Can we "grow" wine?

This issue has come up a few times in my circles recently.

We have used in various documents the word "winegrowing" or the phrase "winegrowing industry" to describe the grape and wine industry. More than a few people have come back and said that no such word exists because cannot grow wine, and suggested alternatives such as grape growing, wine producing etc.

I did a bit of searching to see how commonly used it is - I already knew it was well-used in New Zealand, as the national grape grower and wine maker organisation is called New Zealand Winegrowers (http://www.nzwine.com/) and their national publication is called the New Zealand Winegrower magazine (http://www.ruralnewsgroup.co.nz/winegrower).

Most of the regional grape grower and wine maker organisations include "winegrowing" in their name New Zealand Winegrowers and is used in the popular press, e.g. in New Zealand, and article in Stuff.co.nz and it's associated publication the Marlborough Express, as well as the New Zealand Herald.

Overseas it's used in the popular press, too: The Wine News, Australian Broadcasting Corporation, The Independent....

As well, there are several organisations overseas that incorporate the word into their names:

The California Sustainable Winegrowing Program

The Valais Museum of Wine and Winegrowing

The wine company Krauthaker in Croatia

And in the Texas Wine Regions web site

(did you know that Texas ranks Fifth in wine production in the USA?)

Surprisingly to me, it is also not a new term, being used in the popular press back in the 1960s and 70s

An of course, there's even a Facebook page about it:

So a bit of research finds that yes, it is a common term and that it isn't a new one (at least, in the English Language - I haven't checked for translations of foreign words that might mean the same thing).

This all makes sense, as in essence, we do grow wine. Wine quality comes about to a very large extent from where and how the vines are grown, as this affects the composition of the grapes and the wine that is made from them.

Winegrowing as a term has come about, in my opinion, from the recognition of the importance of the grape, and how it is cultured, to wine production. The essence of wine comes from where the grapes were grown and the manner in which the vines were managed.

And this is what keeps most wine from being a commodity!

Shoot thinning - The importance of keeping your head clear

Note -this post is based on an article I wrote for the Wines of Canterbury newsletter this month...

Spring is all around us in Canterbury, and the grapevines have responded by shooting away madly. From trying to keep pace with the grass growth (trying to keep it as short as possible), now that the frost season is (hopefully) dying away, my attentions have turned to canopy management.

On the ideal, balanced, vine we get even bud break and shoot development and one shoot arising per node left at pruning. While we all strive for the ideal vine, it is something that rarely occurs, so we are left dealing with reality - in the case of my five year old Pinot noir vines, reality means that I occasionally get more than one shoot per node left, and there are a considerable number of extra (non-count) shoots coming from the head region.

Because I have only a backpack airblast sprayer for my own vineyard, the air turbulence it makes isn't all that good, and therefore neither is spray coverage. I need an open canopy to make the most of what the blower can deliver. So this means I can't tolerate all the extra, non-count shoots that have popped up on the vines.

The ideal shoot density for a VSP-type system is around 15 shoots per metre of row, or about 6-7cm between shoots. On cane pruned vines, the internode length of the cane laid down during pruning determined the spacing of the nodes and therefore the expected shoots in spring. So if you have used canes with a shorter internode than this, you will have a potential problem. For me, 18 shoots per metre of row (about 5.5cm between shoots) is okay, but every time you increase the number of shoots per length of row, you're increasing the risk of poor fruit exposure and lesser air movement - neither of which is desirable. And this is not even considering the possibility of extra shoots coming up from nodes or from the older wood around the head.

So I went through a did shoot thinning the last couple of weekends. The general rule is, retain only one shoot per node left at pruning, and if you're taking one off, remove the one with less crop. However, there are times when I left the second shoot on. This happened when there was a blind node next to the node with two shoots - in that case, I would often leave the two shoots, so as to make sure the canopy was continuous and to keep the average shoot number per metre near its target.

Other times, the internodes were shorter than ideal on the cane that I laid down, so then I might remove a shoot from a node position to make way for the neighbouring shoots (see Figure 1).

Figure 1. Compressed internode leading to two closely spaced shoots. I took off the ones (there is a secondary, non-count, shoot pointing toward the camera) on the centre-right to open things up a bit

 

 

 

In yet other cases, shoots would be growing out from the lower side of a cane and shooting sideways rather than up (see Figure 2). I will remove these, too, if they are going to grow to the side and therefore put a lot of leaf in the fruiting zone.

