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Annie Landless

Case Study: Darcy Gander – Vine-Works

Case Study: Darcy Gander – Vine-Works 1000 667 Sectormentor

Vine-Works was founded by James Dodson and Darcy Gander and has been establishing, managing, maintaining and supporting vineyards across the UK for over a decade. They work with single growers, small businesses, farmers, landowners and some of the country’s largest wine producers, providing a complete range of vineyard management and technical services from concept to harvest.

Vine-Works has just started to offer a vineyard management service for small to medium scale vineyards who can’t reasonably have a full time vineyard manager. As part of the service a Vine-Works technical officer will come out to the vineyard 12-16 times a year to ensure that the vineyard is well managed and an experienced independent viticulturist is monitoring important vineyard indicators. They help with deciding how much fruit to drop, what to do for disease management and getting good yield predictions – all the key activities throughout the year.

Of course this type of vineyard monitoring and management takes time but it is extremely valuable information! Many people don’t realise just how important it is to ensure that you do a good quality bunch count, and record bunch weights at harvest in order to get a good yield prediction – this data is invaluable, an asset to the vineyard.

The Vine-Works team are using Sectormentor so that they can easily record the information they need in each season to better manage vineyards for their clients. For example, just as flowering sets in, Technical Officer – Matt – will go out to a number of random sample vines in each block and count the number of inflorescences on the vine, he enters that number for one vine and then the next, and so on. Some weeks later he goes out again and counts the number of bunches, giving a good indication of fruit set – and starting one of the most important metrics of the year – the yield prediction. This information automatically feeds into the Sectormentor Yield Predictor Tool so that a rough initial yield prediction can easily be reached, and then optimised as the season progresses.

“All viticulturalists and vineyard managers collect data in their day to day activities, this data could be perceived as the vine’s method of communicating with us, be it pruning weights to illustrate cropping potential or interveinal discolouring to show nutrient deficiency. By collecting this information we can have a greater insight into a vine’s health.

Historically, vineyard managers have recorded this type of information in notebooks but by collecting data digitally we can quickly turn measurements into viticultural information. This can further be translated into quick and easy-to-read graphics so we can provide an instant response-based vineyard management service.”

Darcy Gander, Vine-Works

Sectormentor also allows for easy data sharing amongst the Vine-Works team, so they can make full use of all of their expertise. For example, Matt sees a leaf that looks a bit unusual in the vineyard, he takes a photo in Sectormentor, records its location, and carries on with his scouting looking for disease and pest pressure around the vineyard. He can send a message to the rest of the team so they can immediately and easily look at the photo of the issue on the Sectormentor dashboard and give their feedback on what they think it might be. Sectormentor is also hugely beneficial to the vineyard owners, because they can login to the dashboard at any time and see what has been happening on the vineyard – plus they know that all the vital information such as phenological dates, bunch weights and much more are stored and accessible in one place. This kind of information is an important asset to the vineyard, and storing it in this way brings the power of the data to the vineyard owner as well as the manager.

Working with Abby, Inti and the team has always been a pleasure. They’re driven, insightful and reliable and we look to working with them long term. Sectormentor has enabled us to cover more ground, analyse data quickly and make informed management decisions immediately. We have been impressed by how much time we save using Sectormentor and how it efficiently and effectively helps us to deliver our vineyard management service.

– Joel Jorgensen, Vine-Works

We are excited to be working with the Vine-Works team to introduce some of our recommended soil health monitoring into the service as well. Due to the damp conditions in the UK managing vines more ecologically can be quite tricky – but focusing on building soil structure through increased biological activity in the soil can really help to guide you in creating a more ecological and diverse vineyard system. Vine-Works aims to introduce this soil health monitoring to the vineyards who want to focus on more ecological farming methods.

We look forward to continuing our journey with Vine-Works! If their service or Sectormentor for Vines sounds interesting to you do get in touch here.

Know your vines #6: Optimise your yield prediction and the power of our Yield Predictor Tool – PART 1

Know your vines #6: Optimise your yield prediction and the power of our Yield Predictor Tool – PART 1 3024 4032 Sectormentor

In our Know your Vines blog series we share practical tips on what metrics to monitor in your vineyard. This is the sixth instalment, stay tuned for more as the seasons unfold! “If you can’t measure it, you can’t improve it.

Use flower and bunch counts to optimise yield prediction

July is the perfect time for many vineyard owners to do bunch counts, as the grapes are forming. An accurate bunch count gets you about half way there to optimising your yield prediction. Getting your yield prediction as accurate as possible is important for small and medium scale commercial vineyards – it’s a great help for the winemakers to know in advance how much they will have of each type of grape, and how much tank space is likely to be taken up. If you get really good at optimising your yield prediction you can consistently get your prediction accurate to within 5% of your actual yield. It’s well worth it!

Luke Spalding, vineyard manager at Everflyht Vineyard, told us: “without a good yield prediction it can create a lot of stress for the vineyard team, as harvesting time can get out of control. Importantly, it also creates stress in the winery when you don’t know how much is coming in or when the harvest is going to stop!”.

We’ve come to realise that each year, yield prediction is a journey, a step by step process of optimisation, learning and understanding. With our new Yield Predictor tool it is possible to save and update yield predictions throughout the season as you gather information on your vines. In this part 1 of our yield prediction blogs we will share how to hone your prediction by getting the bunch counts right, and in part 2 we will talk about getting your bunch weights as accurate as possible from lag phase (or veraison) onwards.

