Early oilseed rape harvest results have been positive this summer where growers managed to get crops established into moisture and growing away from pest attack last autumn.
However, in some areas of England the crop has had a tough time, as either drought or damage from cabbage stem flea beetle adults and larvae caused crop failure.
In areas hardest hit by flea beetle problems, growers will may be considering a reduction in their rapeseed area or take a break from the crop altogether for harvest 2020.
Frontier’s crop production director Charlie Whitmarsh says if there is a slight drop in oilseed rape area, alternative break crops are limited, so he sees winter cereals benefitting most from any potential rotational changes.
“The signs for winter barley this year are good, particularly hybrids. We have growers yielding about 2t/ha more than last year and our trials are up on the five-year average.
“Although I don’t see any radical changes, we could certainly see more second wheats and winter barleys drilled this autumn,” he adds.
One of the key challenges for those growing second cereals is the exposure to increased take-all risk, which is a soil-born pathogen that attacks roots and hinders the uptake of water and nutrients, dragging down yield.
Certis regional technical manager Geoff Bastard says primary infection takes place in the autumn and secondary root-to-root spread occurs as root systems develop through the spring.
The disease is often most severe in second and third cereal crops and Geoff notes that this year’s crops have suffered unusually severe infection following another favourable mild winter.
“I’ve not seen symptoms as bad in all my experience as an agronomist and it is widespread geographically.
“Growers tend to be focussed on septoria or yellow rust, but significant take-all infection like we are seeing this summer can be just as damaging,” he adds.
Poor soil condition
Mr Whitmarsh is also seeing levels in both wheat and barley and not only on the typically high-risk soils associated with the disease.
“We are also seeing it where soil structure and conditions are less than ideal, and rooting has been hindered,” he adds.
This comes as a timely reminder to those considering upping their second cereal area this autumn that careful management is required to limit the effects of take-all in both wheat and barley.
Any nutrient deficiencies should be taken care of, including pH, and cultivations should be well-timed and appropriate to avoid any compaction that may hinder root penetration.
Well-consolidated seed-beds, later drilling and choosing appropriate varieties known to perform well in a second cereal slot can also help.
Mr Whitmarsh recommends winter barley hybrids such as Kingsbarn and Bazooka, with Zyatt, Gleam, Kerrin and Gravity amongst the wheats suited to a second cereal slot.
He adds that early nitrogen and ensuring plants have available phosphate and potash is the spring are also key factors, applying fertiliser in early- to mid-February where conditions allow.
“It is all about giving the crop every opportunity to root effectively and produce the largest root mass possible in the autumn.
“There are trace element seed treatments with phosphite and manganese that can aid rooting, along with Syngenta’s Vibrance Duo (fludioxonil and sedaxane).
“However, where there is take-all risk, our advice – supported by trials over many years – is to treat seed with Latitude (sithiofam) and in some cases, Latitude plus a Vibrance Duo to do everything you can to enhance rooting,” adds Mr Whitmarsh
Second cereal management – key points