What's the weather doing this season?

The Growing Degree Days (GDD) figures for Lincoln through March 13th don't make for pretty reading!!

Currently we sit at 686 GDD (base 10, calculated on a daily basis) while the long term average (LTA, 1931 through 2010) to this point in the season is 812.

 Figure showing the growing degree days for Lincoln, Canterbury based on daily calculations at base 10C

December was the only decent month, having a heat accumulation close to that of LTA, but November, January and February were all cooler than LTA to the tune of about 85% of the value.

Rainfall is about aligned with LTA, the current season to March 13 being about 18mm greater than the LTA of 441mm.

Often, we get a nice March and early April after seasons where the early months' temperatures have been lower than average, but so far this doesn't look like it's happening, with the weather patterns seemingly stuck on cool and unsettled.

The Seasonal Forecast for New Zealand (http://www.niwa.co.nz/seasonal-climate-outlook-march-may-2012) indicates they are expecting more winds from the north-east, which for many of the growing regions in New Zealand, which are along the East coast of the country, means cooler temperatures.

When I look back at the pattern of heat accumulation for Lincoln Uni since the 1998-1999 season when I first arrived in Canterbury, this is the coolest season of them all, bar the 2000-2001 vintage. It's also been a remarkably consistently cool season, whereas in other years it tends to be warmer than LTA at first, then cooler nearer to harvest or vice versa.

So what does this mean for vintage? As long as the fruit stays free of disease (which we've been encouraging through an open canopy), we should be all right. Any opportunity to drop off crop that is tailing behind the average in terms of ripening is a good idea, as well as keeping the canopy open so the fruit dries out more quickly and also gets warming by the sun. We also have to hope that the night-time temperatures don't get too low, as this can be a signal for the vines to get ready for winter and start dropping their leaves! We've already had a couple of nights near 3C!

Our own vineyard, in which we're growing Pinot noir (and a bit of Pinot meunier) for sparkling wine is about 10km from the Lincoln Uni vineyard, but we're harvesting very shortly as the fruit is up to 19 Brix. In a season like this, this show the value of site selection (our vineyard is on the Port Hills and protected from the easterly (and cool) winds), good canopy management and end use of the grapes (sparkling wine, so they are harvested earlier). Of course, that isn't saying anything about how easy it is to sell the wine!

I suppose the good news out of all of this bad weather information is that the December temperatures were reasonably warm, which should mean we still have a decent initiation of flower clusters for the 2012-2013 vintage. 

At least we will have a promising potential to work with!!

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!!

Biodynamics - a viticulturist's view

We have a V&O student forum at Lincoln University, where posts about tastings, announcements, and other tidbits can be seen by all. One student just put up a, shall we say, "incite"-ful post about Biodynamics. That is to say, they were attempting to stir the pot...


I thought I would put in my two cents worth, from my view as a viticulturist, so I've repeated it here:

My experiences with Biodynamics goes back to when I first visited James Millton up in Gisborne more than 10 years ago. He makes fantastic wines, and in one of the more difficult places to grow grapes in NZ due to the increased disease pressure there.

Some of my research dealt with maximising vines' natural resistance to fungal diseases through phytoalexins, so he invited me up there to have a chat and see what they were doing.

As a viticulturist, I came away from it not really wondering what the effects of the Biodynamic preparations were, but rather being impressed with the amount of attention paid to the soil, the vines and the grapes.

Growing organically or Biodynamically means that the viticulturist has to be much more "in tune" with the grapes and the environment. In order to manage diseases, and since they don't have fungicides as effective as synthetic ones, they need to be much more aware of what the canopies are like, and manage them more actively. This means they are out looking at the vines more often and putting into effect management decisions in a timely fashion: staying ahead of the problems.

So my take on this topic is that it isn't necessarily the preparations or ethos of Biodynamics and the Steiner principles that are at work, but rather viticulturists that are much more aware of what is going on in their vineyards, and anticipating problems rather than reacting to them.

Anything that gets people into their vineyards more and looking critically and thoughtfully about their vines has got to be better for the health of the vineyard and the quality of the grapes, regardless if it comes about through a belief in anthroposophism, the principles of organic farming, or an obsessive-compulsive disorder relating to lianas...  :-)

How low is low enough?

First of all, let me say how lucky I feel for my family and home to have made it through the Christchurch earthquake with so little effect - my best wishes go to those that were not so fortunate!

However, despite the 7.1 magnitude earthquake, the vines continue developing! And about 10 hours after it hit, we were out in the vineyard, finishing up the pruning! This because we're on a pretty warm site for Canterbury, and the buds were showing signs of pushing, making it more difficult to prune. At this stage, the buds start getting more susceptible to being rubbed off, so pulling brush can be a very time-consuming affair if they get too far along!

So once that was finished, I could put on a lime-sulfur spray, which should help control any carryover powdery mildew that could have been left as dormant hyphae on canes left for the coming season.

Powdery mildew infections on dormant canes - the dark blotches are areas where the fungal hyphae have gotten into the shoot tissue during the season

Then came the job of getting ready for spring frosts! This takes the form of mowing the cover crop as closely as possible, so that as much solar energy as possible can be absorbed during the day, and the also released at night. A higher growing cover crop can insulate the soil from gathering the sun's energy during the day, and also keep it from radiating that heat at night, causing an increased frost risk.

So as the grass was relatively high, I had to do a first pass, and then another cut with the mower.

Closeup of the first (upper third) and second pass (lower two-thirds) of the mower. You can see that I've cut the grass shorter than it's been in a while as it's more yellow than the grass in the background.

A longer view of the row (sorry for the "Batman" angle!). First pass on the right, and second on the left.

So we're still a ways away from budbreak (meaning green tissue visible on the buds), and therefore the most sensitive time for the shoots to freezing temperature, but even now they are starting to be more susceptible to frosts. I will be keeping the grass as short as possible over the next few months!!

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.

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!