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1.
为明确助剂安融乐(3%卵磷脂·维生素E)对草甘膦异丙胺盐水剂的增效作用,在温室条件下以野芥菜[Brassica juncea(L.) Czern. et Coss.,AABB,2n=36]为供试材料,通过生物测定计算安融乐与2种草甘膦异丙胺盐水剂(商品名为发达和农达,使用剂量为375～6 000 mL/hm~2)混用后(体积分数为0.02%)的ED_(50)值和ED_(90)值、5-烯醇式丙酮酰-莽草酸-3-磷酸合成酶(EPSPS)活性和莽草酸累积量。结果显示,与草甘膦异丙胺盐水剂单用相比,发达、农达与安融乐混用后野芥菜死亡时间提前1 d左右,ED_(50)值和ED_(90)值分别降低690.0、550.5 mL/hm~2和561.0、643.5 mL/hm~2,野芥菜防除效果提高33.9%、36.2%和11.1%、15.0%;野芥菜EPSPS活性IC_(50)值(活性受抑制50%的草甘膦剂量)分别降低21.0μmol/L和25.9μmol/L。莽草酸积累量分别提高0.11%～24.02%和0.21%～27.05%。综上,安融乐对草甘膦异丙胺盐水剂有一定的增效作用,混用后可加速野芥菜EPSPS失活,增加莽草酸积累量,有效提高药剂作用速度,提高对靶标杂草的防除效果。  相似文献   

2.
研究了有机硅喷雾助剂(OSA)对草甘膦在空心莲子草Alternanthera philoxeroides上的沉 积与生物活性的影响。当采用较大喷雾雾滴,施药液量高于632.5 L/hm2时,添加OSA(0.35 g/L) 后,草甘膦药液在空心莲子草上的沉积量显著下降。最大稳定持留量(MRG)由未添加OSA的0.61~0.63 μ L/cm2下降到0.50~0.54 μ L/cm2。分别以33.7和67.4 μ g/株剂量的草甘膦点叶处理空心莲子草,发现添加OSA的处理对再生植株茎叶生长的抑制率分别比对照提高了8.89%和14.83%。草甘膦(有效成分199.3 g/hm2)施药后1 h进行人工模拟降雨处理,添加OSA后药剂对空心莲子草的生物活性比无OSA对照处理提高了20.5%。研究结果表明,添加有机硅喷雾助剂促进了草甘膦在空心莲子草中的向下传导性能,提高了草甘膦水剂在空心莲子草叶片的耐雨水冲刷性能,但会降低草甘膦药液在空心莲子草上的最大稳定持留量。  相似文献   

3.
鉴于高锰胁迫下空心莲子草Alternanthera philoxeroides对草甘膦的耐药性增强,在水培条件下研究了不同浓度锰条件下草甘膦处理后该草体内莽草酸的积累和主要抗氧化酶系统的响应。次高浓度锰(0.31 mmol/L)条件下培养120 d后空心莲子草体内过氧化氢酶(CAT)活性显著高于常规浓度锰处理(0.009 1 mmol/L,对照);高浓度锰(2.45 mmol/L)条件下超氧化物歧化酶(SOD)活性升高,CAT活性下降。草甘膦(按草甘膦酸68 g/hm2)茎叶处理后6 d内,常规锰浓度培养的空心莲子草体内莽草酸含量比用草甘膦刚处理时增加了31.9％~226.0%,且显著高于同一时间次高锰和高锰的处理;不同锰浓度下培养的空心莲子草体内过氧化物酶(POD)和CAT、SOD活性均为先升高后再逐渐下降,但次高锰处理的该3种酶活性均高于对照,高锰处理的SOD和POD活性高于对照,而CAT活性与对照相当。上述结果表明,在较高锰浓度下空心莲子草能启动抗氧化酶系统而能有效地清除自由基;在草甘膦处理后初期,高锰条件下空心莲子草体内莽草酸途径受抑制程度较轻,抗氧化酶活性较高,这可能是空心莲子草耐高锰和高锰条件下该草耐草甘膦的部分机制。  相似文献   

