South East Agronomy Update from Ken McTaggart, Agrii agronomist in Kent

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Our ground seems to be working down very well this autumn; far better than we feared it might thanks to a decent wet spell in late August and our emphasis on shallow cultivation from the top.

Despite going into generally good conditions, later-drilled OSR which normally escapes flea beetle attack better than earlier sowings here has been hit hard this time round. Problems appeared out of the blue at the end of the second week in September and, several days on, some crops are currently in intensive care. A single pyrethroid spray has been enough on earlier drillings. But the jury is still out on how well we’ll be able to get our September-sown crops through the storm.

Sufficient soil moisture and warmth with the lowest level of black-grass dormancy reported for many years promises to stand us in good stead for grassweed control. However, we have yet to see the sort of weed flushes we have been expecting in stubbles ahead of our winter cereals and the amount of black-grass and ryegrass appearing in our rape crops over the past 10 days sounds a clear warning.

It may seem like a long time since harvest and ground conditions may look nicely set. Even so, we have to resist the temptation to make an early start on winter wheat drilling on anything but the most grassweed-free ground. All the Stow Longa research continues to show the importance of not sowing wheat into bad black-grass ground ahead of mid-October. And we know the same applies to the ryegrass which, in many cases, causes us even greater headaches.

So, with wheat drilling just getting underway, we are steeling ourselves to hold our nerve for at least another two weeks on our red-coded fields. This sort of patience doesn’t come naturally with today’s weather uncertainties. But, with plenty of grassweeds still to emerge, it is essential if we are to adequately insure ourselves against the sort of havoc they can so easily wreak.

With this in mind, we are putting the priority on varieties with the highest competitiveness ratings on the 2018/19 Agrii Advisory List, produced as a complement to the RL. At the same time, we will be pushing sowing rates up to 450 or even 500 seeds/m2, where necessary, both to boost competitiveness and compensate for reduced tillering with later drilling.

A well-applied glyphosate spray as close to drilling as possible and minimal soil movement at drilling are also crucial elements of our weed management programme. As are robust residual herbicides, taking the greatest advantage of their better persistency from later drilling.

Most of our pre-ems will be based on flufenacet co-formulated with either DFF alone, pendimethalin or the DFF and flurtamone which extensive Agrii research shows delivers noticeably better black-grass control. In many cases we will be including prosulfocarb in the pre-em and, in the most challenging situations, also using triallate.

Where we need to, we will go back in with a peri-em top-up of flufenacet with picolinofen which gives a valuable extra element of contact activity as well as adding another active to the residual stack, being careful not to overdo the DFF for the risk it poses to following crops like OSR.

Like most, I suspect, we will be making the most of the last year of Deter with all our wheat drillings. Aphid control is arguably less of an issue the later we drill. But we also have fewer spraying windows and it will invaluable with the way slugs have come back with a vengeance in our rape stubbles.

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