摘要:

SummaryMowing musk thistle(Carduus nutansL.) within 2 days of the first terminal heads in a plant population showing anthesis eliminated the production of germinable seed from all mowed stalks. Mowing later than 4 days after anthesis led to significant amounts of germinable seed being produced. Regrowth, which produced viable seed, usually occurred from plants mowed before first terminal heads began anthesis. A single mowing usually did not give satisfactory control due to wide differences in the maturity of plants in a natural population. When the terminal heads had reached late bud or more mature stages, 2,4‐D ester [isoocyt] ester of (2,4‐dichlorophenoxy) acetic acid]at M kg/ha or 2–2 kg/ha did not provide satisfactory control. In general, the most effective herbicide treatments tested at all three stages of maturity were dicamba (3,6‐dichloro‐o‐anisic acid) at 056 kg/ha plus 2,4‐D amine (dimethyl amine salt) at M kg/ha, 2,4‐D ester at 4–4 kg/ha, or dicamba at 0–56 kg/ha. Inconsistent control of musk thistle results from variability within naturally occurring populations. Uneven development of stands as well as variation among plants are suggested

ISSN:0043-1737    

DOI:10.1111/j.1365-3180.1975.tb01331.x

出版商:Blackwell Publishing Ltd    

年代:1975

数据来源: WILEY

摘要:

SummaryThe 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 of14C‐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 terbu

ISSN:0043-1737    

DOI:10.1111/j.1365-3180.1975.tb01332.x

出版商:Blackwell Publishing Ltd    

年代:1975

数据来源: WILEY

摘要:

SummaryAnnual applications of the herbicides atrazine, simazine, linuron and diuron at 45 kg/ha were made to the same plots for 9 consecutive years from 1963 to 1971 in a peach(Prunus persica(L.) Batsch.) orchard located on sandy loam soil near Harrow, Ontario. Soil samples from these plots were collected in late October for the last 3 years (1969–1971) and trees were cut down in December, 1969. Herbicide residues were determined by bioassays based on the fresh and dry weight of oats(Avena sativaL.) and in one year results were confirmed by chemical analysis. Significant accumulation of herbicides was not observed. The maximum residue levels measured in October over the 3 years of sampling were 7′3 kg/ha for diuron, 3–8 kg/ha for linuron, 1–6 kg/ha for simazine and 04 kg/ha for atrazine in the top 15 cm of the soil profile. Simazine and atrazine showed a rapid decrease in amount after treatment but diuron and linuron were degraded more slowly. Measurable residues of all herbicides were confined to the upper 15 cm of the soil profile and the majority of herbicide remained in the 0–5‐cm soil layer. Oats were planted in the orchard plots from 1972 to 1974 to follow the disappearance of the herbicides. All herbicides caused highly significant yield decreases in 1972, atrazine causing the least (38%) and diuron the greatest (86%) reductions. Diuron reduced the yield of oats in 1973 and caused a highly significant decrease in the weight of young oat pla

ISSN:0043-1737    

DOI:10.1111/j.1365-3180.1975.tb01333.x

出版商:Blackwell Publishing Ltd    

年代:1975

数据来源: WILEY

摘要:

RésuméCarbetamide at doses up to 3 kg/ha and propyzamide at 1–25 kg/ha applied in February to two crops each of red clover(Trifolium pratenseL.) and lucerne(Medicago sativaL.) caused no crop damage to either species. Flowering of red clover was substantially increased by both herbicides.Lolium perenne(L.) andLolium midriflorum(Lam.) in red clover were completely controlled by carbetamide at less than 2 kg/ha; removal of these grasses resulted in significant increases in yield of red clover.Poa aimtia(L.) and other grasses were less well controlled in the lucerne crops.Le déskerhage sélectif contre les graminées dans le trèfle rouge(Trifotium pratense)et la luzerne(Medicago sativa)acec le carbétamide et le propyzamide.Le carbétamide à des doses allant jusqu'à 3 kg/ha et le propyzamide à 1,25 kg/ha appliqués en février à deux cultures de tréfle rouge(Trifolium pratenseL.) et de luzerne(Medicago sativaL.) n'ont pas causé de dommages à ces deux espèces. La floraison du trèfle rouge a été notablement accrue par les deux herbicides.Lolium perenne(L.) etLolium muliljiorum(Lam.) ont été complètement détruits par le carbétamide à moins de 2 kg/ha. L'élimination de ces deux mauvaises herbes a provoqué des augmentations sjgnificatives de rendement du trèfle rouge.Poa annua(L.) et d'autres graminées ont été moins bien comba

