Mulch vs. Un-mulch Trial at
Tyrrell's Vineyard
Presenter
Andrew Pengilly
Why this block was chosen
• Block was chosen because of its age, planted in 1928
• Dry grown
• Slow decline in tonnages and sporadic canopy growth over the past
10years
• Sun-burning is a major problem even though the rows face east – west.
• It’s one of three small blocks that Tyrrell's own, that we rely on to make
VAT 1, but the fruit is not always up to standard.
Positives to the Mulch Trial:
•
Canopy is more vibrant, richer in color, leaves last longer through
to the end of the season.
•
Canes are stronger, longer internodes lengths, the bunches don’t
seem to be as condensed or overlap which reduced our disease
pressure
•
The weeds were suppressed throughout the growing season with
only two herbicide applications required.
•
Own Tonnages:
Mulch
Un-mulched
Average tonnages
2.85t/ac
2.0t/ac
2.1t/ac
Positives to the Mulch Trial:
•
Juice analysis
24.1brix
23.6brix
Mulch 3.37pH Un-mulched 3.46pH
6.34TA
6.36TA
•
Winemakers comments:
•
The mulch juice analysis for mulched block is the ideal
benchmark for long term Semillon wines.
•
Winemakers become a little concerned when the pH rises above
3.4 for high end use wine
•
The berries have reduced sunburn
•
Berries are larger, which means that the wine becomes softer and
more elegant.
•
Fruit qualifies for VAT 1.
•
Tonnages ok but like to see Semillon at about 3-5t/ac.
Negative to the Mulch Trial
•
Vineyard layout, being 2.5m row widths makes accessibility a little
difficult , as we try not to drive on the edges of the mulch row.
•
Accessing the right equipment to put the mulch out.
•
We have had to remove some of the mulch from around the base
of the vine.
•
Cultivation threw some soil onto the mulched rows.
•
Slashing the mid row disturbing the mulch
•
The winery could not keep the wine separated from the mulch vs.
un-mulched due to the logistics of such small parcels of fruit.
Negative to Un-mulched Trial
•
Sun-burning still evident
•
Shorter cane and internode lengths
•
Sporadic canopy length
•
During the growing season a hail storm caused slightly more
damage to the berries, resulting in a higher disease risk.
•
Four herbicide spray applications were required during the
growing season
Conclusion to the Mulch Trial
•
Vines look healthier where mulch has been applied
•
Condition of fruit is far better
•
Winemakers liked what they saw in the paddock as well as the
juice analysis results
•
For a season that had low tonnages and high pH throughout the
district the mulched block seemed to perform above the rest
•
Easier pruning and tying down of the canes
•
Continuation of the trial to see the longer term benefits
•
Thumbs up from the winemakers and more importantly Bruce
Tyrrell
Thank You
•
•
Compost Australia
• Darren Faye
Australian Native
Landscapes