Accolade wine trial

Trial: A three year trial of Biostart’s biological products, Foliacin and Mycorrcin, was concluded on the pinot noir block at Mud House Vineyard, Accolade Wines in the Wairau Valley in March, 2021.

Aim

The aim of this three-year trial at Accolade Wines was to see if BioStart’s soil biostimulant, Mycorrcin, and foliar biostimulant, Foliacin, could improve vine health and wine quality on a premium Pinot noir block (Abel clone).

Method

The trial started in the 2018/19 season and continued for three years using the following programme:

• Mycorrcin applied at bud break (10 L/ha) and then 2 L/ha with all weed sprays (2–3 per year)
• Foliacin regularly throughout the season from bud break with all cover sprays at 0.5 L/ha.

Measurements

The measurements were taken for cane diameter in year two, leaf and petiole minerals in year two and three and yield and wine quality measurements (using microvins) in year three.

Results

The results showed the Biostart programme:

Increased cane cross-sectional area

• Cane cross-sectional area increased by 8% in year 2 (Figure 1), this was cane produced in Year 1 of the trial
• Cane cross-sectional area increased by 21% in year three (cane was) produced in the 2019/20 season (Year 2) , this was cane produced in Year 2 of the trial
• Activating the soil microbiology lead to better cane growth.

Better root growth

The treated vines had more roots that spread out over a bigger area allowing the vine to utilise nutrients form a larger volume of soil.

Increased mineral uptake

The Biostart treated vines had higher calcium and magnesium levels in leaf and petiole at flowering (Table 1). Soil analysis in spring of Year 3 showed that soil levels for calcium and magnesium were lower indicating that the plants were utilising the soil nutrition to grow bigger canes.

Activating the soil biology via the Biostart programme had lead to better utilisation of soil nutrients by the vine.

Increased Yield

The 2020/21 season was a challenging year with a cold weather over flowering reducing fruit set across Marlborough and leading to uneven berry sizes in the bunch. As a result no bunch thinning could be carried out.

The Biostart programme produced:

• A 26% yield increase per vine from 4 to 5 kg/vine (an extra 1 kg/vine) (Table 3)
• An 18% increase in bunch number per vine from 47 to 56 or 8.6 bunches/treated vine
• Similar bunch weights for both untreated and Biostart treated vines.

Extrapolating from this for 1,600 vines/ha, this is a yield increase of 1.67 T/ha (from 6.5 to 8.3 T/ha). At an average juice recovery of ~70% from 1 kg of fruit it follows that the Biostart programme delivered about an extra bottle of wine per vine (1,600 bottles/ha; 133 dozen) in year 3.

The yield increase was due to there being more bunches per vine and not to larger bunches.

Juice quality

Juice quality was similar for key parameters for both treatments and was not compromised by the extra yield in the treated vines.  Note the trial was harvested prior to ideal Brix levels were reached in order fit in with the operation of this commercial vineyard.

Microvins

Trial wines were made at Bragato Research Institute and then biochemically analysed by Dr Tanya Ruters. She observed that fermetation was slowed for the treated wine and, while juice measured as similar, the resulting wines had more total acidity and sugers. They were also blind tasted by 15 top Marlborough winemakers who noticed significance differences in mouthfeel properties where the treated wine was perceived as having more astringency and body.

Conclusions

In a challenging grape growing year, the application of the Biostart programme to improve soil biology lead to improved vine nutrition which in turn lead to bigger canes and higher fruit yield without compromising juice quality and improving wine flavour.