4.
为了比较4种助剂Silwet 806、红太阳A8、激健、安融乐对异丙隆防除菵草Beckmannia syzigachne的增效作用及机制,采用整株生物测定法测定4种助剂与异丙隆混用后对菵草的生物活性及对小麦的安全性;采用仪器分析法测定4种助剂对异丙隆药液的表面张力、叶面接触角、干燥时间和在叶面上的沉积量的影响。结果表明:添加4种助剂后异丙隆防除菵草的ED90分别降低为553.11、626.31、819.93、841.54 g/hm2,但异丙隆与Silwet 806混用后对小麦安全性下降。添加4种助剂后,异丙隆药液的表面张力和叶面接触角显著降低,药液在叶面上的干燥时间缩短,沉积量增加,其中红太阳A8的上述指标显著优于激健和安融乐,能够较好地实现异丙隆减量增效的目的。  相似文献   

5.
通过田间小区试验,验证了不同助剂对20%氯氟吡氧乙酸乳油(EC)防除空心莲子草的增效作用,并系统研究了不同助剂对20%氯氟吡氧乙酸EC药液在空心莲子草叶面润湿性能的影响。结果表明:添加氮酮、油酸甲酯或聚三硅氧烷可显著提高20%氯氟吡氧乙酸EC对空心莲子草地上部分鲜重及再生能力的抑制效果,其中以添加聚三硅氧烷的处理增效最为显著,添加聚三硅氧烷后,20%氯氟吡氧乙酸EC对空心莲子草地上部分鲜重、再生茎叶鲜重的抑制率分别为86.95%和81.66%;添加氮酮、油酸甲酯或聚三硅氧烷后,20%氯氟吡氧乙酸EC药液在空心莲子草叶面的表面张力显著降低,接触角减小,滞留量增加,其中以添加聚三硅氧烷的处理效果最为显著,添加聚三硅氧烷后,20%氯氟吡氧乙酸EC的初始接触角小于50°,180 s时接触角均小于15°,表面张力为25.09 m N/m,滞留量为1.891 g/cm2;添加氮酮或聚三硅氧烷可缩短20%氯氟吡氧乙酸EC药液在空心莲子草叶面正、反面的干燥时间,而添加油酸甲酯则会延长其干燥时间。研究表明,添加助剂改善了20%氯氟吡氧乙酸EC药液在空心莲子草叶面的润湿性能,可能是助剂提高20%氯氟吡氧乙酸EC对空心莲子草防效的原因之一。  相似文献   

6.
草甘膦与硫酸铵混合后处理空心莲子草,测定其对植株的抑制作用和体内草甘膦的吸收与传导量。结果表明,加入硫酸铵(1.20 g/L)后草甘膦(300 mg/L)对地下根茎抑制率比对照提高了12.2个百分点。植株经硫酸铵喷雾处理后,地下茎和根系中14C-草甘膦含量分别是对照处理的1.39和1.86倍。药液中水的硬度达到342.0 mg/L时明显降低草甘膦的除草活性,硫酸铵浓度达到12.0 g/L则可基本消除水的硬度对草甘膦除草活性的影响。  相似文献   

7.
 本文以14C-甲霜灵作为示踪剂,运用放射自显影及放射性强度测定技术,研究了甲霜灵在黄瓜植株体内的吸收、分布、传导以及种衣剂的缓释作用机理,结果表明:14C-甲霜灵在黄瓜体内的传导是迅速的,随药剂作用时间的延长,放射性物质在叶部的积累增加,在根、茎、子叶中却降低;种衣剂中的关键助剂——成膜剂,能将种衣剂中的有效成分固着在种子表面,具有使药剂缓释和延长持效期,提高药剂利用率的作用。  相似文献   

