Autumn grass and broad-leaved weed control with Corteva herbicides

Historically, pre-emergence and very early post emergence herbicides have been the mainstay of broad-leaved weed control in oilseed rape.

With the advent of true post emergence herbicides such as Belkar^®, farmers can wait to see how the crop establishes, assess the weed spectrum and then decide on an appropriate tailored herbicide programme.

This helps to manage the upfront investment in crop protection too.

Belkar, launched by Corteva in 2019, contains Arylex™ active, a robust and reliable molecule that will control weeds in temperatures as slow as 2°C, making it an ideal autumn herbicide.

Arylex active can also be found in the spring applied oilseed rape herbicide, Korvetto^®. Astrokerb^® (propyzamide + aminopyralid) and Kerb^® Flo 500 (propyzamide) are also key products in the farmer’s armoury for both grass and broad-leaved weed control in the autumn.

Belkar, containing Arylex (10g/l) and Picloram (48g/l), has a maximum dose of 0.5L/ha and a wide window for application from 1 September to 31 December (BBCH 12-18).

Depending on the germinating weed burden, there are several options that can be considered when applying Belkar.

At two to four true leaves of the crop, an application at 0.25l/ha will take out the weeds which have germinated with the crop, and, in some circumstances, this may be enough broad-leaved control before an application of a propyzamide product, such as Astrokerb or Kerb Flo 500, later in the autumn.

© Corteva Agriscience

In high weed pressure situations where there is a further weed flush, crops can have a second dose of Belkar at 0.25l/ha two to four weeks after the first. 

Depending on farm workload or weed germination, a third option is to wait until six true leaves of the crop and when all the weeds have emerged and apply 0.5l/ha which will take care of the weeds going into the autumn.

Belkar is rainfast in one hour and will work down to 2 °C allowing the grower to make the most of spray window opportunities in the autumn.

Belkar adds a level of flexibility to oilseed rape weed control in terms of rate and timing and can be an alternative to a higher risk preventative approach to weed control strategies, allowing the crop to establish first.

This gives growers and agronomists time to assess the visible weed pressure and determine the impact of pests such as cabbage stem flea beetle and slugs.

Belkar gives control of many key competitive weeds including cleavers, cranesbill, poppy, fumitory and shepherd’s purse with a good spectrum of control.  See full list of weeds controlled here.

Active ingredients:

Belkar® contains halauxifen-methyl (Arylex™ active) and picloram

Astrokerb® contains aminopyralid and propyzamide

Kerb® Flo 500 contains propyzamide 

Korvetto® contains clopyralid and halauxifen-methyl (Arylex™ active)