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2 May 2008

Hemp Farming

Peter Simmul: Industrial hemp is a cannabis variety that is used for the manufacture of commodities that we use in everyday life. The big one, of course, is clothing, and the clothing is manufactured from the bark of the plant itself. In the whole family of cannabis plants globally, there are some hundreds of varieties. And the varieties that are chosen for industrial hemp have no mind-altering components in them at all. The illegal variety has tetrahydrocannabinol in it and these plants don't have that. There are some that are specially developed for seed.

They're short crops - they are of the same height approximately as wheat or barley. And they have outstanding yields in excess of 1 tonne of seed per hectare. Of course, the other varieties that are grown for fibre, like these, these are fast-growing and they grow quite tall and in Tasmania, these varieties will grow up to 3 metres.

Most people don't realise that hemp has a male and a female plant. Now, this one is a male plant. The male plant begins to flower before the female plant becomes obvious. And approximately 40 plants in 100 - 40% of plants - in a hemp crop are male plants.

They give off a lot of pollen, so when it's windy - on a windy day - you will see pollen just flowing like clouds through the crop and that is pollinating the females. Now, the female, it becomes pollinated and it begins to bush up. And as the female becomes pollinated, the male plant just wilts away and dies. The female then fills out and becomes very bushy. And as she becomes pollinated, the little seeds are formed, and you can see one there. And they get bigger and bigger until they start to get a split down the side of the calyx. And at that time, the seed is mature and it will fall out. And that's when the harvesting is at its optimum time.

Now, a lady contacted me and said the leaves are very good for making dye. They have a very rich source of dye in them. The elements of the plant that we're interested in are mainly the stem, and the two components of the stem are the bast fibre and the hurd fibre. This is the bast fibre - this is the bark - on an immature plant. That is would probably still break. But on a mature plant, that's very difficult to break.

Bruce Goss: I mean, just a thin bit like that is extremely strong. There's no way of pulling that apart like that. You'd have to cut it. And imagine if you matted that together in a rope that was 25 millimetres wide or something - you'd be towing trucks with it.

Peter Simmul: Inside the stem is the pith, which is referred to as the hurd fibre. And this is the white part there. And that is approximately 70% of the plant. And that has good insulating properties and good absorbency qualities. So any commodity with the need for absorbency would come from the hurd. The bark is the bast, and that is where your canvases and ropes would come from.

Bruce Goss: I guess we're fairly fortunate in Tassie that we have a poppy industry which is under a control board for policing purposes and licensing and we've gone under that umbrella as far as gaining licences and so forth to grow. But, yes, it is a pretty stringent licence that we have to have to grow the crop. This is the second year that we've been trialling hemp. I guess we were looking for an alternative, something as a break crop from some of our other vegetable crops. We've got the harvesting process down reasonably well for the seed side of it. This is our first attack at growing fibre. And this particular crop will go for a garden mulch. So we'll see how this season goes.

Peter Simmul: Well, the number of products that can be made from industrial hemp are virtually unlimited. If you read the book on hemp, they claim that there's 32,000 commodities that you can make. And with its omega-3, -6 and -9 components, obviously it is a very healthy product.

My main area has been in growing varieties and evaluating varieties and developing cultural management techniques. And this I've been doing since 1995 and we've pretty well got it all sorted out. The future of these crops now depends on the ability to produce a commodity that is marketable.