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1.
建立了小麦植株、麦粒、面粉、麦麸和土壤样品中氨氯吡啶酸的高效液相色谱-串联质谱(HPLC-MS/MS)检测方法。样品用丙酮提取,经N-丙基乙二胺(primary secondary amine,PSA)串联石墨化炭黑柱净化,以Agilent ZORBAX SB-C18 色谱柱分离,以电喷雾电离串联质谱正离子多反应监测(multiple reaction monitoring,MRM)模式进行测定。结果表明: 在0.01、0.1、0.5、1 mg/kg 4个添加水平下,氨氯吡啶酸在小麦植株、麦粒、面粉、麦麸和土壤中的平均回收率在78.9%~97.9%之间,相对标准偏差在3.6%~9.6%之间。该方法样品前处理简单、快速、分析时间短,灵敏度、准确度和精密度均符合农药残留检测要求,适用于小麦和土壤中氨氯吡啶酸残留的检测。 相似文献
2.
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. 相似文献
3.
Effects of various herbicides on mycelial growth of strains of Botrytis cinerea. Pers. and Pénicillium expansum Link, sensitive or resistant to certain fungicides Of seventy herbicides tested, thirty-eight were slightly toxic to B. cinerea (CI50, concentration giving 50% inhibition of the speed of mycelial growth, exceeding or equal to 100g of herbicide/ml of nutrient solution) and, of those, ten had no effect even at 1000 g/ml. The most active products (CI50 less than 10 g/ml) were Chlorthiamid, dichlobénil, nitrofen, propyzamide and phenolic derivatives (DNOC, ioxynil, PCP). In most cases P. expansum was less sensitive than B. cinerea except to endothal, propachlor, prynachlor and certain substituted ureas. Strains resistant to the benzimidazole fungicides (carbendazim, thiabendazole etc.) show increased sensitivity to certain carbamade herbicides (barban, chlorbufam etc.), this indicates the existence of a negative cross resistance between these groups of antimitotic pesticides. Strains resistant to the cyclic-imide fungicides (iprodionc, procymidone, vinclozolin) and to various aromatic compounds (biphenyl. chloroneb, dicloran etc.) may also be resistant to bipyridilium, dinitroanilinc and diphenylethcr herbicides, to chlorthamid. dichlobénil and oxadiazon. This cross resistance between pesticides with different biochemical modes of action has yet to be explained. 相似文献
4.
Degradation if isoproturon and availability of residues in soil The availability and degradation of 14C-ring-labelled isoproturon in soil was investigated over 140 days under controlled laboratory conditions. Degradation of the active ingredient followed and 65 days later only a minor fraction (0.6%) of the parent molecule remained extractable. A demethylated-isoproturon metabolite was detectable in soil from day 15 (2.6%). The amount of 14CO2 derived from the 14C benzene ring label and liberated over time indicated that a total of 13.6% isoproturon was mineralized during the incubation period. In parallel, the amount of 14C residue extracted from the soil by water followed by methanol or remaining within the soil—analysed by combustion—was also determined at intervals. After 140 days, 72% of the radiolabel added remained in the soil as non-extractable residue. The degradation half-life of extractable isoproturon was an estimated 14 days. 相似文献
5.
The effects of soil solarization combined or not with millet residues or paunch contents amendments, on the survival ofMacrophomina phaseolina (Tassi) Goid. and development of charcoal rot of cowpea (Vigna unguiculata), were assessed in a naturally infested soil. Solarization increased the soil temperature to 50°C for at least 4 h per day
during June, leading to a significant reduction (44%) in soil inoculum ofM. phaseolina. Paunch contents or millet residues amendment (3 t ha−1) caused 16% or 35% reduction of initial inoculum density, respectively. The combination of paunch contents or millet residues
amendments followed by solarization, resulted in the strongest effects on inoculum density, with reductions of 46% or 66%,
respectively. The reduction in disease severity, as expressed by the area under the disease progress curve, was 78% or 96%
for the combination of millet residues or paunch contents amendments and solarization, respectively. The stronger effect of
the treatments on disease severity than on inoculum density may be explained by a weakening effect caused by the treatments
on the remaining inoculum. Our results suggest that in the Sahelian zone the combination of solarization and organic amendment
can be a credible alternative to pesticides for managing charcoal rot disease and improving cowpea yield in fields with heavy
infestations withM. phaseolina. 相似文献
6.
