After a few years working with vineyards we have drawn out some of the most valuable data you can collect in your vineyard. Tracking these 10 metrics will help you better understand how to manage your vines and optimise your grape quality and yield.
Producing great wine is both a science and an art, we help take care of the science so you can focus on the art!
Some of these metrics are measured at the level of individual vines, and others are measured on a block by block basis. Most vineyards don’t monitor every vine, but take a representative sample from each block of vines. Not sure which vines to sample? We’ve written some advice on sampling here.
The vineyards we work with use Sectormentor to record all of the metrics featured, and visualise their progress with the trends and tools on the Sectormentor web app to build up a picture of how to best manage their vineyard.
(Bride Valley Vineyard on a frosty morning)
1. Date of bud burst / flowering / picking
Everything in farming is weather dependent. However, by recording the date of bud burst, flowering and harvest, you are better equipped to start predicting your harvest date, which is helpful when planning tank space among other things! If the flowering date is early then you are likely to have an early harvest, and you can get everything in place. The Sectormentor Phenology Tool allows you to visualise these patterns, and you can now import your weather data to Sectormentor to see how these key dates relate to your GDD.
2. Date of frosts and severity
Frost can seriously affect bud burst, flowering and harvest patterns, so it’s good to record the date and severity of any frosts. At the very least it provides context when looking back on data! Read more here.
(Grapes ready for harvest at Davenport Vineyards)
3. Counting flowers per vine
Recording the flowers per vine in late Spring/early Summer allows you to get going with an early yield prediction. It’s only an approximation, as a heavy hail storm during flowering, or persistent rain can still really affect the yield. However it’s good to do these estimates so you can start planning a few months before harvest. The Sectormentor Yield Predictor tool makes creating and saving predictions throughout the year easy – enter your vineyard’s info and the rest is generated automatically!
The Sectormentor app makes it easy to count flowers per vine – when doing a flower count, you can scan the RFID tag at the sample site you’re in and then enter the number of flowers you count on each vine for the next 10-20 vines (depending on your sampling system). ‘Sync’ when back in the office and you will see the average flower count per block straight away in your web app. Read more here
4. Counting bunches per vine
About a month before harvest many vintners count the average number of bunches per vine, which gives a fairly accurate yield prediction alongside average bunch weight. With Sectormentor you can create an updated yield prediction at this stage on the Yield Predictor Tool. Many people also measure their bunch weight over the years to get a good approximate bunch weight for each variety (see below). Read more here.
5. Bunch weight (kg/vine)
Bunch weight at harvest is a key part of any yield prediction program. One important goal of recording bunch weight at harvest is not to predict the yield that year, but to provide an average bunch weight to help with yield prediction in subsequent years. Careful collection and maintenance of bunch weight records from year to year is pivotal to optimising your yield estimation. Proper record keeping will also give the you a good sense of the variation related to climatic conditions. Read more here
6. Measuring grape sugar
Almost all winemakers use a refractometer to help them determine when to harvest. You can either use a refractometer that gives you an Oeschle reading or a Brix reading. Both scales indicate the sugar levels in the grape.
The Sectormentor Ripeness Indicator Tool makes it really easy to visualise the ripening of all your grapes. After you’ve entered your readings you can track the pH, sugar and acidity of your grapes, and notice the pattern of your vineyard. Graphs showing grape sugar over time are not linear – so we know it’s useful to be able to track this process visually, and really helps when deciding when to harvest! Read more about the Sugar:Acid ratio here.
7. Measuring titratable acid (TA)
Acid has an arguable optimum level of 6-9 g/L for reds/whites and 11-13 g/L for sparkling. It’s time to harvest when the acid comes closest to these optimums at the same time that sugar comes closest to optimum level of around 22 Brix. In many cases optimums are not be reached, so there are other rules of thumb for judging readiness of harvest (use Brix:TA Ratio). As Will Davenport told us “Many UK vineyards pick sparkling wine grapes at higher levels than this in years when grapes struggle to ripen.” Read more here about titratable acid readings here.
The Sectormentor Ripeness Indicator Tool makes it easy to visualise the acid levels of all your grapes. After you’ve entered your readings you can immediately observe the ripening patterns of your vineyard.
(Harvest time at Davenport Vineyards)
8. Pruning weight per vine / Cane no. at pruning
Mid-winter is an important time for pruning vines in the UK. If you record the weight of material pruned off each vine and the cane number at pruning time, then you can work out the weight of each cane and understand each vine’s vigour.
The Sectormentor Vine Health Indicator tool allows you to immediately visualise the vigour and health of your vines once you’ve entered your pruning weights and cane numbers. Assessing vigour allows you to determine how many buds per vine you want to prune to. If you have high vigour (or heavy canes), then you can prune for lots of buds to try to manage lower leaf growth. Some vineyards choose to record no. buds per vine as a clear record (and good check) of what actions were taken in the vineyard.
The pruning weight measurement is also used as a guide to whether the vineyard needs more nitrogen applied (compost/manure in organic systems) and is often a better indicator than soil analysis. Read more here.
9. Kgs picked
Everyone wants to know their yield. It’s important to know the total amount picked as your harvest weights can inform pruning techniques, and how you care for your vines going forward. If you can keep collection trays from different blocks separate when harvesting, and count them separately, then you can better understand how an individual block is doing and adopt management techniques accordingly.Read more here
The Sectormentor Harvest Tool allows you to monitor your harvest in real time, and measure up your yield predictions to the reality of that season. After harvest, you can use the tool to reflect on which blocks yielded higher, and decide on your management going forward.
10. Actual number of vines per acre: record dead/missing vines
At the end of each season it’s important to record the number of dead or missing vines in each block. This allows you to calculate the actual number of vines per acre in a block, rather than the number that were originally planted – just 5% missing vines can skew all other predictions. This number is key for yield predictions!
Will Davenport sums it up nicely,
“A vineyard manager / owner can never have too much data, both current year data and historical data, to assist in making decisions and predicting the next 6 months. The normal problem is that collecting and maintaining data can be very time consuming, and that is where Sectormentor helps – it makes it much faster, tidies everything up and allows me to look up things that the vineyard manager has measured.”
You can visualise the number of dead / missing vines in the Sectormentor Vine Health Indicator.
If you would like to find out more about using Sectormentor for your vineyard, please don’t hesitate to get in touch for more information, or subscribe directly here.
Special thanks to Will Davenport for his helpful advice on these metrics.