(1) asulam (e.g. Asulox®, Rattler 400®)
• Use the low rate for broadleaf and curled dock in established lucerne (over 1 year old), and the high rate for other dock species. Apply when dock is in full leaf but before flower stems emerge.
• Do not use in lucerne seed crops.
(2) flumetsulam (e.g. Broadstrike®)
• Can be used in seedling and established lucerne. Apply to seedling lucerne from 2-3 trifoliate leaf stage onwards. Weeds should be seedlings (check label for specific weeds).
• For some weeds, tankmixes with other herbicides (e.g. bromoxynil, diuron, 2,4-DB) are recommended. Uptake additive or wetter must be used. Choice depends upon rate used and weed species (see label).
• Special conditions are recommended for irrigating after spraying (see label).
• When conditions at spraying are less than ideal, or when the crop is not competitive, wild radish and Paterson’s curse are only suppressed, except if treated when seedlings are very small.
• Check label for directions on re-cropping interval after spraying. Sensitive crops (e.g. canola, some legumes) should not be planted for up to 2 years on some soil types.
(3) bromoxynil (e.g. Bronco 200®, Bromicide®, Bronx 200®)
• Can be used once lucerne has one trifoliate leaf. Established lucerne should not be over 15 cm tall. Labels and application rates vary in weeds listed as controlled (see specific labels for detail).
• Weeds should generally be in the seedling stage (again, check individual product labels).
• Can cause some temporary leaf scorch, especially on seedling lucerne. Don’t apply if temperatures over 20°C are likely at, or within several days of, spraying as risk of scorch is increased.
• Bromoxynil can be used in cereals undersown with lucerne.
(4) butroxydim (e.g. Falcon WG®)
• Efficacy may be reduced when grass weeds are stressed. Use the lower rate on seedling grasses at the pre-tillering stage, and the higher rates on grasses at the early tillering (2-3 tiller) stage.
• Always add 1 L Supercharge®, or 2 L DC-Trate® per 100 L spray mix as the preferred adjuvants, except for aerial applications where rate is Supercharge® 1 L/ha. DC-Trate® is not recommended for aerial applications.
(5) diuron (e.g. Diuron 500SC®, Diuron Flowable®, Striker 500SC®, Diurex WG®, Diuron 800WG®, Diuron 900WDG®)
• Several different formulations are available and they vary in recommendations for weed control. (Check individual product labels for details.) Generally, use higher rates in the recommended ranges on heavier soils.
• Recommended for some grass and broadleaf weeds before weed emergence, or soon after.
• Some labels say lucerne should be grazed/cut before application. Some say not to use on winter-active lucernes. Seek specialist advice on product choice.
• Diuron can be tank mixed with certain knockdown herbicides such as SpraySeed® for control of established weed growth.
(6) ftuazifop-p (e.g. Fusilade®)
• Both Fusilade® and Fusion® can be used to control the seedling annual and perennial grasses listed in seedling and established lucerne.
• Add wetter as per label. Apply in at least 100 L/ha to 200 L/ha for established perennials.
• Can be used for spot spraying isolated infestations.
• A Group ‘A’ herbicide, watch for herbicide resistance.
(7) fluazifop-p + butroxydim (e.g. Fusion WG®)
• Use lower rates on grasses up to 4-leaf stage, then higher rates up to early tillering. Add Supercharge® or DC-Trate® at recommended rates.
• A Group ‘A’ herbicide, watch for herbicide resistance.
(8) propaquizafop (e.g. Correct®)
• Check labels for recommendations on tank mixes with Sertin 186® or Sertin Plus® to improve the spectrum of grass control, at reduced rates. Grass weed control will be reduced if weeds are stressed. Best results occur when weeds are actively growing, in their early tillering stages.
• Always add a non-ionic surfactant, e.g. BS1000® or Hasten®. Don’t use crop oils e.g. Synertrol® or Codacide® oil.
