Join us for a walk around a beautiful spot in East Sussex, a 2.6-hectare vineyard run by data lover Luke Spalding. The vines are fairly new, they’ve been in the ground for 4 years and will be producing at full potential in the next year or two. Another 4.5 hectares of vines are due to be planted in May 2021, and the aim is to consistently produce 6-8 tonnes of grapes a hectare in the future. Currently the wine is made at Hambledon, where Luke has built a great working relationship with Felix the winemaker there, the first wines will be released 2021.
The vineyard is 74m above sea level and the site has its challenges; such as extreme south west winds and severe late spring frosts due to its proximity to the South Downs. Luke told us “This is why I wanted the job, if I can deal with these challenges and learn to produce a great crop then I know I am doing something right!”.
The field was previously used for grazing livestock and hay making, so the soil is rich in nitrogen but has an imbalance of magnesium and potassium. This is a blessing and a curse in the Pinot Meunier variety; as it saves on some fertilisers but creates other problems with necrosis on the berries and buds.
Luke spends a lot of time scouting in the vineyard for issues, making observations and recording them with his Sectormentor for Vines phone app. His passion for data started when he was at Ridgeview Wine Estate; he helped monitor links between the number of seeds in a berry, berry size and climatic values that increased berry size and development. In a Californian grape grown to maturity the average is three to four seeds per grape, but how many seeds do English grapes generally have? Luke decided to sample 250 berries across every block in the vineyard, counting seeds to calculate the average seed count per berry for each block, observing how well the fruit had matured. He found there are often only 2 seeds on average in an English grape, a sign the grapes do not fertilise as well as those across the pond. This is because we just don’t have enough sunny growing days over here!
Pre veraison Luke and his assistant Tom recorded bunch counts with the Sectormentor for Vines app to start making an early yield prediction and decide if they need to remove any bunches from the vines to optimise yield and grape quality. They checked the bunch count data displayed by block on their Sectormentor for Vines account and decided to take off quite a few bunches post flowering, which are left on the ground to return fertility to the soil.
Once grapes have been thinned out they will go through and count bunches again to understand how many were actually dropped and update their yield prediction. All this data can be put into the Sectormentor for Vines app so they can observe and understand trends in how their bunch counts are evolving and what their yield might be.
Post veraison, berries grow rapidly in size, generally due to Autumn sunshine causing sugar to build up in the grapes. Luke monitors berry weight to see the impact from different weather patterns and other variables. As it turns out, hot and sunny weather during the growing season is not necessarily what causes dramatic increases in berry size; it is actually a heavy rainfall event in the run up to harvest which makes a huge difference!
We got the low down from Luke: “If you have 10 bunches per vine and each one increases by 10g due to rain, each Ha has 4,132 vines and the site has 10ha that’s an extra 4,132kg. It all adds up!”
As Chalk House is a new vineyard, there are some younger vines which aren’t yielding yet. Luke monitors younger vines, along with dead and missing vines, so he can take them out of his yield prediction, ensuring it is accurate. Luke also keeps track of frost damage and wind scorch by recording incidences on Sectormentor for Vines, so he’s able to stay on top of the problems and make any necessary management changes. He sprays seaweed straight onto frost damaged buds within 24 hours – this does an amazing job helping them recover! He’s also trying a biodynamic treatment of silica to help with wind scorch. This improves cell walls and leaf thickness to make the vines more resilient to the prevailing wind, as well as powdery mildew.
“I use Sectormentor for Vines as a Barometer of how the vine has developed, how many buds have burst, how many shoots do I have, how many clusters do I have and what do we need to drop. That information tells me if I have a problem like necrosis, if I have to shoot thin or if I need do a green harvest.” – Luke Spalding, Chalk House Vineyard
By monitoring bud counts, shoot counts and cluster counts with Sectormentor for Vines, Luke gets a good idea for how the vines are doing and if there are any issues. For example, if he does a bud count and then a shoot count, and finds only 60% of the buds have shoots, he knows there is a problem with necrosis or blind buds and can make a decision on how to manage this in the future.
Growing degree days for a season also provide helpful and informative data for Luke; from several years of monitoring he has found anything higher than -70 GDD in March means bud burst will happen in the first week of April. As Luke points out, “In a cooler climate where everything is so marginal this type of data is really important and can make a huge difference to successful vineyard management.”
We’re excited to continue following Luke’s journey; if you’d like to hear more about what he is up to read this blog post on trialling cover crops, mulching and biodiversity at Chalk House Vineyard.