R. GROVER 《Weed Research》1968,8(3):226-232
Summary. Effective dosages of picloram (4–amino-3,5,6–trichloropicolinic acid) required to reduce fresh weight of sunflowers ( Helianthus annuus L. var. Menonite) were determined for seven Saskatchewan soils under controlled environmental conditions. The relationships between ED50 value and clay content, organic matter content and cation exchange capacity were evaluated by correlation and regression analysis for possible usefulness in predicting dose requirements. ED50 values were also determined for Weyburn loam and in culture solutions adjusted to various pH levels.
There Was no significant correlation between ED50 values of picloram and soil clay content or cation exchange capacity. ED50 values were highly correlated with soil organic matter content, and they increased as the soil pH was lowered or raised from pH 6.5. The increase in ED50 values in the acidic range was attributed to adsorption of the unionized molecules of picloram on the organic matter in the soil. The increase in ED50 values in the alkaline range may be mainly due to reduced uptake of the ionized acid by plant roots. 相似文献
There Was no significant correlation between ED
7.
Steven Walker Michael Widderick Andrew McLean Tony Cook Bill Davidson 《Weed Biology and Management》2013,13(4):144-150
Conyza bonariensis is a major weed infesting zero‐tilled cropping systems in subtropical Australia, particularly in wheat and winter fallows. Uncontrolled C. bonariensis survives to become a problem weed in the following crops or fallows. As no herbicide has been registered for C. bonariensis in wheat, the effectiveness of 11 herbicides, currently registered for other broad‐leaved weeds in wheat, was evaluated in two pot and two field experiments. As previous research showed that the age of C. bonariensis, and to a lesser extent, the soil moisture at spraying affected herbicide efficacy, these factors also were investigated. The efficacy of the majority of herbicide treatments was reduced when large rosettes (5–15 cm diameter) were treated, compared with small rosettes (<5 cm diameter). However, for the majority of herbicide treatments, the soil moisture did not affect the herbicide efficacy in the pot experiments. In the field, a delay in herbicide treatment of 2 weeks reduced the herbicide efficacy consistently across herbicide treatments, which was related to weed age but not to soil moisture differences. Across all the experiments, four herbicides controlled C. bonariensis in wheat consistently (83–100%): 2,4‐D; aminopyralid + fluroxypyr; picloram + MCPA + metsulfuron; and picloram + high rates of 2,4‐D. Thus, this problem weed can be effectively and consistently controlled in wheat, particularly when small rosettes are treated, and therefore C. bonariensis will have a less adverse impact on the following fallow or crop. 相似文献
8.
The effectiveness of‘Tordon 50-d’(5% a.i. picloram plus 20% a.i. 2,4-D both as the triisopropanolamine salts) and various mixtures of 2,4,5-T and picloram were tested for the control of blackberry (Rubus fruticosus L. agg.) in Victoria, Australia. A high correlation was obtained between the % reduction in live canes and the % kill of crowns 13 months after Rubus procerus P.J. Muell. thickets were sprayed with 2,4,5-T or‘Tordon 50-d'. Counting the number of live canes is, therefore, a convenient method of comparing the efficacy of these herbicides for the control of blackberry. ‘Tordon 50-d’was generally more effective than 2,4,5-T but stimulation of suckering from roots was recorded at one site when low rates of‘Tordon 50-d’were used. It was necessary to add high dose rates of‘Tordon 50-d’to 2,4,5-T before there were worthwhile improvements in weed control.‘Tordon 5–20’(5% a.i. picloram as triisopropanolamine salt plus 20% 2,4,5-T as the ethyl hexyl ester) was only slightly more effective in controlling blackberry than‘Tordon 50-d'. The cost and soil residue problems associated with picloram should limit its use as an additive to 2,4,5-T for the control of blackberry in Australia. 相似文献
9.
Tillage and maize (Zea mays L.) residues at up to four times the base level had variable effects on the emergence of four annual weed species in the field. Environmental conditions varied during the three years of the research and interacted with residue and tillage to govern seedling emergence. When tillage affected Setaria faberi Herrm., emergence was greater in untillcd than tilled plots. The effect of residues varied among years. Abutilon theophrasti Medik, emergence from tilled soil was greater than from untilled soil in two of three years. Maize residue at two or four times the base levei reduced emergence. Amaranthus retroflexus L. emergence was often greater from untilled than tilled soil. The effect of maize residues on this species was dependent on tillage and precipitation. Chenopodium album L. emergence was affected by tillage and residues but differences over the three years were inconsistent. Results of this research indicate that tillage and residues interact with weed species, precipitation and other factors to regulate seedling emergence. The reduced soil disturbance and minimal weed seed burial associated with the elimination of tillage appear to have a greater impact on weed population dynamics than surface residues in non-tillage maize production systems. 相似文献
10.
