Issues Surrounding Early Drilling

As we approach the Autumn and seed starts arriving on farm, it can be all too tempting if the weather is looking good to get on and drill it, especially after the very wet conditions last Autumn. However, as we are all too aware there will be draw backs to planting a crop early. This article explores the issues surrounding early drilling to help you make an informed decision on drilling date. But we will also provide some solutions if you do decide to go early.

One of the key issues with drilling earlier is that there is less time to have several stale seed beds. This will result in a larger weed burden in terms of volunteers, grass weeds and broad-leaved weeds. The more times you can get the seed bed to chit and then spray it off, the smaller the weed burden when it comes to drilling time. By pushing drilling earlier, you may only get one or two stale seedbeds before drilling rather than three or four, this will have a significant effect on weed pressure throughout the Autumn, especially grass weeds.

As a result of the lack of stale seedbeds and the germination period of blackgrass the pressure from blackgrass will be higher. NIAB have shown that if you can push drilling back one week from mid-September you reduce the blackgrass pressure by 15% per week. Therefore, by delaying drilling by just two weeks to the end of September you could reduce the weed burden by 30% for free!

Further to blackgrass being more of an issue, the longevity of residual chemistry will also be compromised. A pre-emergence application early to mid-September will start to run out sooner than an application late September to early October. This is due to the higher temperatures making soil microbes more active therefore degrading the active ingredients at a faster rate. You will need top-up the application with more chemistry to keep the weed burden low. The worst-case scenario is when we are forced to use a contact ALS herbicide pre-Christmas on grass weeds which have become too large for the residual chemistry to control. These products can only use once per target in the cropping year. If the target is blackgrass and you use Atlantis in the winter, you CANNOT come back in the spring with any ALS containing herbicide. This is an issue as blackgrass will have a spring flush. The usual strategy is to target the spring flush and anything leftover after the winter with an ALS herbicide application in the spring.

Other issues with drilling early is that of BYDV which can severely limit yield. Without any seed dressings that are active on aphid pests, the crop is at risk of BYDV. Earlier drilling makes the crop more vulnerable as aphids will be more active at higher temperatures and are very likely to move into the crop. If drilling is delayed to October, the aphid pressure is significantly reduced due to lower temperatures.

In addition to BYDV being an issue, general fungal disease will also be more prevalent as the crop will be much larger coming into the spring. Septoria and mildew will be particularly present and therefore may require a pre T0 spray.

Therefore, in terms of chemical spend you will likely be using an additional herbicide, additional insecticide and more fungicide in the spring. Growing an early drilled crop can be a challenge and spray timings will be even more important.

If you are drilling early.

·         Use of Avadex has been shown by our trials to enhance blackgrass kill by up to 30%.

·         Monitor aphid activity closely, you can use the Syngenta app to predict migration. Use Gocha or Stealth if aphid numbers reach threshold.

·         Follow up residual herbicide applications with a post-emergence residual, two to three weeks after the initial application.eg Terrane + Anthem or Fence + Anthem