Australia
November 26, 2012
The practice of burning windrows to destroy weed seeds is widely adopted in WA but unproven to date on the eastern seaboard.
Maurie Street, Grain Orana Alliance (GOA) chief executive officer has set out to change that with his own on-farm trial in NSW’s central west earlier this year.
Mr Street runs the Grains Research and Development Corporation (GRDC)- funded GOA and is well aware of the difficult issue of herbicide resistance.
He says if he and other growers are to retain their no-till farming systems they will need to look further than chemical solutions to manage difficult-to-control and herbicide-resistant weeds.
“I’m a zero-till cropper; I’ve got no livestock in the system and it’s all winter crop at the moment,” Mr Street said.
“I’ve got concerns about herbicide resistance and I felt that we needed to try something different, that wasn’t just another herbicide.
“I was attracted to the concept of windrow burning; it was relatively cheap, easy to set up and was showing really good results in WA.”
He says all it took in the way of set-up was a simple modification to the back of the header.
“I took the straw spreaders and the spinners off and made up a cheap chute for the back, which probably cost me $100 in steel and a couple of hours in the workshop and it worked fine,” Mr Street said.
He admits to concerns about the application of the practice in the eastern, and particularly the northern environment of the eastern seaboard which is dominated by summer rainfall – in contrast to the Mediterranean climate and dry summers of WA.
“I was concerned that that heavy rainfall during the summer would wet the windrows so that they wouldn’t dry properly, this would mean there wouldn’t be a hot enough burn to kill the weed seeds.”
Mr Street says after just one year he can see the promise that windrow burning holds.
“Where I got the system right and got the fire to burn property there is no ryegrass.
“Where I didn’t get the fire to burn properly it’s really obvious – where the windrows are, although the straw is gone, the area is loaded with ryegrass but you go beyond those rows, 10 centimetres from that row and there is negligible ryegrass.”
To control the high density ryegrass patches left behind he has sprayed with careful attention to correct rates and ideal conditions to ensure the resistance weeds don’t re-enter the farming system.
“Next time I hope to get the fire to burn better for a more complete control.
“I think the incomplete control was a function of the temperature and conditions when I burnt the windrows.
“It was really noticeable when the temperature cooled off during the evening, the fire lost its intensity.
“Where it lost its intensity, it didn’t do the job. Where I’d started earlier in the day with higher temperatures it worked really well.”
Mr Street urges growers to be mindful of the threat of herbicide resistance and says he will definitely try windrow burning again.
“I really see that it will be a good tool for us, I was impressed.
“We had a wet summer, a fairly typical summer, with plenty of rainfall and I was really concerned the windrows wouldn’t burn.
“There was moisture right to the soil surface on those windrows. I could scrape the windrow away and it was just mud but where I got those temperatures right the fire burnt right to the ground and there was nothing left.
“Those rows are clean now, there’s no ryegrass in those rows.”
He says windrow burning is one tool of many and offers control of ‘escapes’, resistant weeds that aren’t controlled by herbicide applications.
“It’s part of a package of practices but I see it as a really good tool that allows us to break the total reliance on herbicides.”
To view a video of Maurie Street’s windrow burning experience and for more information on herbicide resistance management, visit www.grdc.com.au/weedlinks.
Species
