:Pendimethalin

Pendimethalin protects crops like wheat, corn, soybeans, potatoes, cabbage, peas, carrots, and asparagus. It is used to control annual grasses and certain broadleaf weeds which interfere with growth, development, yield and quality of agricultural and horticultural crops by competing on nutrients, water and light.

Where weed infestation is particularly bad, yield loss can render wheat production uneconomical.Clarke, Wynn, Twinning, Berry, Cook, Ellis and Gladders Pesticide availability for cereals and oilseeds following revision of Directive 91/414/EEC; effects of losses and new research priorities. In: HGCA Research Review. Nr. 70, 2009. Many other crops are grown in Europe that make a fraction of total agriculture. Herbicide options are limited for these minor crops, particularly in the vegetable sector.Little J.: EU´s pesticide regulation must be challenged. In: FarmBusiness. 2009 S. 26–27. Long-term field studies performed by the German government and institutions together with farmers call pendimethalin efficient for controlling blackgrass, regarding weed control efficacy, crop yield, treatment costs and environmental impact.Gehring, K. and S. Thyssen: Unkrautmanagement im Getreidebau – Herbizid-Leistungszahl – eine mehrfaktorielle Bewertung von Herbizidbehandlungen. LFL Pflanzenschutz. Institut für Pflanzenschutz der Bayerischen Landesanstalt für Landwirtschaft. In: Freising-Weihestephan, Deutschland. 2004.Gehring, K. and S. Thyssen: Unkrautmanagement im Getreidebau – Herbizid-Leistungszahl – eine mehrfaktorielle Bewertung von Herbizidbehandlungen. LFL Pflanzenschutz. Institut für Pflanzenschutz der Bayerischen Landesanstalt für Landwirtschaft. In: Freising-Weihestephan, Deutschland. 2007.Gehring, K.: Ackerfuchschwanz und Windhalm – die zwei bedeutendsten Ungräser im Getreidebau. In: Getreide Magazin. Nr. 1, 2009, S. 20-25.

There is some control of Johnsongrass, but other dinitrolaniline herbicides, such as trifluralin and profluralin, showed much stronger effect.{{cite journal |last1=Jordan |first1=T. N. |last2=Baker |first2=R. S. |last3=Barrentine |first3=W. L. |title=Comparative Toxicity of Several Dinitroaniline Herbicides |journal=Weed Science |date=1978 |volume=26 |issue=1 |pages=72–75 |doi=10.1017/S0043174500032707 }}

In 2012, {{convert|6-12|e6lb|t}} of pendimethalin was used in the US.{{cite web |last1=US EPA |first1=OCSPP |title=Pesticides Industry Sales and Usage 2008 - 2012 Market Estimates |url=https://www.epa.gov/pesticides/pesticides-industry-sales-and-usage-2008-2012-market-estimates |website=www.epa.gov |language=en |date=29 October 2015}}

Pendimethalin acts in both pre-weed-emergence and early post-emergence. Pendimethalin is absorbed into roots and shoots, inhibits cell division and prevents growth,{{cite web |title=4Farmers Pendimethalin 440 EC Infosheet |url=https://4farmers.com.au/wp-content/uploads/2020/11/4F-Pendimethalin-440.pdf |website=4farmers.com.au |publisher=4Farmers Australia Pty Ltd}} to prevent weeds from emerging, particularly during the development phase of the crop. Its primary mode of action is to prevent plant cell division and elongation in susceptible species. In the HRAC classification of herbicides according their mode of action, pendimethalin is listed in group K1, also called group D (Australia) or group 3 (numeric).

A study in the International Journal of Cancer suggests that Pendimethalin exposure is associated with higher incidence of pancreatic cancer.{{Cite journal |last1=Andreotti |first1=Gabriella |last2=Freeman |first2=Laura E. Beane |author-link2=Laura Beane Freeman |last3=Hou |first3=Lifang |last4=Coble |first4=Joseph |last5=Rusiecki |first5=Jennifer |last6=Hoppin |first6=Jane A. |last7=Silverman |first7=Debra T. |last8=Alavanja |first8=Michael C. R. |date=2009-05-15 |title=Agricultural pesticide use and pancreatic cancer risk in the Agricultural Health Study Cohort |journal=International Journal of Cancer |volume=124 |issue=10 |pages=2495–2500 |doi=10.1002/ijc.24185 |issn=1097-0215 |pmc=2674312 |pmid=19142867}} Mechanistic studies linking Pendimethalin to pancreatic cancer are lacking, warranting additional research. A French study found no association with lung cancer.{{cite journal |last1=Boulanger |first1=Mathilde |last2=Tual |first2=Séverine |last3=Lemarchand |first3=Clémentine |last4=Baldi |first4=Isabelle |last5=Clin |first5=Bénédicte |last6=Lebailly |first6=Pierre |journal=Occupational & Environmental Medicine |title=0441 Exposure to dinitroanilines and risk of lung cancer (Lc) by subtypes: Results from the agrican cohort |date=August 2017 |volume=74 |issue=Suppl 1|page=A140.1 |doi=10.1136/oemed-2017-104636.365}}