Figure 2. A sneaky sideways slithering shoot. Definitely up to no good!!

Around the head of the vine things get a bit trickier. A mantra of mine is that thoughts about pruning carry on through the rest of the season. If there is a non-count shoot that could be of use when it comes to pruning later in 2012, then I take pains to preserve it! For instance, I have a couple of vines where the canes laid down originate very close to the fruiting wire, but no growth is available below it to leave as a spur. Therefore, if I get any kind of growth below the wire, I hope to save that in the hope that it might become a decent spur to leave at pruning, or better yet, leave as a cane.

This means I take a bit of extra time to ensure I don't remove something potentially important, but then when it comes to pruning next year, it will make the job easier and therefore faster.

The before and after pictures of shoot thinning can be quite enlightening (Figure 3)! There should be quite a bit of space between shoots at this time of year, which is good for the development of flower clusters for the 2013 vintage (they will be initiated in the month of December, so good light exposure now should mean good light exposure until flowering) and good for airflow.

Figure 3. Before and after pictures of shoot thinning around the head region on a 12 year old Pinot noir vine. Note that no shoots have been left at the top of the head - this is because it's very close to the fruiting wire, so shoots arising from there wouldn't be able to be used effectively at pruning. As well, opening up the head area leaves space for the shoots coming up from below the wire.

The reason why I do this thinning now is that it's a lot easier to see all the shoots, and a lot easier to take them off (especially without damaging neighbouring shoots), but also because I want to ensure I get good spray coverage - some areas around the heads are very densely packed with shoots.

On my ultra-premium vineyard, labour is something that I try not to skimp on. After all, when an academic plants a vineyard, it's bound to be under a lot of scrutiny!!

Moderate wine consumption and health in the news, again!

The debate over whether or not moderate wine consumption is a beneficial or a detrimental thing continues. I suppose it will never end, but here is the latest campaign by some people who are against it.

An article published in The Age, from Melbourne in Australia, "Experts see red over wine 'myth'," details the new push by the Alcohol Policy Coalition to discourage the consumption of alcohol.

The Alcohol Policy Coalition is an Australian group made up of the Australian Drug Foundation, Cancer Council Victoria, Heart Foundation, Turning Point Alcohol and Drug Centre and VicHealth, who share "concern relating to the misuse of alcohol and its health/social impacts on the community."

The "report" they refer to in their press release is really a press release, also, or in their words, a "position statement," so not a report at all. In it, they summarise some information relating to alcohol consumption and its association with non-communicable diseases.


My main concern about this statement is that they use data that result from the misuse of alcohol to support their statements such as, "Every drinking occasion contributes to the life-time risk of harm from alcohol, therefore, any reduction in the dose - that is the amount and frequency of alcohol consumed - will reduce the annual and life-time risk of alcohol related harm."

This is an unsubstantiated remark and of no relation to the information they have presented.

In paragraph two of the statement they say this:

"In 2008, alcohol misuse was responsible for 2.3 million deaths (3.8 per cent) globally."

This is fair enough, however, the key word there is "misuse."

I would hope that the vast majority of people do not misuse alcohol, meaning they have chronic and excessive consumption. It is also worth noting that in the report they cite as the source of the information (World Health Organization Global status report on noncommunicable diseases 2010) that 80% of the deaths are in low to middle-income countries, and therefore only 20% in the high-income countries.

Per capita consumption of alcohol is listed in the WHO report and low-income countries have a value of about 4 litres per capita and high-income at just over 10 litres per capita. Since the consumption level is lower in the countries that have the highest percentage of deaths due to alcohol, I read this as meaning that binge drinking and other forms of alcohol abuse are the reason why so many people are dying there. With more affluent societies, alcohol (and wine in particular) is consumed more regularly, but also more responsibly.

So I'm not convinced by their argument that we should increase taxes on alcohol in places like New Zealand, Australia, or other higher-income countries. The real problem seems to be in other places, where perhaps more control over people's access to alcohol is warranted, or better yet, the institution of policies that educate about alcohol use.

