Annie Landless

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 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