In a 2-year field study, the effects of four heating regimes established by varying temperature or duration of heating on
efficiency of on-farm wastes as soil amendments in controlling Fusarium oxysporum f.sp. cumini (Foc) causing wilt on cumin (Cuminum cyminum L.), were ascertained. Significant improvement in reduction of Foc propagules was achieved with the increase in duration and amount of heat. In 2000, mild heating under shade (heat level 4),
31.8–65.9% reduction in Foc propagules was estimated in all the amendments at 0–30 cm soil depth, which improved by 75.7–86.5% in the treatment where
Foc-infested soil brought from the laboratory was exposed to direct heat (heat level 3) and amendments and irrigation were applied.
Foc propagules were reduced by 76.6–88.3% when infested soil was exposed continuously to dry heat for 56 days (heat level 2),
improving efficiency of amendments by 0.9–13.5% compared with heat level 3. After 56 days of exposure to dry heat, elevating
the temperature by mulching amended soil with a transparent polyethylene film (50 μm thick) for 20 days (heat level 1) augmented
reduction by 80.2–95.5%. In the second season, combining 0.04% of onion, Verbisina encelioides or mustard oil-cake with mustard residues (0.18%) improved the reduction in Foc propagules at all heat levels even at the lower soil depth. Maximum reduction (94.9–100%) in Foc propagules at heat levels 1 to 3 was achieved when residues of Verbisina were supplemented with those of mustard. These results suggest a new approach to improve the control of Foc by combining prolonged heating with on-farm wastes such as Verbisina residues and one summer irrigation. 相似文献
11.
Residual effects of chlorotriazine herbicides in soil at three Rumanian sites. II. Prediction of the phytotoxicity of atrazine residues to following crops Total and plant-available atrazine residues in the top 10 cm soil were measured 120 days after application of 3 kg ai ha?1 to maize (Zea mays L.) at three sites in Rumania. At one site, similar measurements were made 3?5 years after application of 100 kg ai ha?1. Plant-available atrazine residues were estimated by extraction of soil samples with water, and by bioassay using Brassica rapa as the test plant. It was calculated that between 30 and 120μg atrazine 1?1 was potentially available to plants in the different soils. Dose-response relationships for atrazine and the most important rotational crops with maize in Rumania—sunflower, winter wheat, soybean and flax—were determined in hydroponic culture using herbicide concentrations corresponding with the plant-available fractions measured in the different soils. ED50 values were determined by probit analysis and the results showed that sunflower (ED50, 22μg 1?1) was the most sensitive crop, and soybean (ED50, 78μg 1?1) was the least. The residual phytotoxicity of atrazine to succeeding crops in the different soils was predicted using the appropriate availability and phytotoxicity data, and the results showed good agreement with those observed. The results suggest that measurements of plant-available herbicide residues afford a rapid method of assessing possible phytotoxicity to following crops. 相似文献
12.
D. J. Turner 《Pest management science》1972,3(3):323-331
The possibilities are demonstrated of increasing the activity of foliar applied growth regulator herbicides by mixing them with chemicals which injure the cuticle or epidermis. S, S, S-Tributyl phosphorotrithioate (“DEF”) increases the effects of picloram, 2,4,5-T and mecoprop salts on four woody species, privet (Ligustrum ovalifolium Hassk.), poplar (× Populus gelrica Ait.), bluegum (Eucalyptus globulus Labill.) and guava (Psidium guajava L.). Mixtures with esters of the herbicides are not synergistic and often antagonistic. DEF, tributyl phosphorotrithioite, a number of alkyl and aryl phosphates and phosphites and potassium ethyl xanthate enhance the phytotoxicity of picloram solution on dwarf bean (Phaseolus vulgaris L.). Mixtures of picloram with tributyl phosphorotrithioite, tributyl phosphate, mixed acid butyl phosphates, trimethyl phosphate and mixed isomers of tritolyl phosphate are synergistic when applied to guava foliage. Tributyl phosphate and mixed acid butyl phosphates interact similarly with picloram on privet and tributyl phosphate increases the effects of foliar applied mecoprop salt on guava. The mode of action of the additives is not fully understood but there is evidence that DEF facilitates the entry of water soluble growth regulator herbicides into leaves and has little effect on the rate at which the herbicides move through the plant. Tributyl phosphate and mixed acid butyl phosphates are suggested for practical use in herbicide formulations to control woody plants, as they are relatively cheap and non-toxic. 相似文献
13.
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
14.
