OSR as a tool to manage black-grass

08.08.2019

Black-grass is typically viewed as a cereal issue but given the results from a recent survey that BASF ran with CPM, it’s clear that it is also front of mind when growing oilseed rape. 44% of the growers who responded listed black-grass as their biggest problem weed in OSR, and 65% placed it in their top three. However, managed effectively, by taking a holistic and integrated approach it can be a strong rotation choice in your long-term black-grass strategy.

Campaign manager for BASF, Sarah Middleton states that; “There’s no denying that the reputation of OSR has taken a hammering this year, but it really isn’t all doom and gloom. Hybrid varieties like those from InVigor can stand up to the most extreme challenges you are likely to face in the Autumn. OSR hybrids are bred to be more resilient, with strong autumn vigour to grow away quicker, easing some of the fears around cabbage stem flea beetle damage.

Choosing to sow a vigorous hybrid later, gives a double whammy effect, it will hopefully avoid the worst of the adult flea-beetle damage, and also allows you time to prepare a stale seed bed. Like with every control method for black-grass, there is no silver bullet, and you do need to be considerate about how surviving black-grass behaves. Even a handful of plants left unchecked can grow taller and produce more tillers in OSR, creating potential issues for the next year. Careful monitoring, and a multi-pronged herbicide approach over the Autumn and Winter should help overcome those pitfalls.

Just like you wouldn’t give up hope on a wheat crop because of black-grass infestation, don’t give up hope on OSR as a crop, as there are things you can do to not only manage problem weeds, but also achieve a profitable, healthy crop at the end of the season.”

These are the three key reasons Sarah Middleton thinks you should consider OSR as part of your black-grass strategy:

  1. There are several pre- and post-emergence herbicide options available for weed control in OSR, particularly important if resistance has become an issue.
  2. Late sowing varieties can not only help you to escape the flea beetle migration period, but it also allows you time to prepare a good, stale seedbed. InVigor varieties put on leaf and root growth rapidly and establish quickly, meaning good ground cover for competing weeds.
  3. Where a wheat harvest has been late due to uncertain ‘catchy’ weather conditions, later planted OSR can take advantage of soil moisture for rapid growth and establishment. It may also make OSR after spring wheat more viable, as you have more time to get the spring crop off.