By Caine Thompson, Viticulturist & Vineyards Manager, Mission Estate
There are a number of varying views about organic growing, and questions about whether it is achievable, whether it is cost effective, and whether fruit quality and quantity can be consistently produced when compared to ‘conventionally’ grown fruit. There are very few examples where a direct comparison between the two systems has been trialed where information has been collected and recorded about the process and the end results compared. It is with this in mind that we are attempting to answer these questions.
Mission Estate’s company vineyards have been accredited under Sustainable Winegrowing New Zealand for a number of years, with all growers achieving SWNZ status as well. Mission also follows an environmental management system called ISO 14001 where we have been monitoring and measuring environmental impacts for the past 12 years.
The company vineyards at Mission Estate have been reducing chemical input for the past three years and moving towards more organic based products for pest and disease control.
This project is an opportunity to compare growing organically in a trial situation with consultation and advice from Bart Arnst, NZ’s leading organic viticulture consultant, so that we can try and answer some of the questions we have in regards to organic production.
We are very excited about this project and the opportunity that this has provided for us to work with Organic Winegrowers NZ and NZ Winegrowers in this joint project, which will add further knowledge and value to the NZ wine industry.
The project began in early September with Sauvignon Blanc, Pinot Gris and Chardonnay used as the blocks for the project to be undertaken on. These blocks have been divided into management zones for ease of operations so the organic and conventional areas for each variety can be kept separate for comparative purposes.
Early spring: first undervine cultivation for organic blocks
The season to date has proven to be very wet over the winter and early spring periods. This made it difficult to find a window for our first undervine cultivation to occur. The ground finally dried out enough so that cultivation could take place on the 27th of September. The Moteo Ridge – Ridgeback undervine cultivator was used and has done a fantastic job in turning over the soil into the area directly under the vines. The idea being that this area will provide a friable tilth for cultivation in subsequent months.
At this stage the weeds are still fairly suppressed and I don’t envision requiring another cultivation pass for at least another two weeks.
In some parts of the block where the soil was still fairly wet the cultivated strip hasn’t completely ‘turned over.’ It is going to be interesting to see how the next pass of the mechanical weeder deals with these areas. Another recent 90mm of rain in mid October has added to the available moisture within these blocks. We are now waiting for these blocks to dry before we spray these blocks with the next fungicide application.
First advisory visit and public vineyard walk
Bart Arnst visited on the 6th of October so we were able to discuss the blocks in conversion to organics, and the management plan for the year, along with pest, disease and nutrition programs. For powdery and downy mildew control the organic blocks are to receive a sulphur/copper/seaweed/protector program, compared to a sulphur/diathane program in the conventional blocks up until the start of flowering.
A soil drench was also recommended in spring to assist with enhancing the soil microbial diversity and to assist with enlivening the soil. This will be applied in mid October.
At this stage we are shoot thinning all of the Pinot Gris as shoots are 10cm in length and plan to shoot thin the Chardonnay and Sauvignon Blanc once they get to this stage.
We also discussed the economic modeling aspect of the project and the importance of this and keeping records of all costs separately for the organic and conventional blocks of the different varieties. Bart also suggested comparing diesel costs and taking worm counts as another comparison.
In terms of monitoring the three varieties and two growing methods, the following data will be collected for each:– Fruit Quality – Brix, pH, Ta – Yield – kg/vine – Mealy bug monitoring – Botrytis monitoring – Worm counts – Soil tests – Financial costs for all inputs and management tasks
After walking through these blocks with Bart, we hosted a vineyard walk open to the wider Hawkes Bay. The invitation was sent out through Hawkes Bay Winegrowers to anyone that was interested in growing organically or was interested in the project.
There were 30 people in attendance for the field day from every part of the wine industry, from operators to growers, vineyard managers, viticulturists, winemakers to sales managers.
Bart and I gave background about the project, what it was about, who was involved and why it was based at Mission Estate.
The idea was to walk through the blocks and discuss the management plan of the block, early season pest and disease control, and nutrition programs that would be run on the blocks involved. There were numerous questions asked about the project and the management/spray programs that were being run, which provided interesting discussion of ideas and thought processes.
There will be regular field days such as this, with Bart scheduled to make four visits to Mission over the course of the project. Each visit with Bart will provide an opportunity for interested parties to attend further field walks to monitor the progress of the project as it continues through the season. The next visit will be held in December.
I’m really excited about this project and am enjoying the challenge of growing under a different approach and liaising with different people about this project. Thank you to NZ Winegrowers and Organic Winegrowers NZ for providing the funding, support and expertise that has made this project possible.