The other thing that I am always cautious about with studies relating to alcohol consumption and disease incidence is whether or not it is a cause and effect, or if the disease incidence change is due to other factors that are associated with alcohol consumption. We've already mentioned that higher income countries have more alcohol consumption, so you can draw relationships between such things as the number of television sets per household in a country and the level of alcohol consumption. So does that mean that to curb alcohol consumption we should limit the number of televisions?


A bit of an absurd example, but it makes the point - sometimes you can get correlations between factors, but they are not direct cause and effect. You need to look at the information and see exactly what it is they're testing, and make sure that they do have evidence that backs up their claims.

I, personally, am an advocate of moderate wine consumption. However, this is not from the health point of view, but mostly because I find it a fascinating beverage, and that it accompanies food so well. I would never recommend to anyone to start drinking wine because it will make you healthier, but I would recommend people try it and see if they like it.

What I'm not keen on is a tax-grab on alcohol, and wine in particular, under the pretext that we are being saved from ourselves.

New Zealand should concentrate on red wine more than it does. Plus, the secret menace!

Master of Wine Steve Smith, who is also the Director of Wine and Viticulture at Craggy Range in Hawkes Bay, was recently in the news saying that New Zealand should stop for a moment and concentrate on making its reds even better, rather than going off on all these new "fashion" varieties making the rounds (Grüner Veltliner, anyone??).

There's a lot of merit to that sentiment -New Zealand can do great reds, starting with Pinot noirs, Merlots, Syrahs and even overlooked varieties such as Malbec. As well as his mention of Craggy Range and Felton Road, some other noteworthy producers of reds in Aotearoa are Fromm Estate, Forrest Estate, Mount Difficulty, Millton Vineyard, Kumeu River, Te Mata Estate and a host of others on Waiheke Island. And in one fell swoop, I have left out loads of other wineries that produce great tasting reds on a consistent basis...

It will take more work in the vineyard to get this right, starting from the beginnings of site selection and all the rest that goes after it. But done right, and in suitable places, it should be possible to consistently produce great quality reds right here in our little patch of land in the Pacific Ocean.

Let's go to it, guys!!

However, Steve Smith also lets loose a huge cannonball, which is probably the one that should be making headlines in the eyes of viticulturists in New Zealand:

"This year would be the last for the Les Beaux Cailloux [one of their best Chardonnays, ed.] due to the onset of leaf roll virus which is threatening to spread to neighbouring vines with red grapes."

 Grapevine Leafroll associated Viruses, in particular, the Type 3 variant, are insidious beasts, which are working their way through our vines - slowly, but surely becoming something that we will have to manage much more actively in the near future.

It's primary means of spread is via mealybugs or less often, scale insects. The habitat range of mealybug in particular is spreading, and so goes Leafroll Viruses with it.

So far, there is no way to cure infected vines, so control is limited to pulling out infected vines (and often the neighboring vines as well), planting with virus-free stock, and trying to prevent the mealybug vectors from coming in again.

The latter point will be crucial for eventual effective management of the disease - much more research into how the virus and its vector(s) can be controlled is needed, and here in New Zealand conditions - we can't rely on overseas work alone.

Here's hoping that some virologists and entomologists out there and eager to take up the challenge!!

Things that change fruit ripening

I've talked about fruit thinning before, and here's another missive.

Common in commercial practice is to do thinning at colour change, so that you can remove the fruit that is less-advanced in ripening - i.e. the stuff that hasn't gone through veraison as soon as the bulk of it.

When you do this, you're advancing the maturty of the harvested fruit. However, this is only so because you have removed that tail end of the fruit -all the stuff that's less ripe, so that the average brix is higher, and that carries on through to harvest.

But, what if you remove fruit randomly at that point in the season? I don't believe you will see much of an effect on Brix at harvest, if at all.

I think this is because regardless of how much fruit is on the vine (within reason!), the rate at which it will accumulate brix won't change much. The conduit for the sugars to pass through is the phloem, and under the conditions in the vine during ripening, sugars are already moving through and into the berry as fast as they can. Removing fruit might mean the vine has more carbohydrates available, but that doesn't mean that the pipes (phloem) leading to the berries can push more sugar into the berry. There is a limit!

In fact, there is evidence that the size of fruit is related to the diameter of the stem that leads to that fruit (i.e. a larger number of pipes leads to a larger fruit), such as this paper working with citrus. This doesn't necessarily mean cause and effect, but it is a logical conclusion.

