THE MOVEMENT OF PARAQUAT IN PLANTS

Summary. A qualitative study of the movement of the herbicide paraquat from droplets applied to leaves of tomato plants, using ¹⁴C-methyl-labelled and ¹⁴C-ring-labelled paraquat dichloride and di(methylsulphate), has shown that it moves in the xylem with the transpiration stream. The chemical is as well transported from young leaves as from mature ones, and will move through a steam-ringed petiole. The enhancement of the amount of paraquat transported from the treated leaves which occurs when treated plants are kept in darkness for a period following treatment and then exposed to light, is probably due to the greater movement into the xylem through undamaged tissue which can occur in the dark. Once the chemical has been absorbed into treated leaves, light-induced damage is required for significant movement through the rest of the plant to take place, but the damage then inhibits further entry of paraquat into the xylem. The movement of paraquat in broad bean and maize is essentially similar, though the enhancement of movement by a period of darkness after application is much less marked.
La migration du paraquat dans les plantes     

THE PERSISTENCE AND MOVEMENT OF FLUORODIFEN IN SOILS AND PLANTS

Summary. Miller clay and Lufkin sandy loam soils were treated with fluorodifen (4-nitrophenyl 2-nitro-4-trifluoromethylphenyl ether) at 3–4 and 5 kg/ha. The disappearance was monitored using electron-capture gas chromatography. Less than 10% of the herbicide remained 6 months after application. Persistence was increased by incorporation in the loam but not in the clay soil. Little leaching was detected in either soil. Fluorodifen was applied to both roots and leaves of soybean (Glycine max (L.) Merr.), grain sorghum (Sorghum vulgare Pers.), peanut (Arachis hypogaea L.) and morning glory (Ipomoea purpurea L.). The herbicide was absorbed by the treated tissue, but limited trans-location into other plant parts was detected by gas chromatography, autoradiography and liquid scintillation spectrometry. Following root application, higher concentrations of fluorodifen were found in the lower stems of morning glory and grain sorghum than in other species. La persistance et la migration du fluorodifene dans divers sols et plantes Résumé. De I'argile de Miller et des sols sablo-limoneux de Lufkin ont été traités avec du fluorodiféne (4-nitrophényl 2-nitro-4-trifluorométhylphényl éther) à 3, 4 et 5 kg/ha. La degradation a été suivie en utilisant la chromatographic en phase gazcuse avec détecteur à capture d'électrons. Aprés 6 mois d'application il ne fut détecté que moins de 10% de l'herbicide. La persistance fut accrue par l'incorporation dans le sol limoneux mais non dans le sol argileux; il ne fut mis en évidence qu'un faible lessivage dans les deux sols. Le fluorodifene fut appliquéà la fois sur les racines et sur les feuilles du soja (Glycine max (L.) Merr.), le sorgho à grains (Sorghum vulgare Pers.), l'arachide (Arachis hypogaea L.) et le volubilis (Ipomoea purpurea L.). L'herbicide fut absorbs par les tissus traites, mais il ne fut décelé qu'une migration limitée dans les autres parties de la plante, au moyen de la chromatographie en phase gazeuse, de l'autoradiographie, et de la spectrométrie à scintillation liquide. A la suite d'application par les racines, les concentrations de fluorodifene constatées dans les tiges basses du volubilis et dans le sorgho à grain furent supérieures à celles trouvées dans les autres espéces. Persistenz und Translokation von Fluorodifen in Böden und Pflanzen Zusammenfassung. Miller-Ton und Lufkin-Lehmboden wurden mit 3,5 und 5 kg/ha Fluorodifen (4-NitrGphenyl 2-nitro-4-trifluoromethyIphenylather) behandelt. Der Verlust der Aktivsubstanz wurde mit Hilfe der Elektroneneinfang-Gaschromatographic bestimmt. Sechs Monate nach der Behandlung waren weniger als 10% der ursprünglich ausgebrachten Aktivsubstanz noch nachweisbar. Die Persistenz war im Lehmboden, nicht jedoch im Tonboden, durch Inkorporation erhöht; in keinem Boden war nennens-werte Einwaschung zu beobachten. Fluorodifen wurde bei Sojabohnen (Glycine max (L.) Merr.), Körner-Hirse (Sorghum vulgare Pers.), Erdnuss (Arachis hypogaea L.) und Ipomoea purpurea L. sowohl über das Blatt als auch über die Wurzel angewandt. Das Herbizid wurde in das brhandelte Gewebe aufgenommen. Es erfolgte jedoch nur cine geringe Translokation in andere Pflanzenteile, wie die Untersuchung mit Hilfe der Gaschromatographic, Autoradio-graphic und Flüssigkeits-Scintiliations-Spectrometrie ergab. Nach Wurzelapplikation wurden in den unteren Sprossteilen von Ipomoea purpurea und Sorghum vulgare grössere Fluorodifen-Konzentrationen gefunden als bei den anderen Arten.     

