Learning Second Wheat Lessons in Kent

June 2004 - Growing second wheats successfully is a constant learning process, according to Roger Swayne, who manages Christopher Neame's Newlands Farm at Throwley near Faversham in Kent.

The very dry conditions encountered in April and June last year proved to them value of a specialist take-all seed treatment, but only after previous experience had shown they still need to keep to October drilling with their chosen variety.

"We only had 19mm of rain in May last year compared with 70 mm this season," recalls Mr Swayne. "This led to a striking visible difference between our Latitude treated and untreated wheats; a difference that continued to be apparent right through to harvest. We recorded a 22% yield increase where the seed treatment had been used. The extra 0.66t/acre was worth almost £60/acre.

"This contrasted with an inconclusive result the previous year, when we were persuaded to drill Latitude-treated wheat two weeks earlier than normal. That turned out to be a mistake."

Far less dry conditions this season have helped keep all the Newlands Farm wheats going. There have been a few weeks when Roger Swayne has been able to see the effect of the Latitude seed treatment clearly. But by and large, there has been sufficient soil moisture to keep it invisible.

"We've grown Soissons for over ten years," he explains. "As a rule it averages 3.2 t/acre (7.9 t/ha) in the second wheat position. The grain is always sought after, so we get a reasonable premium. The downside is that it doesn't yield as well as some other Group 2s. So good take-all management is essential.

"Take-all is a problem in second wheats for us most years. We follow all the cultural control measures to try and limit the damage."

The Newlands Farm take-all control programme includes keeping the fields as clear of grass weeds as possible; delaying drilling until October; and growing an early, fast developing variety. Seedbeds are consolidated after ploughing, which is done as soon as possible after harvesting to give the land time to settle.

The preferred drilling date for Soissons is mid-October at a seed rate of 90 kg/acre to compensate for its lack of tillering. The rotation is currently changing from a simple wheat/wheat/rape system to include winter beans as an additional break. This will mean oilseed rape will only be grown every sixth year.

"We are finding oilseed rape isn't the cleaning crop it used to be," observes Mr Swayne. "Weeds are definitely becoming a bigger problem in it.

"We've also altered our nitrogen policy with experience, so our second wheats now get their requirement in three applications. "The first split goes on in February. We then follow up with further applications at the end of March and the end of April. "Our over-riding aim is to avoid having a second wheat struggling. And where take-all is a problem, the early nitrogen can be taken-up while the root system is less damaged."

Roger Swayne accepts that justifying the cost of a take-all seed treatment isn't always easy. The problem is they have to make their purchasing decision before they know whether the season will present a particular challenge from the disease.

"It's an extra insurance cost," he points out," adding around £10-15/acre to our certified seed which we always dress with Sibutol for seed-borne disease control.

"Last year, the Latitude more than paid for itself, so we are likely to continue using it in the future. But we will continue doing the same comparison we did last harvest, leaving an untreated area so we can assess the treatment's actual performance."

For the future, Roger Swayne is also considering using Amistar (azoxystrobin) at T1 for its effect on take-all.

"It would have been interesting to spray a patch of untreated Soissons with Amistar, to compare the different approaches and see any differences," he says. "My concern with this course of action, though, is the wider picture with strobilurins and resistance. "The guidelines say that we can only use strobilurin chemistry twice on one crop. Spraying Amistar for take-all suppression uses one of these opportunities. "We may well look at it next year," he concludes. "It's another example of our learning process with second wheats. We are adding to our knowledge of how to make the most of it all the time."