Stressed spring barley and the final fungicide

Awns are out on spring barley crops across the country and while disease pressure has been low it is important to put on a strong final fungicide and keep crops green for as long as possible.

With that said, there are many crops across the country which are in poor condition due to severe drought. Where crops have low yield potential the fungicide spend should be reduced accordingly. Crops which are thin are not going to have high disease pressure.

As temperatures cool down in the coming days and awns are emerging it gives farmers an opportunity to apply the final fungicide when the plant is under less stress. Applying fungicides in high temperatures should always be avoided as this puts undue stress on the crop.

When temperatures are high and weather is dry the risk of disease is low. Uptake of fungicides may also be affected so waiting on temperatures to coll down is important.

Some crops may be receiving their first and last fungicide as pressure has been low and growth has been fast. Those crops which are showing potential should receive an SDHI/triazole mix. Reduced spends on fungicides may include a triazole/strobilurin mix.

Mixing chemistry is important to prevent the build up of resistance, but also to give a broader spectrum of control.

Also Read: Stuck for a product name or PCS number? Check these lists…

Reducing stress

As chlorothalonil is now banned it cannot be used in the final spray on spring barley. Chlorothalonil played a key role in ramularia prevention. However, ramularia is brought on by stress so reducing stress can help to prevent this disease.

Nutrient deficiencies should really have been looked after at this point, but if a deficiency is obvious it should be tackled.

Some research has shown that the application of bio stimulants and seaweeds can help to reduce stress, while magnesium can help with green leaf area and grain fill.