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Seed Treatments 2004

Rob you’ve been running seed treatment trials now for the last 7 years. Can you start off with telling us how the assessments are carried out?

Well Adam, we do the assessments much the same way we do the variety trials. There large strip trials, so we run the full length of the field by the width of the planter and we have three or four replications and usually what happens is after we treat the seed and plant the seed out we would assess the establishment to see how many seedlings have emerged, note if there are any differences there, we’d also then collect samples from leaf samples over usually a four week period, usually on a weekly basis and we would do a count of the thrips that are on those leaves. The way we do that is by actually killing the thrips on the leaves with a metholated spirits solution and then we wash the thrips off, filter them off and actually do a count under a microscope. That count is actually done by CSIRO at Myall Vale.

How does that compare that to visual assessment doing it that way?

Well it’s very hard to count thrips, they move very quickly, they are in the tips of plants so its almost impossible to get an accurate count doing it in the filed, you really need to take them into the lab.

So how do the various treatments compare. You’ve run them for seven years, what’s the sort of comparisons that have come out over that time?

Well it’s pretty easy to say I guess that the granular treatments, the Temik and theThimet are a considerable distance ahead in terms of protection against thrips. They give the best control and the longest control and then when we come to the seed treatments I guess of those Gaucho and Cruiser are quite consistent and much the same in there control, and I suppose for Semevin Super, except visually often we find the Gaucho and the Cruiser look very much the same as the Temik in that there’s very little leaf damage for the first two weeks after emergence.

Have you had the Amparo seed treatment product in some of these trials?

With Amparo being a relatively recent arrival it’s only been tested in a couple of trials so far, but on that preliminary assessment it appears to fit in somewhere between Semevin Super and Gaucho and Cruiser in terms of visual assessment. I haven’t actually got the thrip counts from that yet but I’d expect they would be similar to the other treatments.

For protection against damage how do the various treatments compare?

Well again the granular products are by far the best protection against damage and you get virtually pristine plants from those plots. They’re quite easy to distinguish in the field as you drive past, often they’ll stand out compared to the seed treatments. Then come the Gaucho and Cruiser that are quite good visually, certainly for the first couple of weeks after that two week period they tend to run down and then tend to blend in with the other seed treatments. The Semevin Super generally tends to take a little bit more damage I guess than Gaucho and Cruiser visually but when you actually count the thrips on the plants there’s not a lot of difference.

And Rob one of the questions people will have is about aphids. Can you give us what you have found with aphids in these seed treatment trials?

Well not all seed treatments are registered for aphids but I guess comparing them where we have had aphids on a few occasions, certainly we’ve found again the granular products are both very good, but both Gaucho and Cruiser are very good at controlling aphids as well, and in fact probably control aphids as well as the granular products in terms of absolute control and length of control. I haven’t had a trial where  Amparo has been sited with aphids yet but it has a Gaucho component  so we’d expect some control or pretty good control of aphids in that treatment. Of course Semevin Super doesn’t control aphids at all.

And Rob I guess the key is how have the yields compared between the various treatments over the years?

Well in about 50% of cases we’ve had a yield advantage. In some cases quite a substantial yield advantage up to 10%, but where there has been a yield increase in that 50% of cases certainly the Temik and Thimet have been the best. Where there has been a yield advantage measured the Cruiser and the Gaucho have been much the same and their usually just slightly ahead of Semevin Super.

And as far as recommendations based on the work you’ve done, what would be your recommendation to growers?

Well I think if you’re in a cool season area, or an area that traditionally takes a lot of thrips and you haven’t got as much season to play with it’s very clear now that you probably should be using a granular product like Temik or Thimet I would add this year if growers haven’t already procured those products they need to check with their reseller because I understand they are in relatively tight supply. If you don’t want to use the granular products and you still want a reasonable order of thrip control both Gaucho and Cruiser are both probably the next best products to choose. If you’re in a main stream area, central area or a western area or a northern area Semevin Super or probably Amparo will really provide adequate control.

Further Information:  Robert Eveleigh, John Marshall,  Craig McDonald or David Kelly