BASIS POINTS Selective weed control
Graham Paul’s ‘Longbow’, ‘Relay’, ‘Re-Act’ or ‘T2 alikes’ are the Hawkbits; Autumn Green’. Hawkbit (Leontodon autumnalis) latest BASIS article The common Dandelion and Rough Hawkbit (Leontodon looks at unusual (Taraxacum officinale) gets its hispidus). Rough Hawkbit is a very turf weeds and how name from the corrupted French hairy plant in contrast to Autumn description of the leaves (‘dents de Hawkbit; which has more slen- to identify them lion’ – lion’s teeth) but natives of der, often hairless leaves. Rough France may also know this weed Hawkbit has un-branched flower With spring weather hopefully to survive in this environment is by the name ‘pis en lit’ - a reference stems whereas Autumn Hawkbit around the corner, maybe due to a genetic adaptation that to bed wetting that myth tells us can have two or three branches in it’s time to consider some allows them to withstand condi- can result from picking dandelion its flower stems. strategies for selective weed tions of high salinity. The salt mist flowers! Most people can identify These two Hawkbits can be control. In the UK there are coming from the sea will increase a dandelion but there are several controlled by with two applications over 50 species of broad-leaved the levels of sodium chloride in the other lookalikes that produce a of products containing MCPA, weeds that can be found in soil, which is then absorbed by the similar single yellow flower-head, mecoprop-P and dicamba at a rate mown turf. roots and accumulates in plant which can fool the untrained eye 3.5L/ha, such as ‘T-2-Green’ or Some species will be affected tissues. Abnormally high levels when the weed is found in mown ‘Re-Act’ by mowing closer than they can in plant cells will seriously affect turf. The first of these; Cat’s-ear Another dandelion flower ‘look with products containing 2,4-D, tolerate, so these will only survive the movement of water across cell (Hypochaeris radicata) has fleshy, alike’ is Mouse-ear Hawkweed MAIN ABOVE: Hawkbit Autumn in more natural, less intensively membranes and as a consequence, lobed, hairy leaves that (with a bit (Pilosella officinarum – formerly MCPA and mecoprop-P. Composite managed areas. Coastal environ- growth is slowed or halted com- of imagination) resemble the ‘fight- Hieracium pilosella) This perennial Selective herbicide products are INSET ABOVE: torn’ ears of a tom cat! I have seen herb has long leafy runners and usually formulated from two or Cats Ear Composite ments support a number of salt pletely. This osmotic imbalance can pink flowers and lastly Sea Stork’s- MAIN ABOVE: Thrift Armeria tolerant plants (halophiles) such cause the ‘stunted growth habit’ bill (Erodium maritimum), which maritima many different species of cat but produces a rosette of grey-green more active ingredients in order to extend the spectrum of control to as Buck’s-horn plantain (Plantago that some species exhibit in coastal has simple lobed leaves and small INSET ABOVE: Plantain - Bucks never one with green ears! The leaves that have soft, dense, short coronopus) and Thrift (Armeria regions or it can eliminate them pale pink or white flowers that Horn Plantago coronopus flower stalk is quite different from a white hairs on the underside and deal with as many turf weeds as maritima) that are not normally altogether. rapidly lose their petals. dandelion; being thinner, wiry and long stiff hairs on the upper surface. possible in one spray. Manufactur- found inland. Soil type, pH and the Three other weeds occasion- These species fall into the cat- bearing a few scale-like dark-tipped The florets have red stripes on ers try to match the weaknesses of availability of water will reduce the ally found in coastal turf include; egory of ‘unusual turf weeds’ and bracts. the under surface. one active ingredient with strengths list still further. Sea Plantain (Plantago maritima) are relatively easy to control with Cat’s-ear is relatively easy to The leaves are quite different of another, to create a ‘one product’ The first step in selective weed similar in appearance to Ribwort what I have termed the ‘general control with most general purpose from the dandelion but the flow- answer to weed control in turf. control is to identify the weeds pres- Plantain but with narrower fleshy purpose’ selective herbicides. selective herbicides but some ers can appear similar when fully However, due to the diversity of ent. Starting with seaside plants, leaves, Sea Milkwort (Glaux mari- These are a group of similar products may require a further open because the red stripes are weeds found in managed turf situa- ‘bathed’ in the salty mists that per- tima) a creeping perennial weed products that contain MCPA, application. not visible from above. Mouse-ear tions, the quest for complete control vade coastal habitats. Their ability with stalkless fleshy leaves and mecoprop-P and dicamba such as The next of the dandelion ‘look- Hawkweed is fairly easy to control has so far been elusive. Further-
