was treated with all five herbicides, especially with diuron. Localized placement of these herbicides at the first or second shoot internodes of vetch (Vicia sativa L.) in the soil equally reduced aerial plant growth. Foliar injury to vetch due to placement of these herbicides in the shoot zone of the soil was markedly reduced by simultaneous treatment with trifluraiin or nitralin which prevented adventitious root development on the shoot without otherwise affecting plant growth. This lack of root development on the shoots treated with trifluraiin was associated with a marked decrease in 14C-labelled atrazine uptake, which probably accounted for the reduction in atrazine phytotoxicity. A similar explanation may account for the reduced phytotoxicity of the other herbicides in the presence of trifluraiin or nitralin.  相似文献   

2.
The effect of localized placement of trifluralin on uptake patterns of soil-applied 45Ca in vetch (Vicia sativa L.), pea (Pisum sativum L.) and soybean (Glycine max) and 32P in vetch and pea was investigated in two soil zones in the roots and in the shoot zone before and after plant emergence. When trifluralin was in the upper root zone severe inhibition of lateral roots occurred as well as a marked decrease in uptake of 45Ca and 32P from this zone. Root growth in the lower zone was unaffected, but uptake of 45Ca and 32P was slightly reduced. Compensatory adventitious root growth as well as a marked increase in uptake of 45Ca and 32P occurred in the shoot zone. Neither root growth nor uptake of 45Ca or 32P in the upper root zone were affected by the presence of trifluralin in the lower root region. When trifluralin was placed in the shoot zone after plant emergence, adven-titious roots on the shoots were inhibited and uptake of 45Ca and 32P was reduced.  相似文献   

3.
The phytotoxicities of atrazine, simazine, linuron, lenacil and aziprotryne were increased as the moisture content of the soil increased. Results from studies with 14C-labelled atrazine suggested that these differences could be related to differences in concentrations of herbicide accumulated by the plants. Total uptake of atrazine was directly proportional to water uptake, but a comparison of the amounts taken up with those supplied by mass-flow in the transpiration stream suggested that some exclusion factor was operative. It was concluded that herbicide transport within the soil-plant system was the main factor affecting phytotoxicity under the different soil moisture regimes. The significance of the results to herbicide behaviour under field conditions is discussed.  相似文献   

4.
The sites of uptake of chlorsulfuron in maize (Zea mays L.) were investigated at three different growth stages. Exposure of seedling roots, or shoots separately, to herbicide-treated sand over 4 days resulted in inhibition of both roots and shoots. Exposure of seedling roots to chlorsulfuron-treated soil over 21 days severely inhibited both roots and foliage, while separate shoot exposure also reduced both foliage and root growth. After plant emergence, exposure of the crown root node, growing point and lower stem to treated soil reduced foliage and root growth, but exposure of the shoot above the growing point caused only slight inhibition of foliage and had no effect on roots. The herbicide safener 1,8-naphthalic anhydride (NA) applied as a dust (10 g kg?1 seed weight), or as a 50 mg 1?1 suspension in water to maize seeds, reduced the root inhibition by chlorsulfuron in 4-day-old seedlings. NA completely prevented both foliage and root injury when chlorsulfuron was placed in soil in the shoot zone before emergence, or in the shoot zone below the soil surface after plant emergence. NA slightly decreased injury to foliage, but not to roots when chlorsulfuron was placed in soil in the root zone before emergence. NA seed treatment protected both roots and foliage against injury from foliarly applied chlorsulfuron. Plants were also protected when a suspension of NA in water was sprayed on the foliage seven days before chlorsulfuron. When a mixture of NA and chlorsulfuron was applied to foliage, root injury was reduced more than foliage injury.  相似文献   

5.
Aphid colonies were established on one second-node leaflet of young broad bean plants and sublethal treatments of 14C-labelled phorate were applied to the adjacent leaflets. After 3 days, the amounts of toxic and non-toxic 14C-labelled compounds in the aphids, their honeydew and the untreated foliage were determined. There were no significant differences between the amounts in leaves at the same level on the plant when infested and aphid-free plants were compared, but the aphids and their honey-dew contained two and 23 times as much of the toxic and non-toxic 14C-compounds, respectively, found in the host leaflets. Following translocation to aphids on leaves above or below treated leaflets, the aphid colonies again contained more labelled compounds than the host-plant leaves. The movement of non-toxic compounds into the roots was reduced when the aphid colonies were situated on foliage between the site of treatment and the roots. More of the toxic and the non-toxic fractions were translocated downwards from the third to the second leaf than in the reverse direction.  相似文献   