8.
本文联合应用球孢白僵菌Beauveria bassiana HFW-05与低剂量化学杀虫剂,评价其是否对小菜蛾防治具有协同增效作用,为小菜蛾的有效防控提供新的途径。结果表明,低剂量的化学杀虫剂对菌株HFW-05分生孢子的萌发率、菌丝生长和胞外蛋白酶活性没有影响,甲氨基阿维菌素苯甲酸盐和氯虫苯甲酰胺的增效作用最明显。低剂量甲氨基阿维菌素苯甲酸盐和氯虫苯甲酰胺与HFW-05混用均可明显提高对小菜蛾2龄幼虫的杀虫速度。氯虫苯甲酰胺最低设定浓度10×与HFW-05 3个浓度（1.0×106、1.0×107、4.0×107孢子/mL）混用对小菜蛾的理论LT50均低于1 d,显著低于单独使用HFW-05孢悬液。甲氨基阿维菌素苯甲酸盐4×与HFW-05 3个浓度（1.0×106、1.0×107、4.0×107孢子/mL）混用对小菜蛾的LT50分别为2.4、2.2和1.2 d,显著低于单独使用HFW-05孢悬液。甲氨基阿维菌素苯甲酸盐和氯虫苯甲酰胺均没有影响HFW-05对小菜蛾的僵虫率。表明白僵菌HFW-05与低剂量甲氨基阿维菌素苯甲酸盐和氯虫苯甲酰胺联合应用,在保证白僵菌侵染作用的同时,可有效提高对小菜蛾的致病力,是防治小菜蛾的一项新的有效措施。  相似文献   

9.
布顿大麦草为麦田入侵杂草, 为尽早建立对该杂草的化学防除技术, 本研究采用室内盆栽法测定了布顿大麦草对21种除草剂的敏感性?结果表明:土壤处理剂41%氟噻草胺悬浮剂对布顿大麦草具有良好的防除效果, 42%氟啶草酮悬浮剂?60%丁草胺乳油?40%砜吡草唑悬浮剂?960 g/L精异丙甲草胺乳油对布顿大麦草的防除效果一般, 50%扑草净可湿性粉剂?50%异丙隆可湿性粉剂?45%二甲戊灵微囊悬浮剂?50%吡氟酰草胺可湿性粉剂防除效果不理想; 茎叶处理剂7.5%啶磺草胺水分散粒剂?12.5%烯禾啶乳油?41%草甘膦异丙胺盐水剂对布顿大麦草防除效果好, 5%咪唑乙烟酸水剂?8%炔草酯水乳剂?30 g/L甲基二磺隆可分散油悬浮剂?8%烟嘧磺隆可分散油悬浮剂?7%双唑草腈颗粒剂?70%氟唑磺隆水分散粒剂对布顿大麦草的防除效果一般, 5%唑啉草酯乳油?7.5%双环磺草酮颗粒剂?69 g/L精噁唑禾草灵水乳剂防除效果不理想?氟噻草胺?在推荐剂量492 g/hm2下, 处理21 d后对布顿大麦草的鲜重抑制率为75.40%; 啶磺草胺?草甘膦异丙胺盐?烯禾啶在推荐剂量14?1 500?187.5 g/hm2下, 处理21 d后对布顿大麦草的鲜重抑制率分别为73.96%?60.60%?65.07%?综合本研究结果及除草剂使用特性, 麦田布顿大麦草可采用氟噻草胺土壤封闭或者啶磺草胺茎叶喷雾处理进行有效防除; 油菜田布顿大麦草可采用烯禾啶进行防除; 非耕地布顿大麦草可采用草甘膦异丙胺盐进行防除?  相似文献   

10.
收集草地贪夜蛾致病性莱氏绿僵菌,丰富昆虫病原真菌资源,为草地贪夜蛾绿色防控生防制剂开发提供依据。采用形态学和ITS-r DNA序列分析相结合的方法对菌株Mr006进行了鉴定,以浸渍法生物测定了该菌株对草地贪夜蛾幼虫和蛹的致病力,并进行了田间应用效果评价。结果表明,分离的Mr006菌株鉴定为莱氏绿僵菌;该菌株对草地贪夜蛾幼虫、蛹均有致病力,用孢子浓度为1×107孢子/mL接种后,1～5龄幼虫的校正死亡率分别为91.16%、88.38%、70.71%、53.03%和22.73%,蛹的校正死亡率为76.26%;对草地贪夜蛾1～5龄幼虫和蛹的LC50分别为3.55×104、8.23×104、3.63×106、4.16×107、4.23×108和2.57×105孢子/mL;用孢子浓度为1×108孢子/mL接种后,1～5龄幼虫和蛹的LT50值分别缩短至3.47、3.94、4.90、...  相似文献   

