Harvest is upon us!!
Yes, this is a bit early, but our vineyard was put in from the start to be the basis of sparkling wine (the most recognisable form of which is made in the Champagne region of France) production. The making of sparkling wine is more complex than normal still wine, and requires the grapes to be picked earlier than usual.
So while grapes for table wine might be picked at 25 degrees Brix (specialised term to represent the percentage sugar in them), grapes for sparkling wine might be picked at 18 degrees Brix.
As it turns out, our grapes were actually above that target, but that's okay, as the flavours were really nice for sparkling wine!
An advantage of growing grapes for sparkling wine is that since you harvest them earlier, there is less time for the grapes to be eaten by the birds, less chance that disease will get in there, and thus more time to relax!!
However, not all is complete. The nets need to be taken up, the vineyard mowed, and some water applied through the irrigation system. The latter, because we haven't actually needed to irrigate so far this year, will need to be flushed to make sure there isn't any gunk in there that could block the emitters.
Why irrigate? Well, it has been a while since we had any significant rain. By significant, I mean at least 25mm. So though we've had a few rain events in the past three months, they've all been less than that, so the soil is still pretty dry. I didn't want to apply water right before we harvested as that would have pumped up the berries with more water, which would have diluted the sugars, acids and flavours.
So now that the grapes are off, I can give the vines some water so that they have plenty to be able to photosynthesise lots, and therefore store some energy for next season.
As a side note, we did have about 10mm of rain right before harvest, which did have a significant effect on the berries. Based on some research I was part of in Oregon, this probably occurred by the water being absorbed directly into the berries, or into the leaves and stems, and then into the berries. Whatever happened, the morning right before we harvested the berries were plump and splitting as we were taking some off to sample. By the end of the afternoon (and a hot day!), the berries were no longer turgid.
As well, quite a few of the berries were deflating/shrivelling, caused by a crack in the berry skin. My theory on this is that the swelling of the berries caused some micro-fissures in the skin, which then ruined the integrity of the berry, causing the berries to shrivel as the day wore on and water was lost from them.
This made us very happy that we had decided to harvest, as the berries would not have been in very good shape later in the week!! It was definitely the right time to take them off!!
Monday, March 15, 2010
Friday, March 5, 2010
On and on about netting!
Ah, the netting saga continues!!
I spent the day putting netting on a rootstock trial, as we use the fruit for teaching, and also winemaking. The trial has been very interesting, as the rootstocks were chosen to represent a wide range of rootstock grapevine species, and the control is Chardonnay (Mendoza clone) grafted onto itself, as the graft union probably has an effect on the growth of the vine as well. Unfortunately, we don't have an ungrafted control in the block, as there wasn't room to include it as an eighth treatment (six different rootstocks and the control grafted Chardonnay).
Still, there are intriguing results, with the scion (Chardonnay) trunk circumference to rootstock trunk circumference ratios being quite different among the treatments. Curiously, the Chardonnay grafted onto itself is not resulting in a 1:1 ratio, but is actually the smallest - the scion trunk circumference is the much less than the rootstock's trunk circumference, even though they are the same plant material!
In any case, the netting, which is single over-the-row type netting that I've already put photos up of, is over the vines, and the three rows mostly clipped up. The worst of the bird damage was at the end of the rows that are closest to the Poplar tree windbreak. This is one of the reasons that viticulturists don't like having trees near the vineyard - they provide roosting areas and cover for birds!
I spent the day putting netting on a rootstock trial, as we use the fruit for teaching, and also winemaking. The trial has been very interesting, as the rootstocks were chosen to represent a wide range of rootstock grapevine species, and the control is Chardonnay (Mendoza clone) grafted onto itself, as the graft union probably has an effect on the growth of the vine as well. Unfortunately, we don't have an ungrafted control in the block, as there wasn't room to include it as an eighth treatment (six different rootstocks and the control grafted Chardonnay).
Still, there are intriguing results, with the scion (Chardonnay) trunk circumference to rootstock trunk circumference ratios being quite different among the treatments. Curiously, the Chardonnay grafted onto itself is not resulting in a 1:1 ratio, but is actually the smallest - the scion trunk circumference is the much less than the rootstock's trunk circumference, even though they are the same plant material!
