Spray drift interview with Dr David Loschke and Ground Cover TV
This video was produced by the Grains Research & Development Corporation (GRDC) for their 'Ground Cover TV' program (external site), episode #2, 2010, to inform grain growers about the APVMA's new spray drift regulations. The interview was conducted between the GRDC and former APVMA Principal Scientist Dr David Loschke.
The video contains general information about spray drift. The APVMA is currently developing proposals relating to drift reduction technologies which will impact on the size of required down-wind no-spray zones.
Every product that has enough of a risk that requires some sort of protective no spray zone or buffer zone will have a number of statements – it’ll have a required droplet size that people must use, it will have a prohibition against any spraying during inversion conditions, it will have a requirement for record keeping which is not uniform across the various States, but now for these products it will be required of everyone.
Immediately below those restraints will be the buffer zones themselves, and those will be cases where the particular issue of concern is identified and then a specific distance that must be allowed to remain between where spraying quits and this particular area or object of concern down wind from where spraying is done.
It is important for everyone to understand that the no spray zones, or the buffers zones as they’re often called, they snap into existence at the time you begin spraying and you know which way the wind is blowing and you’ve already done an examination of what is down wind and you know what’s there.
Ground Cover TV
With an increase in a buffer zone, some growers will be thinking ‘this is going to reduce the amount of land that they can actually farm’. How do you answer those concerns?
That’s a concern is very common, and the first reaction of most people. Some people have even asked ‘who’s going to compensate me?’ The first point I always try to make so that people understand it clearly is that the buffer zones are only down-wind buffer zones. Some people have told me ‘that the wind always blows down-wind where I live and it never stops’.
We know from years and years of very detailed Bureau of Meteorology data all around Australia in all the cropping areas that simply is not the case. There are very particular patterns to that. While it might be difficult in one or two days time to find the right window, it nearly always happens that the wind is going to shift direction for enough time for a person to go down and spray a particular end of the field that they couldn’t spray the day before, or two days before. That’s one point.
The other is that the buffer zones that we are putting on labels are based on risk assessments using current, conventional and typical technology and practices that are used throughout Australian agriculture. But what we want everyone to know is that a lot of the practices that are being used are old-fashioned and out of date, and some are simply wrong-headed. What we are hoping to do is to get more people aware of the new options, not all of which are expensive, some of the times we are talking about nothing more than a new set of nozzles (many of the time). Others sometimes involve newer types of equipment or just different types of practices can solve the problem.
Ground Cover TV
You did say that some of the practices are ‘wrong-headed’. What would be an example of that?
It has almost been an indisputable fact in the past that you always wanted to put on a fine droplet spray, and there was no questioning that that was necessary in virtually all cases because the idea was that you had to get uniform coverage. Now there are some products where that is necessary, it’s true. But for many of them it didn’t need to be as fine as they were doing, and for many it doesn’t need to be fine at all.
We’ve found now and we’ve had evidence for a long while, but now we have abundant evidence that 2,4-D for example, and all of those systemic herbicides like that, except in a few unusual herbicides but virtually all of them do extremely well and perfectly well with coarse, very coarse and even extremely coarse which are standard droplet spectrum (people in the industry know what that means).
What we will do as an authority is, we will require every chemical manufacturer who registers a product with us to nominate what is the largest droplet size category for which their product will still be fully effective, and then that’s the one we will use and put on the label and require people to use at least that size droplet category. Then will we do our risk assessment on the basis of that, so this is the motivation for a chemical company to be honest about it.
Ground Cover TV
Up to 750 metres has to be left as the buffer zone if you’re spraying next to remnant vegetation or another crop. Is it possible for growers to actually work to reduce those zones?
Yes, and that’s something I do want everyone to understand, and it isn’t evident yet, because our first step is to try to get these critical reviews done, and get those new labels out there. But in the background while this is all going on, we’ve been working really hard to develop what amounts to an entirely new approach or program that we’re going to put on our website in the next month or two and we’ll give it a name something like Drift Reducing Technology (it’ll be a section on our website) and what it will do is allow or rather act as a reward for people who take up better practices and better technologies.
Note: information on the Drift Reducing Technology (DRT) Incentives Program was published on 17 November 2010.
Ground Cover TV
Of course you’ll need to wait for the research to be done, but when we talk about a reduction of the buffer zone, are we talking about a serious reduction in size?
Aerial buffer zones can be up to 800 metres at times, and it could mean cutting in half, sometimes even less depending on the particular kind of technology we’re talking about. Ground applications, their buffer zones have a maximum of about 300 metres, but they nonetheless could also see very significant drops to that, maybe again as much as half if they were willing to use some of the newer approaches.
Ground Cover TV
Is there a timeframe for the introduction of this review, or is it all happening now?
What we’ll do is run the review, go through the entire process and then that same product will appear with new labels, and it’s only when the new label is there or has been declared to be there that the grower is obliged to follow it. So for all those other products that we haven’t had the time yet, or resources to go out and review, their time will come but for now it’s a matter again, as always, reading the label, reading the current label. That’s the proper lawful label for the product.