#KnowYourVines

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

Monitor grape sugar and acidity to get the balance just right – all made easier with our Grape Ripeness Indicator Tool

As we get closer to harvest, life is getting sweeter for grapes! They are beginning to ripen, which means sugars are generally increasing whilst acidity is dropping. Many vineyards monitor sugar and acidity levels as harvest approaches to help them decide when to start picking. Of course, this is not purely a science, as we are looking to make delicious wine, so tasting the grapes is a key part of the equation. It’s the combination of the art of taste, and the science of sugar and acidity levels that helps ensure you have a smooth well-timed harvest for each block in the vineyard.

Vines at Rathfinny Vineyard

Monitoring sugar and acidity levels
Post veraison, vineyard managers/winemakers regularly monitor the sugar and acidity levels of grapes across the vineyard. A refractometer is used to measure grape sugar, giving a Brix or Oechsle reading. Titratable acid, the total acid content in grape juice, is important for balancing a wine and is measured by neutralising the grape juice with an alkaline solution. It’s important to take a representative sample of grapes when measuring these and to use the same juice for both tests to get a real understanding of the sugar to acid ratio.

These are two of the ten key metrics to monitor in the vineyard. Sectormentor for Vines makes it quick and easy to record all this information and share it with the vineyard and winemaking team so they can see what is happening with the grapes.

Veraison at Chalk House Vineyard

Using the Sectormentor Grape Ripeness Indicator Tool
When you record sugar and acidity readings using Sectormentor for Vines, we automatically plot them on a graph. This makes it easy to see how the ripening is progressing, as it’s not always linear. Weather events have a big impact on ripening and it is helpful to see this displayed graphically.

Davenport Vineyards sugar and acidity levels for different varieties in 2018

Every block with a different variety, clone and rootstock behaves differently, so with this data you may start to see patterns and relationships between blocks. In the graph above you can see how the sugar and acidity levels vary for each variety, and the difference in how quickly each one ripens. Will, at Davenport Vineyards, can use this information to plan when to harvest each variety and the graph is easy to share with his team.

Davenport Vineyards comparison of sugar and acidity levels year on year for a single variety

By comparing ripeness data year on year for the same block it’s possible to identify patterns particular to each block. How long does ripening tend to take for this block? Is this year similar to 2016? Comparing to other similar years will also help you predict harvest dates based on the ripening trajectory.

Are you already using Sectormentor for Vines to monitor sugar and acidity? Log into your Sectormentor account online to try our updated Grape Ripeness Indicator. You’ll find it in the ‘Tools’ section – let us know what you think!

Find out how Sectormentor for Vines helps you record data & manage your vines for the best quality grapes: get in touch here or check out 10 key metrics to monitor in your vineyard.

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

Use bunch weights at lag phase and veraison to optimise yield prediction

In part 1 we looked at optimising your yield prediction by getting accurate bunch counts. As we move through the season there is more information available to us, allowing for our yield predictions to be optimised even further. Part 2 of yield optimisation starts with weighing actual bunches in lag phase, or at veraison, and then again at regular intervals in the run up to harvest. Last-minute losses due to disease can also be taken into account at this stage. Many thanks to Luke Spalding at Chalk House Vineyard for sharing his tips and tricks for getting a good yield prediction.

Third prediction: Weigh bunches at lag phase or veraison
For the next step of your yield prediction it is time to start weighing your bunches! This can be done at lag phase, or veraison. Weighing bunches at this stage you get a better idea of what the bunch weight will be for each varietal this year. Theoretically lag phase is about 55 days after 50% flowering*. In fact, this is one reason why recording 50% flowering is important – so you can identify when lag phase will happen.

*This is based on studies done with Pinot Noir in Oregon State. In more variable cool climates, like the UK, due to the stop-start growing season impacting both flowering and grape berry development stage II (lag phase), the number of days can vary much more (It’s important to always be observing!).

