Case study: feedback and survey results from Max Gifford, owner of Stembridge Vineyards Ltd
Stembridge Vineyard is managed under best practice ‘Sustainable Winegrowing NZ’ standards. Soils are described by owner Max Gifford as ‘mixed alluvial silt with gravel ridges’. Grapes are machine harvested and a Klimmer mechanical vine stripper is used followed by hand pruning.
Post installation - 2007
Two hundred and eighty eight E. bosistoana posts were purchased in July 2007. Max wanted to include the posts in his own trial of alternative vineyard posts. He installed 265 posts in rows immediately after purchase. Each post alternated with two plastic covered Greenspan steel posts. The unused posts were retained for replacements, and 15 were still in stock at the time of the vineyard visit. The balance of Stembridge Vineyards is installed with CCA-treated pine posts. Plastic posts have been tried and rejected.
Follow-up survey findings – 2017
An analysis of the data collected during inspection of the E. bosistoana posts at Max Gifford’s vineyard confirms how well the post performed:
||No. of posts purchased
||No. of posts in service (2017)
||No of posts found broken
||No. of posts failed from decay
||No. of posts in storage
||No. of posts assessed in-ground
The total of 8 posts broken equates to 3% of the total of 275 installed 11 years ago. This indicates an annual breakage rate of 0.3%, compared to 5% in conventional CCA-treated pine posts.
All but two of 50 posts assessed for in-ground decay showed less than 5mm of decay, even after 11 years in service.