Managing Weed Control Effectively

1
Managing Weed Control Effectively Andrew
Robinson Rigby Taylor Limited
2
Regulatory Issues Future Directions

• Focus for the future on approvals for new
  molecules and on -going review of existing
  molecules
• Environmental Fate
• Operator Exposure
• Carcinogenic

3
Regulatory Issues Diuron

• Manufacturers of Diuron formed a Task Force to
  share
• defence costs and data costs
• New data has been submitted by the task force to
  EU
• regulatory authorities during 2007
• Submission is based on new molecule looks
  likely to
• succeed. Could re-appear in UK, however
  application rates,
• application methods and application period
  could change

4
Regulatory Issues Diuron

• Manufacturers sell out to distribution channels
  December 07
• Distribution channels sell out to end users
  December 2008
• End users must use up all material by December
  2008 (bear in
• mind label recommendations etc)

5
Dichlobenil
The Proven solution in Vegetation Management
6

• 6.75 w/w dichlobenil
• Easy to apply granules no need for mixing
• Low dust content
• Lower rate for selective weed control
• Higher rate for total weed control
• Paving / Tarmacadum
• Non-hazardous classification, important in making
  a COSHH assessment

7

• Packaging
• 15kg Pack Size
• 66 x 15kg per pallet
• User friendly
• Compliance with The Manual Handling Regulations

8

• Provides the reliable, effective solution to
  season long annual and perennial weed growth
• Can be relied on to perform year in year out
• Gives selective or total weed control
• Has a non-classified label and possesses one of
  the most acceptable profiles of any modern
  herbicide
• Has a uniform shape and size which gives an even
  distribution for consistent control

9
(No Transcript)
10
How Soil Applied Herbicides Work?


Established Weeds
Weed Seeds
Herbicidal Zone
Embargo G 6.75 dichlobenil
11
Soil Applied Herbicides

• Soil applied and activated by soil moisture and
  rainfall
• A herbicide layer below the soil surface of about
  2.5 - 5cm is established, forming a herbicidal
  zone
• Enters the roots of germinating broadleaved weeds
  and inhibits their development.
• Most germinating weeds die before
  reaching the soil surface

12
Problem Weeds. Control
13
Formulation

• Contains three powerful active ingredients
• 200g/l (19.34) 2,4-D
• 85g/l (8.22) dicamba
• 65g/l (6.29 triclopyr
• EC formulation

14
Key Benefits

• Developed specifically for the control of problem
  weeds in vegetation management
• Safety to neighbouring desirable vegetation
• Outstanding control of a range of deep-rooted
  perennials and brushwood species
• Flexible rates in either stand alone or tank mix
  combinations

15
A Modern Defence Against Invading Weeds

• Application Rates - Amenity Grassland
• Label Recommendation
• 2.0 - 5.0 Litres / ha
• Vegetation Management Control
• 3.0 L / ha
• Check top growth of perennial weeds
• 2.0 L /ha
• In 300 - 400 litres of water per hectare

16
A Modern Defence Against Invading Weeds

• Controls many hard to kill Woody weeds e.g.
• Bramble briar
• Birch, Broom, Ash, Gorse, Oak, Sycamore, Elder
• Blackthorn, Dogwood, Hazel, Willow, Buddleia
• Rhododendren
• Japanese Knotweed

17
A Modern Defence Against Invading Weeds
Controls many hard to kill weeds
- Creeping Buttercup - Common Daisy - Dandelion -
Broad-leaved Dock - Curled Dock - Japanese
Knotweed

• - Common Nettle
• - Creeping Thistle
• - Spear Thistle
• - Plantains
• - Hawkweed
• - Common Ragwort

18
Cut Stump Treatment

• Treatment should be applied immediately after
  felling at any time of the year except during
  spring sap flow
• Application in standing conifer crops should be
  delayed until late summer when extension growth
  has ceased
• Rates of Use - Apply between 20ml to 200ml