In any case, the netting, which is single over-the-row type netting that I've already put photos up of, is over the vines, and the three rows mostly clipped up. The worst of the bird damage was at the end of the rows that are closest to the Poplar tree windbreak. This is one of the reasons that viticulturists don't like having trees near the vineyard - they provide roosting areas and cover for birds!
Saturday, February 27, 2010
Netting -What a pain, but we have little choice!
Okay, the nets are on! With such a small vineyard, it didn't take all that long, but it is the clipping of the nets that takes a lot of time, and thank goodness we had wonderful friends that could help!
In the photo above you might be able to see that we have netting that goes over a single row, with the edges joined at the bottom. We roll them up and clip them in place with curtain hooks.
It's essential that there are no gaps in the netting, even very small ones, as birds are very clever and will search for any access point.
One problem is that sometimes the net is resting against clusters that stick out into the row - birds can sit on the net in these places and peck at the fruit. So outriggers, or something that pushes the netting out away from the fruit, are sometimes used. Most often, some sort of horizontal support is used to push apart the first foliage wire, which then keeps the netting from getting too close to the fruit. We haven't done this at our vineyard yet - we're seeing how it goes, and will try to tuck shoots out to push the nets. If necessary, we will be fabricating some sort of stick to push out the foliage wires, and thus the nets. However, I'm hoping it doesn't come to that!!
In the photo above you might be able to see that we have netting that goes over a single row, with the edges joined at the bottom. We roll them up and clip them in place with curtain hooks.
It's essential that there are no gaps in the netting, even very small ones, as birds are very clever and will search for any access point.
One problem is that sometimes the net is resting against clusters that stick out into the row - birds can sit on the net in these places and peck at the fruit. So outriggers, or something that pushes the netting out away from the fruit, are sometimes used. Most often, some sort of horizontal support is used to push apart the first foliage wire, which then keeps the netting from getting too close to the fruit. We haven't done this at our vineyard yet - we're seeing how it goes, and will try to tuck shoots out to push the nets. If necessary, we will be fabricating some sort of stick to push out the foliage wires, and thus the nets. However, I'm hoping it doesn't come to that!!
Hopefully, this is the only view of the grapes that the birds will get!!
Tuesday, February 16, 2010
Prepping for harvest
After dealing to the powdery mildew in our little vineyard, there were a few things that we needed to get ready in the preparation for eventual harvesting!
The first order of the day was to give the vineyard cover crop a good mow! For me, this is mainly a comfort thing, as it's not that nice to walk through the vineyard if the grass is very tall. This is especially true if the grass is damp from morning dew!
As well as this, the shoots needed a general tidy-up, as they had grown a bit since the last time we were through, and were getting a little tall. This is despite it being not that long ago that we did the shoot topping and positioning. We had some rain recently, and the vines were responding with a fresh spurt of growth.
Then, as the grapes were just starting to colour up (Pinot noir and Pinot meunier), it was time to get the nets on.
Timing of this is a bit tricky, as if you put the nets on too early, the vines grow shoots and tendrils through the netting, which makes it a lot harder to take the net off after harvest, and the vine-y bits cause the netting to tangle.
If you put the nets on too late, the birds discover how yummy the grapes are, and they'll pick off the grapes as they are colouring up. If you're not looking closely, you might wander through the vineyard and think that veraison is being delayed, but in reality, all the coloured berries are being picked off by the birds, leaving little clue that ripening is at hand! As a result, you can lose a lot of crop! Also, if the birds discover the grapes, they will tell their family and friends, and in a matter of hours, decimate the crop of a vineyard.
So in putting on nets, it's better to err on the side of being too early!!
So that's what we've done - just a few berries are starting to turn, so we put the nets on last weekend.
The job is not done, however! We still need to finish clipping the nets - that is, making sure there are no holes in the netting that birds can get through. And they're very clever at getting through spaces you wouldn't think they could!!
The first order of the day was to give the vineyard cover crop a good mow! For me, this is mainly a comfort thing, as it's not that nice to walk through the vineyard if the grass is very tall. This is especially true if the grass is damp from morning dew!
