Take-all in winter wheat - management guidelines (HGCA Autumn 2006)

Crop nutrition

Maintaining correct nutrition is important in minimising take-all and its effects; deficiency of any nutrient should be avoided.

Nitrogen

Take-all destroys roots, reducing a crop's ability to take up nitrogen and other nutrients.

Timing of N applications is important. Nitrogen should be applied earlier to crops at risk of take-all than to first wheats. An early application (around 60kg N/ha) in February/March followed by the main dressing in April is better than a single dressing or later applications. Because uptake by crops with severe take-all is less efficient, the disease may increase leaching losses.

There is evidence that take-all is less severe with ammonium sulphate than with ammonium nitrate, urea or ammonium chloride fertilisers but in well-buffered UK soils the effect is small.

Phosphate

Phosphate-deficient soils (less than 15mg/kg of soil Index 1 or less) favour take-all (Figure 7). Phosphate should be at 20mg/kg soil (Index 2) before the start of a cereal sequence and any deficiency rectified, ideally before the break crop, to reduce take-all risk in the second cereal.


Figure 7. Effects of soil P on take-all in wheat

Rothamsted Research

Other nutrients

Manganese, potash and sulphur deficiencies have been linked to increased take-all severity. Manganese and potash deficiencies should be corrected before the crop is sown. However, severe take-all sometimes occurs even when supplies of these nutrients are adequate.

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