R. GROVER 《Weed Research》1967,7(1):61-67
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 相似文献
Etude de la degradation de t'acide 4-amino-3,5,6-trichloropicolmique dans le sol 相似文献
15.
Effect of orgunic matter added to soil on the adsrption of herhicides. Inffneuce of the composition of the organic matter By preliminary fractionation of two organic substrates (a wheat straw and a crushed lucerne hay) we tried to evaluate the adsorption capacity of their constituents (water-soluble and lipidic substances, hemicelluloses, cellulose and lignin) in soil. Terbutryne and diuron have different affinities with the constituents of the substrates. Lignin is more adsorbent than the other constituents. With regard to adsorption, isolated constitucents form heterogeneous and interacting classes. Consequently it is difficult to define the absorption capacity of non-decomposed organic materials on the basis of their composition. Mineralization, by modifying the composition, the variations in adsorptive power of carbon residues resulting from decomposition of the substrates in the soil. 相似文献
16.
Development during storage of germinability of seeds of Amaranthus retroflexus L. harvested under different conditions The effect was studied of dry storage at 20 ± 1°C for 6 months or in soil 15 cm below the surface during one winter, on the germination behaviour of seeds of Amaranthus retroflexus L. harvested at the level of the main inflorescence on the parent plants grown under natural conditions or in different conditions of controlled photoperiod or temperature. At harvest, the seeds from plants which had developed late (July) in natural conditions were less dormant than those from plants appearing earlier (April); in controlled conditions, plants grown at 20°C in long days (16 h) produced seeds more dormant than those harvested from plants grown either at 20°C in short days (8 h) or at 25°C in long days (16 h). After dry storage or in the soil, this variation in germinability decreased but was never totally suppressed; the seeds retained the characteristics acquired during their formation and maturation. At harvest, for a defined growing condition, the dormancy of the seeds produced depends on the physiological state of the parent plants; after storage, the seeds which were the most dormant at harvest germinated more than the less dormant seeds. Finally, burying has a more favourable effect on breaking dormancy of the seeds than has dry storage. 相似文献
17.
Long‐term survival of blast pathogen in infected rice residues as major source of primary inoculum in high altitude upland ecology 
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下载免费PDF全文 Magnaporthe oryzae is the fungal plant pathogen that causes rice blast. The sources of primary inoculum and overwintering mode of the fungus remain largely unknown. The effect of rice residues on the onset of blast epidemics and the potential for survival of M. oryzae in the residues were studied in upland conditions in Madagascar. Blast disease was observed in a 3‐year field experiment in three treatments: with either infected or uninfected rice residues on the soil surface, or without rice residues. Leaf blast incidence was significantly higher in the treatment with infected rice residues than in the two other treatments at the early stages of the epidemic. In a second set of trials, the survival of M. oryzae on rice residues was monitored. Infected rice stems were placed by lots in three places: on the mulch of rice residues, under the mulch, and buried at a depth of 10 cm in the soil. Each month, samples were taken from the field and tested for sporulation. The survival of the blast fungus decreased rapidly on the stems buried in the soil but remained high for the other conditions. Sporulation of the fungus was observed on stems left on the mulch for up to 18 months. It is concluded that under field conditions, the presence of infected rice residues could initiate an epidemic of blast. The results of this study may help in designing effective management strategies for rice residues infected by M. oryzae. 相似文献
18.
