Climate change and eco-mindedness

TizWine recently sent out a link to an article about climate change in California and its effects on the wine industry (Napa Valley Register).

It's not really focused on climate change in terms of  global warming, but more the climate of perception and ideas about vineyard management.

There is beginning to be more emphasis on looking at more than just dollars in the bottom line. The article describes how some parts of vineyards that were prone to flooding were ripped out to improve flow through it for wet times of the year. Native plants are being planted near vineyards to encourage native fauna (much like the Greening Waipara programme here in Canterbury) and increase biodiversity.

Then, the use of solar panels to generate electricity, the excess of which can be fed back into the grid (There are reasonably good rebate programmes in the States that assist companies to put in alternative energy generations - would that New Zealand had a similar stance), is described - these are sitting on the surface of a pond, which can have multiple benefits in that it would also reduce evaporation from the pond's surface.

Napa is cooler than one might expect from its latitude, primarily because fogs roll in off the ocean during the night, and don't burn off until later in the day. The change in climate will affect this, and I think it would be rather sensitive, too. If the fogs burned off a couple of hours earlier each day, there could be significant effects on the number of heat units gained in those areas. Likewise, if the fogs hang around for longer, things could be a bit cooler. On reflection, that could be a good thing - maybe the alcohol levels in the wines won't get so high! :-)

So to combat this, they're changing the orientation of the vine rows (typically they run north-south, so there is sun on the east side in the morning and on the west side in the afternoon) to more northwest-southeast, so that in the hotter parts of the day the sun-side of the vines don't get the full brunt of the light and heat.

As well, more leaf cover also can reduce fruit temperature and minimise the amount of berry burn:

In this picture, the leaves were removed over a shaded cluster and shoot, and the resulting exposure to the sun has done considerable damage to parts of the berries but also the shoot and rachis!

So keeping some leaves on to get dappled light on the clusters can be a good thing if you are growing in a hot area. Trellising choice also has an influence, as those systems where the fruit is below the canopy (e.g. pergola (overhead) or T-trellis)are better off in those conditions.

 A Parronal vineyard in Chile. Also called a pergola or overhead trellis system. Here shoots have recently been thinned from the vines to create a more dappled light effect on the grapes and ground beneath.

A T-trellis system in Australia. Here the grapes hang beneath the canopy, too, but there doesn't need to be an elaborate overhead wire system to support the vines.

Trellis systems like there are more commonly used for table grapes, where the appearance of the fruit is especially important.

There is no doubt in my mind that we will need to alter management of our vines to suit changes in climate over the next 40 years - as with all things viticulture, planning for it beforehand is the best approach. So read through the climate projections for your area, and make a plan to deal with the possible changes - before they happen and its too late!!!

Messy looking vineyards

While travelling around vineyards in the Niagara Peninsula and also Upstate New York, one of the things that could strike a person used to New Zealand vineyards is that the vineyards are all pretty untidy.

The contrast is that in New Zealand, virtually all the vineyards are two or four-cane vines on vertical shoot positioned (VSP) trellises. the fruit is concentrated near the bottom of the canopy on the vine, and the shoots are all supposed to be trained up. Aside from this, the sides and tops of the canopy are trimmed mechanically to give the vines a nice, neat hedge-like appearance.


Where we are now, the majority of the vineyards are VSP, but there are still lots of shoots going everywhere, up, sideways, down, over etc.

I maintain that one of the reasons that VSP is such a popular trellising system is that it can result in a very neat looking vineyard, which appeals to people's eyes. After all, most of us would take the time to make sure the plants in our gardens look tidy, trimmed and well looked after. What will people think about the state of a vineyard if it isn't in the same kind of shape? (I will have to write later about the pros and cons of a tidy-looking vineyard versus an unkept one! :-)

So what reasons can I come up with for the difference in vineyard appearance between NZ and here?

Well, one reason is the amount of rain that's fallen here this season. By all accounts, it has been a wet year, with much more rain than usual. This means the vines have access to a lot of water, which encourages vegetative growth. So at this time of season, when the grapes are starting to colour up and get into the ripening phase, we would normally expect that the grass between the rows has browned off, and the vine shoots to have stopped growing due to the lack of water.

So because the vines are growing a lot more, it means that to maintain the neat and tidy appearance of all the rows requires more work, for the same end result (this being the quality of the grapes being harvested). If there aren't enough resources (and with the economic downturn, this is a hard reality for a lot of businesses!) to go through and do all the necessary shoot positioning, lateral removal, leaf pulling and trimming, the vines start to look a bit hairy.

So this is one possible reason for the vines not looking like they do in all the coffee-table wine books laying around!

So would NZ vineyards look like this if there was above-average rainfall? Yes, they would. However, this is less likely, as most of the vineyards in New Zealand do not get enough rainfall to support vines through the year, so they have irrigation systems put in, to deliver supplemental water. So even if we have above average rainfall, it may not mean that the vines have luxury amounts of water available to them, and therefore the vegetative response is not the same as it is around here.