2012年1月3日星期二

Evidences showing 2,4-D ethyl ester and pencycuron -induced DNA damage in cyanobacteria and detection by PCR

Authors: Nirmal Kumar, J.I.; Amb, Manmeet Kaur; Kumar, Rita; Bora, Anubhuti
The impact of 2,4-D ethyl ester and pencycuron in inducing DNA damage in three species of cyanobacteria-Anabaena fertilissima, Aulosira fertilissima, and Westiellopsis prolifica as evidenced by PCR-based assays: RAPD and 16S rRNA amplification was examined. Exposure of genomic DNA (in vitro) to pencycuron for 4 days did not produce severe damage in DNA fragments of all three cyanobacterial species whereas exposure to 2,4-D ethyl ester markedly inhibited the template activity of genomic DNA compared to untreated cultures of A. fertilissima. In A. fertilissima a single band of approximately 1000 bp was observed even after 16 days of exposure to 60 ppm pencycuron which suggests that certain segments of DNA are resistant to pencycuron DNA damaging effects. However, a significant effect was observed in the case of W. prolifica for 2,4-D ethyl ester and pencycuron where complete disappearance of fragments was not recorded even after 16 days of incubation and interestingly some new DNA bands were induced. Similar to the effects with RAPD profile, amplification of rRNA was significantly inhibited following exposure of genomic DNA to 2,4-D ethyl ester and pencycuron. Our findings clearly demonstrate that pesticide concentrations affected cyanobacterial DNA and lethality of these microbes might be due to irreversible DNA damage. Thus, it is postulated that PCR assays may be conveniently used for screening DNA damage produced by 2,4-D ethyl ester and pencycuron in all three cyanobacteria examined in this study.

Dicamba Injury to Winter Wheat

Fabian Menalled, Reviewed May 2004
Meghan Trainor, Posted May 2000
As field crops grow and mature, their tolerance to herbicide changes. For this reason, it is critical that postemergence herbicides be applied at the proper time to achieve maximum weed control and minimum crop injury.
As a general rule, annual and biennial weeds are more susceptible to postemergence herbicides when they are in the seedling stage. As weeds mature they become more difficult to control. Also, field crops differ in the periods when postemergence herbicides can safely be applied. This places the grower in the predicament of when to apply the herbicide in order to achieve the least crop injury as well as satisfactory weed control. To minimize the risk of herbicide crop injury, each crop must be considered separately to determine the correct crop growth stage when applications could be done. 
Dicamba is one among many herbicides recommended for postemergence weed control in winter wheat. Banvel, a benzoic acid, belongs to the chemical group of growth regulators. Growth regulator herbicides can act at multiple sites in a plant to disrupt hormone balance and protein synthesis, thereby causing a variety of plant growth abnormalities. Growth regulator herbicides are mostly absorved through the foliage but root uptake may also occur. These herbicides can move in both the xylem and the phloem to areas of new plant growth and can be used to control perennial and annual broadleaf weeds. However, Dicamba can injure winter wheat. 
The best time to apply Dicamba is in the early spring (February through April) after winter wheat has begun to tiller, but before the joint stage. The plant develops additional stems during tillering, but the stems do not elongate.
From the seedling through the tillering stages all leaves appear to originate from the base of the plant. During jointing, stems lengthen as recognized by leaves being attached at different joints (nodes) on the stem. Although some herbicide labels allow for application up to the boot stage, delaying application of Dicamba beyond the joint stage will increase winter wheat injury and decrease weed control.
In conclusion, winter wheat can be treated with Dicamba in the spring after winter dormancy has been broken and before wheat begins to joint. If Dicamba is applied to wheat in the joint stage, significant crop injury may occur. Furthermore, injury in the joint stage will affect head development.


Yangzhou pioneer chemical CO.LTD

Calif. groups protest use of any pesticides

Source:AG Professional
Environmental groups and a few fringe public health organizations in California are protesting the state’s newly announced plans for dealing with crop pests using comprehensive pesticide application planning.
Looking in from the outside, it appears that the state, through its own regulations and regulatory agencies, is strongly in charge of deciding what farmers can do to control insects attacking their crops, but the protestors want complete control with pesticides basically taken off the table to protect crops.
A Los Angeles Times article, tries to explain the situation while giving protestors the main voice. The California Department of Food and Agriculture reportedly is abandoning the “traditional practice of assessing the environmental effects of attacking pests one by one.” Instead, $3 million is being invested in a “comprehensive impact report on eradicating all flies, worms, moths and other insects at once,” according to the Times article.
The protestors suggest any pesticide application poisons the environment, doesn’t work in eradicating problem pests because pests return each year and is contrary to integrated pest management planning without pesticides.
The protestors are aiming their attack at having Gov. Jerry Brown to “abandon the state’s new plan.”

