First Wheat Take-All Trials Sounds Variety Warning

Cambridge (September 2003) - Many wheat varieties are unlikely to show a worthwhile response to a specialist take-all seed treatment when grown after a true cereal break, confirm the latest Allied Grain Fishers trials.

However, the surprising 0.33 t/ha boost recorded from treating RL yield leader, Robigus with Latitude (silthiofam) this season in a first cereal trial suggests particular care needs to be taken to protect the variety from the yield-robbing disease.

All the more so, given yield responses of more than 1 t/ha to the treatment in both September and October sowings recorded on a second wheat trial site with only moderate background levels of take-all.

"Robigus out-yielded the three other varieties in our mid-September drilled first wheat take-all trials quite comfortably, producing 12.45 t/ha from the control single-purpose seed treatment," explained Allied Grain Fishers technical manager, Jim Carswell. "It was, however, the only variety to show a positive yield response to the specialist take-all treatment - to an even more impressive 12.78 t/ha in our first wheat trial. Treatment also appeared to reduce screenings in Robigus.

"That the variety is likely to profit from more take-all management attention than most, was underlined in our 10-variety second wheat trials. In marked contrast to its first wheat performance, when drilled without a take-all treatment in the first week of October, Robigus proved to be the lowest yielding second wheat at just 9.08 t/ha."

Despite relatively low levels of take-all on the site this season, the October-sown Robigus responded to Latitude treatment with a massive 1.25 t/ha yield boost in the Yorkshire Wolds trials. Even so, at 10.33 t/ha, it only just out-yielded Malacca at the bottom of the Allied Grain Fishers performance table.

The specialist take-all treatment also boosted the variety's yield from mid-September sowing by over 1t/ha to a more respectable 11.13 t/ha, lifting it to mid-table in the performance stakes in the second wheat trial. Specific weights were also noticeably improved at both sowing dates where the seed dressing was used.

"This highlights the need to base take-all management on variety as well as soil and rotational risk," Jim Carswell pointed out. "Most varieties grown as second wheats on 'risky' soils are likely to profit from good take-all protection; especially when sown in September.

"While many varieties grown as true first wheats are unlikely to warrant a specialist take-all seed treatment, the big question arises when they follow set aside or spring barley which can pose a significant take-all carryover risk. Under these circumstances, it may well be advisable to give varieties like Robigus which appear to be less tolerant of the disease the best possible protection."