As well as this, the shoots needed a general tidy-up, as they had grown a bit since the last time we were through, and were getting a little tall. This is despite it being not that long ago that we did the shoot topping and positioning. We had some rain recently, and the vines were responding with a fresh spurt of growth.
Then, as the grapes were just starting to colour up (Pinot noir and Pinot meunier), it was time to get the nets on.
Timing of this is a bit tricky, as if you put the nets on too early, the vines grow shoots and tendrils through the netting, which makes it a lot harder to take the net off after harvest, and the vine-y bits cause the netting to tangle.
If you put the nets on too late, the birds discover how yummy the grapes are, and they'll pick off the grapes as they are colouring up. If you're not looking closely, you might wander through the vineyard and think that veraison is being delayed, but in reality, all the coloured berries are being picked off by the birds, leaving little clue that ripening is at hand! As a result, you can lose a lot of crop! Also, if the birds discover the grapes, they will tell their family and friends, and in a matter of hours, decimate the crop of a vineyard.
So in putting on nets, it's better to err on the side of being too early!!
So that's what we've done - just a few berries are starting to turn, so we put the nets on last weekend.
Side netting being attached to the upper foliage wires. These lucky workers are the front line to defense against birds damaging the fruit!
The job is not done, however! We still need to finish clipping the nets - that is, making sure there are no holes in the netting that birds can get through. And they're very clever at getting through spaces you wouldn't think they could!!
Saturday, February 6, 2010
Powdery mildew
I've just been spraying our vines with sufur to control powdery mildew. This nasty disease, caused by the fungus Uncinula necator, infects green tissue on the vine, most commonly showing up on leaves, but also fruit and shoots.
Control is through the application of sulfur, primarily, as this is a pretty soft compound for the environment. There are synthetic compounds available, the most common of which fall into the demethylation inhibitors (DMI) category. However, as long as the green tissue has a covering of sulfur, infection by the fungus is prevented. This requires repeated application through the season, to cover new growth, and also re-cover sulfur that has been washed off, or which has all volatilised. DMIs are great, but there is concern about resistance developing against them, so their use is limited to a certain number of applications per season.
It is the gaseous form of sulfur that is active against powdery mildew, so with heat, the solid sulfur is converted into sulfur dioxide (SO2). However, like with any disease spray, good coverage is essential!
Powdery mildew likes warm and dry conditions: in fact, heavy rain can help prevent infection by washing off the spores!
Careful monitoring for evidence of the disease, which usually starts in those places where the sulfur sprays can't reach (hence the need for good canopy management!), can delay the timing of the first and subsequent sprays, reducing their frequency. However, the disease is like an opportunist - miss one spray and it's likely to take over!
Powdery mildew on a shoot pre-bloom. If the leaves are infected while young, you see this cupping of the leaf margins
Powdery mildew infection on a green shoot.
Powdery mildew infection on a dormant cane. The fungus cannot infect dormant vine material, so this problem came about during the growing season.
Control is through the application of sulfur, primarily, as this is a pretty soft compound for the environment. There are synthetic compounds available, the most common of which fall into the demethylation inhibitors (DMI) category. However, as long as the green tissue has a covering of sulfur, infection by the fungus is prevented. This requires repeated application through the season, to cover new growth, and also re-cover sulfur that has been washed off, or which has all volatilised. DMIs are great, but there is concern about resistance developing against them, so their use is limited to a certain number of applications per season.
It is the gaseous form of sulfur that is active against powdery mildew, so with heat, the solid sulfur is converted into sulfur dioxide (SO2). However, like with any disease spray, good coverage is essential!
Powdery mildew likes warm and dry conditions: in fact, heavy rain can help prevent infection by washing off the spores!
Careful monitoring for evidence of the disease, which usually starts in those places where the sulfur sprays can't reach (hence the need for good canopy management!), can delay the timing of the first and subsequent sprays, reducing their frequency. However, the disease is like an opportunist - miss one spray and it's likely to take over!
Sunday, January 17, 2010
Seasonal update
As I'm back in New Zealand and haven't been here since the beginning of the growing season, one of the things I did was catch up on growing degree day (GDD) accumulation for Lincoln, Canterbury.
The concept of heat accumulation (one way of measuring which is GDD) and how plant growth corresponds with it is an important tenet of modelling the phenology, or seasonal development of plants, and in this case, grapevines.