Yield predictions for different blocks of vines as they progress through the season

First prediction: Inflorescence counts
You may have already started out with a ballpark figure for this year’s yield using inflorescence counts combined with the average weight for each variety-clone block from previous years. This is really easy to do in the Sectormentor Yield Predictor – you just go out and count inflorescences at a number of sample vines out in the vineyard – entering the counts in the app quickly and easily as you go. Then when you log into your account online the Yield Predictor will automatically show you the average inflorescences for each block and the total predicted yield for each block. At this stage you’re working with a fairly crude estimate, but it gets you going!

Sectormentor Yield Predictor tool using flower counts

Second prediction: Bunch counts at flower set
Next, once flower set is complete you can go out and count your bunches, allowing you to see if you have any issues with fruit set (as we talked about here). At this point you can also do your second yield prediction (easy to do in the Sectormentor Yield Predictor) now based on bunch counts — you’re getting closer, and your yield prediction can help you to make a decision on how much you want to thin your grapes (or green harvest).

Thinning the crop is a decision based on craft – you want to optimise yield while ensuring that your not putting strain on the vines. We realise that this is a bit of a balancing act – and this post covers some of the concerns. If you do decide to thin the fruit at this point, you’ll need to go out and do another bunch count afterwards to ensure you know how many bunches you still have. This may feel over the top, but unless you’ve thinned all the vines yourself, it is unreliable to assume exactly the number of bunches you wanted to remove, have actually been removed. The bunch count is the easiest thing to get right, so it’s worth making sure it’s as accurate as possible.

Fine tune your prediction with an updated bunch count after thinning
Every time you do a new bunch count you can do a new yield prediction using the Yield Predictor tool. The tool will automatically update the averages for each new count, as well as remember the bunch weights you entered last time – so it’s really quick to update your prediction and make any minor tweaks! You can also compare your current prediction to predictions you made earlier in the season, to see how the grapes are progressing, and we have a handy graph to show how the total estimated yield has changed, as well as the yield for each individual block.

Everything so far has been about ensuring we get the average number of bunches as accurate as possible. All the estimates have been based on using average bunch weights from previous years – in part 2 of this post we will look at the next steps on the yield estimate journey – getting your estimated bunch weight as accurate as possible for this season. This process starts at the lag phase (just before veraison).

Check out 10 key metrics to monitor in your vineyard and find out how our app Sectormentor for Vines helps you record data & manage your vines for the best quality grapes.

Know your vines #4: How to measure pruning weights

Know your vines #4: How to measure pruning weights 543 407 Sectormentor

In our Know your Vines blog series we will share practical tips on what metrics to monitor in your vineyard. This is the fourth instalment, stay tuned for more as the coming seasons unfold!

“If you can’t measure it, you can’t improve it.

Mid winter pruning weights video with Matt Strugnell, Ridgeview Wine

The onset of chilly winter conditions can only mean one thing in a vineyard, it’s time to prune back the vines. It marks the end of one growing season before the onset of the next.

What can we learn from the remaining canes? Unfortunately vines can’t talk, but their pruning weights can tell you a lot about vine health and vigour. You can use this information to understand how your vines are performing and inform decisions for the season ahead.

We spent the day with Matt Strugnell who has managed Ridgeview Wine Estate for 20 years and pruned a fair few vines in his time! Monitoring pruning weights is integral to his management strategy.

Matt showed us how he has perfected the art of getting pruning weights, starting with how to tame vine branches into neat bundles so it’s easy to record their weight as well

as simple timesaving tricks like using a loop of string, rather than tying up the bundle each time.

Now he records all his pruning weights in Sectormentor whilst he is out in the vines, no more typing things up when he’s back home and navigating multiple spreadsheets to figure out what it all means. With Sectormentor that’s all done automatically, so by the time he’s back in the office he can look on the vine health indicator to see the average pruning weights for each block compared to previous years, as well as cane weight and the crop load. Watch the video below of Matt demonstrating how to measure the pruning weight for one bay of vines.


Scales (Matt uses Berkley fish scales)
String (Loop ends to easily attach to scales)
Warm clothes! 🙂

Monitoring with Sectormentor:
Sectormentor makes it easy to record pruning weights at the touch of a button on your smartphone out in the vineyard. All the information you record is available as soon as you get back to the office. Using our Vine Health Indicator Tool you can see trends in pruning weights, cane weight and crop load (Ravaz Index) for each block providing an early indication of areas that need extra attention or a change in management. Recording pruning weights provides invaluable insights into the long term health of your vines. Many people don’t record them because it is too much effort, but we have made it into a simple 2 step process:
Measure the pruning weights, record in the Sectormentor app

Look at the graphs of the results on Sectormentor dashboard when you are back at the computer, decide on management approaches accordingly.

Check out 10 key metrics to monitor in your vineyard and find out how our app Sectormentor for Vines helps you record data & manage your vines for the best quality grapes.

Know Your Vines #3: Why monitor dead or missing vines?

Know Your Vines #3: Why monitor dead or missing vines? 1920 1440 Sectormentor

In our new Know your Vines blog series we will share practical tips on what metrics to monitor in your vineyard. This is the third instalment, stay tuned for more as the coming seasons unfold!