19
Key Benefits

• Does not harm grasses
• High strength formulation
• All year round applications
• Low application rates
• Fast absorption
• Controls hard to kill weeds

20
Japanese Knotweed

• Forms dense clumps up to 3 metres in height
• Early Spring, plant produces fleshy red tinged
  shoots
• These can reach a height of 1.5 metres by May
  and 3 metres
• by June
• Plants can grow as much as 2cms per day
• Will thrive in any type of soil
• Extensive underground rhizome structure that can
  extend
• several metres
• Does not produce viable seeds in the UK

21
Common Ragwort

• One of the most injurious weeds specified in the
  Weeds Act
• 1959
• Ragwort is normally a biennial (rosette spring
  1st year,
• flowering July/August 2nd year)
• Seeds can be dormant in the soil for up to 20
  years
• Each plant can produce up to 150,000 seeds with
  a 70
• germination rate
• The Ragwort Control Act 2003 Under this
  legislation
• landowners and occupiers have a legal
  obligation to control
• the spread of Ragwort

22
Managing Weed Control ... Horse-tail or Mares-tail
It has two types of growth, in spring brown
asparagus-like shoots appear with cones at the
tips and these produce spores. Later the more
familiar thin green, branched stems appear and
these remain until winter. Both are produced from
creeping underground rhizomes, which go down
about 1.5 metres
23
Glyphosate
24
Glyphosate Chemistry

HO
PO-CH2-NH-CH2-COOH
HO

• IUPAC N-(Phosphonomethyl)Glycine
• Formula C3H8NO5P
• Molecular weight 169.07 g/mol
• Water solubility 15 g/l _at_ pH7

Impossible to formulate as an acid!
25
Whats different

• No performance difference between
  glyphosate/surfactant ratios from 21 to 51
• Whatever surfactant class
• Whatever salt of glyphosate
• Best performance when high surfactant content
  Gallup Hi Aktiv

26
Whats different

• No performance difference between
  glyphosate/surfactant ratios from 21 to 51
• Whatever surfactant class
• Whatever salt of glyphosate

27
Clean Label Products
28
Clean Label Products
29

• Factors which affect performance of all
  glyphosate products
• Hard water
• Poor calibration application
• Nozzle selection
• Equipment condition servicing
• Weather Conditions
• Application Timings
• Application Rates
• Weed Spectrum (Under dosing)

30

• Tank Mixing Issues
• Water Volumes Applied
• Most products are applied at much lower water
  volumes than recommended by manufacturers
• Low water volumes in conjunction with complex
  mixes can exacerbate problems maintain water
  volumes if unsure
• Water Temperature
• Cold water (lt 5 degrees C) makes tank mixing more
  difficult
• Water Hardness
• Hard water, especially if cold as well, makes
  tank mixing more difficult. A water conditioner
  such as Assist will help
• Leaving Sprayers Standing
• Always spray as soon as possible after filling
  the sprayer. Products can be difficult to get
  back into suspension once they have settled out..

31

• Order of Mixing
• It is important to follow the correct order of
  mixing, as shown in the table
• below
• Note that some Micronutrients are solid
  formulations and therefore should
• be added to the tank as indicated for wettable
  powders or WDGs

Observing the above factors (either individually
or in combination) will minimise any tank mix
issues that might otherwise occur
32
Alkaline Hydrolysis

• Breakdown of pesticides due to high pH
  (alkalinity)
• Some pesticides can breakdown into inactive parts
  in a matter of minutes
• The ideal pH for spray solutions is slightly
  acidic (pH 5 7)
• Hard water contains calcium (Ca2), magnesium (Mg
  2) and iron Fe 3)

33
Alkaline Hydrolysis

• Hard water ions can replace pesticide ions
• Water Conditioners lowers pH and ties up hard
  water ions
• A blend of water conditioning agents and
  acidifiers
• Water Conditioners
• Removes carbonates bicarbonates
• Modifies pH of spray solutions