It might also mean that if you think the fruit early enough (within a couple of weeks post-fruit set), you might be able to enhance the ripening of the fruit because the pedicels can grow larger due to the greater amount of carbohydrate available? I wish I knew the answer to that question!!

Water footprints - another eco-measure

Radio New Zealand had an article about water footprints a while ago, which stated that 109 litres of water is used to produce the average glass (125ml) of wine (see the article that prompted it all here). This is not the first time this has been in the news - I found this article in the Economist from back in Feb 2009 and a column from The Wine Economist from late 2008, which cites a special issue (December 2008) of the Wine Business Monthly on the topic...

Water use is a hot topic, both in terms of how much is used, but also what to do with the water afterwards. In fact, there is an internationally focussed meeting about this, specifically aimed at the wine industry, being held in Blenheim later this year (6th International Specialised Conference on Sustainable Viticulture: Winery Waste and Ecologic Impacts Management)

The Radio NZ article was brief, and I didn't hear the audio version of it, but I was intrigued, as figures like this are hard to interpret without knowing what goes into calculating it. So I wrote to Dr. Ranvir Singh, who is a Senior Lecturer in Environmental Hydrology and Soil Science at the Institute Of Natural Resources, Massey University to see if more information was available.

He very kindly replied and pointed me toward reports from the Water Footprint Network, who have published reports on global average values for water "use" for various crops and for animal farming. They were also the organisation behind the 2009 article, which quoted the values as coming from a report by Peter Gleick, who got his data (Table 19) from Waterfootprint.org.

So what is a water footprint? From the Water Footprint Network, it is "a spatially and temporally explicit indicator of direct and indirect water use of consumers and producers."

What does this mean? Similar in concept to the Ecological Footprint, and its sub-category the Carbon Footprint, the Water Footprint attempts to track all actual and "virtual" water use in the production and life of a item.

It's pretty easy to calculate the amount of water that is applied to grapevines, for example, and then set that against the tonnage of grapes harvested and the amount of wine subsequently made. And it's also reasonably straightforward to estimate the amount of water used in the winery through processing of the grapes into wine. There's even the opportunity to take into account the water used in the production of the labels, corks/caps, cardboard boxes etc. and add that to the total.

However, what is virtual water? Well gracious me, Wikipedia has an entry on that, too! The definition they quote there is “the volume of freshwater used to produce the product, measured at the place where the product was actually produced”

Getting back to our 109L per glass, that equates to about 870L of water per litre of wine. Let's look at what the vine contributes to that total.

Grapevines can typically use a couple of litres of water per day during the peak of the growing season, but use less in the Spring and Autumn as the temperatures decrease. So to allow some fudge-factor room, figure maybe 5 months of using 2L per day on average (either water in the soil or water applied through rain or irrigation). That's about 360L per season for the vine.

The amount of fruit a vine will produce varies a lot, but if we look at a typical Sauvignon blanc vine it might produce 4.5kg of fruit (this value varies a lot with vine spacing and other factors, but let's keep it simple...). In the winery this will probably equate to almost 3 litres of juice, which most likely will turn into about 2.9L of wine. So the vine itself is using about 124L of water to produce a litre of wine.

So that's about 14% of the total suggested by the report. The other 76% must come about from the winemaking process, packaging and other items used during the growing of the grapes and production of the wine.

 Flood irrigation has a low capital cost to install, but is not suited to all areas, and quite a bit of water can be lost to evaporation, rather than getting to the vine roots.

However, some studies suggest that daily vine water usage can be upwards of 60 litres per day (e.g. here)! Yes, this is not the average over a season, but in a dry area with vines having a high crop load, the daily average might be quite a bit higher. All of a sudden, the vine is contributing a lot more to the total virtual water use, maybe doubling, tripling the value, or even more.

In-line drippers deliver the water to vines much more efficiently than flood irrigation

So what should we make of all this? With any model system, such as what they are doing with the water use studies, there are a lot of assumptions that need to be made - if there weren't the models would be far too complex to actually use. We've demonstrated with relatively simple calculations that there can be wide variation in the final number depending on the numbers going in.

So taking a value you might hear somewhere doesn't really mean an awful lot until you start investigating what went into the calculation of that number, and understanding how it comes about.