“If you can’t measure it, you can’t improve it.

Counting dead or missing vines for yield prediction, replanting strategy and vine health

At the end of each growing season taking stock of your vines is an important part of vineyard monitoring. Checking how many dead or missing vines there are for each block enables you to calculate the actual number of vines you are managing.

Vines at Bride Valley Vineyard

Here are 3 areas that counting dead/missing vines can help you with:


  • More accurate yield predictions



It’s important to know the actual number of vines in your vineyard when it’s time to calculate your potential yield. Just 5% dead or missing vines can skew results significantly. Yield predictions with the Sectormentor Yield Predictor tool automatically take into account the number of missing vines.


  • Creating a replanting strategy



Having a handle on how many dead and missing vines is the first step to deciding if and when to start replanting them.

Davenport Vineyards decided to do some replanting of vines this year. Late last month, before Owner Will Davenport could even ask, vineyard manager Phil Harris had gone out and counted dead/missing vines in each block. This meant that when Will logged in to Sectormentor he could see exactly how many of each vine variety and clone he needed to order and so he called up potential suppliers right away.

“Previously I would have had to ask Phil to collect the readings and wait until he could give me the bit of paper he noted it down on, as he often works at the other site. It would have been a lot more hassle but using the app made it very simple.” – Will Davenport, Davenport Vineyards

Using Sectormentor For Vines to record information at Davenport Vineyards


  • Understanding vine health



Why are your vines dying? Are there multiple vines which have died in one block? Do you have a vine health issue? These are all questions to ask yourself when you’re counting missing or dead vines. The Sectormentor Vine Health Indicator tool takes into account dead or missing vines so you can identify patterns of disease more easily.

Often issues of this nature can be detected early by monitoring pruning weights; if the weight of pruned material drops from year to year there is likely to be a problem. This way you can address it before you lose the vine.

We spoke to Cathy Smith, vineyard manager at Hush Heath Estate who regularly harvests around 6 tns/acre – one of the highest yielding estates in the country. This is not due to an intensive input system and being cut-throat with the least productive vines, but rather due to diligent management of every single vine, as Cathy explains:

“The plants are like kids, each one is an individual and you have to care for them on an individual basis. When one of the vines isn’t looking so good I don’t understand why people rip it out straight away. I always observe the vine, try to understand what might be stressing it and then care for it for a year or two and see if it gets better, only then would I consider pulling it out. Plants need care and attention just like humans, only plants have one advantage – they don’t answer back!” – Cathy Smith, Hush Heath Estate Vineyard

Check out 10 key metrics to monitor in your vineyard and find out how our app Sectormentor helps you record data & manage your vines for the best quality grapes.

Know Your Vines #2: How are pruning weights helping vineyard managers keep their vines healthy?

Know Your Vines #2: How are pruning weights helping vineyard managers keep their vines healthy? 832 626 Sectormentor

In our new Know your Vines blog series we will share practical tips on what metrics to monitor in your vineyard. This is the second instalment, stay tuned for more as the coming seasons unfold!

“If you can’t measure it, you can’t improve it.

What can we learn from pruning weights?

“Pruning weights are the most important viticultural measurement in our vineyard each year. They indicate the long term health of our vines and keep us on track.” Will Davenport, Davenport Vineyards.

We can learn a lot about the health and development of vines from the winter ritual of pruning. Recording the pruning weight from sample vines in each block is often the earliest indication of changes in the health of your vines. It allows you to understand the language of the vines, months or even years, before you can see any sign of issues.

Thanks to Will Davenport of Davenport Vineyards, Matt Strugnell of Ridgeview Estate and Frances Trappey of Rathfinny Estate for sharing their tips and experiences on this subject.

How to record pruning weight

For each vine in your sample site, place all the pruned wood in a pile and tie it together with twine, weigh the bundle of pruned material with hanging scales and record the weight for each vine into the Sectormentor app. Back in the office, the app will automatically calculate the average pruning weight for that block (or clone/variety/rootstock) and the Sectormentor Vine Health Indicator tool will allow you to compare pruning weights and crop load between different blocks and how they are changing over multiple years.

Pruning at Albury Vineyard (

Using pruning weights to assess long term vine health and fertiliser requirements

Vines with high vigour don’t need any fertiliser (quite the opposite), while vines with low vigour may not be getting everything they need from the soils and so might need that extra helping hand. Managing fertiliser inputs and soil health is essential to growing the best quality grapes. Of course many vineyards rely on mid-season foliar applications of Nitrogen when the vine is clearly sending out signs it’s struggling, but this is often an expensive and reactive way to manage vines. Pruning weights and compost can be a much cheaper alternative that is more beneficial for your vines, the soil and the whole ecosystem on your vineyard in the long run. Hence, increasing ecology, profitability and beauty in the vineyard.

Assessing the vigour of your vines helps understand their long-term nutrient requirements. You would think the obvious way to understand the nutrients available to your vines would be to do soil tests, however, it turns out nitrogen levels in soil tests are not a good indicator of nitrogen levels available to the vine during the growing season (read more about this here) – pruning weights can actually be a much more effective way of understanding the nutrients available to the vine over time.

