bluuebunny/crossref_metadata_2025_split huggingface dataset:
Interference of herbicides with photochemical activities of chloroplasts in six shrub species
Authors: RAO I. MADHUSUDANA , SWAMY P. M. , DAS V. S. R. 
Published: July 2006

Summary:The effects of paraquat and 2,4,5‐T on the photochemical activities of chloroplasts from the leaves of the woody species Carissa spinarum, Maba buxifolia, Flacourtia sepiaria, Chomelia asiatica, Gymnosporia emarginata and Dodonaea viscosa were investigated by comparing the effects on isolated chloroplasts from untreated leaves with those on chloroplasts isolated from herbicide‐sprayed plants. DCPIP and NADP reduction of chloroplasts incubated in paraquat or 2,4,5‐T solution was inhibited, whereas that of chloroplasts isolated from most species sprayed with these herbicides was enhanced after 24 and 48 h. The enhancement was smaller or disappeared after 72 h. The cyclic and noncyclic photophosphorylation rates were suppressed in chloroplasts isolated from herbicide‐treated plants, and also in those from most untreated plants incubated in the herbicide solutions. The differences in reactions of chloroplasts from herbicide‐treated and untreated plants are discussed.
Foliar absorption and translocation of fosamine and 2,4,5‐T in blackberry (Rubus proceras P. J. Muell.)
Authors: RICHARDSON R.G. 
Published: July 2006

Summary:Fosamine (ammonium ethyl carbamoylphosphonate) formulated as a 1% w/v solution in 0–25%v/v Tween 20 was absorbed slowly by detached leaves of Rubus procerus P.J. Muell., 35% of the applied herbicide being absorbed after 96 h. Fosamine does not appear to be rainfast, as up to 80% of the applied herbicide and 99.9% of the removable herbicide were removed from the leaves by washing for 5 min in distilled water. Translocalion of fosamine was rapid in small R. procerus plants and followed a pattern similar to that taken by assimilates: 2,4,5–T did not translocate to the root system as readily as fosamine or assimilates.
The preferential accumulation of picloram at sites of active growth in gorse (Ulex europaeus L.)
Authors: FIELD ROGER J. , HAI PHUNG HONG 
Published: July 2006

Summary:Application of 14C‐picloram to single spines of 6 month old, soil grown, vegetative plants of gorse (Ulex europaeus L.) resulted in its translocation to regions of meristematic and metabolic activity, with significant accumulation in the stem apex and root nodules. Dissection of the root system of plants grown in nutrient solution revealed a greater mass of picloram in differentiated root tissue than in root apices, although the concentration of chemical in the latter fraction was greater than in the former. Loss of picloram to the nutrient solution was interpreted as preferential leakage from the root nodules because of the lack of picloram accumulation in this fraction. In reproductive plants bearing flowers and floral buds the picloram was diverted from the root tissue fractions to the floral organs, which constituted the primary sink.
Absorption, translocation and metabolism of 14C‐glyphosate in several weed species*
Authors: SANDBERG C. L. , MEGGITT W. F. , PENNER DONALD 
Published: July 2006

Summary:The pattern and extent of 14C‐glyphosate [N‐(phosphonomethyl)glycine] translocation from the treated leaf and metabolism of 14C‐glyphosate were studied in field bindweed (Convolvulus arvensis L.), hedge bindweed (Convolvulus sepium L.). Canada thistle [Cirsium arvense (L.) Scop.] tall morning glory [lpomoea purpurea (L.) Roth.] and wild buckwheat (Polygonum convolvulus L.). 14C was translocated throughout the plants within 3 days with accumulation in the meristematic tips of the roots and shoots evident. Cross and longitudinal sections of stems and roots showed that the 14C was localized in the phloem. Field bindweed translocated 3–5% of the applied 14C from the treated leaf, hedge bindweed 21.6%, Canada thistle 7.8%, tall morningglory 6.5%, and wild buckwheat 5%. Field bindweed, Canada thistle, and tall morningglory metabolized the parent glyphosate to aminomethylphosphonic acid to a limited extent. This metabolite made up less than 15% of the total 14C. Of the total 14C applied to excised leaves, 50% had disappeared within 25 days.
Studies on the longevity and germination of seed of Eleusine indica and Crotalaria goreensis
Authors: HAWTON D. , DRENNAN D. S. H. 
Published: July 2006