11.
The weed species, prickly sida (Sida spinosa L.) and sicklepod (Senna obtusifolia L.), were treated with 14C-glyphosate alone and formulated with different polyethlylane oxide (PEO) surfactants in tallow amine ethoxylate and non-ionic alkoxylate series to determine the amount of 14C-glyphosate absorption and translocation. The surface tension, contact angle, and 14C-glyphosate distribution were significantly affected by both the presence of different waxes on the plants and by the addition of surfactants to the glyphosate. The surface and contact angle values of the surfactants, with and without glyphosate, showed a significant increase as the PEO number increased in both surfactant series. A higher absorption of the 14C-glyphosate was recorded for S. spinosa compared with S. obtusifolia. The absorption and translocation of the 14C-glyphosate increased with the increase in the PEO number of tallow amine ethoxylate. In the case of the non-ionic alkoxylate surfactant series, an increase in the absorption of 14C-glyphosate was recorded when the surface tension and contact angle values decreased. There was no significant difference in the translocation values obtained in the two species after the addition of the surfactants. The amount of 14C-glyphosate absorbed by the treated leaf was significantly higher in the case of S. spinosa compared with S. obtusifolia. A linear relationship was observed with the physical properties, 14C absorption, and the efficacy of glyphosate with the addition of the non-ionic alkoxylate surfactant series. The percentage control was higher with the higher PEO surfactant in the tallow amine ethoxylate surfactant series and with the lower PEO surfactant in the non-ionic alkoxylate surfactant series as the two series are chemically different.  相似文献   

12.
The non-ionic surfactants, Tween 20 (polyoxy-ethylene 20 sorbitan monolaurate) and Renex 36 (polyoxyethylene 6-tridecyl ether) enhanced the retention of a glyphosate-dye spray solution by barley (Hordeum vulgare L.) leaves. Tween 20 also enhanced absorption of 14C-glyphosate applied as droplets to barley leaves whereas Renex 36 similarly applied, reduced both absorption and movement of 14C-glyphosate. Renex 36 alone or mixed with glyphosate increased leakage of electrolytes from barley leaf segments whereas neither Tween 20 nor glyphosate, alone or mixed together, had any effect. No 14C-glyphosate complexes were detected in mixtures with either surfactant and neither surfactant affected the pH of the glyphosate solution. The results indicate that the reported enhancement of glyphosate phytotoxicity by Tween 20 is due to increased retention and absorption of the herbicide while the reported antagonism caused by Renex 36 is due to reduced glyphosate absorption and movement possibly as a result of alteration of membrane integrity.  相似文献   

13.
不同除草剂对空心莲子草的控制作用评价   总被引：2，自引：0，他引：2  
采用盆栽试验,测定了氯氟吡氧乙酸、草甘膦和五氟磺草胺对不同生育期空心莲子草的控制作用,以株防效、鲜重防效和再生抑制率为指标,评价了不同除草剂对空心莲子草的控制效果。结果表明,药后7 d,氯氟吡氧乙酸、草甘膦和五氟磺草胺对不同生育期空心莲子草的株防效,均低于15%;药后15 d,氯氟吡氧乙酸和草甘膦对不同生育期的空心莲子草的株防效、鲜重防效均达100%,但五氟磺草胺对不同生育期的空心莲子草的株防效较差。药后30 d,氯氟吡氧乙酸和五氟磺草胺对不同生育期空心莲子草的再生抑制作用较强,抑制效果达74%以上;草甘膦对生长后期的再生抑制作用达81.3%。空心莲子草苗期对不同除草剂的反应最为敏感。氯氟吡氧乙酸可以作为水生环境和旱生环境下防除空心莲子草的重点药剂,草甘膦可用于旱地空心莲子草的防除,五氟磺草胺可作为水生环境条件下防除空心莲子草的主要药剂之一。  相似文献   

