Late season, yes, but it could be worse!
We've had a bit of an Indian Summer here, with a frost on April 10th, and then warm weather afterward.
While the season from September to January was miserably cool, with monthly temperatures being well below the long term average, February and March were slightly above average, and April is shaping up to be a decent month as well.
For those grapes that have kept their integrity through now, this is good news. We had 6mm of rain yesterday, but today was a nice warm and windy northwester, which has helped to dry out the clusters and should prevent an infection period for Botrytis from occurring.
There may be life yet in this difficult vintage for Canterbury!!
Sunday, April 25, 2010
Sunday, April 18, 2010
Curing virused vines?
I've just read some exciting news in the December/January issue of New Zealand Winegrower (yes, I know it's taken me a while to get around to reading it!! :-)
Some work being done by doctoral student Elaine Chan, Mike Pearson of the University of Auckland and Robin MacDiarmid of Plant and Food Research (pages 80-82) suggests that it might be possible to cure vines of virus diseases, or at least, be able to prevent virus from spreading from the infection point.
Viruses such as Grapevine Leafroll are major issues to grapegrowers around the world, so the thought that this might be able to be done is pretty fantastic! At the moment, infected vines are pulled out and replaced, and in some cases, the vines next to the infected one are removed as well, to lessen the possibility it may spread.
If researchers can figure out how to get plants to ramp up a defense mechanism against viruses, much as animals do, then the implications for grapegrowers would be tremendous (perhaps both pro and con!).
The idea is to duplicate the action of a protein in animals that signals the presence of viral agents. That protein would tell the surrounding tissue to stop making proteins, which the virus needs in order to replicate itself and spread through the rest of the plant. If that was done, then the plant could use other means to stop the virus from spreading from the infection point, say, by a hypersensitive response, where the tissue immediately surrounding the infection point dies, thereby isolating the virus. This response is well known in the area of fungal infections, for example.
They are also mooting the possibility that a plant equivalent of interferon could be developed, which would stimulate the plant to produce more of these signalling proteins and therefore stop the virus in its tracks.
These are not new ideas (see this article "Is there a plant interferon?"), but it's interesting to see that people are looking at this from the standpoint of grapevines.
If, and it's still a big "if" at this point, this was able to be accomplished, vines would be able to stop infection before it started, and infected vines could be cleansed of existing infection. It remains to be seen if such a thing could be done with today's vines, or if new vines would need to be developed which have this capability.
As well, sometimes viruses can help to make better quality wine. The Mendoza clone of Chardonnay, for example, is thought to produce lots of the smaller berries it's well known for because it is infected with a mild strain of Leafroll virus. I'm sure there are other instances where the virus (or related "disease" organisms) may be holding back the natural vigour of vines, or changing the fruit morphology in some way that led to a clonal selection. Sometimes, you have to take the good with the bad!!
Some work being done by doctoral student Elaine Chan, Mike Pearson of the University of Auckland and Robin MacDiarmid of Plant and Food Research (pages 80-82) suggests that it might be possible to cure vines of virus diseases, or at least, be able to prevent virus from spreading from the infection point.
Viruses such as Grapevine Leafroll are major issues to grapegrowers around the world, so the thought that this might be able to be done is pretty fantastic! At the moment, infected vines are pulled out and replaced, and in some cases, the vines next to the infected one are removed as well, to lessen the possibility it may spread.
If researchers can figure out how to get plants to ramp up a defense mechanism against viruses, much as animals do, then the implications for grapegrowers would be tremendous (perhaps both pro and con!).
The idea is to duplicate the action of a protein in animals that signals the presence of viral agents. That protein would tell the surrounding tissue to stop making proteins, which the virus needs in order to replicate itself and spread through the rest of the plant. If that was done, then the plant could use other means to stop the virus from spreading from the infection point, say, by a hypersensitive response, where the tissue immediately surrounding the infection point dies, thereby isolating the virus. This response is well known in the area of fungal infections, for example.
They are also mooting the possibility that a plant equivalent of interferon could be developed, which would stimulate the plant to produce more of these signalling proteins and therefore stop the virus in its tracks.
These are not new ideas (see this article "Is there a plant interferon?"), but it's interesting to see that people are looking at this from the standpoint of grapevines.
If, and it's still a big "if" at this point, this was able to be accomplished, vines would be able to stop infection before it started, and infected vines could be cleansed of existing infection. It remains to be seen if such a thing could be done with today's vines, or if new vines would need to be developed which have this capability.