Summary:The longevity of seed of Eleusine indica (L.) Gaertn. and Crotalaria goreensis Guill. & Perr. stored at various depths in a krasnozem soil in pots was studied over 3 years under natural climatic conditions on the Atherton Tableland of Queensland. Australia. In the first year the maximum percentage of seed which emerged was 68% for E. indica and 48.3% for C. goreensis. In the second year the percentages were 2.0 and 19.3. respectively and in the third year they were 0.2 and 1.4. In the case of both species emergence was greater from the 0–5 cm depth than from the 5–10 cm depth. Some of the seed buried at the 5–10 cm depth germinated but failed to emerge. Significantly more hard seed of C. goreensis remained at the 5–10 cm depth (25.7%) than at the 0–5 cm depth (9.8%) after 3 years. However, much of this seed was either dead or moribund and the percentage of truly viable seed (c. 5%) was the same at both depths.In depth of emergence experiments the emergence of seed of both species did not vary significantly in the 0–4 cm depth ranges. At depths greater than 4 cm emergence declined. No E. indica seed emerged from 8 cm or deeper and no C. goreensis seed emerged from 12 cm or deeper.
Effect of herbicides alachlor, metolachlor and oryzalin on soybean (Glycine max) leaf nitrate reductase activity*
Authors: LOLAS P. C. 
Published: July 2006

Summary:Experiments were conducted in the field, greenhouse, and with leaf disks in test tubes to determine whether the herbicides alachlor, metolachlor, and oryzalin, commonly used for weed control in soybeans [Glycine max (L) Mer.] affect in vivo nitrate reductase activity. Plants in the field, growing in soil treated at the recommended rates were sampled at 30 and 60 days after planting. Plants grown in the greenhouse in pots non‐treated and treated at the recommended area rates and at 1/2 and 3/2 times these rates were sampled at 20 and 40 days for chemical assay. In addition plants were grown in the greenhouse and sampled at 30 days for chemical assay after direct addition of the herbicide dilutions to the reagent solutions. No differences, statistically significant according to Duncan's test at the 5% level were revealed between controls and any treatment.
Einfluß des Applikationsortes auf die Penetration und Translokation von Diclofop‐methyl bei Flughafer (Avena fatua L.)
Authors: WALTER H. , KOCH W. , MÜLLER F. 
Published: July 2006

ZusammenfassungBei Flughafer wurde der Emfluß verschiedener Applikationsorte zwischen Spitze und Basis des Sprosses auf die Penetration und Translokation von 14C‐Diclofop‐methyl untersucht. Die Penetration liegt an der Basis der Blattspreitc am 1. Blatt um 64% und am 2. Blatt um 95% höher als an der Spitze des jeweiligen Blattes. Die Translokation von 14C‐Diclofop‐mcthyl in basipeitaler Richtung ist begrenzt. Daher ist die Menge an 14C‐Diclofop‐methyl an der Sproßbasis, dem Hauptwirkort, um so höher, je näher das Herbizid zur Sproßhasis appliziert wird. Hinsichtlich einer möglichst optimalen Verteilung von 14C‐Didofop‐methyl in der Pflanze erwies sich die Applikation an die Basis del Blattsprciten als am günstigsten. Dies beruht u.a. darauf daß es bei diesem Applikationsort zu einem Einlaufen der Herbizidlösung in die Blattscheidc und infolgedessen zu einem mechanischen basipetalen Vordringen innerhalb dieser in den Bereich der mcristematischen Gewehe der Sproßbasis kommt. Als Konsequenz daraus ergibt sich die Forderung nach einer möglichst gezielten Deponierung von Diclofop‐methyl in den Bereich der Sproßbasis.
Availability to plants of herbicide residues in soil. Part I: A rapid method for estimating potentially available residues of herbicides
Authors: STALDER LUKAS , PESTEMER WILFRIED 
Published: July 2006

