Managing fungal diseases in berry crops

Feb. 12, 2023 | 5 Min read
Botrytis grey mould is a common disease facing berry growers, making the recent registration of Miravis Prime fungicide vitally important from both a production and resistance management perspective.

Botrytis grey mould is a common disease facing berry growers, making the recent registration of Miravis Prime fungicide vitally important from both a production and resistance management perspective.

Miravis Prime fungicide contains two actives, incorporating the proven performance of fludioxonil (Group 12) with the powerful active pydiflumetofen (Group 7), which together inhibit the onset of disease and reduce the risk of fungicide resistance.

Miravis Prime is registered for botrytis in all berries, including blueberries, raspberries, blackberries, dewberries and currants in both field and protected cropping. It is also registered to control powdery mildew in strawberries.

“Miravis Prime inhibits botrytis infection at four stages of disease development – spore germination, formation of germ tubes, appressorium development and mycelium growth,” says Syngenta Technical Services Lead Dr Brandy Rawnsley.

“Fungi treated with Miravis Prime cannot grow on the surface or penetrate the plant, breaking the disease cycle.”

Located at Elimbah on Queensland’s Sunshine Coast, Paradise Fruits has 12 hectares of raspberries under tunnels as well as a nursery for growing plug plants for strawberry growers. Farm manager Brett O’Neill said they trialled Miravis Prime fungicide for botrytis control last year and after seeing good results have incorporated it into their disease management program this season.

“We trialled Miravis Prime last year in our strawberry nursery where we can get a lot of botrytis. Some tunnels were sprayed with Miravis Prime, some with Switch and some were unsprayed,” Mr O’Neill said.

“We saw good enough results in our trial to start using Miravis Prime in our raspberry crops in 2022.”

At Paradise Fruits, the raspberry growing season runs for 12 months of the year, using a prima cane and floricane production system in coir bags.

Miravis Prime fungicide can be applied at any stage of berry production, from flowering through to just prior to harvest.

“The 1-day withholding period of Miravis Prime is a major advantage when we have flowering and fruiting going on at the same time and we’re picking at all stages of the year,” Mr O’Neill said. “With its short withholding period, we will choose Miravis Prime rather than our traditional fungicides.”

Local Syngenta territory sales representative, Wayne Richardson said Miravis Prime fungicide should be applied preventatively as part of a protectant program with applications beginning when conditions favour disease development and before symptoms develop.

“With a maximum of two applications per crop, Miravis Prime fungicide offers excellent protection when used in rotation with fungicides from alternate modes of action.

“It is rainfast within one-hour and the suspension concentrate formulation offers good compatibility with other crop protection products.

“Miravis Prime is tank mix compatible with a lot of other products, so growers can do most things in one pass.”

Another benefit of Miravis Prime fungicide is that it is soft on beneficial insects. “Unlike some other products out there for powdery mildew or botrytis, Miravis Prime fungicide is compatible with IPM programs, which for some is a huge bonus,” Mr Richardson said.

Stuart Doyle is an independent agronomist, and his company AgVista Australia is based out of Launceston one of two main regions for blueberries in Tasmania, the other region being the south east of the state.

He has clients growing four main berry crops, and last season found that botrytis a consistent issue across all berry crops, with botrytis and powdery mildew equally bad in strawberries.  

Several of his clients used Miravis Prime fungicide in raspberries and strawberries. 

“Miravis Prime performed to expectations and definitely out-performed non-systemic protectant products,” Mr Doyle said.  

“Miravis Prime is a low-withholding period product, so there’s definitely an operational benefit. I will very happily put Miravis Prime into our fungicide rotations this season.”  

Mr Doyle also emphasised the importance of good stewardship of new products that come into the market.  

“Soft fruits are a high rotation crop and they are pushing many fungicides to breaking point,” he said. With not a lot of new actives coming into the market, we need to be careful with the stewardship of these fungicides to get life out of these new products.”  

Some fungicide mode of action groups have a higher risk of resistance to them than other groups. As such, CropLife Australia has a recommended resistance management strategy for the control of powdery mildew and botrytis. These details can be found under the resistance management tab on the CropLife website.

Categories Specialty tree crops

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