R. L. AMOK 《Weed Research》1975,15(1):47-52
The response of blackberry (Rubus fruticosus L. agg.) thickets and of pastures to picloram granules applied in winter or spring was studied in Victoria, Australia. A dose of 10–12 kg ha?1 killed the thickets provided that the litter was no more than 2–3 cm deep. 5·6 kg ha?1 was equally effective if the top growth was mown before the granules were applied. The reason for the greater effectiveness of picloram on mown thickets is not clear, but may involve reduced carbohydrate reserves, reduced dilution of picloram in the roots, or greater accumulation of picloram at sites of meristematic activity. The value of picloram granules for the control of blackberry is discussed in terms of soil residues and cost. Ecologie et destruction des ronces (Rubus fruticosus L. agg.) V. Lutte au moyen du piclorame granulé. La réaction des ronces à l'état de buissons ou dans les pâtures, après traitement au piclorame granulé, appliqué en hiver ou au printemps, a étéétudiée dans l'Etat de Victoria, Australie. Une dose de 10 à 12 kg/ha a détruit les buissons à condition que la litière n'ait pas plus de 2 à 3 cm de profondeur. La dose de 5,6 kg/ha a étéégalement efficace, à condition que les tiges aient été fauchées avant que les granulés n'aient étéépandus. La raison de la meilleure efficacité du piclorame sur les plantes fauchées n'est pas claire, mais il se peut que la fauchaison provoque la réduction des réserves en hydrates de carbone, réduise la dilution du piclorame dans les racines ou provoque une accumulation plus forte de piclorame dans les sites d'activité méristématiques. La valeur des granules de piclorame pour la lutte contre les ronces est discutée en tenant compte desrésidus dans le sol et du prix de revient. Ökologie und Bekämpfung der Brombeere (Rubus fruticosus L. agg.) V. Bekämpfung mit Picloram-Granulat In Victoria (Australien), wurde im Winter und im Frühjahr Picloram-Granulat in Brombeerdickichten und auf Weideland angewendet, um die Wirkung auf die Brombeere (Rubus fruticosus L. agg.) zu untersuchen. 10–12 kg ha?1 brachten die Dickichte zum Absterben, vorausgesetzt, dass die Streu nicht stärker als 2–3 cm war. Die gleiche Wirkung wurde mit 5.6 kg ha?1 erzielt, wenn vor der Granulatanwendung die Spitzen der Pflanzen abgemáht wurden. Die Ursache für die bessere Wirkung von Picloram bei den derartig gemähten Dickichten ist unklar. Möglicherweise ist diese Wirkung im Zusammenhang mit verringerten Kohlenhydratrcserven, einer weniger starken Verdüinnung von Picloram in den Wurzeln, oder einer starkeren Anreicher-ung des Herbizids an Orten meristematischer Aktivität zu sehen. Die Brauchbarkeit von Picloram-Granular für die Brom-beerbekämpfung wird unter dem Gesichtspunkt der Rückstände im Boden und der Kosten besprochen. 相似文献
19.
Mixtures of wet vegetable wastes (Brassica, carrot or onion) and dry onion waste were composted at 50 °C for 7 days. The incorporation of the raw or composted vegetable waste mixtures into sandy loam, silt and peat soils reduced the viability of sclerotia of S. cepivorum in glasshouse pot bioassays. The reduction in viability was dependent on waste type, rate of incorporation, duration of exposure and soil type. Onion waste was the most effective waste type in reducing sclerotia viability in all three soils. The Brassica and carrot wastes were as effective as the onion waste in silt soil but less effective in sandy loam and peat soil. A 50% w/w incorporation rate of the wastes gave the largest reduction in viability, with an increase in reduction over time. Composted onion waste reduced sclerotia viability under glasshouse and field conditions although the effect was smaller in the field. Composted onion waste incorporated into soil at 50% w/w reduced the incidence of Allium white rot on onion seedlings in glasshouse pot tests. Incidence and control of the disease differed with soil type. The most consistent control was achieved in peat soil whereas no control was observed in silt soil. Incorporation of the waste 2 months prior to sowing or transplanting reduced seedling emergence in sandy loam soil and growth in all three soil types. The potential for field application of composted vegetable wastes as a sustainable method for control of Allium white rot and waste disposal is discussed. 相似文献
20.
Two herbicides used for post‐plant weed control in commercial forests in New Zealand, terbuthylazine and hexazinone, are not endorsed for use on land certified by the Forest Stewardship Council (FSC). These herbicides are effective for controlling competitive woody weeds, such as Cytisus scoparius (broom). To investigate the potential of non‐residual, alternative herbicides for the control of C. scoparius after planting, a range of treatments were implemented at two trials. The trials were established in newly planted Pinus radiata plantations where C. scoparius dominated. The objectives were to (i) optimise application rates of alternative herbicides and compare their efficacy to current practice and (ii) identify if treatment efficacy varied across sites. Treatments at each site included weedy and weed‐free controls, current practice using terbuthylazine and hexazinone, applied as both spot treatment and broadcast application, and a range of new treatments consisting of different dosage combinations of clopyralid, triclopyr and picloram. Broadcast application of the clopyralid, triclopyr and picloram mixture showed increasing weed‐control efficacy against C. scoparius with increasing dose rate, resulting in increased tree volume. Broadcast application of the clopyralid, triclopyr and picloram mixture at 75% or 100% of a typical industry use rate (100% industry rate includes clopyralid 1.5 kg a.i. ha?1, triclopyr 0.15 kg a.i. ha?1 and picloram 0.05 kg a.i. ha?1) achieved greatest tree volume by year four with tree volumes exceeding that obtained using the operational spot treatment with terbuthylazine and hexazinone. Treatment rankings were similar between locations. The result supports the use of clopyralid, triclopyr and picloram to control C. scoparius during the first year of P. radiata establishment. 相似文献