Yangzhou pioneer chemical CO.,LTD

2011年12月31日星期六

Efficacy of Pencycuron Against Isolates Representing Different Anastomosis Groups of Rhizoctonia solani and Rhizoctonia-like Binucleate Fungi

By: Donald R. Sumner
Pencycuron was evaluated for efficacy against isolates of Rhizoctonia solani and Rhizoctonia-like binucleate fungi in soil in the greenhouse at 10.0, 1.0, and 0.1 g/g of soil. Soil was infested separately with isolates of R. solani (AG-2 type 1, AG-2 type 2, and AG-4) and isolates of Rhizoctonia-like binucleate fungi (CAG-2, CAG-3, CAG-4, and CAG-5) from soil and plants in Georgia. Of the 14 isolates, only one isolate of R. solani AG-2 type 1 was resistant to pencycuron and caused root and hypocotyl rot in snap bean at all dosages tested. Root and hypocotyl rots of snap bean caused by isolates of R. solani AG-2 type 2, AG-4, a second isolate of AG-2 type 1, and isolates of CAG-5 were controlled by pencycuron at 10.0 and 1.0 g/g of soil. Colony-forming units of only one isolate each of AG-2 type 1, CAG-4, and CAG-5 were detected in soil 3 wk after treatment at 10 g/g.


Binding of dicamba to soluble and bound extracellular polymeric substances (EPS) from aerobic activated sludge: A fluorescence quenching study

By: Pan; Xiangliang; Liu; Jing; Zhang; Daoyong; Chen; Xi; Song; Wenjuan; Wu; Fengchang
Binding of dicamba to soluble EPS (SEPS) and bound EPS (BEPS) from aerobic activated sludge was investigated using fluorescence spectroscopy. Two protein-like fluorescence peaks (peak A with Ex/Em = 225 nm/342-344 nm and peak B with Ex/Em = 275/340-344 nm) were identified in SEPS and BEPS. Humic-like fluorescence peak C (Ex/Em = 270-275 nm/450-460 nm) was only found in BEPS. Fluorescence of the peaks A and B for SEPS and peak A for BEPS were markedly quenched by dicamba at all temperatures whereas fluorescence of peaks B and C for BEPS was quenched only at 298 K. A dynamic process dominated the fluorescence quenching of peak A of both SEPS and BEPS. Fluorescence quenching of peak B and C was governed a static process. The effective quenching constants (log K-a) were 4.725-5.293 for protein-like fluorophores of SEPS and 4.23-5.190 for protein-like fluorophores of BEPS, respectively. Log K-a for humic-like substances was 3.85. Generally, SEPS had greater binding capacity for dicamba than BEPS, and protein-like substances bound dicamba more strongly than humic-like substances. Binding of dicamba to SEPS and BEPS was spontaneous and exothermic. Electrostatic force and hydrophobic interaction forces play a crucial role in binding of dicamba to EPS. (C) 2010 Elsevier Inc. All rights reserved