It goes a little something like this:
Plants need heat to grow. At its most basic, this is because the enzymes that do the chemical work in plants can't function when it gets cold (in fact, this is true for animals as well -it's one of the reasons cold blooded animals hibernate in the winter. Warm blooded animals use energy to generate heat, which keeps the enzymes working). So below a certain temperature threshold, plants won't grow. As the temperature rises above that threshold the enzymes work faster and faster, up until the temperature gets so high as to prevent the enzymes from working again (around the mid 30s in celcius).
So measuring the accumulation of heat during the growing season results in a pretty good match of how far along the vines have come, or what stage they have gotten to. One question, though, is what do you set the temperature threshold at?
Based pretty much on enzyme activity in relation to temperature, 10C is the most commonly chosen base temperature (the temperature below which there is no plant-active heat accumulation). However, this may differ for different types of plants, and even for different times of the season (e.g. it seems that for the process of budbreak, a base temperature of 4C is omre appropriate, and for the first leaf appearances, 7C, Moncur et al. 1989).
Setting aside those special circumstances, a pretty straightforward way to quantify heat accumulation is to take the average temperature for a month (which falls within the growing season) and if it is greater than 10C, subtract 10 from it. That result is then multiplied by the number of days in the month, which gives the number of growing degree days for that month:
[ (average temperature for the month-10) * (number of days in the month) ] = GDD
In other words, on average each day was X amount over 10 degrees, and over the whole month, X times the number of days equals the amount of plant-useful heat that was experienced. Note that negative GDDs are not counted (though it's cold, the plants don't regress - they just sit there until it warms up again)
So to put some numbers in there, if the average temperature of November was 12.6C (as it was at Lincoln in 2009), 2.6C times the 30 days in the month equals 77 GDD accumulated.
If this value is calculated for each month of the year, we can follow the heat accumulation in a useful way, especially when comparing one year to another, or comparing on location to another.
In the case of the former, the graph for the 2009-2010 season looks like this, given the data collected up through November:
Growing degree calculations for the 2009-2010 season (up through November, the orange line) and for the long term average (LTA, the blue line), which is the average over the last 40 years.
The Long Term Average (LTA, blue) is the smooth sigmoidal curve, which signifies that heat accumuation is slower (the line is more horizontal) in the spring and autumn, and quicker (an more vertical line) during summer. The number in parentheses is the LTA GDD accumulation for Lincoln - a paltry 924GDD.
You can see that up to this point in the season, the orange line (current season) is below the LTA line, which means that the season has been cooler than average. If you squint just right, you can make out that the last orange dot corresponds to 77GDD, which is what we calculated above. This also means that there was no accumulation of plant-useful heat in October, or earlier in the season (at least, when based on monthly averages - more on that in another post!).
If you want to compare seasons, this way of looking at the data is fine, but if you want to see the differences more clearly, you can plot the current season's GDD relative to the LTA, which looks like this:
Growing degree calculations for the 2009-2010 season (orange) and for the LTA (the blue line, which is the X-axis). This figure is showing the same data as the previous one, but in a slightly different way.
Now it is pretty plain to see that we're veering away from the LTA. If the line is below zero (the LTA blue line), then there has been less heat accumulation than the LTA, and if it's above, there has been more, and it's been a warmer season.
You can also see more clearly what's happening for each month. If the line moves down, then the month has been cooler than LTA; if it slopes up, then it's been warmer. If the line is parallel to the LTA, then the average temperature for the month has been the same as the LTA.
So what we'd like to see is the line above the LTA - sadly, up through most of December, this has not been the case!
The concept of heat accumulation (one way of measuring which is GDD) and how plant growth corresponds with it is an important tenet of modelling the phenology, or seasonal development of plants, and in this case, grapevines.
It goes a little something like this:
Plants need heat to grow. At its most basic, this is because the enzymes that do the chemical work in plants can't function when it gets cold (in fact, this is true for animals as well -it's one of the reasons cold blooded animals hibernate in the winter. Warm blooded animals use energy to generate heat, which keeps the enzymes working). So below a certain temperature threshold, plants won't grow. As the temperature rises above that threshold the enzymes work faster and faster, up until the temperature gets so high as to prevent the enzymes from working again (around the mid 30s in celcius).
