GCTV Ep#13 Small Conical Snails Narrator: Debra Bishop
Tiny but troublesome, conical snails are an increasing problem for some growers in AustraliaÕs
southern cropping regions. Svetlana Micic: Dept of Agriculture and Food
WA Oh look at that you have just got them all
under the stubble here. Narrator:
East of Albany on WAÕs south coast, colonies of snails cluster on fence posts and burrow
in soil and thick stubble such as canola, contaminating harvested crops and clogging
equipment. Scott Smith: Albany Grain grower
Bloody mongrels. Narrator:
Scott SmithÕs family has farmed here for generations.
But over the last five years, snails in this region, and to a lesser degree slugs, have
been increasing costs and decreasing quality. Scott Smith:
We went out and bought a new seed cleaner, we clean all our canola now because of contamination.
In the cereals it can be quite difficult because you cannot necessarily clean the snails out
of grain we had quite a lot of wheat this year downgraded from Noodle and APW grades
down to GP, which is very disappointing. Narrator:
ItÕs a problem measured in tonnes. Scott Smith:
We had about 400 hectares of canola up at Copper Valley this year and we probably cleaned
out four tonne, three and a half to four and a half tonne of pure snails. Narrator:
Scott has grazed stock to crush snails, reduced stubble and eliminate green feed sources strategies
recommended by the Department of Agriculture and Food WA. Svetlana Micic:
In this case we can actually see that grazing a paddock has caused the stubble to be broken
down and the movement of stock over this paddock has decreased the amount of green plant material
because the more green plant material that is present over summer, the more places there
are for snails to harbour under and also they do form a ready food source if we do get any
summer rains. Narrator:
Another strategy baiting, has brought Scott mixed results. Scott Smith:
The problem with the baiting is it is very expensive and you do not kill all the snails,
you just drop the numbers back and just continually have a problem. Svetlana Micic:
SARDI has just finished a scoping study to look at the application of baits being used
by fertiliser spreaders and what they have found is that if you can calibrate your fertiliser
spreader you will get better bait coverage. Narrator:
GRDCÕs recent Snail and Slug study has now been extended into three years of funded research
focussing on better management and control. Scott Smith:
We probably really need to know a way of breaking their life cycle properly and being confident
that we can do it. Narrator:
Growers like Scott are keen for information and desperate for solutions. Scott Smith:
Same old story as weeds we would love a spray but I am not sure that is going to happen. Narrator:
Surveys in WA have found snails from Esperance to Geraldton. Narrator:
Common farming practices can aggravate the problem, minimum tillage and stubble retention
provide protection for snails and liming strengthens their shells, building resistance to hot summers. Svetlana Micic:
So it is not to not-lime, it is just if you are liming it is to be aware of it and manage
those paddocks that are being limed. Narrator:
Impacts of the infestations vary. Svetlana Micic:
Some growers are reporting that it is causing not just damage to crops and emergence but
it has also become a major grain contaminant. What we have been asking growers to do to
decrease numbers of small the pointed snail is to bait before they seed and after seeding
especially if they are going to be planting canola into a paddock that has had a lot of
snails. Narrator:
Some growers use burning but erosion can be a risk. Scott Smith:
Burning is not really an issue or option for us because our country is light its quite
fragile and the district has seen a lot of wind erosion events in previous years before
we all got into minimal till. Other than that we are waiting for a silver bullet. Svetlana Micic:
There is no silver bullet. It is a matter of using a number of techniques
from baiting to managing stubbles to decrease the snail population over time.
Late summer, especially if we have had some rainfall, is a good time to inspect your paddocks
because areas of green are very easy to find snails under, though slugs can be more challenging
to find. Narrator:
While research continues Scott hopes for eradication knowing control minimising crop damage is
the key. Scott Smith:
Very very tricky, very expensive, takes a lot of time and the answers for us and our
lighter country, I do not think are there yet. Ends 3