That is, with thy wine, take a grain of salt.... :-)


Here are some links of potential interest on the topic of water use:

Sonoma Wine Company, Graton Facility - A winery that was successful in reducing their water use

New Recycling Technology Turns Winery into Water Saver
A winery re-using water that has come from the winery


Wine Business Monthly article on winery water use

Sustainable Farming Fund project looking at benchmarking water use in the vineyard

Water use efficiency of table and wine grapes in Western Cape

Frosts in California (and elsewhere!)

I have mentioned frosts before (August 14 and October 17, 2009), but some recent news brings this subject up again.

Early season frost is a big problem in New Zealand, but also in a lot of other growing regions around the world, such as in Ontario, which I've talked about before. The latest news from California, in an article from Western Farm Press, details the aftermath of a couple of frost events on April 8-10 in areas south of San Francisco. Damage estimates suggested that about one-quarter of the 10,500 hectares of grapes in the Paso Robles area will have a crop that won't be commercially worth harvesting.

Any grower worth his weight in quality secateurs should know what the frost risk is when looking to develop a vineyard, and if the risk is perceived as being great enough, some sort of management system will be planned for the development

Results of a severe spring frost - all green tissues of the vine are completely decimated

If the frosts are mild, then passive means, such as having bare soil between the rows in the spring, which will maximise heat accumulation during the day and release at night, can give from 0.5 to 1.0°C protection (of course, careful decision making in site selection is the best means of passive management!).

Active means of management include such things as taking advantage of an inversion layer (where a layer of warm air sits above the cold air at vine level, and which tend to form on still nights with clear skies) and sending up a helicopter to push the warm air down to mix with the cold.

However, if the frosts are very frequent, then installing a permanent system becomes cost effective, such as the wind machines I've already written about, or using water sprinkled over the vines.

A frost fan installed in Central Otago. Plenty of snow-capped mountains around the area!

There are some big differences between the wind and water methods. The movement of air method relies on mixing the warmer air in an inversion layer with the cold air on the ground. This works great unless 1) the inversion layer doesn't have enough warm air to raise the temperature of the cold air to above freezing or 2) there is no inversion layer.

The former is heartbreaking, as you might be successfully fighting off the freezing temperatures, then just before dawn and the temperature rise that comes with it, the inversion layer is all used up and the grape buds freeze.

The latter has the same outcome, but then you don't have to spend all night running around trying to combat the frost!!

In some cases, the conditions are not right for an inversion layer to form, or the cold might be coming in as a mass of freezing air, for example, from nearby hills or mountains that have recently been covered by snow (this appears to be what happened in California recently). In this case, since there is no warm air around, fans and helicopters won't help. However, the application of water to the plants will work for all types of frost events.

The idea behind the application of water is that as water goes from liquid to solid form (freezes) it releases heat (heat of fusion).

So as long as water is freezing on the plants, heat is being released, effectively keeping the temperature at 0°C. Plant tissues can survive this temperature and even a bit lower without damage, so as long as enough water is supplied to always have some in the process of crystallising, the ice, and grape buds or shoots inside, will be kept from temperatures that might damage them.

Two types of post-mounted micro-sprinklers - these use quite a bit less water than the traditional impact-type overhead sprinklers

The down side is that if enough water is not applied, the temperature can continue to decrease, so if the application system breaks, or the water runs out, before the air temperature rises sufficiently, you can lose the new growth.

In the foreground row visible in this picture there is a number of vines where less growth is visible. This is because the sprinkler at the top of the post (centre left in the photo) failed during a frost event, meaning that the vines were not continuously covered with water - thus once the freezing stopped, the temperature of the ice and tissues within dropped to damaging levels. Note that there is a frost fan in the background - the fan isn't able to cover the area that these vines are in, so the sprinklers were put in to provide protection there.

My preference, if I were to plant in an area that was prone to frost events, would be to use water sprinklers. However, in some cases there wouldn't be enough water available for this. Large dams can be build to provide a source of water, but sprinkling even a hectare of ground with water for a decent frost can require up to 40 cubic metres of water per hour depending on the system used!

The concerning thing is that with global changes to climate, we should be prepared for more extreme weather events - in this context, we need to be ready for more severe frosts later in the season. Seeing as how some grape growing regions in New Zealand can have a potentially damaging frost in almost every month of the year (historically, anyway), this isn't good news!!!

Hands up those who thought being a viticulturist was a cushy job!!