46 GI APRIL 2013 APRIL 2013 GI 47 BASIS POINTS Selective weed control
Graham Paul’s ‘Longbow’, ‘Relay’, ‘Re-Act’ or ‘T2 alikes’ are the Hawkbits; Autumn Green’. Hawkbit (Leontodon autumnalis) latest BASIS article The common Dandelion and Rough Hawkbit (Leontodon looks at unusual (Taraxacum officinale) gets its hispidus). Rough Hawkbit is a very turf weeds and how name from the corrupted French hairy plant in contrast to Autumn description of the leaves (‘dents de Hawkbit; which has more slen- to identify them lion’ – lion’s teeth) but natives of der, often hairless leaves. Rough France may also know this weed Hawkbit has un-branched flower With spring weather hopefully to survive in this environment is by the name ‘pis en lit’ - a reference stems whereas Autumn Hawkbit around the corner, maybe due to a genetic adaptation that to bed wetting that myth tells us can have two or three branches in it’s time to consider some allows them to withstand condi- can result from picking dandelion its flower stems. strategies for selective weed tions of high salinity. The salt mist flowers! Most people can identify These two Hawkbits can be control. In the UK there are coming from the sea will increase a dandelion but there are several controlled by with two applications over 50 species of broad-leaved the levels of sodium chloride in the other lookalikes that produce a of products containing MCPA, weeds that can be found in soil, which is then absorbed by the similar single yellow flower-head, mecoprop-P and dicamba at a rate mown turf. roots and accumulates in plant which can fool the untrained eye 3.5L/ha, such as ‘T-2-Green’ or Some species will be affected tissues. Abnormally high levels when the weed is found in mown ‘Re-Act’ by mowing closer than they can in plant cells will seriously affect turf. The first of these; Cat’s-ear Another dandelion flower ‘look with products containing 2,4-D, tolerate, so these will only survive the movement of water across cell (Hypochaeris radicata) has fleshy, alike’ is Mouse-ear Hawkweed MAIN ABOVE: Hawkbit Autumn in more natural, less intensively membranes and as a consequence, lobed, hairy leaves that (with a bit (Pilosella officinarum – formerly MCPA and mecoprop-P. Composite managed areas. Coastal environ- growth is slowed or halted com- of imagination) resemble the ‘fight- Hieracium pilosella) This perennial Selective herbicide products are INSET ABOVE: torn’ ears of a tom cat! I have seen herb has long leafy runners and usually formulated from two or Cats Ear Composite ments support a number of salt pletely. This osmotic imbalance can pink flowers and lastly Sea Stork’s- MAIN ABOVE: Thrift Armeria tolerant plants (halophiles) such cause the ‘stunted growth habit’ bill (Erodium maritimum), which maritima many different species of cat but produces a rosette of grey-green more active ingredients in order to extend the spectrum of control to as Buck’s-horn plantain (Plantago that some species exhibit in coastal has simple lobed leaves and small INSET ABOVE: Plantain - Bucks never one with green ears! The leaves that have soft, dense, short coronopus) and Thrift (Armeria regions or it can eliminate them pale pink or white flowers that Horn Plantago coronopus flower stalk is quite different from a white hairs on the underside and deal with as many turf weeds as maritima) that are not normally altogether. rapidly lose their petals. dandelion; being thinner, wiry and long stiff hairs on the upper surface. possible in one spray. Manufactur- found inland. Soil type, pH and the Three other weeds occasion- These species fall into the cat- bearing a few scale-like dark-tipped The florets have red stripes on ers try to match the weaknesses of availability of water will reduce the ally found in coastal turf include; egory of ‘unusual turf weeds’ and bracts. the under surface. one active ingredient with strengths list still further. Sea Plantain (Plantago maritima) are relatively