What’s left to put in the sprayer?
Barrie Hunt Technical Development Manager Monsanto UK Ltd. Some assumptions
Focused on herbicides, or weedkillers
Amenity use – not agriculture or horticulture
For total weed control or Control of tough broad-leaved weeds, woody plants and scrub. Twenty-four herbicides have been developed in the UK for total weed control or control of tough broad-leaved weeds and scrub
Number of new discoveries 9
8
7
6
5
4
3
2
1
0 1900-40 1940s 1950s 1960s 1970s 1980s 1990s 2000s The first total herbicide …(after fire, flood or pestilence!)
Sodium Chlorate Holds the record for the longest herbicide UK ‘registration’ ever 99 years! From 1910 to 2009 Total weedkiller for paths, drives, around buildings, waste land. Very inflammable! Clothing or rags wetted by the spray could ignite spontaneously if left to dry in bright sunlight. Dead vegetation was particularly flammable Was usually sold formulated with a fire suppressant Amitrole 2,4,5-T 1940s-60s: Bromacil The Rise of Organic Chemistry
Dalapon Dichlobenil Picloram Monuron
2,3,6-TBA Diuron
Chlorthiamid Simazine
Atrazine Paraquat 4-CPA 1974: Monsanto, a little known company, introduced a new weedkiller
Roundup® herbicide
360g ae/l glyphosate
Present as IPA (isopropylamine) salt
Surfactant system based on tallow amines
Non-selective total herbicide with systemic action
Non-residual
Amenity rate was 3½ pints an acre.
Launch Price: £55/5L Average weekly wage: £54; Pint of beer 20p Such a simple molecule…
Glycine is a naturally occurring amino acid. HO H N It is the simplest amino acid
It is one of the protein-creating O H amino acids. Glycine Colourless, sweet-tasting, crystal Phosphorylation
A phosphoryl group is attached to the glycine to make glyphosate. HO N PO H Phosphorylation of amino acids 3 occurs very widely in nature. O H Estimated that 156,000 protein phosphorylation sites exist in Glyphosate humans. [N-(phosphonomethyl) glycine] Less means more… The arrival of sulfonyl ureas
Flazasulfuron in 1989 and Sulfosulfuron in 1995 ushered in the era of sulfonyl ureas. Highly active herbicides delivered at doses measured in grams not kilograms. 37.5 g/ha Flazasulfuron
vs. 5,000 g/ha Simazine
vs. 500,000 g/ha Sodium chlorate
Work by inhibiting Acetolactate Synthase (ALS) enzyme production.
Single site active so significant risk of resistance development A new Picolinic Acid for the new Millennium
Aminopyralid was introduced in 2000
A new pyridinecarboxylic (or picolinic) acid product from Dow AgroSciences
Very difficult and specialist area of chemistry of which Dow are the experts!
Joined Picloram (1963) and Triclopyr (1973) as important amenity products from this chemical family. ‘Natural’ herbicides
For completeness I’ll mention the ‘natural’ weed control products.
Key ones in UK would be:
Acetic acid
Pelargonic acid
Entirely contact action.
Fast but effects short lived on anything other than very small seedlings
Very high doses required.
Frequent repeat application for subsequent regrowth Active Reported Sodium Chlorate 1910 Borax 1942 2,4,5-T 1944 4-CPA 1950 Diuron 1951 So, with all this Monuron 1951 2,3,6-TBA 1952 Amitrole 1953 chemistry there must Simazine 1956 Atrazine 1957 be plenty of options? Paraquat 1958 Dalapon 1960 Dichlobenil 1960 Bromacil 1962 Picloram 1963 Chlorthiamid 1964 Glyphosate 1971 Triclopyr 1973 Glufosinate 1981 Imazapyr 1983 Diflufenican 1985 Flazasulfuron 1989 Sulfosulfuron 1995 Aminopyralid 2000 Active Reported Sodium Chlorate 1910 Borax 1942 2,4,5-T 1944 4-CPA 1950 Diuron 1951 Unfortunately we’ve Monuron 1951 2,3,6-TBA 1952 Amitrole 1953 lost many of these Simazine 1956 Atrazine 1957 active ingredients. Paraquat 1958 Dalapon 1960 Dichlobenil 1960 Bromacil 1962 PicloramPicloram 19631963 Chlorthiamid 1964 Glyphosate 1971 TriclopyrTriclopyr 1973 Glufosinate 1981 Imazapyr 1983 Diflufenican 1985 Flazasulfuron 1989 Sulfosulfuron 1995 Aminopyralid 2000 Availability of active substances today
No. of new discoveries 9 Lost 8 Reduced/limited 7 Available 6
5 75% 4 of all molecules lost or of 3 limited use 2
1
0 1900-40 1940s 1950s 1960s 1970s 1980s 1990s 2000s Availability of active substances today
The re-Approval of glyphosate What happened next?
Following assessment by both European Food Safety Authority (EFSA) and European Chemicals Agency (ECHA) the European Commission drafted a new regulation for the re-Approval of glyphosate in mid-June 2016. The regulation proposed renewal for 10 years, rather than the full 15 years.
This was submitted to the Standing Committee on Plants, Animals, Food and Feed (SCoPAFF) for discussion and voting. Despite three meetings (18-19 July, 5-6 October, 25 October) this proposal failed to gain Qualified Majority Vote (QMV) status and was rejected.
15 Where are we up to?
Following the 26 October meeting the European Commission re-drafted the regulation and proposed renewal for just 5 years. No other changes were included. There were no further use restrictions proposed. The proposed uses still included amenity, forestry, aquatic, hard- surface etc. This was voted on at the SCoPAFF meeting on 9 November.
16 Next steps
The vote was inconclusive with no QMV for or against renewal.
The decision then passed to the Appeals Committee
On 27 November 2017 the Appeals Committee discussed and voted on the proposal. A qualified majority was achieved in favour of renewing the authorisation for 5 years.
Glyphosate therefore has been re-Approved and remains on the market in the EU. Glyphosate Resistance – A Real Threat!
No reported cases of glyphosate resistance in UK
In Europe resistance has been reported in amenity situations
Roadsides and railways
Fleabane (Conyza) species are involved so far.
Cause?
Over reliance on the same herbicide i.e. glyphosate
Not following label recommendations
No or limited IWM strategies Minimising Risk
Whenever possible use mixtures of herbicides Consider integrating non-chemical control measures Monitor and assess herbicide performance after spraying to detect any loss in control
Good record-keeping and assessment after spraying is essential in the early detection of resistance. Prevent survivors: Repeat applications to surviving plants presents the greatest risk! If resistance is suspected:
Contact your supplier and/or the product manufacturer Act quickly to prevent spread- use a strategy involving alternative herbicides and non-chemical techniques Collect seed samples for testing to confirm resistance To summarise…
Sodium chlorate was the first ‘amenity’ herbicide introduced in the early years of the last century.
The rise of organic chemistry has delivered a flurry of new herbicides since the 1940s.
This included the arrival of Glyphosate in 1974
Initially priced at more than a week’s wages, the product ushered in cost-effective low hazard amenity weed control.
Unfortunately, today we have lost 75% of previously available products.
That made it even more important that it was successfully renewed for a further 5 years.
Now that it has been re-Approved we must implement effective stewardship to prevent resistance development. Thank You! Glyphosate – Past, Present & Future
Barrie Hunt Technical Development Manager Monsanto UK Ltd.