Will Davenport, vineyard owner at Davenport Vineyards, monitors pruning weights from sample sites in his vineyard using the Sectormentor For Vines app. As Will told us “the simplest thing to understand about pruning weights is that it’s all about how your pruning weight changes from one year to the next. If a vine is healthy and has everything it needs it will either increase or maintain the same pruning weight. If the pruning weight in one block of vines begins to decline, that is a very early warning sign that the vine isn’t getting everything it needs. As we are organic, this early indicator has been vital for us to maintain the long term health of our vines. As soon as we see a dip in pruning weights we are able to apply compost to that block, years before any deficiencies might be visible. Identifying issues like this early is vital, as compost takes about 2 years to affect the vine’s vigour.”

In the graph below you can see the average pruning weight per vine for some of the varieties grown at Davenport vineyards from 2017-2018. It is obvious that the Bacchus New had a serious decrease in pruning weights from 2017-2018. Therefore Will and his team applied compost to just this block.  It is clear that in Will’s case monitoring pruning weights has saved him time and money in the long run.

Using pruning weights to assess vine balance and vigour

If you want to compare pruning weights across vineyard blocks or different vineyard sites (e.g two sites of Chardonnay that have different planting spacing) then it helps to use a measure with comparable units such as Cane Weight and Crop Load (the Ravaz Index). As always it is not an exact science but these measures can help you to establish a standard for your own vineyard. This information and evidence can also be extremely helpful when looking to find a new buyer for grapes, or even taking on a new vineyard manager.

Looking at pruning weights combined with cane numbers at pruning time allows you to calculate the weight of each cane and therefore assess the vigour of vines across your vineyard. Cane weight is calculated from the pruning weight/cane no. at pruning. Cane weight can be used to compare vigour of similar vines on different sites, or also to benchmark vine vigour to being high, medium or low compared to other vineyard sites or blocks. With this information in mind you can decide how many buds to prune to in the future. e.g to make sure leaf growth is controlled for vines with high vigour, you would prune for more buds.

The Crop Load (indicated by the Ravaz Index), is the balance between reproductive growth (grape weight) and vegetative growth (pruning weight). It’s a useful measure that indicates vine balance and has also been closely linked to grape quality (especially sugar levels) in numerous studies. The Ravaz Index is calculated by doing the Harvest kgs/Pruning Weight. Generally it should be anywhere in the range of 5-10, but this often isn’t the case in more unusual vine-growing climates such as the UK. Instead of worrying about the standard, it is important to define your own crop load for your vineyard and, as more of us establish the optimal crop load on our vineyards, we can potentially start to define a standard for the UK.

Pruning in the snow at Ridgeview Vineyard (

At Ridgeview Wine Estate vineyard manager Matt Strugnell started monitoring pruning weights about ten years ago. He uses the Ravaz Index to give an indication of how balanced the vines are. Both Matt and Will pointed out that if you have an awful year with a flowering or fruitfulness issue it completely throws the ratio out as you will have less bunches but the pruning weight will remain consistent year on year. However Matt says it’s still very useful, for example he told us “in the last few years the Ravaz Index for our Chardonnay on SO4 rootstock has begun to increase compared to that on 3309, essentially the SO4 rootstock vines are still heavily cropping but the pruning weights are dropping. The vines didn’t look noticeably different but this gave us a heads up that something was changing and we need to pay extra attention to that area. We now make sure we remove a bit of fruit in early Summer and are looking more closely at nutrition for those vines.”

Matt pointed out that “even though the index will move depending on the conditions of the season (in a higher cropping year you will have a higher index) it can be very helpful to compare vine balance across different blocks within the same year, and can be an early warning sign for longer term issues before they become visible”. The team at Ridgeview do also score the cane vigour by eye – charge counting (no. of buds left on vine at winter pruning). They find the combination of the more objective pruning weights and more subjective charge count sets them in good stead for this season and the many seasons ahead.

Pruning at Rathfinny Estate in March (

Using pruning weights to reflect and predict

Monitoring pruning weights enables you to look back at the vigour of your vines, but also forward to what your highest yield could be. In a paper by G. Stanley Howell he describes how “in the early 1920s, Partridge proposed to use the weight of cane prunings produced in year 1 as an indicator of the upper limit of a vine’s capacity to produce and ripen a crop in year 2.” This was drawn to our attention by Frances Trappey, Vineyard Analyst at Rathfinny Estate, who started monitoring pruning weights for the first time last year. Although she got interesting results reflecting on the past growing season and vine balance, nothing directly informed their actions for this year. However after reading the paper quoted above, Frances said “This opened my mind to the value of pruning weights as both a retrospective and predictive measure. So, I will be doing pruning weights again this year, but with a different mindset”.


Pruning weights are a way of listening to your vines, not just looking at them, and vineyard managers are using this as an earlier way to sense both long-term vine health and even total potential yield for the following year. Of course monitoring pruning weights can take time and you need to be diligent with recording everything – this is where Sectormentor is your new best friend and will help save you time and money. One of the most daunting tasks, is which bits of the vineyard should I measure pruning weights from? With Sectormentor we help ensure you have specific sample bays already setup, so you only need to measure pruning weights for those vines. Using our contactless tags and smartphone app it’s easy to record the pruning weights in the vineyard as you go, no paper necessary. Finally, once you get back home all the data is already sorted and visualised for you. Our new Vine Health Indicator will allow you to immediately see changes in the long term health of vines in each block (or clone/rootstock) as well as monitor your vine balance block to block and year to year – important indicators to manage an ecological, profitable and beautiful vineyard! Please email us at if you would like to use Sectormentor in your vineyard. Thanks again to Will, Matt and Frances for their contributions to this post.