Summary:A simple extraction method with water is described which allows the quantitative determination, within 1 day of the residues of soil‐applied herbicides which are potentially available to plants. The validity of this method has been examined with a growth test using Brassica rapa in soils containing residues of different ages.
Characteristics of glyphosate inhibition of growth in soybean and tobacco callus cultures
Authors: LEE T. T. 
Published: July 2006

Summary:Callus cultures or tobacco (Nicotiana tabacum L. cv. While Gold and N. glauca‐langsdorffii, a tumour‐forming amphidiploid hybrid) and soybean Glycine max L., cv. Chippewa) were used lo study the effect of glyphosate [N‐(phosphonnmethyl) glycine) un growth and interactions with growth hormones. Glyphosate inhibited growth both in the dark and light but showed a greater toxicity in the dark. This was contrary to its effect on chlorophyll degradation which was accelerated by light. The inhibition of growth was not reversed by simultaneous addition of aromatic amino acids to the medium. Thus the results suggest a multiple glyphosate action. The tobacco callus tissue was more sensitive to glyphosate than the soybean callus tissue, confirming a difference in tolerance between plant species. Despite the inhibitory effect of glyphosate. the treated tissue revived after being transferred to a glyphosate‐free medium. The glyphosate‐induced growth inhibition in soybean and tumour‐forming tobacco callus cultures also was reversible by high levels of indole‐3‐acetic acid (IAA), which itself was inhibitory Theglyphosate‐IAA interaction in the tissues which were sensitive to IAA suggests that the inhibition of growth by glyphosate was related to auxin levels in these tissues.
Effect of dalapon‐sodium on nitrification and denitrification in a tropical loam soil
Authors: WEERARATNA C. STANLEY 
Published: July 2006

Summary: Résumé: ZusammenfassungA loamy soil treated with dalapon‐sodium was incubated under aerobic or anaerobic conditions with added ammonium or nitrate nitrogen respectively. The incubated dalapon‐sodium treated soil and controls were analysed periodically for NH4+N and NO3‐N. Results indicated that the herbicide retarded nitrification and denitrification by up to 8 and 12 weeks respectively.Effet du dalapon‐sodium sur la nitrification et la dénitrification dans un sol de limon tropicalUn sol de limon traité avec du dalapon‐sodium a été mis en incubation dans des conditions aérobies ou anaérobies avec addition d'azote ammoniacal ou nitrique respectivement. Le sol traité avec du dalapon‐sodium et mis en incubation a été analysé périodiquement, ainsi que les témoins, pour NH4+N et NO3‐N. Les résultats ont montré que l'herbicide retardait la nitrification et la dénitrification respectivement jusqu’à 8 et 12 semaines.Wirkung von Dalapon‐Na auf Nitrifikation und Denitrifikation in einem tropischen LehmbodenEinem mit Dalapon‐Na behandelten Lehmboden wurde Ammon‐ bzw. Nitratstickstoff zugesetzt und unter aeroben bzw. anaeroben Bedingungen gelagert. Der mit Dalapon‐Na behandelte Boden und die entsprechenden Kontrollen wurden periodisch auf NH4+‐ und NO3‐‐Stickstoff untersucht. Die Ergebnisse zeigten, dass das Herbizid die Nitrifikation um bis zu 8 und die Denitrifikation bis zu 12 Wochcn verzögerte.
Yield loss in barley associated with Sinapis arvensis L. (charlock) after continuous routine use of herbicide
Authors: RICHARDSON M. J. 
Published: July 2006

