bluuebunny/crossref_metadata_2025_split huggingface dataset:
THE MOVEMENT AND METABOLISM OF PYRAZON IN TOLERANT AND SUSCEPTIBLE SPECIES*
Authors: STEPHENSON G. R. , RIES S. K. 
Published: July 2006

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
STUDIES ON THE DEGRADATION OF 4‐AMINO‐3,5,6‐TRICHLOROPlCOLINIC ACID IN SOIL
Authors: GROVER R. 
Published: July 2006

Summary. Picloram was incubated at concentrations of 0, 0·25, 0·5 and 1 ppmw in Regina heavy clay topsoil maintained at moisture‐holding capacity and a t 25° C The herbicide was quantitatively bioassayed at regular intervals. There was a lag period prior to degradation at all concentrations. The duration of the lag period increased as the concentration of picloram in the soil was increased. Al the end of each lag period, the degradation of picloram occurred as a first‐order reaction, i.e. the rate of degradation was independent of the concentration of picloram in the soil. Due to the pronounced variations in the duration of the lag periods with concentration, the assignment of half‐value or half‐life periods to picloram degradation in soil is considered to be of doubtful significance.Etude de la degradation de t'acide 4‐amino‐3,5,6‐trichloropicolmique dans le sol
THE COMBINED ACTION OF 3‐AMINO‐1,2,4‐TRIAZOLE AND AMMONIUM THIOCYANATE ON PHOSPHATASE ACTIVITY IN COTTON THISTLE (ONOPORDUM ACANTHIUM L.)
Authors: MICHAEL P. W. 
Published: July 2006

Summary. In phosphatase extracts prepared from untreated leaves of Onopordum acanthium, phosphatase activity was stimulated by amitrole (0·04 M) and ammonium thioeyanate (0·04 M), alone and together. The effect of the mixture of amitrole and ammonium thioeyanate was more than additive in experiments set up at pH 4·0, less than additive at pH 4·6 and roughly additive at pH 5·3 and 5·8. The effect of amitrole alone could be explained simply in terms of the increase in pH it effected.In leaves harvested 4, 7 and 9 days after spraying rosettes with 1/8 lb/ac (140 g/ha) amitrole and 1/4 lb/ac (280 g/ha) ammonium thioeyanate, alone and together, more than additive or additive increases in phosphatase activity of plants sprayed with the mixture were recorded. These increases are interpreted as being due to increases in the amount of soluble protein.Inorganic phosphate levels showed different trends with time in plants treated with amitrole alone compared with plants treated with the mixture of amitrole and ammonium thioeyanate.These interactions between amitrole and ammonium thioeyanate are taken to indicate a possible chemical basis for the increased herbicidal activity of the mixture over amitrole alone.Histochemical studies on the mature leaves of rosettes showed that phosphatase activity was confined to the vascular tissues while in the very young leaves it was high in the chlorenchymatous tissue and appreciable in the epidermal and hair cells.Attention is drawn to the strong buffering action of amitrole in the pH range 4·0–5·3. This may be relevant to herbicidal activity, the vacuolar pH of the outer cells of leaves of Onopordum being in the range 4·8‐5·2.L'action combinée du 3‐amino‐1,2,4‐triazole et du thioeyanate d'ammonium sur l'activité de la phosphatase chez Onopordum acanthium L.
RELATION BETWEEN STRUCTURE AND HERBICIDAL ACTIVITY OF SUBSTITUTED BENZOTHIADIAZOLES (2,1,3)
Authors: KOOPMAN H. , van DAALEN J. J. , DAAMS J. 
Published: July 2006

Summary. A large number of substituted benzothiadiazoles (2,1,3) was synthesized. In this report, the herbicidal activities of some halo‐ and alkyl‐substituted benzothiadiazoles (2,1,3) are described. It was found experimentally that at least one of the positions 5 and 6 in the molecule must be unsubstituted. Some di‐ and tri‐substituted derivatives had excellent herbicidal activities, in contrast to tetra‐substituted benzothiadiazoles (2,1,3). Relation entre la structure et I'activité herbicide des (2,1,3) benzothiadiazoles substitués
FACTORS AFFECTING THE ACTIVITY OF DI‐ALLATE AND TRI‐ALLATE
Authors: BANTING J. D. 
Published: July 2006