Check out 10 key metrics to monitor in your vineyard and find out how our app Sectormentor for Vines helps you record data & manage your vines for the best quality grapes.



Patricia A. Skinkis, How to Measure Dormant Pruning Weight of Grapevines

Stanley Howell, stainable Grape Productivity and the Growth-Yield Relationship: A Review

Paul Schreiner, Patricia A. Skinkis, Monitoring Grapevine Nutrition

Soil health in your vineyard: Do you know your earthworms?

Soil health in your vineyard: Do you know your earthworms? 590 442 Sectormentor

A resource created by Jackie Stroud, soil scientist at Rothamsted Research, also known as ‘The Worm Lady’!

Did you know there are three different types of earthworms at work in your soil? Each type lives in a specific layer and performs a unique function which contributes to the soil’s health and therefore your vine’s health. Find out why a decline in soil health is worrying for all wine lovers on Decanter.

Really you want to have all three types of worms working in harmony. The living litter feeders break down organic matter on the surface making nutrients available for uptake by vines, the top-soil worms work on building good soil structure (aggregation) and nutrient mobilisation, and then the deep-burrowers keep water flowing from the soil surface to deep pools below, as well as increasing aeration and root development.

Monitoring earthworm activity will give you a good overview of the soil health in your vineyard. All you need to do is dig a 20cm deep hole in the ground and count the different earthworms you find in each layer. Counting the number of worms is a good indicator of life in the soil. If you go one step further and identify what type of worm it is, then this can tell you much more about what the worms are working on and help uncover any necessary changes you need to make in your soil management.

However, you need to make sure you can identify which worms are which before you head out to the field!

You can use this AHDB info sheet that Jackie Stroud put together as a resource for learning about the types of worms and how to effectively count earthworms.

Find out how Sectormentor for Vines helps you record earthworm counts & learn how your soil is changing. Email for more details!

The art and science of accurately predicting your vineyard yield

The art and science of accurately predicting your vineyard yield 1920 1440 Sectormentor

Why do crop estimates?

Crop estimates are important for many reasons for both grower and winemaker. Growers want to produce high quality fruit to get the best price for their grapes, or if it’s for their own wine, then to get the best quality wine. Ideally, the grower really wants to get the best quality grapes AND maximise their yield AND maintain the health of the vineyard. The crop load also affects harvest costs and logistics such as the timing of harvest, ensuring you have enough pickers etc. Of course crop load can also affect vine health.

As one researcher writes, “Overcropping a vine has many well documented negative impacts on fruit and vine quality including reduced and delayed fruit ripening, potential vine stress that may lead to increased susceptibility to winter injury, disease problems especially late season rots and other significant problems. Undercropping can also affect wine quality, as well as cheat you of valuable revenue.”

Vintner Will Davenport also pointed out “Knowing your (accurate) crop estimate can help to understand if fruit thinning is necessary and how much of the crop needs to be removed in order to keep the vine healthy and ripen the remaining grapes.”

Winemakers are also interested in crop estimates as they need to juggle tank space, and want to know which grapes are coming in when. Plus they need to know how many grapes they will be buying, and what they will then produce and have to sell.


Getting your initial crop estimate

Early in the season, often around flowering, you establish the number of clusters by going out and counting the number of flowers (we are referring to the whole inflorescence as a flower here) in each different block, or plot, of similar vines. This is a quick and easy way to give you an estimate of the number of bunches of grapes you will have, and therefore a general estimate of your yield.

There are a few things that can affect the accuracy of this part of the prediction significantly. If there is a frost, or a heavy rain/hail incident before fruit set and many flowers are lost, or if just before picking badgers come and eat all your fruit. But for the most part the majority of flowers will turn into bunches and bunch number is pretty predictable.

Using the Sectormentor for Vines app it’s very easy to collect flower counts on your phone and then the app automatically averages those counts for you, per block or variety. Our yield predictor tool is setup to assume 100% fruit set initially, but if there is some incident that changes this, it’s easy to go back and reduce the % fruit set for each block or variety.



Finding average bunch weights for your vineyard

The variable that is much less easy to anticipate in yield prediction is bunch weight. This varies every year depending on weather and the many other facets of the natural world that keep us on our toes. It is also often different for each variety or clone. It is only once you monitor bunch weights for each plot for a number of years that you start to have a pretty good idea of the average bunch weight for your vineyard, or at the very least the maximum and minimum average weights.

If you aren’t already monitoring this, then we definitely recommend recording average bunch weight for each block starting this harvest, this information is invaluable in the long term, we would consider it an asset to the vineyard! Of course this is very easily recorded and accessed with the app.