Summary: Résumé: ZusammenfassungUncontrolled S. arvensis (charlock) in barley, after many years successful control with herbicides, was associated with yield losses of 48‐71%, mostly due to smaller ear populations. Curtailing herbicide use by spraying in alternate years only might not be a suitable strategy for reduction in herbicide usage where charlock is a dominant weed. Pertes de rendement dans les cultures d'orge, provoqueés par Sinapis arvensis L. aprés l'utilisation routinière et continue d'herbicides La non destruction de Sinapis arvensis dans l'orge, après de nombreuses années de lutte efficace avec des herbicides, a provoqué des pertes de rendement de 48 à 71%, dues principalement à des populations plus faibles d'épis. La réduction de I'utilisation d'herbicide, par des traitements alternés d'une année à l'autre, ne semble pas constituer une stratégie adéquate pour diminuer l'emploi des herbicides, là où la moutarde est une mauvaise herbe dominante. Ertragsverluste in Gerste durch Sinapis arvensis L.(Acker‐Sent) nach ständigem Routineeinsatz von Herbiziden Wurde S. arvensis in Gerste, nachdem es über viele Jahre erfolgreich mit Herbiziden bekämpft worden war, nicht bekämpft, dann war das mit Ertragsverlusten von 48–71% verbunden. Der Ertragsrückgang war hauptsächlich auf eine geringere Ährenrahl zurückzuführen. Eine Beschränkung des Herbizideinsatzes in Form von Spritzungen nur in jedem zweiten Jahr, durfte deshalb auf Standorten, wo der Acker‐Senf als dominierendes Unkraut vorkommt, keine òrauchbare Alternative zur Einsparung von Spritzungen sein.
The influence of reduced cultivations and direct drilling on the long‐term decline of a population of Avena fatua L. in spring barley
Authors: WILSON B. J. 
Published: July 2006

Summary:Changes in the numbers of Avena fatua seed, incorporated into soil, were monitored in four successive spring barley crops which were harvested early for silage to prevent seed shedding.In the first year there were four times as many seedlings after tine cultivation compared with ploughing, but this was reversed in the second year as re‐ploughing brought up dormant seeds and gave more seedlings than tine cultivation. Only 11–14% of the sown seeds produced seedlings during the 4 years. When the seeds were first buried to 25 cm by ploughing, and the barley was direct drilled without cultivation, only 0.4% emerged as seedlings.Few viable seeds remained in the soil after 4 years whether the soil was cultivated annually or not but seed numbers decreased more rapidly with tine cultivation than with ploughing. A few of the deeply buried seeds persisted where the land was direct drilled without cultivation.
Control of Solatium karsensis in grain sorghum
Authors: MONAGHAN N.M. , BROWNLEE H. 
Published: July 2006

Summary: Solatium karsensis Symon, an Australian native perennial, has become an important weed in irrigated summer crops in far western New South Wales. A screening trial of 14 herbicides showed that atrazine was the most effective treatment, though 2,4‐D also suppressed S. karsensis in grain sorghum (Sorghum bicolor L. cv. Rico) for the duration of the crop. Grain sorghum yields were higher in plots treated with atrazine at 2–5 kg (a.i.) ha−1 than for any other herbicide treatment or the untreated control. Because the root system remained viable annual herbicide application would be necessary for the continued control of 5. karsensis.
Effects of glyphosate on synthesis and degradation of chlorophyll in soybean and tobacco cells
Authors: LEE T. T. 
Published: July 2006

Summary:The chlorophyll content increased with time in callus cultures of soybean (Glycine max L., cv. Chippewa) and tobacco (Nicotiana tabacum L., cv. White Gold) grown in the light on a standard medium. Addition of 0.5 mmol/1 glyphosate [N‐(phosphonomethyl) glycine] to the medium completely inhibited chlorophyll accumulation in the tobacco callus. Soybean callus required 40 times more glyphosate to initiate inhibitory effects on chlorophyll content. The inhibition was not reversed by simultaneous addition of casein hydrolysate or aromatic amino acids, suggesting that aromatic amino acid levels were not limiting for chlorophyll synthesis. In leaf discs of soybean and tobacco, glyphosate accelerated chlorophyll degradation in the light, but not in the dark; there was little difference in response between the two plant species. Young leaves of tobacco were more sensitive than mature leaves to glyphosate effects with glyphosate‐induced net losses of chlorophyll of 24 and 14% respectively after 5 days. Such rates of loss cannot explain the complete inhibition of chlorophyll accumulation in the callus tissue, suggesting that there was an inhibition of chlorophyll synthesis by glyphosate.
The influence of tillage on the weed flora in a succession of winter cereal crops on a sandy loam soil
Authors: And F. POLLARD , CUSSANS G.W. 
Published: July 2006