6.
The effect of placing terbutryne in different soil layers with reference to different depths of sowing of peas was studied by measuring plant top growth. Increasing the depth of sowing resulted in greater plant injury by the same layer of herbicide-treated soil. Exposing the upper part of the emerging epicotyl (nearest the soil surface) to soil treated with terbutryne was more injurious than exposing the lower part of the epicotyl (nearest the seed). Uptake of 14C-labelled prometryne and terbutryne by pea seedlings during emergence and early growth was measured according to different soil-zone treatments. The absorbed amount of each herbicide decreased in the order: root system, lower epicotyl, upper epicotyl. Translocation of the herbicides to the foliage was higher from the upper than from the lower part of the epicotyl. Shoot and root uptake and translocation of prometryne were higher than of terbutryne.  相似文献   

7.
The concentrations of haloxyfop in nutrient solution required to reduce the total plant dry weight of soybean (Glycine max L. Merr. ‘Evans’), red fescue (Festuca rubra L. ‘Pennlawn’), and tall fescue (Festuca arundinacea Schreb. ‘Houndog’) by 50% (GR50) were determined. The GR50) values for soybean, red fescue and tall fescue were 76 μM, 3μM and 0.4 μM, respectively. The reduction in growth in roots and shoots of soybean was similar. In contrast, the relative reduction in root tissue weight was greater than that for foliar tissue in both grass species. The amount of 14C-haloxyfop in soybean roots or shoots was higher than in red fescue or tall fescue. Red fescue accumulated less haloxyfop in the foliage than in the roots. On the other hand, similar amounts of 14C-haloxyfop accumulated in both organs in both soybean and tall fescue. 14C-haloxyfop appeared to be actively absorbed by the roots of all species. Soybean absorbed more nutrient solution, but utilized it less on a per gram dry matter produced basis than the grass species. Differences in the uptake and translocation of haloxyfop by roots do not account for differences in tolerance between species. However, a higher level of retention of haloxyfop in the roots of red fescue than in tall fescue may provide the former with an additional selectivity advantage under conditions where there is significant root exposure to the herbicide.  相似文献   

8.
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   

9.
二硝基苯胺除草剂对大豆生育影响的研究   总被引：4，自引：0，他引：4  
作者于1981～1983年所作的系统田间与盆栽试验证明,二硝基苯胺类除草剂中的氟乐灵、二甲戊乐灵对大豆苗期生育有明显抑制作用,表现为:(1)出苗延迟,幼芽下胚轴肿胀、脆弱、矮化,子叶革质状,单位面积用药量对幼芽矮化的影响比混土深浅大;(2)侧根显著受抑制,这种抑制作用局限于药土层,混土深度对大豆侧根的抑制比用药量高低的影响更显著;(3)根瘤菌形成受抑制,根瘤数减少,叶面积减小。随着大豆生长,上述抑制作用逐步消失,对大豆产量无显著影响。在供试3种除草剂中,丁乐灵对大豆生育无影响。从安全、经济、高效考虑,氟乐灵与二甲戊乐灵的适宜用量为1.0公斤,丁乐灵为1.5公斤/公顷,将药剂施于大豆种子之上的土层为宜,亦即施药后耙地不宜过深,将药剂混拌于0～6厘米土层为佳。  相似文献   

10.
Summary. We conducted studies to determine the effects on corn (Zea mays L, var. Indiana 654) and pea (Pisum sativum L. var. Alaska) of localizing various herbicides in the soil, using a double plastic pot technique which ensured separate exposure of the root and shoot zones of the plants to treated soil. Effects on corn and pea were similar in relation to site of uptake. 2,4-D-amine, naptalam, simazine, diuron and dalapon-sodium entered primarily through the roots. Some shoot entry and also severe inhibition of roots occurred in soil treated with 2,4-D and naptalam; these were noticed only to a slight extent with the other three herbicides. EPTC, chlorpropham and trifluraiin were most effective when applied to the shoot zone. Little effect on foliage growth was evident when the root zone alone was treated. However, roots in treated soil were severely inhibited by these three herbicides. Dinoseb displayed a contact type of action, injuring both shoots and roots. Treatment of both zones had an additive effect. Entry of chlorthal-methyl which was tested on a susceptible species, sorghum (Sorghum vulgare Pers.) was mainly through the shoot, with only a slight effect on top growth when roots alone were treated. Roots in treated soil were slightly inhibited. Localisation de l'absorption des herbicides appliqués sur le sol  相似文献   