叶锈病侵染对大麦碳素代谢的影响

 本研究用¹⁴C同位素示踪法测定叶锈病侵染引起的大麦幼苗光合作用和光合产物分布的病变。试验以植株第一叶和第二叶所得的结果基本相同:接菌7天后病叶总光合量逐渐降低(10天后降低到健叶的60%以下)而单位绿叶面积光合率则明显提高(10天后提高约20%),且这种光合病变与锈病严重度间呈密切的线性相关(r ≥ 0.949,P<0.001);接菌3天后病叶光合产物的输出明显受阻,其截留的¹⁴C物质大量增加(为对照的3倍多)而输运到根和茎部的¹⁴C物质却严重减少。这些病变无疑是叶锈病抑制大麦植物生长发育的主要生理原因之一。     

THE REACTION OF TRIFOLIUM REPENS (L.) IN GRASSLAND TO 2,4-D, MCPA AND MIXTURES OF 2,4-D AND MCPB

Summary. Eight experiments were carried out on a range of pasture lypes under different management and in different years to lest the reaction of white clover ( Trifolium repens in grasstand to doses of up to 4 lb/ac of the herbicides MCPA-sodium or-potassium and 2,4-D-amine. The initial effect of the treatments was to reduce the amount of dover in the sward, the size of the reduction varying greatly from field to field for any one dose. In general, the higher the dose, the more severe was the depression of the clover 1 month after spraying. Both herbicides at 2 and 4 lb/ac caused substantial depressions on some of the fields. The growth of the treated clover was examined during the year following spraying. The ability of the clover to recover from the initial depression varied considerably in the different fields; on some, recovery started in the year of spraying and on others in the following year. Quick recovery was usually associated with a high initial resistance but there were fields in which the clover showed contrasting rates of recovery following similar depressions. The experiments produced no clear-cut evidence as to why the initial resistance and speed of recovery varied in different fields. In one experiment the effects of MCPB-sodium and 2,4-D-amine on white clover were compared separately and in a series of mixtures. An examination made 6 weeks after spraying showed that MCPB at up to 8 lb/ac had no significant effect on the clover, whereas 2,4-D at 1 lb/ac caused a 22% reduction. Mixtures containing up to 0.37 lb 2,4-D and up to 6 lb MCPB caused no reduction while those containing 0.75 lb 2,4-D and 4 lb MCPB were not significantly different from 1 lb 2,4-D alone.
Reaction de Trifolium repens (L.) en prairie au 2,4-D, au MCPA, et aux mélanges de1, 2,4-D et de MCPB     

大麦感染黄花叶病毒后过氧化物酶、酯酶同工酶的变化

大麦黄花叶病毒(BYMV)是一种多粘菌介体传播的土传病毒,筛选抗病品种及建立简便有效的检测方法是选育工作中急需解决的问题。利用等电聚焦凝胶电泳技术分析同工酶的变化,可为育种学家提供生化分析参考。     

THE REACTION OF WHEAT TO 2,4-D ETHYL ESTER APPLIED IN DIFFERENT DILUENTS

Summary. In experiments at two sites in Western Australia, 2,4-D ethyl ester was applied to Gabo wheat at the early tillering, advanced tillering and boot stages. A standard dose of 6 oz/ac a.e. was sprayed in diesel oil (4 pints/ac), water (4 pints/ac) and water (8 gal/ac), and half of each plot received a double application, to give twice the dose and twice the volume. The weed populations were negligible and differences obtained were attributable to the direct effects of the treatments on the wheat.
The most satisfactory treatment was 6 oz/ac applied in 8 gal/ac water at the early tillering stage. Contrary to previous evidence, application at the advanced tillering stage resulted in yield reduction, and it is supposed that the reaction of the wheat was affected by insufficient soil moisture during the later stages of growth. Application in 4 pints/ac water gave lower yields than application in 8 gal/ac, while with 4 pints/ac oil, yields were rather less than with 4 pints/ac water. Although there were some statistically significant effects on the germination and unit weight of the grain, these were not considered to be of practical importance.
Réaction du bléà l'ester éthylique du 2,4-D appliqué dans divers diluants     