14.
Summary A biotype of Conyza albida resistant to imazapyr was discovered on a farm in the province of Seville, Spain, on land that had been continuously treated with this herbicide. This is the first reported occurrence of target site resistance to acetolactate synthase (ALS)-inhibiting herbicides in C. albida . In order to characterize this resistant biotype, dose–response experiments, absorption and translocation assays, metabolism studies, ALS activity assays and control with alternative herbicides were performed. Dose–response experiments revealed a marked difference between resistant (R) and susceptible (S) biotypes with a resistance factor [ED50(R)/ED50(S)] of 300. Cross-resistance existed with amidosulfuron, imazethapyr and nicosulfuron. Control of both biotypes using alternative herbicides was good using chlorsulfuron, triasulfuron, diuron, simazine, glyphosate and glufosinate. The rest of the herbicides tested did not provide good control for either biotype. There were no differences in absorption and translocation between the two biotypes, the maximum absorption reached about 15%, and most of the radioactivity taken up remained in the treated leaf. The metabolism pattern was similar and revealed that both biotypes may form polar metabolites with similar retention time (Rf). The effect of several ALS inhibitors on ALS (target site) activity measured in leaf extracts from both biotypes was investigated. Only with imazapyr and imazethapyr did the R biotype show a higher level of resistance than the S biotype [I50 (R)/I50(S) value of 4.0 and 3.7 respectively]. These data suggest that the resistance to imazapyr found in the R biotype of C. albida results primarily from an altered target site.  相似文献   

15.
The transport and differential phytotoxicity of glyphosate was investigated in maize seedlings following application of the herbicide to either roots or shoots. One-leaf maize seedlings (Zea mays L.) were maintained in graduated cylinders (250 mL) containing nutrient solution. Half of the test plants were placed in cylinders (100 mL) containing different 14C-glyphosate concentrations; the remainder received foliar appliation of 14C-glyphosate. After 26 h, the roots and the treated leaves were washed with distilled water, and the plants placed again in cylinders (250 mL) containing fresh nutrient solution for 5 days. Plants were weighed, and split into root, seed, cotyledon, coleoptile, mesocotyl, first leaf and apex. The recovery of 14C-glyphosate was over 86%. For both application treatments, the shoot apex was the major sink of the mobilized glyphosate (47.9 ± 2.93% for root absorption and 45.8 ± 2.91% for foliar absorption). Expressed on a tissue fresh weight basis, approximately 0.26 μg a.e. g−1 of glyphosate in the apex produced a 50% reduction of plant fresh weight (ED50) when the herbicide was applied to the root. However, the ED50 following foliar absorption was only 0.042 μg a.e. g−1 in the apex, thus maize seedlings were much more sensitive to foliar application of the herbicide.  相似文献   