Summary:Weed populations on sandy loam soil were monitored from 1973 to 1976 in a 5‐year experiment comparing different tillage regimes for continuous winter cereal cropping. Tillage treatments were mouldboard ploughing, shallow or deep tine cultivation and direct drilling. The best available chemical weed control which could be universally applied to all treatments was used.There were marked differences between weed species in their response to tillage. Poa annua L., Matricaria spp., Aphanes arvensis L., Cerastium holosteoides Fr. and Sambucus nigra L. were favoured by reduced cultivation and by direct drilling. Polygonum aviculare L. and Fumaria officinalis L. were discouraged by shallow soil disturbance but Avena fatua L. was favoured by tine cultivation. The remaining twenty‐four species either showed no consistent response to tillage or were present in numbers too low for reliable conclusions to be drawn. The practical implications of the results are discussed.
The comparative behaviour of simazine and terbacil in soils
Authors: JENSEN K. I. N. , KIMBALL E. R. 
Published: July 2006

SummaryAdsorption of simazine (2‐chloro‐4,6‐bisethyl‐amino‐1,3,5‐triazine) was 2.2–4 times greater than that of terbacil (5‐chloro‐6‐methyl‐3‐t‐butyl‐uracil) in the same soils and adsorption of both herbicides was 2–4 times greater in the topsoils than subsoils. Adsorption was inversely correlated with herbicide movement in a thick‐layer chromatography system. One year after application of 3 kg/ha to field plots, simazine residues were highest near the soil surface, whereas terbacil residues increased with soil depth in the sandy and sandy loam soils. Total residues recovered from the upper 25 cm of soils was 5% or less of the simazine originally applied, and 10% or less of the applied terbacil. In an oat seedling bio‐assay, the GR50 values were generally 1.5–3 times higher for simazine than for terbacil in the same soils.
Effect of salt stress on the structure and carbon flow mechanism in a noxious weed Parthenium hysterophorus L.
Authors: HEGDE B. A. , PATIL T. M. 
Published: July 2006

SummaryEffect of salt stress on structural changes, ion uptake, rate of photosynthesis and path of carbon in the exotic weed Parthenium hysterophorus have been investigated. Photosynthetic leaf area, chlorophyll and carbon assimilation rates were adversely affected by salt stress. Increased Na+ uptake caused decrease in K+ and Ca2+ absorption. Originally a C3 plant, P. hysterophorus appears to form aspartate as a primary product of photosynthesis when exposed to NaCl. The stimulation of PEP carboxylase activity also occurred due to salt stress. Excessive accumulation of malate during steady state of photosynthesis was possibly due to inhibition of malic enzyme. It appears that although the plant switches over to an ‘aspartate producer’ when exposed to salt, further utilization of photosynthetically assimilated carbon is through malate. Being a weed, the plant appears to be highly adaptive to stress conditions.
Die Verunkrautung neuangelegter mediterraner Weidetypen im Gebiet Mogod/Tunesien
Authors: ZITZEWITZ W. V. 
Published: July 2006

