CROPS WATCH: Rust under control; time for T1 on wheat

Looking after crops isn’t straightforward; a bit like the weather on the day of filming this installment of CROPS WATCH.

TerraChem agronomist John Mulhare summed up the last few weeks simply – “things did not go according to plan”.

Corbel at T0 was intended to control the yellow rust problem in a crop of Bennington winter wheat, but as John said: “I never in my life saw or had to spray for yellow rust on my farm before.”

Yellow rust can reduce yield by 50% and as the disease began to spread rapidly John took action on the extreme situation with an application of 0.5L/ha of pyraclostrobin and 0.75L/ha of Vareon (prochloraz, proquinazid, tebuconazole) on April 8.

T1 due in the coming days

Having tackled the rust problem John is now looking towards a T1 spray next week when leaf 3 is fully emerged.

T1 application:
  • Treoris – 2L/ha;
  • Rubris – 1L/ha.

John also advised anyone who has latent mildew in their crop, that has not applied a mildewcide, to keep an eye out for the disease as temperatures rise in the coming days.

The disease will have to be hit hard if it returns. Talius and Midas are control options.

Mid-season plant growth regulator may need to be adjusted depending on crop growth. Growers should keep a close eye and adjust the rate of Terpal accordingly – 1-1.25L/ha. This may be applied at the T2 fungicide timing.

Crop stress

Many crops across the country are under stress. John put some crop discolouration down to harsh winds and cold weather in recent weeks.

Phytotoxicity is also a problem in some crops which were sprayed with growth regulators and wild oat sprays when temperatures were dropping at night time.

Ensuring that basic nutrition is correct helps crops to fight against this stress.

“The more nutritionally satisfied the crop is the hardier it is and the less problems you’re going to get with these types of reactions,” he added.