North: Yellow rust triggers spring spraying program

March and April have so far provided the combined total of 12mm of rainfall. Needless to say, crops are not appreciating this lack of water. It remains to be seen what the impact of this will be on yields, but the light land must be losing yield potential with every passing dry day.

Yellow rust arrived in winter wheat crops with a bang on 10 April, triggering a rush to arms. Many crops had been sprayed already and those that were due an application received one quickly. The arrival of yellow rust starts the spray programme with every effort made to keep the spray interval below 25 days. On varieties not prone to yellow rust, the main discussion points have been when to spray and how little active ingredient to use in this dry weather? In short, you should still spray, and you can cut rates, but not by huge amounts.

Most oilseed rape crops will have either received a sclerotinia spray or will be due imminently. My favoured mix has been based around prothioconazole with a partner product. Most of the models for sclerotinia risk were triggered earlier in the month, but with no rain and no flowers, I have advocated delaying until petal fall. Weevils have been common on headlands, but in field numbers are variable. As a consequence, some crops have been sprayed and nearly all headlands will receive a spray.

Winter barley now has awns visible and would, under a normal spring conditions, receive a further growth regulator and disease spray. But the crop is under huge drought stress at the moment and I think adding another growth regulator into the system would be risky. We are delaying the final spray until the awns are fully out and will base the programme on yield potential and disease pressure.

Spring crops were drilled into nearly ideal conditions and they shot out of the ground with great speed. Unfortunately, they will soon be desperate for a drop of water. Spring beans have received weevil sprays as notching is very noticeable. Spring barleys are just receiving a herbicide often coupled with manganese and a small amount of morpholine.

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