Take-all can have a significant effect on second wheat crops across the country, including the north where fewer problems might be expected, a take-all survey has discovered.

Ten second cereal HGCA Recommended List trial sites were monitored for take-all last season.

Nine out of the 10 showed significant take-all, with an average index across all sites of 37 by GS65.

An index of 0-10 indicates no take-all, while a score of over 50 is regarded as a severe infection.

But the average masks considerable variation between sites, with final indexes varying from 12 to 66, study leader, Monsanto’s David Leaper says.

“Our study clearly shows infections and disease losses can be a serious risk just about anywhere.

“But one of the most surprising things was the level of take-all in more northern areas, where you might expect it to be less of a problem given the cooler and later springs.”

There was a clear correlation between the levels of take-all at mid-flowering and yields, with the worst affected site yielding only 6.27t/ha, while the least affected yielded 10.11t/ha.

“Many factors are responsible for yield loss in second wheats (eg eyespot, fusarium), but take-all will probably be the most important one.”

Early results suggest a similar take-all pattern is likely this season, with 10 out of 13 sites showing significant levels of the disease.

But this does not necessarily mean more white-heads and yield loss, he notes.

“This will depend on whether there is drought stress during the main grain filling period.”

While little can be done this late in the season for crops suffering from take-all, growers with at risk crops should assess root samples during the grain fill period, he says.

“You may need to apply a seed treatment next season.”

paul.spackman@rbi.co.uk