MOVEMENT OF 2,6-DICHLOROBENZONITRILE IN SOILS AND IN PLANTS IN RELATION TO ITS PHYSICAL PROPERTIES

Summary. The movement of the herbicide H133 (2,6-dichlorobenzonitrile) in soils and in plants is shown to be governed mainly by its relatively high volatility, its low solubility in water and its strong adsorption on lignin, on humic matter and on lipid material. Some evidence for a transformation of H133 in plants is presented.
Les déplacemcnts du 2,6-dichlorobenzonitrile dans les sols et dans les plantes et leurs relations avec les proriétés physiques     

成株期叶锈病侵染对大麦植物光合作用和产量的影响

 应用¹⁴C同位素示踪分析法研究叶锈病(Puccinia hordei)在花期后(GS71)侵染对大麦植物光合作用的影响,结果表明,给叶片接菌后0至8天内无明显的光合病变,8天之后叶片的总光合量下降而单位绿叶面积光合效率提高,且这种下降%和提高%分别与锈病严重度呈显著的直线相关(r² ≥ 0.980,P<0.001);植株上单叶发病后其它器官的光合作用略有增强,全株叶片发病后穗部光合作用的增加达到显著水平(P<0.05)。
叶锈病在抽穗期(GS55)侵染后,植株籽粒产量和千粒重减低(P<0.01),而病叶干物重则显著增高(P<0.01),本文分析讨论了这些变化的生理机制。     

大麦品种对黄花叶病抗病性的鉴定

1979～1984年在萧山县和上海县等8个县重病田,经9～16点次,自然诱发鉴定了国内、外大麦品种(系)3822个,其中于潜六棱大麦和嵊县无芒六棱等12个品种均不发病,用电镜检查也未见到病毒质粒,这些品种可作为抗源,其中有2个品种已用于抗病育种。大麦品种抗性以二棱最弱,四棱中等,六棱较强,无芒六棱类型品种的抗性最强。至今在二棱大麦中还未找到高抗品种。上海病土的致病性远比浙江病土强,认为黄花叶病毒可能存在不同株系。同品种年间抗病程度差异不大,即年度间抗性较稳定。发病始期与大麦品种的生育期早、迟无关,而与品种感病性有关。     

THE CHEMICAL CONTROL OF BARLEY GRASS IN DRYLAND LUCERNE

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.     

TRANSLOCATION AND PERSISTENCE OF 2,4-D IN POPULUS TREMULA L.

Summary. Treatment of aspen ( Populus tremula L.) with 2,4-dichlorophenoxyacetic acid (2,4-D), using a leaf spray, basal bark spray or a stem injection method of application, resulted in some reduction of stump regrowth although downward translocation of 2,4-D was slight. Persistence of 2,4-D in dead leaf tissue and in woody tissue near the injection sites was observed. This persistence could in certain circumstances be noted 6 years after treatment.
Migration et persistance du 2,4-D chez Populus tremula L.     

我国大麦条锈病菌的生理分化

 我国大麦条锈病主要由条形柄锈菌大麦专化型引起,病菌有明显的生理分化。对西藏大麦条锈菌鉴别寄主进行扩充改进,初步建立了一套在我国较为适用的大麦条锈菌鉴别寄主,由7个品种组成:喜马拉6号、矮秆齐、早熟3号、永1394、永802、科品2号、辉县红(小麦)。这套鉴别寄主可清楚地将大麦专化型和小麦专化型区分开;并将采自西藏、青海、甘肃、陕西和河南5省区的40个大麦专化型菌系区分为4个毒性类型。以毒性中等的大麦型1号和毒性较弱的大麦型2号分布较广,大麦型3号和大麦型4号则只见于西藏的标样中。     

THE EFFECTS OF PICLORAM AND 2,4-D ON PLANT CELL MEMBRANES

Summary. The herbicide Tordon 50D (picloram + 2,4–D) caused severe shrinkage of the protoplasts of all cells of Pinus radiata needle segments within 24 h of treatment. Measurements of the resistance of these tissues to low-frequency and to high-frequency electrical currents showed a loss in the integrity of the plasmalemma within 4–8 h of treatment. Tordon 22K (picloram) had no such effects. The results with Tordon 50D could be attributed solely to the 2,4-D content.
Both Tordon 50D and Tordon 22K disrupted chloroplast structure in leaf discs, and the integrity of cell membranes in stem tips, of Eucalyptus viminalis.     