ISSN:0043-1737    

DOI:10.1111/j.1365-3180.1975.tb01334.x

出版商:Blackwell Publishing Ltd    

年代:1975

数据来源: WILEY

摘要:

RésuméLa solubitilé et les cinétiques de dissolution dans l'eau de I'atrazine, de la propazine et de la simazine ont étéétudiées à différentes températures. L'ordre apparent des réactions de dissolution est de I pour l'atrazine et la propazine, 2 pour la simazine. La solubilité et les constantes de vitesse sont des fonctions croissantes de la température. Les énergies d'activation de la vitesse de dissolution sont de l'ordre de 4,1 à 4,8 kcal mole‐1. Elles correspondent à une diminution de 30% ilti temps de demie‐réaction pour une augmentation de température de 10°C. II apparaît ainsi que l'eflicacité d'un traitement peut dépendre en partie de l'importanee des pluies e

ISSN:0043-1737    

DOI:10.1111/j.1365-3180.1975.tb01335.x

出版商:Blackwell Publishing Ltd    

年代:1975

数据来源: WILEY

摘要:

RésuméLa terbutryne est très adsorbée par les acides humiques tandis que l'atrazine l'est peu, cn milieu acide seulement. L'influence du pH sur l'adsorption et l'effet compétitif des cations Ca2+, Al3+et Fe3+montrent que la forme protonée des molécules des deux herbicides peut être adsorbée selon un mécanisme du type échange d'ions; la forme neutre des molécules de terbutryne pourrail être adsorbée selon d'autres mécanismes. La désorption de la terbutryne s'accompagne d'un phénomène d'hystéqerésis plus marqué dans le cas des molécules neutres et, en milieu acide, le calcium manifcste un faible pouvoir de déplacement vis‐à

ISSN:0043-1737    

DOI:10.1111/j.1365-3180.1975.tb01336.x

出版商:Blackwell Publishing Ltd    

年代:1975

数据来源: WILEY

摘要:

SummaryA survey was undertaken to establish the sensitivity of seventeen algal strains belonging to the Chlorophyceae to a selected range of herbicides up to a concentration maximum of 10 ppm under in vitro conditions. The herbicides were found to vary considerably in their toxicity to algae and a sequence was established based upon the magnitude of this toxicity: diuron>bromacil>paraquat>monuron>diquat>linuron>2, 4‐DB>barban>dicamba, dichlobenil, dalapon, picloram>bromoxynil, 2,3,6‐TBA>2.4‐DP. 2,4,5‐T and EPTAM. Of the algae, the most sensitive genera were Hormidium and Haematococcus, and the strain most sensitive to a wide range of herbicides was Hormidium barlowi (strain

ISSN:0043-1737    

DOI:10.1111/j.1365-3180.1975.tb01337.x

出版商:Blackwell Publishing Ltd    

年代:1975

数据来源: WILEY

摘要:

SummaryAlthough large numbers or viable seeds of C.arvensearc formed in some districts of Victoria, the germination percentage declines rapidly in the first 2 years. No seedlings were established from seed artificially spread on pastures, although at two sites 6–8% and 12–6% of seed sown 0–5–1′0 cm deep into bare soil gave emerged seedlings, and 78% and 93% respectively of the seedlings survived. It is unlikely that Carvenseis spreading rapidly by seed under the present management of permanent grassland.Patches of C.arvensewere shown to have a pattern of development similar to plants such as Pteridium and Calluna that degenerate behind an advancing front. The annual rate of vegetative spread in pastures was about 150 cm and extremely variable (range

ISSN:0043-1737    

DOI:10.1111/j.1365-3180.1975.tb01338.x

出版商:Blackwell Publishing Ltd    

年代:1975

数据来源: WILEY

摘要:

SummaryLocalized 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 in14C‐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 nitrali

ISSN:0043-1737    

DOI:10.1111/j.1365-3180.1975.tb01339.x

出版商:Blackwell Publishing Ltd    

年代:1975

数据来源: WILEY

ISSN:0043-1737    

DOI:10.1111/j.1365-3180.1975.tb01340.x

出版商:Blackwell Publishing Ltd    

年代:1975

数据来源: WILEY