16.
Growth analysis, absorption and translocation studies were conducted to compare a 1-aminomethanamide dihydrogen tetraoxosulfate (GLY-A) formulation of glyphosate with two isopropylamine (GLY-IPA-1, GLY-IPA-2) formulations of glyphosate on velvetleaf. The two isopropylamine formulations differed by the presence of a surfactant in the formulation, GLY-IPA-1 containing surfactant whereas GLY-IPA-2 did not. Four- to six-leaf velvetleaf was treated with GLY-A and GLY-IPA-1 and GLY-IPA-2 (0, 50, 67, 89, 119, 158, 280, 420, 560 and 840 g AE ha(-1)) with and without ammonium sulfate (AMS; 20 g L(-1)). GLY-A and GLY-IPA-2 included a non-ionic surfactant (2.5 mL L(-1)) in the spray solution at all herbicide concentrations. No additional surfactant was added to GLY-IPA-1. The IC50 value for GLY-A was 88 g AE ha(-1) compared with 346 and 376 g AE ha(-1) for GLY-IPA-1 and GLY-IPA-2 respectively in the absence of AMS. When AMS (20 g L(-1)) was added to the spray solution, the estimated IC50 values were 143, 76 and 60 g AE ha(-1) for GLY-IPA-1, GLY-IPA-2 and GLY-A respectively. Absorption of 14C-glyphosate into the third leaf of five- to six-leaf velvetleaf was three- to sixfold greater 72 h after treatment (HAT) when applied as GLY-A compared with GLY-IPA-1 and GLY-IPA-2 respectively in the absence of AMS. AMS (20 g L(-1)) increased absorption of 14C-glyphosate in all glyphosate formulations two- to threefold, but differences among the formulations remained. Approximately three- and sixfold more 14C-glyphosate applied as GLY-A had translocated out of the treated leaf compared with GLY-IPA-1 and GLY-IPA-2 respectively by 72 HAT. Adding AMS (20 g L(-1)) increased translocation of 14C-glyphosate out of the treated leaf approximately 2.5-fold for all three formulations. The increased efficacy of GLY-A versus GLY-IPA-1 and GLY-IPA-2 on velvetleaf is due to the greater rate of absorption and subsequent translocation of glyphosate out of the treated leaf. AMS increased the efficacy of all three formulations by increasing absorption and translocation of glyphosate in the plant.  相似文献   

17.
Influence of picloram on Cirsium arvense (L.) Scop, control with glyphosate   总被引：1，自引：0，他引：1  
Low rates of picloram in mixture with glyphosate provided a rapid enhancement of the onset of injury to the shoots of Cirsium arvense (Canada thistle or creeping thistle) under field (0.07+1.0 and 0.07+1.5 kg ha?1) and greenhouse (0.035+0.42 and 0.07+0.84 kg ha?1) conditions. Picloram slightly reduced the amount of 14C-glyphosate absorbed at 24 and 48 but not 72 h after treatment. Movement of 14C-glyphosate from the treated leaves to the shoot apex, remainder of the shoot and roots was reduced in the presence of picloram. Necrosis of the treated leaves above the treated spots was evident, presumably indicating acropetal movement of either or both herbicides. With the picloram + glyphosate mixtures there was increased shoot regrowth over glyphosate alone at 1 year after treatment under field, and with certain mixtures at 18 days and 4 weeks after treatment under greenhouse conditions. Following application of the mixtures, accumulation of glyphosate in the shoots may be responsible for the enhanced onset of shoot injury while failure of enough glyphosate to translocate to, and cause death of, the roots may be responsible for the increased shoot regrowth over glyphosate alone.  相似文献   

18.
The uptake, translocation and metabolism of glyphosate [N-(phosphonomethyl) glycine] by Canada thistle (Cirsium arvense (L.) Scop.) (susceptible) and leafy spurge (Euphorbia esula (L.)) (resistant) were examined in an attempt to elucidate the nature of the differential sensitivity. The pattern of uptake and translocation was similar in both species. Glyphosate moved readily in the apoplast and the symplast. High humidity and/or surfactant greatly increased the amount of 14C-glyphosate absorbed and translocated over that in low humidity and/or without surfactant. No 14Cmetabolites were detected in either species 1 week after treatment with 14C-glyphosate. More of a glyphosate spray solution containing a fluorescent dye was received and retained on Canada thistle by virtue of its growth habit than on leafy spurge. More glyphosate should therefore be available for uptake by Canada thistle and this may account for the differential sensitivity of these two species.  相似文献   

19.
在人工气候室培养空心莲子草,植株经草甘膦与乙烯利混合处理后,测定对植株的抑制作用和草甘膦的吸收与传导量。结果表明,加入乙烯利(100mg·L~(-1))后草甘膦(300mg·L~(-1))对地下根茎抑制率比对照提高了13.6个百分点。植株经乙烯利喷雾处理后,基芽、地下茎和根系中~(14)C-草甘膦含量分别是对照的3.56、1.75和2.35倍。放射性成像图显示,植株地下茎与根系中~(14)C-草甘膦传导量明显高于对照。  相似文献   