THE TRICK! How to get a more accurate crop prediction

To get an accurate yield prediction is part art, and part science. Knowing your average bunch weight stands you in good stead, but we have spoken to quite a few vineyards and all those that consistently get within 5% accuracy on their yield prediction use the beautifully simple art of going out and actually looking to judge (guestimate) what the average bunch weight will be this year, and then use that to adapt their yield prediction. This happens around the time of veraison, when vineyard managers will return to each plot in the vineyard and look at sample vines, visually estimating the eventual bunch weight for each bunch on the vine. This is the ‘art’ part and definitely gets easier the more experience you have.



How do other vineyards do it?

We have heard some clever ways of doing this:

Once at least 50% of the grapes have gone through veraison, Nigel Riddle at Wodetone Vineyard in Dorset picks a large bunch of grapes for each block and weighs it so that it’s 100g (take off extra grapes if it’s too heavy). He then goes to a series of sample vines and holds the 100g bunch in front of the bunches on the vine. By visually comparing with the 100g bunch in his hand, he can estimate the average weight of the bunches on the vine. After doing this for a while he doesn’t even need to carry around the 100g bunch with him as he can reasonably estimate the weight of each bunch just by eye. We chatted with Nigel and he agreed that to get started it might be best to compare the 100g bunch to each individual bunch on every vine at your sample site and record visually estimated weights on a bunch by bunch basis. But as you get better you can begin to record an estimated average bunch weight on a vine by vine basis.

At Davenport Vineyards the team have been working with the same vines for many years and they use a combination of historical data and visual surveying to optimise their prediction. They go out to their sample sites just as veraison begins and count the number of bunches on each vine. This gives them an accurate % flower set number which is helpful in future years, it also verifies the actual number of bunches on each vine. At this point they also do an estimate of the average bunch weight on each vine. The Davenport team do this purely by eye, they know what the maximum and minimum average bunch weight was for that variety and block in previous years. They use this range of numbers and their experience from past years to judge if the grapes on each vine are larger/smaller compared to previous years, and then estimate an average bunch weight for each vine at the sample site based on this. Will recommends making a best-case and worst-case scenario yield prediction for each variety based on the range of bunch weights you would expect for that variety. Luckily, this is easy to do using our yield predictor!

Another US-based vineyard told us how they use the lag weight method. Lag phase is a period of little or no growth in berries between two periods of rapid growth, it’s the point where the plant puts its energy into hardening the seeds and starts really building sugars shortly after. It happens just around veraison, and approximately 50-60 days after bloom. (See the graph below for a nice visual representation of lag phase). The vineyard manager will actually weigh the clusters on the sample vines at lag phase. It is estimated that grapes increase in size by 50% from lag phase to harvest, and therefore they multiply the lag cluster weight by approx 2 to estimate the final cluster weight and yield. Then in the weeks before harvest they will go out and look again and based on previous years experience they might increase or decrease the cluster weight multiplier (e.g 1.8 rather than 2).

Of course a vital part of this method is getting the multiplier correct for each block/variety based on how big the clusters look on the vine that year. It was also interesting to hear that Nigel at Wodetone doesn’t use a multiplier in his estimates when he weighs the 100g cluster a number of weeks before harvest, however he consistently gets good estimates. Nigel pointed out that most sparkling wine is harvested at 18 Brix, rather than 22 Brix, so we would expect a much lower weight increase between veraison and harvest for sparkling wines. We reckon it’s a combination of slightly smaller grapes at harvest for sparkling wine in the UK, and the fact that we humans are ever-optimistic in our estimations, which means that his method works perfectly without taking into account any increase in weight of individual bunches.


Do the same thing each year

A key to getting a good consistent yield prediction is to use the same method each year. It is also important to not be disheartened when you are starting out, as predictions may be up to 20% out, this is ok initially! As you get more experience and build up your numerical vineyard history it will all become more accurate and easier.  If you are consistently getting it way out after a couple of years, then you probably need to sample more vines…or rethink your methodology.

Using Sectormentor for Vines for your yield prediction

We have built Sectormentor for Vines to work with both the art and science of vineyard monitoring. The app makes it very easy to collect bunch counts and bunch weights out in the vineyard and then the yield predictor makes it easy to turn that information into a yield prediction for each block or area of vines you want (see diagram below). The tool is also flexible so that you can consider minimum and maximum predictions. Of course this is just one of the many tools the app provides, including a Ripeness Monitor, Soil Health Indicator and more. Please get in touch with any questions or if you’d like to hear more about how the app might work for you.

UPDATE: We’ve recently upgraded our Yield Predictor Tool so that you can optimise your predictions with flower / bunch counts, and bunch weights! Learn all about the updated features in Part 1 & Part 2 of our more recent blogs about this!


How do you do your yield prediction? Do you have another method you think works well?

We are always learning what works and how people do crop estimates on their vineyard so please do email us if you have anything to add or any questions.


Thank you to Nigel Riddle at Wodetone Vineyard, Will Davenport and Phil Harris at Davenport Vineyards and the following resources for help putting this article together.

How to prepare for data collecting in your vineyard

How to prepare for data collecting in your vineyard 1920 1440 Sectormentor

Monitoring and analysing your vines helps to predict grape yield and when to harvest your grapes to get the highest quality.

How many vines should I monitor?

First you need to create a sampling plan which is clear and easy to manage – making sure it’s actually doable is the most important element. If it’s too complicated you are likely to lose patience with it! Research recommend you sample 3% of your vineyard – this is the minimum suggested to get a representative sample for predicting your grape yield. In our experience many commercial grape growers sample closer to 1-2% of the vineyard and can still get very good predictions — the key is to make sure you are regularly going out and looking and adjusting any predictions based on what you see. It is after all an art and a science!