easy to control with Cat’s-ear is relatively easy to The leaves are quite different of another, to create a ‘one product’ The first step in selective weed similar in appearance to Ribwort what I have termed the ‘general control with most general purpose from the dandelion but the flow- answer to weed control in turf. control is to identify the weeds pres- Plantain but with narrower fleshy purpose’ selective herbicides. selective herbicides but some ers can appear similar when fully However, due to the diversity of ent. Starting with seaside plants, leaves, Sea Milkwort (Glaux mari- These are a group of similar products may require a further open because the red stripes are weeds found in managed turf situa- ‘bathed’ in the salty mists that per- tima) a creeping perennial weed products that contain MCPA, application. not visible from above. Mouse-ear tions, the quest for complete control vade coastal habitats. Their ability with stalkless fleshy leaves and mecoprop-P and dicamba such as The next of the dandelion ‘look- Hawkweed is fairly easy to control has so far been elusive. Further-
46 GI APRIL 2013 APRIL 2013 GI 47 BASIS POINTS
“Most speedwells flower very early in the spring so they are often difficult to control before the flowering stage”
more, repeated use of products that from early treatments may require leave some weeds uncontrolled can, a second spray. SELF ASSESSMENT over several seasons, lead to domi- The two species of Medick have nation by these resistant species. similar shaped leaves and flowers Use the questions below to Two weed groups spring to mind in to the Trefoils. Spotted Medick check your understanding of this respect; the yellow clovers and (Medicago arabica) has obvious this topic. Readers can claim the speedwells can both increase dark spots on the leaves that easily BASIS points if the questions Germander Speedwell. The latter, such as thistle, speedwell or yellow Germander Speedwell (Veronica trefoils then it may be prudent to in numbers to the extent that the separate it from all of the others. MAIN ABOVE: Medick - Spotted are answered correctly small flowers become highly visible, Black Medick (Medicago lupu- Medicago arabica chamaedrys), has two opposite treat the area with a tank-mix to requiring specialist herbicides to lina), a perennial, can be distin- INSET ABOVE: Black Medicago 1) What is the term used for lines of long hairs on the stem and extend the capabilities of a general remove them. guished from the yellow trefoils by lupulina salt tolerant plants? is notoriously difficult to control, purpose product such as ‘Relay’ or with frequent reports from users ‘T-2-Green’ with another amenity The yellow clovers are all mem- its ‘mucronate’ leaf tips. These are RIGHT PAGE BOTH IMAGES: a) Halogenic, b) chlorophile, bers of the pea family (Fabaceae); short, abrupt points on the end of Speedwell - Ivy Leaved c) halophile, d) osmotrope of re-growth after 6 weeks of treat- approved product. three species of Trefoils and two the leaf mid-vein. The seed pods Veronica hederifolia ment with some products. To achieve control of deep-rooted species of Medick. These five spe- are kidney shaped and turn black 2) Alongside the weed Other species occur in local weeds, consider using a mix with a cies can all be found in UK turf and when ripe . Autumn Hawkbit, which other environments and particular product containing 2,4-D amine, are fairly difficult to control and Black Medick can be controlled member of this family was habitats such as Marsh and Heath such as ‘Depitox’. Difficult weeds, even more difficult to identify! with the general purpose products mentioned? Speedwell. Like the yellow clovers, for example speedwell or yellow To distinguish between the three at the highest dose (where a range a) Rough Hawkbit, b) Smooth if they are left uncontrolled by trefoil would require a mix with one yellow trefoils look for leaf hairs, leaf of rates is recommended) but Hawkbit, c) Lesser Hawkbit general broad spectrum herbicides, of the specialist herbicides referred size and the number of flowers in retreatment may be necessary in d) Mouse-ear Hawkbit they can proliferate to the point that to in the relevant sections above. the flower head. some cases. Best control is indi- they dominate the sward. Most • Hop Trefoil (Trifolium camp- cated with the specialist herbicides 3) What term describes a leaf speedwells flower very early in the In order to stay legal when estre)has sparsely hairy leaves and suggested