Treating second wheat seed with a specialist take-all fungicide will more than pay for itself in the vast majority of circumstances, regardless of the season, even with wheat at £60/tonne, according to the most comprehensive study of national take-all control trial evidence ever undertaken.

The study involved no less than 116 rigorously-conducted independent and commercial trials undertaken with seed dressing, Latitude (silthiofam) across a wide range of sites throughout the UK over the past five seasons.

Even though this included at least 28 trials in which take-all hardly developed at all, the average yield response to the seed treatment was fully 0.55 t/ha. What is more, only six trials (5%) recorded no yield increase whatsoever; 50% saw increases of half a tonne or more; and in nearly 70% the response was sufficient to more than cover the cost of treatment with wheat at just £60/tonne (Figure).

“Average responses are all very well, but with a highly variable disease like take-all, the most important consideration is the consistency of response,” points out Monsanto specialist, David Leaper who co-ordinated the study. “That's why our investigation includes all the replicated trials to which we have access over as many years as possible.

“The results are particularly revealing.  First and foremost, they show a consistent response from Latitude treatment over five very different seasons. Even in 2003 and 2004, generally regarded as low take-all years, 96% and 100% of the trials respectively showed a yield response. This confirms take-all is endemic within second wheats, regardless of whether they show it or not.

“The fact that a positive cost:benefit has been recorded from Latitude treatment over two thirds of all trials with wheat at a lowly £60/tonne further underlines the consistent value of the second wheat seed treatment,” David Leaper adds. “Especially so since a quarter of the results came from sites showing little, if any, take-all incidence.”  

Further analysis of the trial data shows worthwhile responses to treatment regardless of yield level. In 54% of the 72 second wheat trials with control yields in excess of 8t/ha, for instance, the recorded yield increase was sufficient to more than cover the cost of treatment with wheat at £60/tonne.

“With the strength in depth of this evidence, no one need have any hesitation about using Latitude as a matter of course on their second wheats wherever take-all has been considered a risk in the past,” David Leaper stresses.

“In almost every case it will more than pay for itself even at the lowest conceivable wheat price. Add to this average responses of three quarters of a tonne or more where take-all proves problematic, not to mention the ability to get second wheats drilled far earlier than normal with excellent crop safety,  and treatment could well be the difference between success or failure with the crop in many cases.”