High humidity levels combined with rainfall can lead to high disease pressure in vegetable crops. In this column, Western Australian broccoli grower Brad Ipsen discusses the fungicides that his operation uses to effectively combat devastating diseases such as white blister, which is known to occur in the state’s south-west region during December and January.

Western Australian broccoli grower Brad Ipsen knows only too well the dangers of rainfall, high levels of cloud cover and humidity – hence the need for a good spray management program to safeguard his crops.

These very conditions presented at the family’s Twin Lakes property near Manjimup in the state’s south-west during the latest broccoli season.

The region sits in an 850-millimetre rainfall zone and even though this can vary by 150 mm – generally downward in recent times – it can cause high disease pressure, particularly when humidity levels are higher during December and January.

“If we start getting cyclone cloud from the north-west resulting in high humidity and high temperatures – and because our plant density is around 47,000 plants per hectare – this lends itself to high foliage mass, and can lead to high disease pressure,’’ Brad said.

He said white blister, which causes tiny white flowers on the heads that also reduce yield, was one of the major diseases Twin Lakes guards against. Soft rot and downy mildew also can be an issue.

“If unchecked, white blister can be very devastating and wipe out a whole planting. You need to have a good spray program in place,” Brad said.

“We base our program around the use of Ridomil Gold^® Plus, but the use of Infinito^® has allowed us to come into crops with fungicide late.

“If you use Ridomil too late in the crop, it can change the colour in the head from green to brown, which is not attractive when you sell on appearance. If conditions are good, we also won’t always use it – we will use something that’s better tolerated by the crop.’’

E.E. Muir & Sons Regional Manager Brad Giles, Western Australian broccoli grower Brad Ipsen and Bayer Territory Business Manager Ian Cook check crop development at the Ipsen family’s Twin Lakes farms in Manjimup.

Disease control

A Bayer product, Infinito^® combines two active ingredients with different modes of action that provide excellent control of white blister and downy mildew at all key stages of their lifecycle. It offers an in-built resistance management solution for growers.

The liquid suspension concentrate formulation is quickly rainfast, highly systemic with strong translaminar activity and, importantly, has no withholding period.

“I always like liquid formulations – they are better to put through the boom. It is an easy liquid to measure, and it pours well. Some liquids don’t stay in solution very well; they precipitate out, but this stays in solution very well,” Brad said.

“I love the fact it has no withholding period in broccoli and allows disease control late in the crop – its fit in our program well. Some other fungicides have three- to 14-day withholding periods.

“Another thing I like about it is that it’s pretty compatible in a tank mix, so I can use it with a range of other products. It doesn’t seem to interfere with anything else I want to put in.’’

The Ipsens use a UK-manufactured 24-metre Househam specialist vegetable sprayer with an air boom, applying Infinito several times according to conditions at 1.6 L/ha with an adjuvant to enhance adherence to plants and a typical water rate of 750 L/ha.

Brad said he was satisfied with the management of white blister using this fungicide.

“We’ll keep using it. It’s effective, easy to use, cost-effective and it’s repeatable and reliable. I know I can trust it.’’

E.E. Muir & Sons Regional Manager Brad Giles supports the Ipsens, and he said Infinito had found a strong fit in programs in combination with older fungicides still on the market, particularly for later crop stages.

“When crops are high and lush, this is perfect to use at that time. Activity from other products at that stage just isn’t up to where this is at the moment,’’ Brad said.

Find out more

Please click here for further details about Infinito^® Fungicide. Infinito^® and Movento^® are Registered Trademarks of the Bayer Group.

Cover image: Bayer Territory Business Manager Ian Cook and E.E. Muir & Sons Regional Manager Brad Giles pictured discussing disease management in broccoli at the Ipsen family’s property near Manjimup in WA’s south-west.