Bride Valley Vineyard

Which vines should I monitor?

We recommend ‘proportional stratified sampling’, which in basic terms means splitting your vineyard into smaller somewhat homogeneous blocks. Maybe your vineyard is already naturally broken down, for example you may plant different varieties or clones in blocks in the vineyard, that makes it simple! If you have a large-ish area of vines that significantly under or over performs in comparison to other area you could also define this area as its own block.

If you don’t have anything like this in place already, don’t worry! Think about your number of rows and the number of bays on each row, and draw a simple map of the vineyard, then outline the different blocks of vines that are similar. When using Sectormentor it’s also good to think about what you need this information for? For example, often (especially initially) vintners manage all clones of a specific variety in the same way. However, they will still setup Sectormentor to monitor based on blocks of clones, that is because they need to do separate yield predictions for each clone for the winery and therefore to get that level of information they need to ensure they are sampling enough vines within each clone.

The key questions to ask yourself when determining what will be your ‘block’ of vines are: when harvesting, what do you (or your winemakers) want to know the yield for, each variety? Each clone?  Each clone-rootstock combo? And when doing a specific activity, or yield prediction, do you want to make decisions based on variety? Or clone? or….?

Oxney Organic Estate Vineyard

How do I choose sample sites?

Once you have your blocks defined, you can decide which vines to sample within each block. It is suggested you sample 1-3% of vines in each block using a systematic method of selecting random samples (systematic sampling). You should always start a few rows in to avoid getting skewed results from the rows on the edge of the vineyard.

When you use Sectormentor to record counts a sample sites you have a few options:

  1. You can use scan a contactless (RFID) tag, which immediately identifies the sample site you are working in. Contactless tags make it simple, because you can attach them directly to the vine supports, and then scan them when you want to collect data at their location. Each sample site can have it’s own contactless tag.
  2. You can also use the GPS function on the Sectormentor app to set the location of your sample sites, so you can view them all on a map and find them easily out on the field. (Many people use this alongside the contactless tags)
  3. Some vintners choose to sample randomly and go to a set number of vines, but at ‘random’ locations each time. On the largest vineyards this is sometimes more convenient, but it’s often not the most accurate method because we humans aren’t very good at choosing random locations on the fly. It is also possible to setup Sectormentor this way if you’d prefer – if you are interested let us know and we can set this up for you.

RFID tag at Bride Valley Vineyard

What is an example of systematic sampling?

Let’s look at an example setup. Let’s say you have a vineyard split into 2 blocks, based on 2 different clones planted. Each of these blocks is relatively homogeneous. Consider one block, if a block has 30 rows with 20 bays in each row, and each bay has 5 vines. This means there are 100 vines/row. So that is 3000 vines in that block (see diagram below). You plan to sample close to 3% of the vines, then you have to sample 90 vines.

Using systematic sampling, you could pick every 5th row to sample, excluding edges. And if each row has 20 bays, you could have a system across the vineyard of always sampling from the 3rd, 9th and 15th bays. These bays are where you put the RFID tag and start the sampling from.

For efficiency we suggest sampling multiple bays at each location, so in this example you would always sample 3 bays from the tag, so if the tag was at bay 3, then you would use that tag to sample bays 3, 4 and 5.

Alternatively you could do systematic sampling across the entire vineyard for example every 4th vine on every 6th row. So you go to every 6th row and sample vines 4, 8, 12, 16, 18, 22 etc along that row. Although this method could potentially be more comprehensive, it can take longer to complete, and may not be manageable for your vineyard. For this method, we recommend putting one RFID tag at the end of the row, so you have sample rows instead of bays. When you scan the RFID tag the Sectormentor app will automatically remember which row you are on and save the data for all vines along that row.

One North Eastern US study states: Crop estimation helps ensure consistent production of high-quality fruit over multiple years in our variable climate. A grape grower who is unable to invest in, or elects to ignore, developing operational competence in crop estimation is likely to be at a competitive disadvantage in tightening markets.”

Interested in understanding more about your vines?

Check out our Sectormentor app which makes data collection in the field simple and easy, as well as analysing trends turning that data into helpful insights at home on your computer. If you have any questions don’t hesitate to get in touch with us:

Case Study: Graham Fisher – Bride Valley Vineyard

Case Study: Graham Fisher – Bride Valley Vineyard 1920 1440 Sectormentor

Bella and Steven Spurrier planted the first vines at Bride Valley Vineyard, Dorset, in 2009. They produce delicious English sparkling wines from their 10 hectares of Pinot Noir, Pinot Meunier and Chardonnay grapes. It hasn’t been an easy ride but the chalky slopes of Dorset are perfect for the vines as they are now all flourishing!


The vineyard manager Graham Fisher has been there since near the beginning and is committed to managing the vineyard using minimal intervention and more ecological methods. Strips of phacelia and wildflowers line the vines to increase biodiversity and predation of moths, meaning most years they don’t spray against Light Brown apple moth. They have been experimenting with using parasitic wasps as a biological control method. They use an undervine weeder, and are working on ways to increase the efficiency of this tool and therefore justify not using chemicals/herbicides and, even have their own sheep to graze amongst the vines, providing free fertiliser and chomping down the grasses.


