Tassie spud growers try Emblem

Technical business development manager with Tasmania’s largest rural merchandiser Roberts Ltd, Stuart Millwood said at this time of year Tasmanian potato growers were planning their crop spray programs for protection against sclerotinia, early blight (target spot) and late blight for the coming season.

The company’s potato specialist – providing agronomic services to more than 50 potato growers – Mr Millwood’s territory covers more than 1600 hectares of irrigated processing-potatoes in Tasmania’s midlands and northeast, which produce Russet Burbank and Ranger Russett potatoes for Simplot, and Innovator for McCains.

Last season, Stuart Millwood and his client-growers trialled the newly-registered Emblem (fluazinam) fungicide in a few paddocks, and achieved very good results against sclerotinia and late blight.

Although fluazinam is recognised globally as one of the most active late-blight fungicides, and a standard treatment for sclerotinia, it was not previously registered in Australian potatoes.

Already registered for controlling diseases in Australian grapevines, apples and brassicas, last year Emblem was also successfully registered by Crop Care for potatoes – to become the only fungicide on the Australian market for controlling both late blight and sclerotinia.

“Emblem provided fantastic control of both major potato diseases in the field last season, so we will use a lot more this season,” Mr Millwood said.

“It provides Tasmanian growers with another tool for controlling sclerotinia. Although seasons vary in terms of sclerotinia pressure, in more recent years most seasons have been considered high pressure, with wind damage to stems allowing an entry point for the disease.

“Growers have struggled to control sclerotinia, but in our trial paddocks last year, Emblem provided superior control.

“This season as part of their protective fungicide programs, I will be advising growers to include Emblem at 50 per cent row closure for protection against sclerotinia and late blight.”

Crop Care technical representative for Tasmania and Gippsland, Matt Gratton said Emblem had provided an important new chemical group (Group 29) for effective control of late blight and sclerotinia.

“Its multi-site activity also makes it low-risk for developing resistance,” Mr Gratton said.

He said in most Australian potato-producing districts, late blight occurred sporadically in wet conditions, appearing rapidly, spreading aggressively and potentially causing significant damage to potato foliage and tubers.

“Sclerotinia is also a problem in Australian potato crops in wet conditions – from rainfall or irrigation – so Emblem’s registration against both diseases provides a valuable disease-management tool for Australian growers.”

Emblem’s potato registrations were backed by two seasons’ field trials by Peracto in the Lileah district of northwest Tasmania – a district where both diseases were highly likely to develop in crops grown without a suitable fungicide spray program.

Mr Gratton said late blight had been successfully controlled with fluazinam, proving more effective than mancozeb.

In trials in commercial potatoes managed with optimum irrigation for maximum production, fluazinam also proved effective against sclerotinia, and superior to other treatments including boscalid and iprodione fungicides.

“Other advantages of Emblem for Australian potato growers, include its flexible application window, and its rainfastness after two hours (for up to 40mm of rain) – offering protection even in wet conditions.

“Crop Care recommends that Emblem be applied as a protectant treatment, before late blight or sclerotinia become established in the crop.

“Early application before row closure has proved useful for controlling sclerotinia and protecting the crop against late blight. Application later in the season has also protected tubers and contributed to maximum yield and quality.”