Take-All Control Shows Its Value In Low Risk Wheat Trials

September 2003 - Highly economic responses to specialist take-all treatment have been recorded in national second wheat trials this season, despite very low recorded disease levels, a well-regarded second wheat variety and particularly high untreated yields.

The trials conducted by Masstock as part of its SMART Farming programme at Cullompton in Devon involved Deben drilled in late September into a decent seedbed.

The control plots, receiving a standard single purpose seed dressing and a full foliar fungicide programme, produced a very commendable 11.31 t/ha at harvest. Root assessments throughout the season showed notably low background take-all levels and less than 1.5% whiteheads were recorded in the crop in early July. Even so, seed treatment with the specialist take-all fungicide Latitude (silthiofam) boosted yields by more than 6% (0.7 t/ha) to within a whisker of 12 t/ha.

"With wheat at £75/t that's an extra £52.50/ha for a treatment cost of less than £25/ha - a 2:1 payback," explained Masstock seed and crops manager, David Neale. "And in a situation in which we would expect the least response to take-all treatment.

"We've seen similarly good yield responses to the take-all treatment across the country this season in wheats after barley and set aside as much as in second wheats," he pointed out.

"Add to this responses of up to 1 t/ha in barley crops, together with 5-10% improvements in wheat bushel weights and barley screenings, and the value of minimising the impact of take-all is clear; even when the disease does not appear to be especially threatening."

Following this season's trial and farm experience, David Neale is more convinced than ever of the value of the best possible take-all management in everything but true first wheat situations; especially with September drillings.

"Don't listen to anyone who advises you to let up on take-all control just because you're growing a good second wheat variety or putting-in wheat after set aside or barley rather than wheat," he stressed. "As so many growers found to their cost this season, anything that compromises wheat rooting can be particularly damaging when the crop comes under spring or summer stress.

"Until take-all treatments came along we really had no way of knowing just how much damage the disease was actually causing and in how many different rotational situations. Our work with Latitude, in particular, is providing us with an increasingly good insight into the yield and quality benefits of positive take-all management.

"For those in high risk situations it's often the difference between success and failure," observed David Neale. "Equally, it's proving to be the icing on the cake for many facing a lower apparent disease risk. To my mind it has to be an important consideration whenever wheat is not being grown after a true cereal break."