Northern wheatbelt bracing for powdery mildew challenge
- Grower Stories
- Product News
17 Juni, 2016
- Grower Stories
- Product News
17 June, 2016
Local Landmark agronomist Grant Thompson said over the past 20 years, he had never seen the disease so widespread.
“You can generally get it in a couple of varieties and closer to the coast, where there are humid canopies, but last year it was very widespread,’’ Grant said.
“It rained, then it was dry for a period and this dulled the disease, and then it rained again and there was head infection. There was a lot of white powder coming off crops at harvest.
“In hindsight, one spray was not enough. We could have done two to three spray strategies.’’
He said there was strong potential for widespread powdery mildew again this year.
“It’s a stubble borne disease, so there is a large portion of the northern agricultural region that has powdery mildew fruiting bodies attached to stubbles.’’
Rob Kitto, who farms on the Casuarina Sandplain south-west of Mullewa, was one grower who was “caught by surprise’’ with the disease last season.
Rob and his wife, Tanya, who have four children, Jemma (16), Ebony (15), Maddison (13) and Thomas (12), operate a continuous cropping program of wheat (4000 hectares), lupins (3500 ha) and canola (500 ha) at their ‘Erangy Spring Farm’ property.
“We normally get a bit of powdery mildew, but it’s not much of an issue because the weather usually works in our favour,’’ Rob said.
“Last year though, it went super-sized. We were finding it in crops before the good winter rain, then June was warm and dry and we were still finding it, but thought we would be okay. Then it rained and it infected everything – and it was hard to keep on top of.’’
He said they firstly applied Folicur® fungicide over everything, however it did not perform well and so they then turned to the broadspectrum triazole fungicide, Prosaro® 420 SC from Bayer, for the worst affected crops.
“With Folicur, people were not seeing any difference after 10 days, but with Prosaro, we noticed the difference in 10 days. The disease levels dropped off. It cleaned up the plants really well and the crops got away again.’’
“Prosaro is that much better than all the rest of them. You are better off doing it and doing it well.’’
The Bayer fungicide was applied at the label rate with 100 L/ha of water.
The disease, combined with the dry finish and frost events, had quite an impact on crops.
“Some parts of crops that were not frosted or affected by the disease yielded 3.5-4 t/ha, but other areas were down to zero,’’ Rob said.
“We were looking at an average 2.6-2.8 t/ha wheat crop. When it comes in at about 1 t/ha less, it’s pretty disappointing.’’
He said there had been some rain in the region and some volunteer cereals, so careful monitoring would be required for the coming season.
“At least now, we have a better understanding of what we are dealing with.’’
“We will run the liquid kit on the seeder bar with a suitable fungicide and that should get us through to flag leaf. At $4/ha, you just have to put it on. We will also monitor the pressure a lot more. We will be proactive – and you need to have chemical on-hand. You need to get onto it early.’’
Grant said most farmers who applied Prosaro achieved better control than those using other triazole fungicides.
“It’s $10/ha compared with $2-$4/ha, but the better quality product did a better job than cheaper triazoles,’’ he said.