Kicking of this season’s crop walk and talk series, Hutchinson’s agronomist, Andrew Cromie, highlighted the issues affecting wheat and oilseed rape (OSR) establishment in Wisbech, Cambridgeshire.
As across much of the South East, slow weed emergence has been a dominant factor, which has forced some growers to postpone drilling wheat, particularly where high black-grass populations are expected.
Mr Cromie says: “This year has been a high black-grass dormancy year, but high temperatures and a lack of rainfall has also meant soils have been very dry and so weed emergence in general has been slow.
“If we don’t get any rainfall in the near future, this could impact on the efficacy of pre-emergence treatments.”
During the crop walk, Mr Cromie identified fields that typically suffer from varying black-grass populations. Drilling dates have been varied at this particular site, depending on the level of black-grass anticipated.
See also: North/south divide in drilling decisions
Sandier fields, which typically had lower levels of the weed, had recently been drilled [September 29]. Here there was no visible black-grass.
While plants had just started to emerge in some heavier fields, Mr Cromie still recommended delaying drilling by around two weeks to optimise black-grass control.
“Currently we can see some low levels of black-grass emerging but we know there is a lot more left in the seed bank," he said.
“Where soil types are heavier, we expect black-grass populations to be greater. In these areas, we plan to delay drilling until the black-grass has chitted and plan to control it using a total herbicide.”
Mr Cromie also advises growers to take into account the resistant status of the black-grass in order to plan the order in which fields are drilled.
At the site, much of the black-grass has been confirmed as RRR resistant. However, where growers are still getting a response from ALS herbicides, Mr Cromie recommends drilling these fields first, allowing the worst affected fields more time to chit.
Where black-grass is present, Mr Cromie plans a pre-emergence treatment based largely around flufenacet, with the addition of DFF where broad-leaved weeds are present.
OSR, variety Campus, drilled on August 15 appeared reasonably free of pest damage, despite slug pressure being high and CSFB being problematic in the past on this particular farm.
Mr Cromie puts this down to rapid early growth, which was helped by the use of starter N and a direct drilling establishment method.
“One of the benefits of using a direct drilling method is that you retain moisture in the soil which is very important for getting a good establishment.
“We have had a history of CSFB problems on the farm, this year, so we have used starter fertiliser in order to get a better establishment, encouraging the plant to grow away from the problem
Another benefit of this is improved rooting, which was evident on assessment.
“As we can see we have got excellent lateral roots and a really strong tap root, allowing the plant to forage for nutrients and water much better.”
Wet weather throughout much of the year has meant slug pressure has been particularly high. However, with soil temperatures high and successful establishment, most oilseed rape on-farm had grown away from the slug threat.
“Here, the majority of plants have grown away from being susceptible to slug damage. In other parts of the country or on other farms, plants may not be quite so well developed and could still be at risk to slug damage. These may require another treatment of slug pellets,” Mr Cronie says.
While there were no aphids to be seen within OSR crops, he advises growers to continue to monitor aphid numbers in the coming weeks.
“It is important that we look out for the peach potato aphid as this is responsible for transmitting turnip yellow virus into the crop.”