• Allow 10 days to elapse between application of these products and application of post-emergence broadleaf herbicides.
(9) paraquat (e.g. Paraquat 250®, Gramoxone 250®, Nuquat 250®, Maxitor 250®, Paradox 250®, Boa 250®, Shirquat 250®)
• Paraquat is a very dangerous (S7) herbicide — follow safety precautions as recommended on label.
• For autumn/early winter applications, use dose rates 1.2-1.6 L/ha. For late winter/early spring applications, use 1.6-2.4 L/ha. Use higher rates for dense weed stands.
• For residual weed control, or if Paterson’s curse, shepherd’s purse and some other broadleaf weeds are present, tank mix with diuron. If mintweed is present, tank mix with atrazine. Refer to labels for rates.
(10) sethoxydim (e.g. Sertin 186®, Sertin Plus®)
• Efficacy against grass weeds may be reduced if weeds are stressed (e.g. lack of moisture, extremes of temperature, affected by another herbicide), or if weeds are too advanced in their development. See label for specific weed recommendations.
• Apply when majority of grass weeds are in the 2- to 6-leaf stage and are actively growing. On winter weeds, when applying less than 100 L/ha spray volume, use 1 L of spray oil. In all other situations, use 2 L spray oil/ha.
• Can be tank mixed with Fusilade® for complementary activity on some grasses.
• Addition of oil is not required for Sertin Plus®.
• See label for dose rate refinement for various grass weeds under different conditions.
(11) atrazine (e.g. Maizina 500®, Gesaprim 600SC®, Atrazine 500®, Nu-trazine®, Atrazine 900DF®, Atragranz®, Atradex WG®)
• Registered at low-dose rates only for use in lucerne older than one year, against mintweed.
• Apply alone, or in tank mix with knockdown herbicides, when first germination of mintweed seedlings are 5-9 cm high, using low-volume boom spray applying 140-170 L spray mixture/ha.
(12) imazethapyr (e.g. Spinnaker®)
• Before deciding to apply Spinnaker®, check label for advice on recommended plant-back interval for subsequent crop plantings.
• Spinnaker is best used as an early post-emergence treatment, with residual benefits in seedling lucerne as well as pre-emergence to weeds in established lucerne.
• Apply following cutting or grazing, if necessary in mixture with registered knockdown products.
• Use post-emergence to weeds in seedling lucerne (from first trifoliate leaf stage in spring-sown lucerne, and from second trifoliate stage in autumn-sown lucerne), or in established lucerne as above, following cutting or grazing.
• See Table 5.2 for weeds that can be controlled with pre-emergence or post-emergence applications only.
• For higher weed populations, apply the higher rates of product.
• Most weeds have emerged by the time it is safe to spray in seedling lucerne. Therefore, the label lists only weeds controlled post-emergence, or pre- and post-emergence in this situation.
• In established lucerne, Spinnaker application can be timed either before the anticipated time of weed emergence, or after weed emergence. This allows a broader spectrum of weeds to be controlled. Application needs to be timed to suit the spectrum of weeds anticipated.
• If weeds controlled only by post-emergence application have emerged in established lucerne, Paraquat or SpraySeed® can be added to Spinnaker to kill these germinations (autumn/winter).
• Where Spinnaker is applied to emerged weeds, always add a non-ionic surfactant, e.g. BS1000®, with or without Boost® (to improve knockdown). Or preferably add an esterified canola oil, e.g. Hasten® @ 0.5-10/oV/V (500 m1-1 L/100 L).
• For wild oats, ryegrass, barley grass and wild radish, a follow-up herbicide of a different type may be needed for continued control. Some weeds may be stunted rather than killed. Post-emergence treatment gives best suppression of nutgrass.
• A Group ‘B’ herbicide — a high-risk group for herbicide resistance.
(13) paraquat + diquat (e.g. Spray-Seed 250®)
• For established lucerne (older than one year). The label lists ‘for control of most annual weeds:
• Spray 1.6 L/ha in autumn and 2.4 L/ha in winter after weeds germinate. Graze/cut the lucerne to reduce the height to 2-4 cm before spraying.