我国大麦黄花叶病毒主要分离物对大麦品种致病性的研究

 大麦黄花叶病是我国长江中下游和东部沿海大麦的重要病害,造成严重减产。我们以往初步研究认为,我国各地大麦黄花叶病毒对大麦品种的致病性存在差异。     

相生植物在生物防治中的作用

本文从适应农林业可持续发展策略的要求出发,通过对有害生物治理历史的回顾,对有害生物治理策略与措施发展过程的分析,提出“相生植物”新概念,论述了植物作为生物类群中重要组成部分,应该作为生物防治中的重要因子,与动物、微生物一样具有重要的地位。还分析了利用相生植物控制有害生物的可行性与科学依据以及在未来生物防治、植物保护中的重要作用。     

THE ADSORPTIVE BEHAVIOUR OF ACID AND ESTER FORMS OF 2,4-D ON SOILS

Summary. The adsorption of acid, n-butyl, and iso-octyl ester forms of 2,4-D (2,4- dichloiophenoxyacetic acid) was studied for several Canadian prairie soils. The k values for the acid ranged from 0·09 to 1·30 and were correlated to the soil organic matter and not to the clay content. The Q , values (μg adsorbed/g of organic matter) for the acid were 7–2±l. The n-butyl and the iso-octyl esters hydrolysed to the acid form in the aqueous medium and this process was accelerated in the presence of the moist soil. Consequently, the k values for the esters, using slurry type adsorption experiments, or their distribution coefficients, using leaching columns, could not be determined. It was concluded that the adsorptive behavior of the two esters in moist soil was similar to that of the acid form.
Comportement des formes actde, et ester du 2,4-D quant à leur adsorption dans tes sols     

EFFECT OF TEMPERATURE ON THE ACTIVITY AND PERSISTENCE OF AMITROLE AND 2,4-D

Summary. One leaf of each of several tomato plants 5–6 weeks old maintained at 55, 70 or 85° F was dipped in 0.05 M amitrole or 0.005 M 2,4-D solution. The treated leaf was removed 1 week later. Scions taken from untreated plants were grafted to the treated plants at intervals up to 4 months after treatment.
Amitrole-treated plants maintained at 55° F were killed within 1 month but those at 70 and 85° F recovered.
Plants treated with 2,4-D showed typical symptoms when maintained at 70 and 85° F but no symptoms at 55° F. Scions grafted on plants maintained at 55, 70 and 85° F for 60 days after 2,4-D treatments exhibited typical symptoms. Grafts made more than 60 days following the 2,4-D application did not exhibit symptoms except a slight malformation on the plants held at 55° F.
New growth on the scions grafted up to 103 days after amitrole treatment on plants which had been maintained at 70 and 85° F exhibited typical amitrole symptoms (i.e. white foliage) but scions grafted after this lime did not. New shoots developing from buds on the treated plants also produced green growth 115 days after treatment but produced white foliage prior to that time.
Effet de la température sur l'activi'ité et la persistance de l'aminotriazole et du 2,4-D     

相生植物在生物防治中的应用

本文从适应农林业可持续发展策略的要求出发,通过对有害生物治理历史的回顾,对有害生物治理策略与措施发展过程的分析,提出“相生植物”新概念,论述了植物作为生物类群中重要组成部分,应该作为生物防治中的重要因子,与动物、微生物一样具有重要的地位。还分析了利用相生植物控制有害生物的可行性与科学依据以及在未来生物防治、植物保护中的重要作用。     

THE TRANSLOCATION AND DISTRIBUTION OF THREE LABELLED HERBICIDES IN PASPALUM DISTICHUM L.

Summary Plants of Paspalum distichum L. with two stolons growing over water were treated separately with the sodium salt of 2,2-dichloropropionic acid-³⁶C1 (dalapon), 3-amino-1,2,4-triazole-¹⁴C (amitrole) and 1,1'-dimethyl-4,4'-dipyridylium dichloride-¹⁴C (paraquat) at four different situations on one stolon. Autoradiographs showed that both the amitrole and dalapon label accumulated in the apices of the treated stolons and in some of the young shoots growing from the base of the plant. The ¹⁴C from the paraquat label showed predominantly xylem translocating with no apical accumulation and little basal translocation. The results indicate that young basal shoots rely to some extent on assimilates from the mature stolons but that there is little transport between mature stolons.
La migration et la distribution de trois Herbicides marqués dans Paspalum distichum L.