11.
Chlorimuron ethyl uptake into excised soybean root tissue was investigated using 14C-labelled herbicide. Chlorimuron ethyl accumulated in the root tissue, reaching a maximum concentration after 2 h and then declining over the next 2 h. The herbicide did not accumulate against a concentration gradient. The tissue concentration was linearly correlated with the external herbicide concentration. The Q10 between 15 and 25°C was 1.6. Addition of KCN and anoxia reduced uptake. The efflux of 14C that had accumulated in root tissue segments occurred in two phases: a rapid phase with a T½ value of 6.3 min and a slower phase with a T½ value of 172 min. Chlorimuron ethyl uptake and efflux in excised soybean root tissue closely resembled that previously observed in velvetleaf, a sensitive weed species.  相似文献   

12.
The uptake and translocation of 14C-labelled ethofumesate [(±)-2-ethoxy-2,3-dihydro-3,3-dimethylbenzofuran-5-yl methanesulphonate] was studied in sugar-beet seedlings following soil and foliar applications. After soil applications, the roots absorbed and translocated to the foliage more ethofumesate or its metabolites than did the emerging hypocotyls. Ethofumesate or its metabolites did not accumulate in either roots or hypocotyls after exposure to treated soil. When sugar-beet leaves were treated with the herbicide at the two-leaf stage, acropetal translocation was rapid but there was no translocation out of the treated leaves. Furthermore, ethofumesate or its metabolites were not translocated basipetally after either soil or foliar application.  相似文献   

13.
Ficld bean (Vicia fab a L. cv. Maris Bead) was susceptible both to simazine and dimefuron applied to the root system in culture solution at concentrations of 0–5 and above. Pea (Pisum satirum L. cv. Kelvedon Wonder). however, exhibited significantly greater tolerance them field bean to dimefuron between concentrations of 0.5 and 1.0. The Hill activity of isolated chloroplasts from pea was more sensitive to dimefuron than that from field bean qualitative (autoradiography) and quantitative experiments dcmonstrated that root-applied 14C dimefuron was more readily transported to the shoot system in bean than in pea. A double-pot experiment revealed that the effective site of uptake by the field bean is the root system: foliar uptake of 14C-dimefuron was shown, but little movement of label from the treated leaf oceurred. Adsorption of dimefuron on a calcareous loam soil was relatively low. It is concluded that fieltolerance exhibited by field bean to pre-emergence applications of dimefuron is due principally to depth protection: in pea. retention in the root provides an additional basis iS for tolerance.  相似文献   

14.
Summary. The effects of localized herbicide placement at different internodes of pea ( Pisum sativum L. cv. Alaska) shoots below the soil surface after plant emergence were studied by removing the soil from around the shoots and replacing with herbicide-treated soil. The first internode proved insensitive to linuron, diuron, atrazine and simazine at 4·5 kg/ha, while treatment of the second and third internodes markedly reduced plant growth 4–6 days after treatment. Separate exposure of the first internode alone, and the second and part of the third together to 14C-labelled atrazine indicated no difference in herbicide metabolism. However, a two- to threefold increase in 14C uptake and movement to the foliar parts occurred when the second and part of the third internode was treated, as compared to first internode treatment. Thus the differential sensitivity of the internodes to atrazine, and possibly to the other herbicides, may be because the more mature first internode allows less uptake and subsequent movement to the foliar parts.
Absorption dans la zone des tiges des herbicides appliqués dans le sol chez Pisum sativum L.  相似文献   

15.
施氮量对滴灌高产春大豆根系生长及产量的影响   总被引：1，自引：0，他引：1  
为揭示施氮量对滴灌高产春大豆根系生长及产量的影响规律,在田间滴灌条件下采用挖掘取样法研究了0 kg·hm~(-2)(N_0)、75 kg·hm~(-2)(N_(75))、150 kg·hm~(-2)(N_(150))、225 kg·hm~(-2)(N_(225))4种施氮量对新大豆27号0~80 cm土层根系干物质量、侧根长度、表面积、根系活性、伤流量、根瘤数、根瘤质量及产量的影响。结果表明:随着施氮量的增加,0~80 cm土层根系总干物质量、侧根总长度、侧根总表面积呈现先增后降的变化趋势,均以N_(150)处理最高,在R_5(始粒期)期分别较N_0增加27.3%、49.46%、38.14%,其中,0~20 cm土层分别较N_0增加27.0%、29.02%、34.24%;R_5期N_(150)单株伤流量较N_0增加176.0%,R_2(盛花期)期0~20、20~40 cm土层根系活力N_(150)分别较N_0增加44.3%、25.1%;R_5期N_(150)单位面积根瘤数及质量分别较N_0减少8.74%、34.6%;施氮可增加产量,以N_(150)产量最高,为4 889.62kg·hm~(-2),氮肥农学利用效率3.58 kg·kg~(-1)。施氮增加产量主要是促进0~20 cm土层根系生长,提高0~40 cm根系活力的结果。  相似文献   