So measuring the accumulation of heat during the growing season results in a pretty good match of how far along the vines have come, or what stage they have gotten to. One question, though, is what do you set the temperature threshold at?
Based pretty much on enzyme activity in relation to temperature, 10C is the most commonly chosen base temperature (the temperature below which there is no plant-active heat accumulation). However, this may differ for different types of plants, and even for different times of the season (e.g. it seems that for the process of budbreak, a base temperature of 4C is omre appropriate, and for the first leaf appearances, 7C, Moncur et al. 1989).
Setting aside those special circumstances, a pretty straightforward way to quantify heat accumulation is to take the average temperature for a month (which falls within the growing season) and if it is greater than 10C, subtract 10 from it. That result is then multiplied by the number of days in the month, which gives the number of growing degree days for that month:
[ (average temperature for the month-10) * (number of days in the month) ] = GDD
In other words, on average each day was X amount over 10 degrees, and over the whole month, X times the number of days equals the amount of plant-useful heat that was experienced. Note that negative GDDs are not counted (though it's cold, the plants don't regress - they just sit there until it warms up again)
So to put some numbers in there, if the average temperature of November was 12.6C (as it was at Lincoln in 2009), 2.6C times the 30 days in the month equals 77 GDD accumulated.
If this value is calculated for each month of the year, we can follow the heat accumulation in a useful way, especially when comparing one year to another, or comparing on location to another.
In the case of the former, the graph for the 2009-2010 season looks like this, given the data collected up through November:
Growing degree calculations for the 2009-2010 season (up through November, the orange line) and for the long term average (LTA, the blue line), which is the average over the last 40 years.The Long Term Average (LTA, blue) is the smooth sigmoidal curve, which signifies that heat accumuation is slower (the line is more horizontal) in the spring and autumn, and quicker (an more vertical line) during summer. The number in parentheses is the LTA GDD accumulation for Lincoln - a paltry 924GDD.
You can see that up to this point in the season, the orange line (current season) is below the LTA line, which means that the season has been cooler than average. If you squint just right, you can make out that the last orange dot corresponds to 77GDD, which is what we calculated above. This also means that there was no accumulation of plant-useful heat in October, or earlier in the season (at least, when based on monthly averages - more on that in another post!).
If you want to compare seasons, this way of looking at the data is fine, but if you want to see the differences more clearly, you can plot the current season's GDD relative to the LTA, which looks like this:
Growing degree calculations for the 2009-2010 season (orange) and for the LTA (the blue line, which is the X-axis). This figure is showing the same data as the previous one, but in a slightly different way.
Now it is pretty plain to see that we're veering away from the LTA. If the line is below zero (the LTA blue line), then there has been less heat accumulation than the LTA, and if it's above, there has been more, and it's been a warmer season.
You can also see more clearly what's happening for each month. If the line moves down, then the month has been cooler than LTA; if it slopes up, then it's been warmer. If the line is parallel to the LTA, then the average temperature for the month has been the same as the LTA.
So what we'd like to see is the line above the LTA - sadly, up through most of December, this has not been the case!
Thursday, January 7, 2010
China - the sleeping ice wine giant? (part 2)
And now for the continuation - How China has affected world ice wine production...
Ice wine is deliciously sweet, and due to the many things that have to go right for it to be produced (see part 1) and the low juice yield from the grapes, it is very expensive. So it is very sought after in many places, and also a target for counterfeiters. Some Niagara Peninsula producers were shocked to find that "icewine" was being sold under their brand in China.
There is, apparently, a lot of adulterated table wine being sold as icewine in China, which has a negative impact on the reputation of brands making it the right way, and therefore getting the special characteristics of the wine style that are so yummy.
However, that is not to say that all ice wine being made in China is fake! Changyu winery partnered up with a Canadian company some years ago to develop an expansive vineyard specifically for icewine production. Those Vidal vines are now coming into full production - all 5000 mu (about 333 hectares) of them (there is some confusion over the actual area planted. Some web sources say 5000 acres, but two signs I saw at Changyu say they have 5000 mu (1 mu = 0.067 ha)). The plan is to make icewine under similar conditions as required by the Canadian VQA system, and supply a quality product (Changyu Golden Valley Icewine) to the domestic market.
