John Mats
John Mats

In 1994, an organic Penfolds Chardonnay-Sauvignon Blanc (93 harvest) was judged to be the best wine of the annual Organic Wine Challenge. Over one hundred organic wines were entered in the competition, from all over the world. The wine has continued to be successful in shows and compares well with organic and non-organic wines.

The vineyard and the wine are certified by NASAA. There have been certified organic wines in Australia for ten years but this is the first Australian organic wine to be released only into overseas organic markets and the first certified product by a major Australian wine maker. An organic red is also made with grapes from the Clare Estate, for export. The wines are not available on the domestic market. The main organic varieties include petit merlot, cabernet sauvignon, petit verdo, shiraz. and chardonnay.

Tim Marshall spoke to vineyard manager, John Matz, on a recent trip to the Clare Valley.

Tim: How much of the property is organic?

John: "We started with 25 hectares of certified vines in 1993 and we are now up to about 55 hectares of the Clare Estate, comprising E Block F Block and G Block, from a total farm area of just over 200 hectares. We also have another small area under conversion."

Tim: Why have you chosen to use only certified organic inputs?

John: "To protect the integrity of the product, Southcorp uses only certified products. We check all our inputs with NASAA, and even prefer NASAA certified inputs to other certifications. NASAA has been very helpful and we work closely with the Certification Office, and we encourage manufacturers of genuine organic products to become certified by NASAA."

"There are too many doubts over some products, and even some snake oil salesmen out there. Certification makes it easier to make the hard decisions about which products to use and to sieve out products which don’t make the mark."

Tim: How has your fertility and inter-row management changed since conversion?

John: "We started by using clovers and medics in the mid row, with straw mulch under the vine, and relied heavily on liquid seaweed products for fertility inputs. Crop levels were being maintained, although marginally below conventional yields, but we noticed a decline in wood vigour at pruning. The Sauvignon Blanc in particular was looking particularly ordinary."

"We put together a task force including Wendy Allen and our nutrition consultants Peter Scholefield and Ben Robinson. They concluded that we needed more nitrogen."

"This season we have trials with two NASAA certified compost products, and using a certified Fish product through the drip and as a foliar."

"Management of the mid row has changed because of problems with earth mite, which thrived in the clover and medics in the cover crop."

"Scholefield and Robinson suggested we use limited cultivation and green manure, so now we have alternate rows of cereal and legumes."

"It was not easy to find a fertiliser for the cereal row, to get bulk. After trialing some other products, we now use a pelletised chicken manure at reasonably high rates for the cover crop."

"NASAA has allowed us to use 15 tonne of composted manure per hectare. When we applied this under the vine there were some weed problems, but the result was good when broadcast, as the green manure grows better."

Organic vines at Penfolds Clare estate
Organic vines at Penfolds Clare estate

Tim: Are the vines now performing to your satisfaction?

John: "Because we have had low inputs since 1991, the vineyard needs inputs. F Block is maintaining well, because we started that later and had learnt a little from our first experiences."

"We have reworked most of our practices too. The problems have not only been from low inputs, they have also been from management. The same could be said of the conventional vineyard too."

"Looking back we think the crops were too high and the vines were loosing vigour. They are now pruned more severely to drop some crop and the vines are more healthy and even."

We have changed the irrigation scheduling too."

"We did a lot of soil testing and experimented with liquid gypsum and fixing salinity and other soil problems."

"We now schedule irrigation better. though still a little restricted by the design of the old irrigation system. We schedule according to need and the capacity of the soil to take in water, perhaps using two shorter irrigations where we would have used a longer one."

Tim: When I was last here, you were using straw mulch and the Clemens under vine weeder where there was a major frost threat.

John: "We do still use the Clemens and we have two Braun weeders now too."

"The task force suggested some of our nitrogen problem was exacerbated by the use of straw under vines, robbing available nitrogen."

"We like the under vine weeders, but we are also looking at thermal weeding with a gas appliance."

Tim: What sprays do you use in the organic section?

John: "We use copper and sulphur, perhaps a little more pro-actively now that we can't use phosphorous acid."

Tim: Has your experience with organic viticulture been worthwhile?

John: "E Block is our long term sustainable project and we are committed to it. We have learnt a lot from observing E Block and the result is that our conventional fungicide program is now basically Copper and Sulphur, except for a few hot pockets of powdery and maybe some Botrytus treatments in the Riesling."

"We don't use insecticides for light brown apple moth, even though this is a major area for that pest. The use of isomates is so successful, we don't need Chlorpyriphos even in the conventional vines."

Tim: Is there a good market for organic wines?

"There is definitely a market for organic wines, even though it is not recognised by the buying public. By that I mean that a good organic wine should be able to perform in any market, not just the organic section. Our organic white recently won a bronze at the Clare show, competing with all comers, not just other organic wines."

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