Summary. Factors investigated included the susceptibility of Avena fatua L. at various stages of growth, the amount of moisture needed to activate di‐allate in Regina heavy clay, the vapour action of di‐allate in soil, the effect of organic matter on the availability of di‐allate, and the persistence of di‐allate and tri‐allate in Regina heavy clay.A. fatua sown at depths of 5–15 cm was killed by di‐allate or tri‐allate. as were seedlings treated at the 15–2‐leaf stage. Seedlings of spring wheat (Triticum aestivum L.) survived rates of 24 oz/ac if the shoots were 1–3 cm long prior to exposure.When di‐allate at 16 oz/ac was mixed with a 5 cm layer of Regina heavy clay (wilting point 19–6%) slightly less than 15% soil moisture was required to give complete control of A.fatua. Further experiments indicated that a large percentage of A. fatua seedlings were killed by the action of di‐allate vapour in the soil.In other tests the activity of di‐allate and tri‐allate was reduced when the percentage of organic matter in the soil was increased by adding peat. This could explain why there is little damage to wheat sown in treated soil of high organic content while similar rates can cause extensive damage in soils of low organic content.Under comparable conditions tri‐allate persisted for a longer period in the soil than di‐allate. Both chemicals exhibited a lag period after which their breakdown appeared to follow a first‐order reaction. Differences in the period of persistence were attributed to a much longer lag period and a slightly slower rate of biological breakdown for tri‐allate as compared to di‐allate.Facteurs affectant l'activité du di‐allate et du tri‐allate
SITE OF UPTAKE OF SOIL‐APPLIED HERBICIDES*
Authors: PRENDEVILLE G. N. , ESHEL Y. , SCHREIBER M. M. , WARREN G. F. 
Published: July 2006

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
COMPETITION OF WILD OATS (AVENA FATUA L.) IN WHEAT AND FLAX*
Authors: BOWDEN B. A. , FRIESEN G. 
Published: July 2006

Summary. This project was designed to study various aspects of wild oat competition in spring wheat and flax. From ten to forty wild oat plants/yd2 were sufficient to cause significant yield reductions in wheat when grown on summerfallow land or when ammonium phosphate fertilizer was added to stubble land. However, when wheat was grown on stubble land without the benefit of a fertilizer treatment, seventy to one hundred wild oat plants/yd2 were needed to suppress wheat yields significantly. This would suggest that on stubble land, soil fertility was a more important factor than moderate densities of wild oats in determining eventual crop yields. In these experiments, wild oats reduced the number of tillers per plant, but did not significantly affect the protein content of the harvested grain.Only ten wild oat plants/yd2 were sufficient to reduce flax yields significantly on both summerfallow and stubble land. The only exception was in 1966, when flax grown on summerfallow land was not significantly affected until the density of wild oats reached forty plants/yd2. This confirms the general observation that flax is a poor competitor with wild oats.The results suggest that wild oat competition had already commenced prior to emergence of wheat, particularly with the higher densities of wild oats. In general, competitive effects increased with time and with wild oat density. In flax, severe competition had already taken place prior to the 2–3‐Ieaf stage of the weed in 1964, but did not become severe until after the 2–3‐leaf stage of wild oat growth in 1965 and 1966. Again, competitive effects increased with time and with wild oat density.Results of a final series of experiments, suggested that the optimum seeding date for flax in Manitoba is the latter part of May or the first week of June. Yield reductions due to wild oat competition became very severe as seeding dates were delayed.La compétition de la folle avoine (A vena fatua L.) avec le blé et le lin
PHYTOTOXICITY OF PARAQUAT ON WHITE AND GREEN HIBISCUS, SORGHUM AND ALPINIA LEAVES*
Authors: BOVEY R. W. , MILLER F. R. 
Published: July 2006

Summary. Paraquat was applied to while, variegated and green leaves of Hibiscus rosa sinensis L. Visual observations and moisture loss determinations revealed that the rate of tissue kill by paraquat was reduced in while tissue. Evidence from paraquat absorption and concentration studies indicated that phytotoxic differences were not due to amount or rate of absorption or protoplasmic susceptibility, but to differences in chlorophyll Content of treated leaves. Desiccants such as dinoseb, not dependent upon chlorophyll for rapid action, were equally affective on white and green leaves. The same reduced activity of paraquat on white leaf tissue was demonstrated for other species.Phytotoxicité du paraquat appliqué sur les feuilles blanches ou vertes de l'hibiscus, du sorgho et de l'alpinia
THE PHYTOTOXICITY OF SOME HERBICIDES IN FIELD AND POT EXPERIMENTS IN RELATION TO SOIL PROPERTIES
Authors: HANCE R. J. , HOCOMBE S. D. , HOLROYD J. 
Published: July 2006

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
CHEMICAL CONTROL OF FERTILE SPARTINA TOWNSENDII (S.L.) ON THE CHESHIRE SHORE OF THE DEE ESTUARY I. FIELD TRIALS ON SPARTINA SWARD
Authors: TAYLOR MONICA C. , BURROWS ELSIE M. 
Published: July 2006