for the yellow trefoils. or bract with an abrupt point at spring (March/April) so they are tank-mixing it is important has 25 to 40 flowers per head. Spotted Medick may also respond the tip? often difficult to control before the to stick with the following • Lesser Trefoil (Trifolium dubium to these recommendations but I a) Periodate, b) stylate, flowering stage. guidelines: – also known as yellow suckling could not find a label or other refer- c) dentate, d) mucronate The majority of speedwells can be clover) has similar sized leaves to ence to confirm this. controlled with specialist selective • Check with your supplier that Hop Trefoil but they are usually Speedwells are members of the 4) What characteristic do all herbicides containing fluroxypyr, the proposed mixture is suitable hairless and there are between 15 genus Veronica, which includes Speedwells have in common? for instance; ‘Cabadex’, ‘Praxys’, ‘ for the intended use. A supplier and 25 flowers per head. about 15 UK species, many of which a) Blue flowers, b) hairy Swiftsure’ and ‘Trafalgar’. The offering to support a mix should • Slender Trefoil (Trifolium are found in turf and will require leaves, c) they are all annuals dual purpose moss control product have tested it and will know if there micranthum – also known as Least specialist selective herbicides to d) flowers have only 2 stamen ‘Jewel’ that contains carfentra- are any compatibility issues or Yellow Trefoil) has smaller leaves control them. All speedwells have zone–ethyl and mecoprop-P will effects on the performance of the and flowers with only 2 to 10 flow- flowers with only 2 stamens but 5) Yellow clovers found in also give moderate control of speed- products. ers in the flower heads. vary considerably by the leaf shape, turf are all members of which well species. • Note that when mixing two The yellow trefoils are best size, hairiness and by the colour of botanical family? or more pesticides in a tank-mix controlled with specialist selective the flowers; which can range from a) Figwort (Scrophulariaceae) Tank-mixing to increase weed all conditions of approval on all of herbicides containing mixtures deep blue to lilac, with some that b) Pea (Fabaceae) spectrum the product labels and safety data with fluroxypyr such as ‘Cabadex’, are almost white. c) Carrot (Apiaceae) sheets must be complied with. ‘Praxys’, ‘Swiftsure’ and ‘Trafalgar’. The more common varieties d) Rose (Rosaceae) In circumstances where the • If any product in the mix is sub- The general purpose products will found in turf include; Slender, weeds present in turf include deep ject to a LERAP requirement, then give some control but re-growth Ivy-leaved, Thyme-leaved and rooted or difficult to control weeds this applies to the tank-mix as well.
48 GI APRIL 2013 APRIL 2013 GI 49 BASIS POINTS
“Most speedwells flower very early in the spring so they are often difficult to control before the flowering stage”
more, repeated use of products that from early treatments may require leave some weeds uncontrolled can, a second spray. SELF ASSESSMENT over several seasons, lead to domi- The two species of Medick have nation by these resistant species. similar shaped leaves and flowers Use the questions below to Two weed groups spring to mind in to the Trefoils. Spotted Medick check your understanding of this respect; the yellow clovers and (Medicago arabica) has obvious this topic. Readers can claim the speedwells can both increase dark spots on the leaves that easily BASIS points if the questions Germander Speedwell. The latter, such as thistle, speedwell or yellow Germander Speedwell (Veronica trefoils then it may be prudent to in numbers to the extent that the separate it from all of the others. MAIN ABOVE: Medick - Spotted are answered correctly small flowers become highly visible, Black Medick (Medicago lupu- Medicago arabica chamaedrys), has two opposite treat the area with a tank-mix to requiring specialist herbicides to lina), a perennial, can be distin- INSET ABOVE: Black Medicago 1) What is the term used for lines of long hairs on the stem and extend the capabilities of a general remove them. guished from the yellow trefoils by lupulina salt tolerant plants? is notoriously difficult to control, purpose product such as ‘Relay’ or with frequent reports from users ‘T-2-Green’ with another amenity The yellow clovers are all mem- its ‘mucronate’ leaf tips. These are RIGHT PAGE BOTH IMAGES: a) Halogenic, b) chlorophile, bers of the pea