Get Ahead of Slugs with 7‑Day Pre‑Drilling Approval

Why slug risk matters during OSR establishment

Oilseed rape seedlings are highly susceptible to slug feeding because their growing point is above ground.

Serious damage can occur until plants reach the four true-leaf stage, making the establishment period critical for monitoring and control.

The AHDB damage-risk threshold for oilseed rape is just one slug per trap in cereal stubble, where conditions are suitable for slug activity.

“The dry summer may have meant growers saw very little slug activity, but that shouldn't be allowed to create a false sense of security as conditions change,” says De Sangosse managing director Phil Carpenter.

“The crop needs moisture to establish, but improving soil moisture can also change slug activity. What matters is what is happening in the field now.”

“We haven't had much of a green bridge post-harvest in many areas of the UK this year due to the dry hot conditions so don't let the first food source for slugs be your newly drilled crop.”

In warm soils OSR can germinate in 24 hours and push through the surface in 3-5 days. Having the 7 days pre-drilling application as an option can buy important time for growers when peak drilling is the focus and resources are stretched.

Still to drill? Use the pre-drilling window

For growers with OSR still to drill, there is an opportunity to begin managing slug pressure before vulnerable seedlings emerge.

De Sangosse ferric phosphate pellets are approved for application up to seven days before drilling, once seedbed preparation is complete.

“Growers don't need reminding that OSR is vulnerable to slugs. What may be less well known is that they don't necessarily have to wait until drilling to start managing the threat,” says Phil.

“Where monitoring identifies active slugs and treatment is justified, the seven-day pre-drilling approval gives growers an opportunity to get ahead of the population before the crop becomes vulnerable.”

The timing should not be viewed as a reason for routine treatment. Instead, it provides additional flexibility to match pellet application to the risk identified in an individual field.

Monitor. Assess. Act where required. Then continue monitoring.

The same seven-day pre-drilling approval also applies to cereals, providing an additional timing option as attention turns to autumn cereal drilling over the coming weeks.

Already drilled? Keep monitoring

The pre-drilling opportunity is only part of the picture this autumn.

Where OSR has already been drilled or is emerging, monitoring should continue closely as conditions change.

AHDB recommends monitoring OSR from sowing until the four true-leaf stage. Crops that experienced little slug pressure immediately after drilling may therefore still need attention if increasing soil moisture leads to greater activity.

“Some OSR is already up, some is being drilled now and some growers are still waiting,” says Phil.

“There isn't one recommendation that fits every field. The important thing is to keep reassessing risk through establishment rather than relying on what conditions were like a week or two earlier.”

Pellet quality matters too

Timing is only part of successful slug control. Once applied, pellets need to be found and consumed, remain available as conditions change and be distributed consistently across the treated area.

De Sangosse ferric phosphate pellets combine premium durum wheat and Colzactive technology, our proprietary advanced wet-process manufacture and proven best in class spreadability up to 36m working widths.

Together with approval for application up to seven days before drilling in oilseed rape and cereals, this provides a robust option for protecting autumn crop establishment.