You may be aware that a couple of grape growers in Marlborough have recently challenged the quality of Stanmore Farm vines.

It is important that you hear the facts directly from us. At Stanmore Farm we are proud of the excellent reputation we’ve built up over years of dedication to be one of the best nurseries in the business. That’s why we want to make sure you have the benefit of the facts behind the rumours, so you can continue to have confidence in us to provide the very best quality vines. 

In 2014 and 2015 we supplied one Marlborough-based customer with approximately 15,000 Sauvignon blanc grapevines. 

In 2016, the grower advised a proportion of vines had died (less than 1% and well within the 3% industry standard for loss). Not only did we replace the vines, but over several months we carried out our own analysis invested in independent analysis and advice from Eaton Crop Care, Plant Diagnostics in Christchurch, Plant & Food Marlborough and Dr David Jordan. Each concurred that the plant mortality rate was within industry standard, but assessed there were a range of issues that contributed to the vines dying.

The expert analysis diagnosed that a combination of factors contributed to the plant loss, including site/soil, plant management and weather conditions; leading to Cylindrocarpens (blackfoot), Botrysophaeria (trunk disease) and Verticillium Wilt (a soil-borne fungus that attacks vines when planted in ex cropping ground). This vineyard had nightshade plants at the bases of many vines and potatoes planted down the rows – both crops known to host the Verticillium fungus. There was also Glyphosate damage, among other management issues.

Where Cylindrocarpens is concerned, the advice was “Cylindrocarpen destructans mostly affects younger vines (up to 10 yrs old) causing a general decline and often eventual death. The fungus may be present in soil or may be introduced in planting material and is most troublesome in poorly drained soils and/or compacted soils. The fungus can produce resistant spores which can remain viable in the soil for a number of years. Infected plants are best removed and soil disinfested by planting green crops such as mustard as well as  pre- inoculation with mycorrhizal fungi which can help reduce incidence of blackfoot. However, the greatest predisposing factor for this disease is usually the soil conditions which may need remedial action.”

And “Botryosphaeria (associated with Grapevine Trunk Disease complex) enters through wounds such as pruning cuts; research has shown that the application of a wound dressing can significantly reduce disease infection. It is possible that these fungi could have entered during the graft process.”

Despite the analysis confirming a range of contributing factors, we replaced 345 (2.3%) plants in total for the grower, between 2016 and 2017. Very recently we have offered to replace any further plants that have deteriorated after the very wet spring.

Meanwhile, a second grower in Marlborough, who planted over 32,000 vines we supplied in 2014, lost around 10% of his vines over the past 3 years which is obviously higher than we would like and certainly warranted investigation. We found parts of his vineyard planted in an area of compromised drainage, and as expected, there were many dead vines in this area. 

He subsequently appears to be contacting growers challenging the quality of Stanmore Farms’ product and suggesting a systemic quality issue. This is despite us working closely with him to identify the issues, and to fund half the replanting cost of replacement vines, plus the full cost of buying 3250 vines from a different nursery.

We take these criticisms very seriously and want to assure you that nothing has changed in terms of our commitment to growing the very best vines and working closely with our customers to ensure they achieve the very best results.

From a customer service perspective, we stand by our product and always have. We support customers with detailed instructions about site preparation and management, and we offer free site visits and free advice. Any issues growers have, we address quickly and directly with technical support, expert advice and vine replacement when need be; often over and above our contract terms.

All nurseries have had and will continue to experience a level of vine loss. Here at Stanmore Farm, we produce certified vines that are true to type, virus tested, traceable / trackable and with high physical specifications. But as with any plant, there are always risks to survival. This is what the NZW GGS covers.

From a nursery perspective:

  • We have always used mustard as a green crop for fallow years when we rest the soil – in fact, we believe we were the first nursery in New Zealand to do so. Mustard acts as a fumigant against fungal pathogens in the soils
  • We have always used Trichoderma and Mycorrhizal fungi to support healthy vines and protect against pathogens as a pre-planting dip and a fertigated product through the growing season
  • We have rich, healthy soils that we use organic mulches on, and our plants have a reputation for good quality, premium grade vines with a high standard of physical specs (good roots and length, thick diameter, strong grafts).

As a viticulturist, I have worked in the industry since 1988 as a consultant, company viticulturist and contract grower/manager and nurseryman and we at Stanmore Farm pride ourselves on our long-standing relationships with customers who are consistently satisfied with the quality of vines they receive from us.

There is no doubt that as New Zealand’s climate warms and we get extreme and erratic weather events and seasons like last year’s ‘Big Wet’, grapevine wood diseases are increasingly impacting vine performance across the country. This is also true internationally. New Zealand Winegrowers is giving considerable focus into researching these threats to our industry, especially given Sauvignon Blanc is one of the most susceptible varieties to these diseases.

Dr David Jordan, Viticulturist at Vine to Wine to Market says, “As an industry, our understanding of these diseases is still rudimentary and there appear to be a number of contributing factors that result in an infection having an impact on vine performance.

New Zealand is not alone in their concerns with wood diseases in grapevines, as Dion Mundy and K Clapperton state in their “Review of grapevine trunk and root disease in New Zealand” (commissioned and published by NZ Winegrowers in 2013) that since the late 1980s trunk disease problems have emerged as a serious problem in the grapevine industry internationally.”

At Stanmore Farm we are working closely with fellow nurseries through VINA and the wider industry to ensure we are at the forefront of efforts to evolve New Zealand’s growing and management practices so that our vines are resilient to disease and achieve the performance we need to maintain a sustainable wine industry.

Through VINA, we and other nurseries have funded a trial in Marlborough looking at Grapevine Trunk Disease including young vine ecology and preventative treatments and hot water treatment. We have investigated pathogenic fungal populations on newly planted and young vines and we are looking at developing diagnostic tests for fungal pathogens.

There are other important areas of vine health research which can flow on from this, including investigating links between environmental stressors and the onset of trunk disease symptoms.

In the meantime, we want to make sure that we continue to be trusted to deliver the very best quality product available. As has always been our way, we’re happy to work with our customers to ensure satisfaction. If you have any questions, please call us.

Lastly, may we also take this opportunity to wish you and your family all the very best for the festive season.

Warm regards

Kate Gibbs

Viticulturist

Stanmore Farm