family (Fabaceae); short, abrupt points on the end of Speedwell - Ivy Leaved c) halophile, d) osmotrope of re-growth after 6 weeks of treat- approved product. three species of Trefoils and two the leaf mid-vein. The seed pods Veronica hederifolia ment with some products. To achieve control of deep-rooted species of Medick. These five spe- are kidney shaped and turn black 2) Alongside the weed Other species occur in local weeds, consider using a mix with a cies can all be found in UK turf and when ripe . Autumn Hawkbit, which other environments and particular product containing 2,4-D amine, are fairly difficult to control and Black Medick can be controlled member of this family was habitats such as Marsh and Heath such as ‘Depitox’. Difficult weeds, even more difficult to identify! with the general purpose products mentioned? Speedwell. Like the yellow clovers, for example speedwell or yellow To distinguish between the three at the highest dose (where a range a) Rough Hawkbit, b) Smooth if they are left uncontrolled by trefoil would require a mix with one yellow trefoils look for leaf hairs, leaf of rates is recommended) but Hawkbit, c) Lesser Hawkbit general broad spectrum herbicides, of the specialist herbicides referred size and the number of flowers in retreatment may be necessary in d) Mouse-ear Hawkbit they can proliferate to the point that to in the relevant sections above. the flower head. some cases. Best control is indi- they dominate the sward. Most • Hop Trefoil (Trifolium camp- cated with the specialist herbicides 3) What term describes a leaf speedwells flower very early in the In order to stay legal when estre)has sparsely hairy leaves and suggested for the yellow trefoils. or bract with an abrupt point at spring (March/April) so they are tank-mixing it is important has 25 to 40 flowers per head. Spotted Medick may also respond the tip? often difficult to control before the to stick with the following • Lesser Trefoil (Trifolium dubium to these recommendations but I a) Periodate, b) stylate, flowering stage. guidelines: – also known as yellow suckling could not find a label or other refer- c) dentate, d) mucronate The majority of speedwells can be clover) has similar sized leaves to ence to confirm this. controlled with specialist selective • Check with your supplier that Hop Trefoil but they are usually Speedwells are members of the 4) What characteristic do all herbicides containing fluroxypyr, the proposed mixture is suitable hairless and there are between 15 genus Veronica, which includes Speedwells have in common? for instance; ‘Cabadex’, ‘Praxys’, ‘ for the intended use. A supplier and 25 flowers per head. about 15 UK species, many of which a) Blue flowers, b) hairy Swiftsure’ and ‘Trafalgar’. The offering to support a mix should • Slender Trefoil (Trifolium are found in turf and will require leaves, c) they are all annuals dual purpose moss control product have tested it and will know if there micranthum – also known as Least specialist selective herbicides to d) flowers have only 2 stamen ‘Jewel’ that contains carfentra- are any compatibility issues or Yellow Trefoil) has smaller leaves control them. All speedwells have zone–ethyl and mecoprop-P will effects on the performance of the and flowers with only 2 to 10 flow- flowers with only 2 stamens but 5) Yellow clovers found in also give moderate control of speed- products. ers in the flower heads. vary considerably by the leaf shape, turf are all members of which well species. • Note that when mixing two The yellow trefoils are best size, hairiness and by the colour of botanical family? or more pesticides in a tank-mix controlled with specialist selective the flowers; which can range from a) Figwort (Scrophulariaceae) Tank-mixing to increase weed all conditions of approval on all of herbicides containing mixtures deep blue to lilac, with some that b) Pea (Fabaceae) spectrum the product labels and safety data with fluroxypyr such as ‘Cabadex’, are almost white. c) Carrot (Apiaceae) sheets must be complied with. ‘Praxys’, ‘Swiftsure’ and ‘Trafalgar’. The more common varieties d) Rose (Rosaceae) In circumstances where the • If any product in the mix is sub- The general purpose products will found in turf include; Slender, weeds present in turf include deep ject to a LERAP requirement, then give some control but re-growth Ivy-leaved, Thyme-leaved and rooted or difficult to control weeds this applies to the tank-mix as well.
48 GI APRIL 2013 APRIL 2013 GI 49