Changyu Golden Valley Icewine bottles on display at the Yantai International Wine Festival. These are the Golden Diamond wines. There are also two higher price point labels, the Blue Diamond and the Black Diamond ones. Prices for 500ml bottles were 228RMB, 418RMB and 838RMB, respectively. This translated into approximately USD33, 60 and 120, resp.
Some information about the icewine vineyard development. Picture taken in the Changyu Wine Museum, in Yantai, Shandong Province.
The location was chosen so that conditions for quality icewine production would be met most every year, and because the scale is so massive, that means a lot of wine can be produced!
A photo of a photo of the vineyard in Huanren - appropriately icy! Picture taken in the Changyu Wine Museum.
Even considering this is all in China, I still wonder about where they will get all the labour to tend the vines and harvest the fruit!
A photo of a photo of a "Hardworking farmers harvesting grapes in coldness." Picture taken in the Changyu Wine Museum.
And since China does things big, just how significant is this planting in Huanren? In 2008, about 6500 tonnes of grapes were registered for icewine production in the Niagara Peninsula. The Changyu development should produce about 1000 tonnes of grapes (significantly more come from vineyards other than theirs). So a significant boost. Even more significant when the latest info says that only 1750 tonnes were registered to be made into icewine for the 2009 vintage, due to a downturn in the icewine market.
While I'm not a huge fan of the wine style (too sweet for me, generally), it certainly has, and deserves, a place in the market, and is also a good reminder of how versatile a product the grape is!
NB, you might be interested in reading this article, which has more detail on the plantings in Huanren...
Ice wine is deliciously sweet, and due to the many things that have to go right for it to be produced (see part 1) and the low juice yield from the grapes, it is very expensive. So it is very sought after in many places, and also a target for counterfeiters. Some Niagara Peninsula producers were shocked to find that "icewine" was being sold under their brand in China.
There is, apparently, a lot of adulterated table wine being sold as icewine in China, which has a negative impact on the reputation of brands making it the right way, and therefore getting the special characteristics of the wine style that are so yummy.
However, that is not to say that all ice wine being made in China is fake! Changyu winery partnered up with a Canadian company some years ago to develop an expansive vineyard specifically for icewine production. Those Vidal vines are now coming into full production - all 5000 mu (about 333 hectares) of them (there is some confusion over the actual area planted. Some web sources say 5000 acres, but two signs I saw at Changyu say they have 5000 mu (1 mu = 0.067 ha)). The plan is to make icewine under similar conditions as required by the Canadian VQA system, and supply a quality product (Changyu Golden Valley Icewine) to the domestic market.
Changyu Golden Valley Icewine bottles on display at the Yantai International Wine Festival. These are the Golden Diamond wines. There are also two higher price point labels, the Blue Diamond and the Black Diamond ones. Prices for 500ml bottles were 228RMB, 418RMB and 838RMB, respectively. This translated into approximately USD33, 60 and 120, resp.
Some information about the icewine vineyard development. Picture taken in the Changyu Wine Museum, in Yantai, Shandong Province.The location was chosen so that conditions for quality icewine production would be met most every year, and because the scale is so massive, that means a lot of wine can be produced!
A photo of a photo of the vineyard in Huanren - appropriately icy! Picture taken in the Changyu Wine Museum.Even considering this is all in China, I still wonder about where they will get all the labour to tend the vines and harvest the fruit!
A photo of a photo of a "Hardworking farmers harvesting grapes in coldness." Picture taken in the Changyu Wine Museum.And since China does things big, just how significant is this planting in Huanren? In 2008, about 6500 tonnes of grapes were registered for icewine production in the Niagara Peninsula. The Changyu development should produce about 1000 tonnes of grapes (significantly more come from vineyards other than theirs). So a significant boost. Even more significant when the latest info says that only 1750 tonnes were registered to be made into icewine for the 2009 vintage, due to a downturn in the icewine market.
While I'm not a huge fan of the wine style (too sweet for me, generally), it certainly has, and deserves, a place in the market, and is also a good reminder of how versatile a product the grape is!
NB, you might be interested in reading this article, which has more detail on the plantings in Huanren...
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