Pendimethalin exposure can reduce apoptosis.{{cite journal |last1=Sarıgöl Kılıç |first1=Zehra |last2=Ündeğer Bucurgat |first2=Ülkü |title=The Apoptotic and Anti-Apoptotic Effects of Pendimethalin and Trifluralin on A549 Cells In Vitro |journal=The Turkish Journal of Pharmaceutical Sciences |date=2018 |volume=15 |issue=3 |pages=364–369 |doi=10.4274/tjps.94695|pmid=32454683 |pmc=7227839 }}

Herbicide resistance increases production costs and limits herbicide options, cultivations and rotations. Up to 2009 pendimethalin did not show resistance. It is not cross-resistant with other grass weed herbicides. So pendimethalin supports other supplementary grass weed herbicides using other modes of action.Moss, S. R. and R. Hull: The value of pre-emergence herbicides for combating herbicide-resistant Alopecurus myosuroides (blackgrass). In: Aspects of Applied Biology. Nr. 91, 2009. Lolium rigidum has evolved resistance to pendimethalin, at least in part due to increased cytochrome P450 activity. This resistance mechanism in ryegrass (shared with other dinitroanilines like trifluralin, see for longer explanation) is by an opposing mutation to resistance to prosulfocarb, a thiocarbamate herbicide. By evolving resistance to one, the weed devolves its resistance to the other.{{cite journal |last1=Chen |first1=Jinyi |last2=Yu |first2=Qin |last3=Patterson |first3=Eric |last4=Sayer |first4=Chad |last5=Powles |first5=Stephen |title=Dinitroaniline Herbicide Resistance and Mechanisms in Weeds |journal=Frontiers in Plant Science |language=English |doi=10.3389/fpls.2021.634018 |date=25 March 2021|volume=12 |doi-access=free |pmid=33841462 |pmc=8027333 }}

Pendimethalin is registered globally for a wide range of crops, according to human and environmental safety standards by the European Commission, US-EPA, Canada-PMRA, Japan, Brazil-ANVISA and others.

Pendimethalin is not toxic to mammals, though interestingly the oral LD₅₀ for rats and mice is 1050-1620 mg/kg, yet for dogs and rabbits it is much less harmful, at over 5000 mg/kg. For comparison, table salt's LD₅₀ is 3000 mg/kg. There may be chronic effects however; repeated or prolonged skin exposure may cause eczema, hives or Quincke's oedema. Prolonged exposure by other routes may affect changes to the liver.{{cite web |title=4Farmers Pendimethalin 440 Safety Sheet |url=https://4farmers.com.au/wp-content/uploads/2020/11/4FARMERS-PENDIMETHALIN-440-HERBICIDE.pdf |website=4farmers.com.au |publisher=4Farmers Australia}}

Pendimethalin is highly persistent in soil and water. It has high potential for bioaccumulation, and it is moderately mobile in soil,{{cite web |title=4Farmers Pendimethalin 440 EC Leaflet |url=https://4farmers.com.au/wp-content/uploads/2020/11/4FARMERS-PENDIMETHALIN-440-HERBICIDE.pdf |website=4farmers.com.au |publisher=4Farmers Australia Pty Ltd}} despite it adsorbing strongly into soil.{{cite web |title=PRE-EMERGENT HERBICIDES FACT SHEET |url=https://grdc.com.au/__data/assets/pdf_file/0032/575069/GRDC_PreEmergentFS_2022_Final-approved-version.pdf |publisher=Grains Research and Development Corporation |date=2022}}

Tradenames include Pendimethalin 440, Satellite, Halts, Prowl, PRE-M, Stomp, Stealth and Pendulum, Hilpendi etc.

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{{Aniline Herbicides}}

Category:Anilines

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Category:Endocrine disruptors

Category:Preemergent herbicides

Category:Alkyl-substituted benzenes

Category:Secondary amines

Category:Group 3 herbicides