Take-all levels this spring are the highest for the
past three years, according to early season root assessment results
from Allied Grain's second wheat performance trials at Haywold
Involving 10-14 varieties grown as second and subsequent wheats
on the same site to the same protocols, these trials provide an
excellent basis for monitoring take-all incidence over the years. Especially
so since they involve earlier and later drillings made with or
without the same take-all seed dressing at the same time each year,
almost to the day.
“Over the past three years we've drilled our earlier
Haywold trials consistently between September 12th and 16th and
our later ones between October 1st and 2nd,” explained Allied
Grain Trials andTechnical manager, Jim Carswell. “We've
also been consistent in sampling roots for early take-all levels
between March 5th and 10th to make comparisons between seasons
as valuable as possible.
“This year's results suggest we could be in for a
particularly damaging take-all year,” he pointed out. “Without
a specialist take-all seed treatment, indeed, our early drilled
trials had an average Take-all Index of 16, while the later drillings
averaged 8. In both cases, these are the highest levels we've
recorded in recent years.
“As we've come to expect, infection levels were markedly
lower across the Latitude (silthiofam) treated plots. But again
the indices were higher than in the past three seasons.”
Allied Grain Haywold 'Second Wheat' Trials - Early
Season Take All Indexes
Jim Carswell attributes the high level of current root infections
to the mild and persistently moist soil conditions of the past
winter. He points out that while his records show a lower than
average winter rainfall at Haywold, they also reveal there has
hardly been a day on which the site has not received some rain.
“From October through to the spring, our crops have sat
in damp soil,” he observed. “This and the mild weather
has been just the ticket for the take-all fungus.
“We didn't see a high level of take-all damage last
year. But this was mainly because the wet summer allowed crops
with impaired root systems to survive relatively well. This
year, the build-up of infection will be further encouraged when
temperatures warm up in spring and could prove highly detrimental
for crops encountering moisture stress over the summer.
“We simply cannot afford to let down our guard as far as
take-all is concerned, “Jim Carswell concluded. “While
there is relatively little that can be done at this late stage,
I would advise growers who haven't treated their second wheats
with a specialist take-all seed treatment, in particular, to do
everything possible to encourage root development and discourage
the disease in the next few weeks. This means taking special care
with fertilisation and T1 fungicide choice.”