The lag phase prediction method is often thought to be the most accurate when done correctly, however as Chalk House vineyard manager Luke Spalding explained, “For many people the best time to start weighing bunches is veraison – it’s easy to see when that is, so you don’t have to worry about counting the number of days since 50% flowering for each varietal. The issue is that for some vineyards, waiting until veraison is too late, they need to be able to get a more accurate yield prediction as early as possible.”

Whether you choose to start measuring actual bunch weights at lag phase or veraison, the method is very similar. You need to go out and randomly select as many bunches as is reasonable from each block (Luke recommends 15-25 bunches per 1000 vines for smaller vineyards). We have seen a number of different methods used by different vineyard managers to select random bunches in a bay. Two options are:

1. Select a mix of 1st, 2nd (and 3rd bunches if you have them)
2. Select every other bunch in one random bay

Once you have selected your bunches from the block, you are now ready to weigh your bunches. You just need an average bunch weight, so if you know how many bunches you picked, then you can weigh them all together and divide the total weight by the number picked to get the average.

Use the bunch weight multiplier

Yield prediction calculation using bunch weights and multiplier

The rule of thumb is that in a ‘normal’ year, your bunches will increase in weight by a factor of 1.65-1.9. We call that number the weight multiplier.  The multiplier differs for lag phase and veraison.

At this point you start to really optimise your yield prediction to be much more accurate. This is the first time you have got a real idea of the bunch weights for this year. Go to the yield predictor tool, enter in the average bunch weights for each block, and adapt the multiplier to ~1.65 for veraison weights, or ~1.8 for lag phase weights. Of course getting the multiplier right is key, which is why it’s important to measure bunch weights at lag/veraison each year, and then again at harvest. This allows you to understand the weight multiplier for each of your varietals/clones. If you don’t have any previous data then using a weight multiplier of around 1.65 (veraison) or 1.8 (lag phase) initially is a good place to start.

Optimising yield prediction year on year
With the yield predictor tool you can now compare how this prediction compares to your previous prediction, and you can easily see the total predicted weight for the vineyard as well as the predicted yield for each block. In the previous prediction you were using average weights, now you are using actual weights from this year with a multiplier – does it look too high or too low? If things are looking exceedingly good this year, then maybe do another yield prediction with a weight multiplier of 2 – for example the harvest of 2019 in the UK people were seeing weight multipliers of 2 or more from veraison to harvest, but that was of course a very unusually prolific year. Also there can be considerable variation between different varietals when it comes to the weight multiplier, so if you do have past years data then it’s best to customise the weight multipliers for each block based on the history at your site.

Fourth prediction: Include last minute losses due to disease/pest pressures

Yield prediction calculation including potential loss from Botrytis

To see how things are progressing you can go out and weigh more bunches 4 weeks after veraison. How have the bunches developed? How much bigger will they get by harvest?

Of course there can be unforeseen issues with disease pressure in the final weeks. This is easily accounted for in the yield predictor by adding in what % of the crop you have lost due to the problem. This will update your yield prediction estimates in the final stages of your yield prediction journey.

Weigh bunches at harvest
It is key to measure the average bunch weight at harvest and enter that into Sectormentor too. You can either go and pick random bunches on the morning of harvesting a particular block, or you can harvest the sample bays from each block before harvesting the rest of each block (you have already counted the number of bunches for sample bays so you can easily work out the average bunch weight by weighing all the bunches that are harvested from that bay).

This number of average bunch weight at harvest is vital so that in future years you can figure out what the actual veraison-harvest weight multiplier is for each block in your vineyard. It also helps to get a very good idea of your average harvest bunch weight for a particular block over many years, so that those early predictions that rely on this weight become more and more accurate.