Summary. Trials with dalapon, paraquat and fenuron in 1963 and 1964, and with bromacil and amitrole‐T in 1964, were carried out on mature Spartina sward. Dalapon, paraquat and fenuron all gave complete kill on some plots in 1963. In 1964, paraquat gave variable results and lower percentage kills than in 1963, whereas dalapon and fenuron were more consistent. Fenuron allowed a greater degree of regeneration than dalapon and was uneconomic at the high dose (60 lb/ac) required for complete kill. Dalapon gave the best results and with 100 lb/ac there was 98–100% kill 2 years after treatment. At 50 lb/ac results were initially good, but there was more regeneration in the second season after spraying. Bromacil at 5 and 20 lb/ac and a mixture of 5 lb/ac bromacil and 4 lb/ac amitrole‐T maintained more than 99% kill lor 2 years after application.La lutte chimique contre les formes fertiles de Spartina townsendii (s.l.) sur la cóte du Cheshire dans l'esluaire de la Dee I. Essais au champ sur des pelouses de Spartina
CHLORAMBEN (AMIBEN) DEGRADATION JN SOIL
Authors: WILDUNG R. E. , CHESTERS G. , ARMSTRONG D. E. 
Published: July 2006

Summary. When columns of three soil types were perfused with a microbial medium containing 5·7 and 26·9 ppm 14COOH‐labelled chloramben, there was a rapid decrease in the 14C activity remaining in solution, attributable to soil adsorption. Soil pH and organic matter content were the primary factors controlling chloramben adsorption. Soil pH may enhance adsorption through its effect on the number of soil anion exchange sites, and sites for polyvalent cation bridging and H bonding. Following adsorption, liver decreases in solution 14C‐chloramben activity were attributed to degradation;14CO2 evolved during perfusion amounted to 25–30% of the total decrease in 14C‐chloramben from solution. It was concluded that more than 90% of the 14C‐activity remaining in solution could be attributed to intact chloramben. Thus, decarboxylation appeared to be the primary mechanism of chloramben degradation in soils. Lag phases observed during degradation and subsequent investigations with re‐amended solutions implicated the soil microflora; even at chloramben concentrations of 26.9 ppm no toxic effect on the chloramben‐degrading micro‐organisms was apparent.Dégradation du chlorambène [amibène) dans le sol
THE BASIS OF THE DIFFERENTIAL PHYTOTOXICITY OF 4‐HYDROXY‐3,5‐DI‐IODOBENZONITRlLE*
Authors: DAVIES P. J. , DRENNAN D. S. H. , FRYER J. D. , HOLLY K. 
Published: July 2006

Summary. Entry of ioxynil‐14C into portions of leaves was greater with mustard than with barley or pea and was unrelated to stomatal density. Measurement of ioxynil content of sprayed plants showed that by increasing the concentration of ioxynil and adding a surfactant, almost as much ioxynil could be made to enter barley as entered mustard from a lower concentration without surfactant. Auto radiographs showed that a limited amount of 14C was translocated to a small extent in plants following localized application of ioxynil‐14C. An experiment comparing leaf removal by cutting with destruction of equivalent leaf areas by ioxynil treatment suggested a greater translocated effect of ioxynil with mustard than with pea or barley. Les principes de la phytotoxicité différentielle du 4‐hydroxy‐3,5‐di‐iodobetZonitrile II. Absorption et migration
STUDIES ON HERBICIDE CONTENTS IN ROOTS OF SKELETON WEED (CHONDRILLA JUNCEA L.) FOLLOWING LEAF APPLICATIONS
Authors: GREENHAM C. G. 
Published: July 2006

Summary. The herbicides studied were 2,4‐D, 2,4‐DB, dicamba and orthoarsenic acid. Herbicide content in the roots was taken as an overall measure of penetration into and absorption by the leaves, and of translocation to the roots.A significantly greater 2,4‐D content resulted from foliar application at pH 3–5 than at higher values, though at pH 8–5 the inclusion of triethanolamine significantly increased the 2,4‐D content. No evidence was obtained that a greater 2,4‐D content should result from foliage applications of 2,4‐DB than from 2,4‐D. Dicamba gave a greater herbicide content than 2,4‐D when applied at high concentration at 20° C but not at 25° C, probably because of less injury at the lower temperature.Concentrations of Tween 20 up to 2% had no deleterious effect on the 2,4‐D content; on the other hand 2,4‐D content was lowered by 0–25% or more of cetyltrimethyl‐ammonium bromide. Poor wetting is not the cause of the variable herbicide contents sometimes obtained.Orthoarsenic acid, which has given better control of the weed than 2,4‐D, was very poorly translocated; its effectiveness is due to its high intrinsic toxicity.Etudes sur la teneur en herbicide des racines de Chondrilla juncea L. á la suite d'applications sur les feuilles
THE YIELD AND QUAEITY OF RED BEET SEED AS AFFECTED BY DESICCANT SPRAYS AND HARVEST DATE
Authors: AUSTIN R. B. , LONGDEN P. C. 
Published: July 2006