Graham was immediately taken with using Sectormentor to help him manage the vines. He didn’t have the time or patience to note down and then type up bud counts, bunch numbers, or document different experiments he was doing. Luckily Sectormentor solved this for him, now he can count bunch numbers, pruning weights and more with a quick tap of the phone. Then once back at the office immediately he can compare pruning weights for different blocks and varieties of vine, predict yield for the year ahead combining this years and previous years data.


Here’s a Q & A with Graham on how data contributes to vineyard management at Bride Valley:


How did you manage the vineyard before using Sectormentor? Like lots of people, with a notebook and pen and as a consequence I have lots of notebooks squirrelled away.

How important are data and tools in the vineyard to you? Very, the ability to compare things like yield per vine, per block historically allows me to see how the vineyard is performing and in the case of yield trials whether they have been successful or not.

Do you think it’s important for vineyards to collect data? Absolutely, without collecting data it would be impossible to assess the success or otherwise of the vineyard and what the impact of the viticultural practices is on the viability of the vineyard.

What information are you most excited about using?  To be able to compare the performance of the various trials we have running with the rest of the vineyard visually using charts rather than just a series of numbers!

What has been the main benefit of Sectormentor to you? It has shortened the process of collecting data and made it so much easier, also to be able to compare data from different blocks/trials/years visually right away.

Can you explain a little about the experiment you are doing with different pruning techniques and cane numbers? Very simply, yields in the UK are quite low compared to our European cousins due to our marginal climate, so we are conducting trials to see if retaining more canes at winter pruning will increase yields over the long run without it being detrimental to the health of the vine.

What’s next for Bride Valley? For a relatively small and new venture, we have had a fair bit of success with overseas exposure and sales, going forward we want to increase our yields and our sales in the UK.

What do you hope to see in the future for vineyards in the UK? Better weather and increased yields without losing the quality. Like most vineyard owners/managers it’s all about finding a balance between efficiencies and controlling costs, without impacting on the environment. Being financially and environmentally sustainable is the goal for everyone in my opinion.


If you’ve got any questions about monitoring data in your vineyard we’d love to have a chat with you. Email us at

The Vineyard Helpers

The Vineyard Helpers 655 386 Sectormentor

While keeping up-to-date with vineyards across the globe on instagram we’ve come across an array of very important vineyard assistants who keep watch, control pests & weeds and nurture the soil & vines. This is an ode to all the furry, feathery and invertebrate friends who call a vineyard home.


The Vineyard Manager

Bacchus the vineyard dog runs a tight ship at Tuffon Hall Vineyard in East Anglia. They’ve been producing award winning english wines since 2014.

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Bacchus looking very dapper in the vineyard! ?

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The Marketing Manager

Bacchus the vineyard cat knows his way around the winery, wine bar, wedding venue and 24,000 vines growing over 16 acres at Hidden Spring vineyard!


The Security Manager

Keeping watch over the beast from the East at Dallwood Vineyard in Devon. The 3,000 vines were planted in 2009/2010 by a group of local villagers with a collective dream to produce great English wines.


The Pruning Expert

Billy doesn’t miss a trick when it comes to pruning, here he is checking the vines are present and correct at Hattingley Valley Wines, who produce english sparkling in Hampshire.


The Harvest Manager

Happy Harry is the resident vineyard dog at Broadley Vineyards, a family run winemaking business in the US with a sustainable focus.


The Grape Inspectors

It looks like Baci is in charge of quality control of these sustainably grown Pinot Noir grapes at Mirabel Vineyards in the Okanagan Valley, Canada.

A beautiful red admiral butterfly taking a closer look at organic grapes at Davenport Vineyards in Kent. Will Davenport has been growing vines since 1991 and also has a winery dog called Marvin!

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Picking Faber today among the butterflies

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A handsome vineyard dog at Humbleyard Vineyard in Norfolk checks on the white grape varieties before his human picks them from the vines. They have 10,000 vines covering 8 acres, plenty of space for a run about!


The Lawn Mowers

Tucked away down a Cornish lane near the coast you’ll find these two professional lawnmowers at Trevibban Mill Vineyard.

And then….. a whole flock of lawnmowers stampede into biodynamic vineyard Limeburn Hill, near Bristol. They take their jobs very seriously!


The Soil Gardeners

Very welcome little helpers: the long wigglers aren’t far behind the sheep at Limeburn Hill vineyard too.


The Pollinators

Busy bees tend to the largest vineyard in the UK Denby Wine Estate and organic vines at Albury Vineyard in the Surrey Hills.


The Pest Patrol

A group of majestic chickens on the hunt for rogue pests amongst biodynamic vines France.


The Cleaning Team

Chickens, pigs and vines living together in harmony at Hanzell Vineyards. They take a holistic and sustainable approach to preserve the health of their vineyard for future generations.


The Heavy Lifter

Working horses tend to the earth at Costers del Priorat in Italy.


and finally…

The Easter bunny!


If we’ve missed any vital vineyard helpers let us know, there’s always space for a few more. If your vineyard helpers or you are interested in learning more about your vines talk to us about how to start monitoring data and analysing trends in vineyards. 🙂