16.
The action of atrazine and its biodegradation products on the membrane transport of potassium in roots was evaluated in both sensitive and resistant plants. Excised roots of maize and oat showed inhibition of potassium uptake efficiency in the presence of 1.4 × 10?4M atrazine and 1.4 × 10?4M deethylated atrazine. Other biodegradation products such as 2-chloro-4-amino-6-ethylamino-1,3,5-triazine,2-chloro-4,6-,bisamino-1,3,5-triazine, and 2-chloro-4-amino-1,3,5-triazine showed no inhibitory effect on the K+ uptake capacity. Two maize hybrids showing different uptake efficiency were inhibited differently by atrazine. We suggest that atrazine and deethylated atrazine inhibited the K+ transport interacting directly with the plant cell membranes without discerning between resistant and sensitive plants.  相似文献   

17.
Summary. In loamy soil with a low humus content (0·8% organic carbon) simazine at a concentration of 2'5 ppm reduced growth of shoots, roots and trunk diameter in 1-year-old scions of five apple varieties on M IX rootstock. The most susceptible was Cox's Orange Pippin; 5 ppm was lethal for this variety only. In experiments with vertically divided pots, where one part of the root system developed in soil with simazine (2–5 ppm and 5–0 ppm for apple and 5·0 ppm for plum) and the other part in simazine-free soil, there was less effect on shoot growth and less leaf damage than where all the soil contained simazine. Growth of that part of the root system in soil containing simazine was stimulated.  相似文献   

18.
BACKGROUND: Enhanced atrazine degradation has been observed in agricultural soils from around the globe. Soils exhibiting enhanced atrazine degradation may be cross-adapted with other s-triazine herbicides, thereby reducing their control of sensitive weed species. The aims of this study were (1) to determine the field persistence of simazine in atrazine-adapted and non-adapted soils, (2) to compare mineralization of ring-labeled (14)C-simazine and (14)C-atrazine between atrazine-adapted and non-adapted soils and (3) to evaluate prickly sida control with simazine in atrazine-adapted and non-adapted soils.RESULTS: Pooled over two pre-emergent (PRE) application dates, simazine field persistence was 1.4-fold lower in atrazine-adapted than in non-adapted soils. For both simazine and atrazine, the mineralization lag phase was 4.3-fold shorter and the mineralization rate constant was 3.5-fold higher in atrazine-adapted than in non-adapted soils. Collectively, the persistence and mineralization data confirm cross-adaptation between these s-triazine herbicides. In non-adapted soils, simazine PRE at the 15 March and 17 April planting dates reduced prickly sida density at least 5.4-fold compared with the no simazine PRE treatment. Conversely, in atrazine-adapted soils, prickly sida densities were not statistically different between simazine PRE and no simazine PRE at either planting date, thereby indicating reduced simazine efficacy in atrazine-adapted soils.CONCLUSIONS: Results demonstrate the potential for cross-adaptation among s-triazine herbicides and the subsequent reduction in the control of otherwise sensitive weed species. Copyright (c) 2008 Society of Chemical Industry.  相似文献   

19.
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   

20.
The average endogenous GSH content of eight lines of inbred corn was almost twofold greater than ten varieties of hybrid corn. When inbred and hybrid corn lines were treated with R-25788, the average GSH content increased by 56 and 95%, respectively. R-25788 protected two special inbred corn lines, GT 112 (atrazine susceptible) and GT 112 RfRf (atrazine resistant) from EPTC injury by increasing the GSH content and GSH S-transferase activity in roots. Most of the radiolabel from [14C]R-25788-treated plants remained in the root tissues whereas the radiolabel in [14C]EPTC-treated plants was evenly distributed between foliar and root tissues. From radiolabel experiments, hybrid corn seedlings were found to absorb more R-25788 from soil than EPTC. There was no difference between inbred and hybrid corn in the amounts of R-25788 or EPTC taken up or in the enhancement of GSH S-transferase activity caused by R-25788.  相似文献   

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