Astrokerb^®

Excellent black-grass control
Astrokerb is a unique formulation containing both propyzamide and aminopyralid.

The propyzamide in Astrokerb gives excellent black-grass control, the same as Kerb® Flo 500.

There is no known weed resistance to propyzamide so Astrokerb (and Kerb Flo 500) will control fop/dim and ALS-inhibitor resistant black-grass in oilseed rape.

Broad-leaved weed control

Aminopyralid in Astrokerb controls broad-leaved weeds, it:

• works when temperatures are cold
• binds to living cellulose of the broad-leaved weed
• is not metabolised but released and works when the weed starts to grow            
• washes off trash
• controls ALS-resistant poppies and mayweeds

 Winter Oilseed Rape

Product Registration Number:
MAPP 16184

Active Ingredient:
5.3 g/l aminopyralid and 500 g/litre propyzamide

Pack Size:
10.0 litres

Formulation:
Suspension Concentrate

Maximum Individual Dose:
1.7 l/ha – the black-grass rate. In other situations use 1.5 l/ha

Maximum Total Dose:
One per crop

Latest Timing:
Before 1st Feb in the year of harvest

Water Volumes:
200–300 l/ha

Spray Quality:
Medium as defined by the BCPC

LERAP:
None

Astrokerb and oilseed rape straw: Do not bale or remove straw from the field unless it is to be used for burning for heat or electricity production.  The straw should be chopped and thoroughly incorporated after harvest. Do not feed animals with treated straw, or use it for animal bedding, composting or mulching.

To optimise Astrokerb's performance, there are three areas to be considered – soil temperature, soil moisture and weed seed depth. Soil temperatures need to be cooling - around 10ºC and falling at 30 cm depth, meaning the herbicide is slower to breakdown and that longer persistence is achieved throughout the weed germination period. 

Good levels of soil moisture are needed to help the herbicide distribute evenly in the top few centimetres of the soil thus the soil moisture deficit should be less than 50 mm and falling. Soils must not be waterlogged or saturated. Care must be taken to avoid any risk of contamination to water and importantly, all aspects of good Stewardship applied.

The propyzamide in AstroKerb forms a shallow layer in the soil, about 2.5-5 cm. Black-grass seed germinating in this zone will be well controlled however, black-grass germinating below this will be poorly controlled. High levels of control are achieved where less mixing of the soil takes place (direct drilling etc.) and thus black- grass seed remains within the top 5 cm of soil. Avoid deep cultivations in a preceding winter wheat crop and in the oilseed rape crop as this will distribute black-grass seed throughout the soil profile away from the 5 cm propyzamide zone of activity.

Decades of trials and wide field experience across the UK has demonstrated that using full-rate Kerb Flo 500 or Astrokerb from November onwards when soil temperatures are 10^oC and falling gives the most reliable and most persistent control of black-grass year after year.

Tank mixes, sequences and programmes

Wide range of fully supported tank mix partners

• Centurion Max – do not tank mix – sequence only
• Remember only 2 fop/dim applications can be made to an OSR crop. Consider a programmed approach with Astrokerb to maximise volunteer cereal and other grass weed control.
• Astrokerb in mixture with PGR fungicides, especially if the crop is under stress, may cause an additive PGR effect.
  
• Call Corteva Agriscience Hotline (0800 689 8899) for the latest tank mix information, sequences and programmes involving Astrokerb

Do I need a dry leaf for application of Kerb Flo 500 or Astrokerb?
The propyzamide active in Kerb Flo 500 is soil acting so spraying wet weeds at run-off or light rainfall after application is not an issue. Ideally, the rainfastness of Astrokerb is 1 hour for the aminopyralid element. Spraying on a drying leaf is OK but if rainfall falls within 1 hour and causes run-off efficacy may be reduced. All applications should be made with due regard to water stewardship, i.e. do not spray where there is a risk of run-off to adjacent watercourses.

Can I apply Kerb Flo 500 or Astrokerb in a frost?
Kerb Flo 500 may be applied in frosty conditions but avoid application onto frozen ground where subsequent rainfall could result in run-off into watercourses. For Astrokerb please ensure frost is off the target broad-leaved weed.

Which broad-leaved weeds does Astrokerb control over Kerb Flo 500?
Astrokerb applied at 1.5 l/ha or 1.7 l/ha will give very good control of small (2-4TL) mayweed, poppy, chickweed, groundsel and pansy. When applied at 1.7 l/ha, Astrokerb can give high levels of control of mayweed and poppy (up to 8TL) and chickweed (up to 5 branches). Control of groundsel falls off after the 6TL stage, but is very good earlier.

What is the optimum timing for Astrokerb?
When targeting black-grass in winter oilseed rape, we recommend soil temperatures at or below 10°C to get sufficient activity from propyzamide. The objective is to keep the propyzamide in the top 5 cm of soil for as long as possible. Propyzamide breaks down slowly when soil temperatures fall below 10^oC. Good control is achieved when a lethal concentration is reached in the weed and is a function of the length of time the weed is in the propyzamide zone and the concentration of propyzamide in the zone. Astrokerb will also give good control of poppy and mayweed at this timing. 

The propyzamide in Astrokerb forms a shallow layer in the soil, about 2.5-5 cm, black-grass seed germinating in this zone will be well controlled however, black-grass germinating below this will be poorly controlled. High levels of control are achieved where less mixing of the soil takes place (direct drilling etc.) and thus black-grass seed remains within the top 5 cm of soil. Avoid deep cultivations in a preceding winter wheat crop and in the oilseed rape crop as this will distribute black-grass seed throughout the soil profile away from the 5 cm propyzamide zone of activity.

Can the straw from oilseed rape treated with Astrokerb be used for animal bedding?
Oilseed rape straw from crops treated with Astrokerb needs to remain in the field and must not be baled and used for bedding. It may be removed from the field to be used for burning for heat or electricity production.