It’s an art and a science..
Yield estimation is a real art. The more in tune you are with your vineyard and the more you know your vines, the easier it will become – if you are consistently getting within 15% of the actual yield then that is considered good in cool climates. However, if you are very committed and refine the details, meticulously measuring bunch weights at lag/veraison and harvest each year, getting clear on your weight multipliers for each block, then many vineyard managers believe you should be able to get within 5% accuracy every time.

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

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.

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

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

The value of knowing % Fruit Set

After the buds have burst, flowering is over (or almost over)…the caps are off and the grapes are beginning to form – we are well and truly into another season and the countdown to harvest has begun, yet again! In this post, we wanted to tell you a bit about % fruit set and why this a useful metric. If you did an inflorescence count prior to flowering then it’s very easy to determine what % of your inflorescences have “set” fruit.

Photo: Vines just finished flowering – fruit set just starting…

Fruit set is vital in the phenological progression of the vine, as it is the moment that the fruit actually comes into being -it’s the first indicator of how abundant (or not) the harvest might be. Knowing the % fruit set helps you to know if the vine is out of balance or if something went wrong at this point and you need to do things differently in future years.

Of course, a key factor that affects fruit set is outside of our control – the weather! High winds and heavy rain (or worse, frost), can really damage flowers’ ability to turn into fruit. But poor management decisions, as well as reduced vine health, can also impact fruit set – so this is an indicator to learn how to learn from!

“We monitor fruit set to make sure we are managing the vineyard as effectively as possible. You have to be very careful during flowering, especially with any sprays, it can be very delicate and you can cause poor fruit set. So we always check % fruit set to learn and improve our management in following years.” – Joel Jorgensen

Poor fruit set in vines can be due to carbohydrate supply, water supply and mineral imbalance. Here is a nice description of how and why from a US vineyard outreach officer:

‘Deficiencies of any of the essential mineral nutrients (e.g Zinc, Boron) can affect fruit set detrimentally.  Unbalanced C:N status of the vine can also result in poor flower development and fruit set. Overly vigorous (lower C:N ratio) or weak vines (higher C:N ratio) with insufficient or in-efficient leaf area (e.g. due to herbicide damage, insect feeding, disease attack)  tend to have reduced fruit set and loose clusters.’ (Reference)

Different varieties can also be more or less likely to set all their fruit, so starting to understand different varietal and block behaviours with fruit set helps to build up a picture of those vines over time and optimise vineyard management based on the expected fruit set. This also means you can pay special attention to any areas of the vineyard that are particularly susceptible at flowering:

“Flower set is dependent on the weather but some varieties are more prone to poor fruit set in certain conditions. When we count inflorescences, we assume 100% fruit set. In August when we count bunches post flowering we then update the yield prediction. And also determine the % fruit set so we can manage the blocks accordingly going foward.” – Will Davenport, Davenport Vineyards.

How to calculate fruit set?

Go out and do an inflorescence count as the flowers come into bloom. Then sometime after flowering is all finished, and the caps have blown off, go out and count the number of bunches. ‘No. of bunches’ divided by the ‘No. of inflorescences’ will give you the % fruit set. Using Sectormentor makes this easy:

Monitoring with Sectormentor:
Sectormentor makes it easy to record flower / inflorescence counts and bunch counts at the touch of a button on your phone out in the vineyard. All the information you record is then available as soon as you get back to the office. You can easily see the % fruit set for each block, and this is recorded year on year, so you can start to build up a picture of each block and how the fruit sets for that specific clone, variety, location. This is about really knowing your vines!

Check out 10 key metrics to monitor in your vineyard and find out how our app Sectormentor helps you record data & manage your vines to build ecology, profitability and beauty for your vineyard.

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.

Equipment:
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.

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.

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 (https://twitter.com/AlburyVineyard/status/953623920262905856)

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 (https://twitter.com/RidgeviewWineUK/status/968503347933274113)

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 (http://rathfinnyestate.com/estate-news/2018/03/31/march-2018-gallery/)

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”.

Summary

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 info@vidacycle.com 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.

References:

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