20.
Rhizome segments from Alternanthera philoxeroides were shaken in solutions of 14C-glyphosate for 24 h to establish a range of internal tissue concentrations. Rhizomes were killed at concentrations of 16 μg g?1 dry weight and above and survived at concentrations of 8 μg g?1 dry weight and below. Plants grown in the field for 10 weeks in declining photoperiod were used to investigate the uptake and translocation of 14C-glyphosate after application of a constant dosage in either 1.0-or 0.2-μl droplets corresponding to concentrations of 1.06 and 5.3 g 1?1, of glyphosate acid, respectively. Use of smaller droplets of higher concentration increased absorption of 14C, but did not improve translocation. Uptake by treated leaves was 25 and 41% of the applied glyphosate for the large and small droplets respectively, but translocation to underground parts of the plant was about 7% of applied 14C-activity. Radiolabel accumulated in new rhizomes was equivalent to about 0.5 μg g?1 dry weight of glyphosate, at least 30 times below the concentration required for tissue death. Absorption et transport de glyphosate C14 chez Alternanthera philoxeroides (Mart.) Griseb. I.Concentrations dans les rhizomes nécéssaires pour l'inhibition Des fragments de rhizome d'Alternanthera philoxeroides ont été trempés dans des solutions de glyphosate C14 pour aboutir à un éventail de concentrations internes des tissus, Les rhizomes ont été tués à des concentrations de 16 μg g?1 PS et plus, et ont survécu à des concentrations de 8 μg g?1 PS et en-dessous. Des plantes cultivées en plein champ pendant 10 jours en photopériode décroissante ont été utilisées pour étudier l'absorption et le transport du glyphosate C14 après l'application d'une dose constante dans des gouttelettes de 1 ou 0,2 μl correspondant à des concentrations de 1,06 et 5,3 g l?1 de glyphosate C14 acide respectivement, L'utilisation de gouttelettes plus petites de concentrations plus é1evées a augmenté l'absorption du C14, mais n'en a pas amélioré le transport. L'absorption par les feuilles traitées était de 25 et 41% du glyphosate appliqué pour les grandes et les petites gouttelettes respectivement, mais le transport vers les parties souterraines de la plante était d'environ 7% du C14 appliqué. Le radio-marqueur dans les nouveaux rhizomes était équivalent à environ 0,5 μg g?1 PS de glyphosate, soit au moins 30 fois en-dessous de la concentration nécessaire à la mort des tissus. Aufnahme und Translokation von 14C-Glyphosat in Alternanthera philoxeroides (Mart.) Griseb. I. Für die Hemmung erforderliche Konzentration im Rhizom Rhizomteile von Alternanthera philoxeroides wurden 24 Stunden lang in 14C-Glyphosat-Lösungen geschüttelt, um eine Reihe von Konzentrationen in den inneren Geweben einzustellen. Die Rhizome wurden bei Konzen-trationen von 16 und mehr μg g?1 TM abgetötet und überlebten bei Konzentrationen von 8 μg g?1 TM und weniger. Die Aufnahme und Translokation von 14C-Glyphosat nach der Applikation einer konstanten Dosis in 1,0-oder 0,2-μl-Tröpfchen, entsprechend Konzentrationen von 1,06 und 5,3 g l?1 Glyphosat-Säure, wurden an Pflanzen untersucht, die im Freiland 10 Wochen lang bei abnehmender Photoperiode gewachsen waren. Der Gebrauch kleinerer Tropfen höherer Konzentration führte zu mehr Absorption von 14C, förderte aber nicht die Translokation. Das Glyphosat wurde von den behandelten Blättern zu 25 bzw. 41% aus den großen Oder den kleinen Tröpfchen aufgenommen, aber die Translokation in die unterirdischen Pflanzenteile war etwa 7% der ausgebrachten 14C-Aktivität. Die in neuen Rhizomen akkumlierte Radioaktivität entsprach 0,5 μg g?1 TM Glyphosat, mindestens 30mal weniger als für die Abtötung von Gewebe erforderlich.  相似文献   

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