ZusammenfassungIm humiden Nordwesten Tunesiens wurden mit Hilfe von pflanzensoziologischen und bodenkundlichen Untersuchungen unter Einbeziehung von bereits vorliegenden Bewirtschaftungsdaten die Ursachen der Verunkrautung auf neuangelegtem Grünland untersucht. Die Jahr‐zu‐Jahr‐Schwan‐kung der Verunkrautung ist sehr verschieden. Hingegen verandert sich der Jahresgang der Verunkrautung kaum von Jahr zu Jahr.Die Ursachen fur die Verunkrautung der Klee‐Gras‐Weiden, die auf den sandigen Boden deutlich starker ist, als auf den schweren Boden, ergeben sich aus der Unzuläanglichkeit des Standorts, insbesondere aber aus einer Vielzahl von Bewirtschaftungsfehlern. Gefördert wurde die Verunkrautung u.a. durch: (1) Die ungünstige Niederschlagsverteilung in den Jahren 1970/71, 1972/73 und 1973/74; (2) Weideverfahren mit holier Besatzdichte, kurzer Freβzeit und langerer Ruhezeit; (3) Achtlose Weideführung auf winterlich übernäβten Boden; (4) Unkrautbekämpfungsmaβnahmen mit ungeeigneten Herbiziden; (5) Verschiedene Schädlinge und Krankheiten, die bevorzugt den Klee befallen.Die Verunkrautung der mehrjährigen Mäh‐weiden mit Festuca arundinacea ist nicht sehr ausgeprägt und nimmt, bedingt durch den jährlichen Schnitt im Frühjahr, über die Jahre merklich ab. Nach dem Schnitt stellt sich kurzzeitig eine sehr spezifische Verunkrautung mit ausdauernden Pflanzen ein. Es werden Vorschläge zur Einschrankung der Verunkrautung durch Haltung von Vieh auf Standweide gemacht.
Control of problem weeds of maize on the Transvaal Highveld (South Africa). III. Crotalaria sphaerocarpa Perr. ex. DC.
Authors: ALAN C. M , VISSER J. H. , GROBBELAAR N. 
Published: July 2006

SummarySixteen different herbicides and herbicide mixtures were evaluated for their efficiency in controlling Crotalaria sphaerocarpa Perr. ex. DC. using percentage mortality and relative plant dry mass as criteria of herbicide efficiency. Paraquat and a mixture of atrazine and Tronic were the only treatments which effectively controlled the weed at all ten leaf stages tested. Atrazine alone and ametryne alone were 100% effective only for the first four leaf stages. Other treatments were relatively ineffective.The wax coat on the leaves of C. sphaerocarpa possibly impedes the absorption of lethal quantities of some herbicides, resulting in an apparent resistance. This phenomenon, probably accounts for the fact that this plant is considered to be a problem weed.
Factors affecting the activity of GR7 in stimulating germination of Striga hermonthica (Del.) Benth.
Authors: BABIKER A. G. T. , HAMDOUN A. M. 
Published: July 2006

SummaryExperiments with the alkaline heavy clays of the Sudan Gezira showed that when the strigol analogue GR7 was applied to moist soil prior to subjecting Striga hermonthica seeds to moist conditions (‘conditioning’) for 7–14 days, there was no significant increase in germination. Conditioning of seeds in soils treated with GR7 had an adverse effect on the responsiveness of seeds when GR7 was added again after conditioning. Under ideal conditions, when GR7 was applied to conditioned seeds in moist soil, up to 75% germination could be induced by 2.0 kg/ha incorporated to 2–3 cm depth. Residual activity of GR7 persisted in air‐dry soil, but at 50% moisture there was complete loss within 1 day. However, when conditioned seeds were put into the soil immediately after GR7 application its activity increased with increasing soil moisture.
Chemical weed control in irrigated direct‐seeded rice in the Sudan Gezira
Authors: BABIKER A. G. T. 
Published: July 2006

SummaryUnrestricted weed growth resulted in serious yield losses (60–75%) in rice (Oryza saliva L.). Hand‐weeding once at 2 weeks after crop emergence was ineffective, but weeding at 2 and 2 weeks after crop emergence brought yield losses down to 20%. Pre‐emergence application of bifenox and oxadiazon (12 l) and post‐emergence application of molinate + propanil gave crop yields comparable to that of the clean weeded control (91–129%). Grain yields obtained with pre‐emergence application of oxadiazon (25 EC) and post‐emergence applications of propanil, bentazone + propanil, and bifenox alone or as a tank mix with propanil or bentazone were considerably less than those obtained from the clean weeded plots. Bifenox, oxadiazon (12 l) and propanil + molinate gave adequate and persistent weed control (72–97%), and did not damage rice. Oxadiazon (25 EC) gave good weed control but resulted in a serious stand reduction. Post‐emergence application of propanil, propanil + bentazone bifenox alone or as a tank mix with propanil or bentazone had no adverse effect on crop stand, but gave poor control of grasses (0–40%).