New Pesticides Regulation enters into force in Europe

Author:Claudio Mereu
Regulation 1107/2009 of the European Parliament and Council of 21 October 2009 concerning the placing of plant protection products on the market entered into force on 14th December 2009 and became effective on 14 June 2011. It replaces the current legislation on plant protection products (subject to some transitional measures), which is laid down in Council Directive 91/414/EEC and several implementing Regulations.
Broadly speaking, the harmonized authorization system for active substances used in plant protection products, as originally set out in Directive 91/414/EEC, is maintained. Indeed, the placing on the market of plant protection products is still subject to a two-steps process whereby active substances are approved at the EU-level (with the inclusion into a ‘positive list’ - Annex I to the new Regulation) while formulated products are authorised at the national level based on ‘Uniform Principles’ laid down in a new implementing Regulation 546/20111. However, the criteria underlying each of these two steps have changed remarkably.
From a procedural standpoint, in order to obtain an approval for the active substance, the applicant must first submit a comprehensive dossier on the substance, including full information on the nature and composition of the substance, details of tests carried out on crops and plants, safety data and means of detection, to a Rapporteur Member State (RMS). The RMS is then responsible for carrying out a full evaluation of the substance and submitting a draft assessment report to the Commission, the other member states and the European Food Safety Authority (EFSA). On the basis of this assessment report, EFSA will organize a peer review of the evaluation with the other member states and present its conclusion to the Commission within 120 days after the end of the commenting period. Based on the EFSA conclusions, the Commission will decide, through the regulatory ‘comitology’ procedure, whether or not to include the substance in Annex I.
From a substantive standpoint, Regulation 1107/2009 introduces new hazard-based “cut-off criteria” for approval based on the intrinsic properties of the active substance, safener or synergist. In essence, the approval process should not proceed further if the substance is a carcinogen, mutagen or reproductive toxicant (“CMR”), a persistent organic pollutant (“POP”), a persistent-bioaccumulative-toxic substance (“PBT”) or a very persistent and very bio-accumulative substance (“vPvB”). Moreover, substances meeting the criteria for endocrine disruption will be under special scrutiny (however, the Commission is yet to adopt specific criteria). However, strictly legally speaking endocrine disruption is not a cut off criterion.
The new regulation also has a wider scope in that it provides for the approval of safeners and synergists, a negative list of co-formulants and a future list of adjuvants to be adopted by the Commission, as well as new provisions for treated seeds and parallel imports.
Importantly, the new Regulation provides that active substances shall become candidates forsubstitution if certain conditions are met (e.g., where the ADI, ARfD or AOEL is significantly lower than another active substance or the substance meets two criteria for PBT), and plant protection products may be subject to a comparative assessment and substitution where there are other products presenting significantly lower risk for human health or the environment without entailing significant economic and practical disadvantages for the user.
The approval of an active substance may be subject to conditions and restrictions, such as restrictions on then means of application of plant protection products containing the active substance, crops to which they can be applied, limitation of use to professional users, monitoring after use and other risk-mitigation measures. Further measures are provided for in relation to the inspection and monitoring on production, storage, transport and use of plant protection products.
For active substances on the market when the regulation enters into force (and which have been or are being subject to the ongoing review programme under Article 8(2) of Directive 91/414/EEC), a review of the authorization will be carried out in the timelines foreseen under the old legislation, using the new criteria laid down in the new regulation.
The authorization of plant protection products will continue to be done by national authorities in line with harmonized EU rules and procedures. However, the new regulation introduces compulsory mutual recognition of authorizations only among Member States within the same defined zone, with a degree of flexibility to accommodate local conditions. Three zones have been defined on the basis of relevant factors, such as similar climatic, agricultural and ecological conditions:
North zone - Denmark, Estonia, Latvia, Lithuania, Finland and Sweden.
Central zone - Belgium, Czech Republic, Germany, Ireland, Luxembourg, Hungary, Netherlands, Austria, Poland, Romania, Slovenia, Slovakia and the U.K.
South zone - Bulgaria, Spain, Greece, France, Italy, Cyprus, Malta and Portugal.
Lastly, Regulation 1107/2009 contains important new provisions on data confidentiality and data sharing to avoid the duplication of testing of plant protection products on vertebrate animals. In short, as regards confidentiality, the Regulation now contains a positive list of data which are in principle regarded as confidential (e.g., manufacturing process, impurities unless they are toxicologically relevant, see Article 63). As regards data sharing, data owners and prospective applicants must “make every effort” to ensure that they share tests and studies involving vertebrate animals against “fair share of the costs” incurred by the data owner. Broadly speaking this obligation applies to both vertebrate and non-vertebrate animal tests. However, in the case of vertebrate studies, should the parties concerned fail to reach an agreement, the Member State authorities are entitled to refer to the studies for the benefit of the prospective applicant, while the data owner has a claim before a national arbitration panel or Court for a “fair share” of the costs. Regulation 1107/2009 does not define in detail the procedure, timing or criteria for data sharing, nor does it specify what constitutes a “fair share”. Accordingly, unless the Commission adopts a guidance document on data sharing these critical aspects may be further clarified by arbitration panels and Court decisions.
In conclusion, the new Regulation has tightened the rules and process for the placing on the market of plant protection products. Behind the stated intention of achieving a high level of protection for human health and the environment, the EU has increased significantly the standards that industry will have to meet in order to commercialise its products in the future. While benefitting from a new, comprehensive and fully harmonised regulatory platform the agrochemical industry will be faced with many new hurdles and variable parameters such as the ‘substitution principle’ and comparative assessment, amongst others, requiring a close coordination of business, scientific and legal considerations.

Yangzhou pioneer chemical CO.,LTD

2011年12月29日星期四

About pencycuron: Comparison of Seed Treatments and Soil Drenches with Fungicides for the Control of Rhizoctonia Diseases of Spinach

By: Hsing-lung Liu
Seed treatment and soil drench were used for screening chemicals that inhibiting Rhizoctonia diseases of spinach. In the laboratory and greenhouse tests, Tolclofos methyl, Flutolanil, Iprodione, and Pencycuron were better than other chemicals in these two treatments. Furthermore, two trials in the field, Tolclofos methyl, Flutolanil and Pencycuron were the most effective with the soil drench had better result than the seed treatment for control the Rhizoctonia diseases of spinach