Trials reduce yield loss in frost events

Imtrade Australia has been working on the product, Encrypt, for almost five years with original screening results showing 20 to 25 per cent yield retention after a frost.

The original idea came from a paper published based on a lab study that was looking into plant stress, but the concept itself is entirely new and absolute blue sky thinking.

Imtrade national technical manager Michael Macpherson said the company was still not 100pc sure the product was going to go to market, but so far it was showing promising results.

"What we're seeing is that in a flower frosting situation, where you can guarantee the crop has undergone enough frost to get a yield loss, the crop is retaining a percentage of the yield potential," Mr Macpherson said.

"We had unfrosted and untreated crops, so we knew what the full potential of the crop was, then we were able to control frost and some of the treatments.

"With Encrypt, we saw about 20 to 25pc yield increase when compared to the no-product applied frosted control.

"That's still below the unfrosted untreated, so it sits in the middle and while this product isn't going to avoid frost, it aims to decrease the yield loss of that frost."

After gathering the initial data, Imtrade was able to gain investment from the Grains Research and Development Corporation (GRDC) through a grant to continue development of the product.

That grant was received in 2018 and helped the company to run the first year of field trials last year.

"Because we're going into this blind, there are a lot of things the industry still doesn't know about frost and how it behaves, so we put together a trial design in the first year that we thought would tease out the information we needed," Mr Macpherson said.

"What we found is that we had too many varieties, too many times of sowing and as a result we ended up with too much noise in the data without enough replications of the individual treatments across varieties.

"We're now in the second year of field trials and what we've done is pruned the trial design right back, so just Scepter, Mace and Wyalkatchem and massively increased the replication to try and control that site variability."

While the original trial design wasn't perfect, results were still achieved but they were only 90pc significant, rather than 95pc.

Regardless, that result showed a 20 to 25pc yield retention for both Scepter and Mace.

The site which forms this year's field trial has not been hammered too badly by frost, so it is possible Imtrade will need to repeat the trial again in 2021 to get the required data.

The product helps plants to deal with stresses, so there may be some other benefits in other stress situations such as waterlogging and heat, however those are yet to be tested.

Imtrade wants to focus on frost first and see where that could go and once that's finished make a decision as to what to explore next.

Mr Macpherson said Encrypt was not a plant growth regulator, but could be thought of in the same way because it's sprayed on the plant very early, before stem elongation.

"It enters the plant and moves about in the vascular system, so up and down and we know that because we've seen it moving in the residue studies, but that's about all we can tell you at this point," he said.

"It's not sunscreen, there are some products out there that are like a latex that coats the leaf, but this isn't like that.

"Our product is a chemistry that is absorbed by the plant and moves within it, but what it's doing in there, to be quite frank, we don't know."

Imtrade is first focusing on developing a commercial product, providing sufficient data to get it a registration and guaranteeing it works agronomically in the field, before taking it to market because growers need a solution.

After that, the company will figure out the biomechanics of it and worry about the PhD behind it at a later point.

Mr Macpherson said the product didn't have crop safety or residue issues, with significant data to show that.

"All we have to demonstrate now is enough data on efficacy, but we're so seasonally dependent on that, so it will just depend on how long it takes," he said.

"It could be another couple of years before we get sufficient data, as they're full-year trials and we don't know the results until we harvest because there is nothing else to see in the crop, so realistically it could be three to four years before anything is on the market.

"We're also not promising anything, we're not 100pc saying it's going to work, but we're trying something because at the moment there are very limited options for frost."