As well, sometimes viruses can help to make better quality wine. The Mendoza clone of Chardonnay, for example, is thought to produce lots of the smaller berries it's well known for because it is infected with a mild strain of Leafroll virus. I'm sure there are other instances where the virus (or related "disease" organisms) may be holding back the natural vigour of vines, or changing the fruit morphology in some way that led to a clonal selection. Sometimes, you have to take the good with the bad!!
Saturday, April 10, 2010
What's happening in Marlborough?
Just got back from a tour through Marlborough with the Lincoln University Viticulture I students!
And an eventful time to be going through and talking with a number of people in the industry, working in large and small outfits.
Overall, the prognosis is good for the industry, in that regional yields are looking to come in slightly below the predicted total, which means there won't be an additional lump of wine to try to sell over the coming year. The other news is that everyone is really happy with the quality of the fruit coming in - the season was pretty cool, but the last weeks of the season have been ideal, and this combined with the lower crop loads (some by the effects of nature at fruit set, but some also due to people keeping crop loads down). Good news indeed!!
The big boys were in the early phases of harvest (getting close to 50% about now), but some of the smaller outfits (Fromm, Staete Landt) were pretty much through!
I've more detailed info (in snippet form) at http://twitter.com/sabrosiavit
And an eventful time to be going through and talking with a number of people in the industry, working in large and small outfits.
Overall, the prognosis is good for the industry, in that regional yields are looking to come in slightly below the predicted total, which means there won't be an additional lump of wine to try to sell over the coming year. The other news is that everyone is really happy with the quality of the fruit coming in - the season was pretty cool, but the last weeks of the season have been ideal, and this combined with the lower crop loads (some by the effects of nature at fruit set, but some also due to people keeping crop loads down). Good news indeed!!
The big boys were in the early phases of harvest (getting close to 50% about now), but some of the smaller outfits (Fromm, Staete Landt) were pretty much through!
I've more detailed info (in snippet form) at http://twitter.com/sabrosiavit
Saturday, March 27, 2010
Post harvest activities
Well, harvest is done, the grapes have been pressed and the juice recently inoculated with yeast! The winemakers job has begun, but the viticulturists job continues!
I got out into the vineyard today to flush the irrigation system to ensure that the lines would be free of debris that could potentially clog the emitters. Once this is done, the vines got a nice six hour drink, at 1.2 litres per hour. This should be enough to wet the soil under the emitters to a good depth, and get water to the roots. The vines will now have access to plenty of water that should allow them to photosynthesise and store nutrients needed for next season's growth. Many leaves have yellowed by this point, but there are still lots of green leaves that can do useful work.
This is the first irrigation of the season, so in some ways, it is pretty unusual to have this happening after harvest!!
As well, I mowed the vineyard, which keeps walking down the rows pleasant, especially if you're doing it early in the morning or after a bit of rain.
If we're lucky, there will be another month and a half of useful photosynthesis going on. As temperatures fall in the late part of the season, the vines take this as a signal to get ready for winter, drop their leaves, and harden off the shoots. They become a lot less green and the shoots develop a brown periderm, which protects them from low temperatures and otherwise harsh conditions. Once the leaves have fallen off, we will call the shoots canes instead!
I got out into the vineyard today to flush the irrigation system to ensure that the lines would be free of debris that could potentially clog the emitters. Once this is done, the vines got a nice six hour drink, at 1.2 litres per hour. This should be enough to wet the soil under the emitters to a good depth, and get water to the roots. The vines will now have access to plenty of water that should allow them to photosynthesise and store nutrients needed for next season's growth. Many leaves have yellowed by this point, but there are still lots of green leaves that can do useful work.
This is the first irrigation of the season, so in some ways, it is pretty unusual to have this happening after harvest!!
As well, I mowed the vineyard, which keeps walking down the rows pleasant, especially if you're doing it early in the morning or after a bit of rain.
If we're lucky, there will be another month and a half of useful photosynthesis going on. As temperatures fall in the late part of the season, the vines take this as a signal to get ready for winter, drop their leaves, and harden off the shoots. They become a lot less green and the shoots develop a brown periderm, which protects them from low temperatures and otherwise harsh conditions. Once the leaves have fallen off, we will call the shoots canes instead!
Monday, March 15, 2010
Harvest already?
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!!
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!!
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!!
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