• Tank mix with diuron to improve control of Paterson’s curse and shepherd’s purse. Do not use the tank mix if oversowing.
• See label for directions on operator safety, use of protective clothing etc.
(14) quizalofop-p (e.g. Targa Forte®, Targa®, Tzar®, Leopard®, Hi Jack®, Navigator®, Pantera , Genie®)
• Apply to common couch (from seed only) from 2- to 4-leaf stage. For other grasses, apply from 3-leaf to early tillering (mid-tillering for wild oats, and 3-tiller for Johnson grass. Where two rates are given, use the lower on plants up to commencement of tillering. Use the higher rate on tillering plants, or in dense weed infestations. Add wetter + oil (preferred — see label).
• Can be used for spot spraying paspalum, Johnson grass, kikuyu and some other grasses. See ‘spot spraying’ on label.
• A Group ‘A’ herbicide — a high risk group for herbicide resistance.
(15) haloxyfop (e.g. Verdict 520®, Typhoon 130®, Appeal®)
• Check the formulation of the particular brand of this herbicide before use, and follow label rates. Apply after 2 trifoliate leaf stage of lucerne and from 2-leaf to early tillering of grasses.
• Rate selection depends upon formulation of product chosen and growth stages and additives used. If lucerne has been grazed or cut, allow grasses to develop fully expanded leaves before spraying.
• A Group ‘A’ herbicide — a high-risk group for herbicide resistance.
(16) 2,4-DB (e.g. Buticide®, 2,4-DB Herbicide®)
• Check particular product formulation and dose rates. Generally, applications should be made to seedling lucerne from 1-5 trifoliate leaf stage (1-8 on some labels). Applications to smaller or larger lucerne seedlings can damage plants.
• Apply to established lucerne after grazing/cutting (to a height of 10 cm). Weeds should be in the seedling stage (some up to small rosettes — see labels). Use the lower rates in the ranges given when weeds are small seedlings, e.g. 2-4 leaf.
(17) chlorthal-dimethyl (e.g. Chlorthal dimethyl 750 WP®, Warrant 750WP®)
• For pre-emergence weed control in seedling and established lucerne.
• Apply at seeding or early spring, for established lucerne stands, before weeds germinate. Use sprinkler irrigation immediately after spraying until the soil is wet.
• Use high-volume spray application i.e. 450 L or more of water/ha.
• Some weeds common in Queensland lucerne paddocks, that are NOT controlled include: Bathurst burr, bellvine, bladder ketmia, cobbler’s pegs, bindii, marshmallow, Mexican poppy, mintweed, noogoora burr, prairie grass, shepherd’s purse, thornapples, turnip weed, variegated thistle, wild turnip, wild relish. Others not controlled are also listed on the label.
• A Group ‘D’ herbicide - for weed resistance management.
(18) 2,2-DPA (e.g. Propon®, Cerelon®)
• For the control of annual and perennial grasses including couch, paspalum, Johnson, cumbungi and rushes.
• Slow-acting — results may not be evident for 6-8 weeks.
• Apply to lucerne after cutting or grazing.
• Do not use more than 1 kg/ha on seedling lucerne.
• A wetting agent, e.g. Activator or Chemwet 1000, at label rates, may increase efficacy.
• A Group ‘J’ herbicide — for weed resistance management.
(19) methabenzathiazuron (e.g. Tribumax 700WP®)
• For post-emergence control of annual broadleaf weeds in established lucerne that is at least oneyear old.
• Spray after grazing or mowing and when soil is moist after rain or irrigation. Spray when weeds are veryyoung, i.e. within five weeks after weeds germinate. Age of weeds is more important than size.
• Weeds should not be under stress such as drought, and should be actively growing.
• Read label for other mixing detail.
• A Group ‘C herbicide — for weed resistance management.
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