Summary. Diquat and sodium monochloroacetate (SMA) were used to desiccate seed crops of red beet in experiments from 1963 to 1965. The seed plants became brown and dry about 7 days after spraying and were then judged suitable for combine harvesting, although this was not done in these experiments. Yields of seed 7 days after spraying were as good as those from the control plants, but were lower than the control yields when harvested 14 days after spraying. In laboratory tests in moist sand at 20° C the percentage of the embryos which germinated was not markedly affected by diquat or SMA treatment. The emergence of seedlings in the field, however, was affected adversely by treatment of the seed crop with 11 and 22 oz/ac of diquat ion in 1963 and by SMA at 20 lb/ac in 1964 and 1965. Diquat at 6·6 oz/ac in 120 gal/ac water in 1964 and 1965 had no serious adverse effects on embryo emergence. Residues of diquat ion in seed varied from 2 to 4 ppm, but the impairment of embryo emergence by diquat was believed to be due to the premature arrest of growth of the seed on the desiccated plants.It is concluded that when harvesting conditions are poor, desiccants could be valuable.Influence des traitements dessicants et de la date de récolte sur le rendement et la qualité de la sentence de betterave rouge
EFFECTS OF DESICCATION AND TEMPERATURE ON SURVIVAL OF CYPERUS ESCULENTUS TUBERS AND CYNODON DACTYLON RHIZOMES
Authors: THOMAS P. E. L. 
Published: July 2006

Summary. The effects of all combinations of five desiccation treatments, two temperatures and three durations of desiccation on the survival of Cyperus esculentus tubers and two‐node Cynodon dactylon rhizome fragments were examined in laboratory and glasshouse experiments. Cyperus esculentus tuber survival was greater at 22°C than at 4°C. Duration of desiccation did not influence tuber survival, except at the lower temperature.Survival of Cynodon dactylon rhizome fragments was greatly influenced by desiccation treatment, duration of desiccation and the interaction of these two factors. No buds survived when rhizomes reached 50% of their original weight, indicating good tolerance of desiccation since the original dry‐matter content of rhizomes in this experiment was 41·2%.
CHLORTHAL DEGRADATION IN SOILS AND ITS UPTAKE BY PINE SEEDLINGS
Authors: IYER J. G. , CHESTERS G. , WILDE S. A. 
Published: July 2006

Summary. Similar chlorthal (dimethyl 2,3,.5,6‐tetrachloroterephthalate) degradation patterns were found in pot cultures of white pine and Monterey pine grown in a sandy soil and in fallow cultures of the same soil. After 120 days, the content of chlorthal plus its degradation products (as measured by 14C‐activity) had decreased to 37% in the fallow and white pine cultures. A somewhat slower rate of degradation in soil (average 45%*C‐activity remaining) was observed for the Monterey pine cultures. Thus in 120 days, 55–63% of the added chlorthal had been lost from the soil system. A negligible amount of this could be accounted for by plant uptake. After 60 days of growth the rate of degradation in soil was greatly curtailed suggesting that the accumulated degradation produces were able to inhibit the further degradation of the herbicide.Analysis of *C‐labelled extracts from the pine tissue showed that uptake of chlorthal varied from 0–25 to 1–2% of the total amount of the chemical added to the soil. Degraded, as well as intact chlorthal, were found in both Monterey and white pine tissue. Very limited mobility of chlorthal in the plant was observed and the concentration in the shoots was less than 10 pm. About 80% of the absorbed chlorthal remained in the root systems. Plant growth led to a rapid dilution of absorbed chlorthal. The growth of both species of pine was rapid and apparently healthy in chlorthal‐treated soil and comparable to that of the control plants.
EFFECT OF PYRAZON ON PHOTOSYNTHESIS OF VARIOUS PLANT SPECIES
Authors: ESHEL Y. 
Published: July 2006

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.
SOME EFFECTS OF DROPLET SIZE AND POSITION ON THE RESPONSE OF LETTUCE TO SUB‐LETHAL DOSES OF MCPA
Authors: WAY J. M. 
Published: July 2006

Summary. Senescent, expanded or expanding leaves of lettuce plants were treated individually with MCPA. The subsequent development of auxin‐induced symptoms throughout the plants was recorded. The number of leaves affected and the severity of the symptoms increased with application to the less mature leaves. In addition more leaves were affected when the application was made to larger plants than to smaller ones. These results were associated with absorption/translocation differences in the leaves of different ages, and in their spatial relationship to tissues at particularly susceptible stages of development. In further experiments, applications of similar weights of MCPA to lettuce plants in droplet sizes of approximately 100 μ and 500 μ were compared. There were consistent trends for the small droplets to produce greater effects.Quetques effets de la taille des gouttelettes et de leur position sur la reaction de la laitue à des doses sub‐létales de MCPA