Efficiency is key for a large vegetable growing operation such as Premium Fresh, which produces a range of crops across the north of Tasmania.

The spray program to manage key diseases needs to quickly control damaging problems such as downy mildew in onions and brassicas, while working with the wet conditions often seen in the region.

As Premium Fresh farm manager Deon Gibson explains, downy mildew can be devastating, particularly when showers of rain in spring create humid conditions and high disease pressure. 

“Downy mildew is a real issue in onions for us here in Tasmania, and in other crops also. It can wipe the whole crop out if you're not onto it, and so in most crops we grow, we've got to run a fungicide program to keep on top of mildews,” Mr Gibson says.

Infinito is a fungicide developed by Bayer for the vegetable market and can be used as a protectant against downy mildew in both onions and brassicas, and white blister in brassica vegetables.

As Tim Walker, lead agronomist with Walker Ag Consultancy, explains, Infinito is unique as it has two actives, Group 28 and Group 43, with no known resistance globally, which he sees as a critical part of a resistance strategy program in both brassicas and onions.

“It's important for me as an agronomist to have these two unique modes of action, Group 28 and 43. We do not want to build up resistance to these diseases in the plants, so we're very lucky to have Infinito as another tool in the shed,” Mr Walker says.

“I recommend Infinito in an onion program when disease pressure is high. It's one of the big guns that we pull out when we know that the pressure is more than likely going to cause these diseases, so we'll prevent that by using Infinito in the right conditions,” he said.

“We've seen some really good results with Infinito in both onions and brassicas over the last few years. Once the conditions favour the disease, we are applying the chemistry and stopping the downy mildew.”

Mr Gibson said the two modes of action of Infinito are very attractive.

“We've tried to break things up to get away from resistance issues, and so we introduced Infinito because it's got two different actives we haven’t used before,” he said.

“Resistant management with chemicals is always a concern for me. If people don't take it seriously, it could be devastating for the whole industry.

“Infinito having the two actives is a real plus, and if we use it properly, we'll have it for a long time.”

Premium Fresh prides itself on quality produce, and a cornerstone to that is keeping mildew out, resulting in a clean, healthy crop. The withholding periods of Infinito play an important role in achieving this, allowing for flexibility and late season spraying.

“There's a nil withholding period on Infinito for brassica vegetables, which is fantastic, as we can keep that crop nice and healthy right up to the day of harvest, and it's only a very short seven day withholding period for onions,” Mr Walker explains.

“Another advantage of Infinito is it's completely rain fast once it’s dry on the plant, which is incredibly short. So, where there's a high rainfall in certain times of year, which is often when fungicides are needed, or even in an irrigation program, we're not disrupting anything by using Infinito as it dries incredibly quickly.”

Mr Gibson agrees it’s critical for busy farmers to be able to apply downy mildew fungicides and at times be able to irrigate soon afterwards.

“When we use Infinito, we're not having to wait in our irrigation program. We can often spray that day and be back in there with the irrigators that evening, so that's quite good,” he says.

“We’ve had seasons where we didn’t have any downy mildew issues at all after using Infinito, which has surprised me because nearly every season there are hotspots in crops, and no matter how hard you try, there always seem to be issues, so the performance has been quite impressive.”

“Financially, the cost of Infinito is far outweighed by the benefits of increased yield and quality compared to any other chemistry we've used in past years.”

Adding to the efficiencies is the good compatibility Infinito displays, with Mr Waker also recommending tank mixes of Infinito and Movento.

“Infinito is compatible with a lot of chemicals, including the insecticide Movento, which is really good for controlling thrips in an onion crop,” he adds.

“I have actually recommended Movento and Infinito together in an onion crop, which is great, as you only have to do a single pass, and this is possible on brassica crops as well.”