The first of many obstacles to the finish line …

It’s quite disturbing when you’ve been waiting all winter for green growth from the tiny compact grape buds, only to have them cleaned out by cutworms!

Neatly chewed grape bud by cutworm

The warm weather that moves the grape buds out of dormancy is also stimulating the emergence of a small larvae from the soil, known as the cutworm. If you’ve been spending time in the garden lately, then you will have come across one of these soft bodied larva. Forming a characteristic C when disturbed, they hide in the soil by day, emerging at night to wreak havoc.In BC there are 17 species of cutworm that can attack and eat emerging grape buds, but the most significant one is the moth  Abagrotis  orbis. Over the winter, these larvae hide under leaf debris in the soil, waiting for the right conditions (ah… warm) to emerge. In a few nights, the cutworm will climb the vines and feed on the developing buds. Because of their voracious appetite, a tremendous amount of chewing damage can happen overnight. Once the shoots start growing, they quickly grow to a size that cutworm feeding has minimal impact.

Cutworm damage to grape bud
Photo courtesy of H. Buchler.

Although this pest can be easily controlled with pesticides, it`s hard to apply a preventative spray. Cutworm populations vary considerably from year to year and often they don`t cause enough damage to warrant a spray. At this time of the year it is critical that the vineyard is monitored frequently for signs of feeding damage.

In our vineyards, because of our crop expectaions, we usually do not apply a control spray unless we see 5 % or more chewed buds in a block.Research has shown that damage tends to be lower in vineyards with mixed cover crops, especially if they are populated with Draba verna and  Shepherd’s purse, Capsella bursa-pastoris.

If you want to learn more, information can be found at the BC Ministry of Agriculture site: http://www.agf.gov.bc.ca/cropprot/grapeipm/cutworms.htm

Draba verna

Shephard`s Purse

Finding optimum ripeness: Part 1 Brix, TA and pH

Oct 18 pinot gris just prior to picking

Now that harvest is over, it’s a perfect time to reflect over the past season and learn from the picked fruit and now developing wines what worked and what needs improving.  It’s also a great time to think about how the fruit changed and matured post-veraison. It seems that the fruit ripens differently every season, and our challenge is to identify optimum ripeness.

As we get into the end of summer and the cooling fall weather, we all want to know how far off picking is. As the viticulturist, it’s interesting for me to track how the fruit is changing after veraison and how the ripening compares with previous years. It also helps to ease my anxiety as I follow the inevitable ripening of the fruit. As the winemaker, Ian is looking for optimum ripeness in the fruit for the styles of wines we are producing. Picking only happens when optimum ripeness is reached.

For Ian and the winemaking team, one of the easiest ways to determine relative ripeness is by collecting measurements of sugar as Brix, acidity as titratable acids, and pH.

Stefan collecting fruit measurements

Sugar levels are the easiest and most obvious measurement to landmark fruit ripeness. Sugar levels are measured using a refractometer to get a Brix value. Brix measurements are a measure of dissolved solids in grape juice and 1 Brix unit is equal to 1 g sucrose in 100 g solution. Brix measurements directly correlate to sugar levels, are easy to test for, and because it is so consistent across a block of wine grapes, it’s a good predictor of values at the winery in tank or at the press pan. The only problem with measuring Brix is that there is no correlation between sugar levels and grape berry flavour development, and subsequently wine flavour development.

Titratable acidity or TA is a measure of the acids in the ripening grape juice. Most of the acids being measured are malic and tartaric acid. When tasting fruit, this measure will reinforce what Ian is tasting for when he is looking for ‘balance’ between sugar and acidity. Normally, TA values will decline as sugars or Brix values increase, as the acids are converted to sugar in the ripening berry. If sugars get too high, acidity can drop to low levels, negatively affecting longevity and balance in the finished wine.

pH values provide another measure of acidity. This value also indicates the relative balance between acids and sugar. pH also indicates the ability of the wine to resist oxidation and subsequently, an ability to age. In larger operations, winemakers look for specific Brix to pH, or Brix to TA ratios when making decisions to pick, and these ratios also give a good indication of balance between acidity and sugars.

Brix, TA and pH measurements are easy to collect and can uniformly represent a vineyard block as long as correct sampling procedures are followed. These values allow Ian a snapshot of where the vineyard block is in the ripening window. However, these values alone do not correlate with optimum ripeness as defined by flavour, colour, texture or longevity of the finished wine. For Ian to pick the fruit at optimum ripeness requires additional information that can only be obtained by tasting the fruit.

To Pick or Not to Pick ….

Harvest is a time of year of conflicting emotions and motivations. At this time of year, Ian (winemaker) and I (viticulturist) are often at odds. I’m at my peak of anxiety, waiting for the fruit to reach full ripeness and hoping that nothing untoward happens to interrupt the final growth stage of the grape. I watch every weather forecasting service, dreading the forecast low temperatures. I prowl the vineyards looking for the first signs of late season disease, and bird and animal damage. I start tasting grapes as soon as the first colour comes on and I report every early nuance of flavour with acid-etched teeth and a sore tummy. I’m so eager to have the fruit ripen, come off and be taken into the hands of the winemaking team. Ian on the other hand, is the model of relaxed patience. As an experienced winemaker, he’s slow to warm to the grapes, more than happy to wait patiently while the fruit develops colour, flavour and texture. He’s had enough experience to know ripeness when he tastes it and regardless of the environmental pressures on the fruit or the ever-decreasing window of ripening weather, the fruit is not ready to pick until it’s ready to pick. Ultimately, it is the winemakers call on when the fruit is picked. You can only imagine the level of my anxiety with a harvest that started so much later than normal.

The process of ripening takes many paths and determining optimum ripeness must take many components into consideration. Not just the anxiety level of the viticulturist.

Decanter Wine Awards Dinner

from left to right: Ian Sutherland, Valeria Tait, Barry Sali, Barbara Holler, Steven Spurrier, Roxanne Sali, Tony Holler

London, London, London!
Centre of the wine universe.  And Decanter Magazine World Wine Awards are arguably the most prestigious wine awards on the planet.
As Poplar Groves’ owners, we were invited to the Gala dinner to receive the gold medal for our 2008 Syrah. The honor made sweeter by being the only Canadian winery to receive gold in any category. Black ties, glitter and cleavage, and rubbing shoulders with the great winemakers of the world made for a very pleasant evening at the Royal Opera house. We would love to get used to this.

One of the highlights was meeting up with Steven Spurrier, originator of the Chardonnay du Monde and giant in the wine world. The awards dinner was definitely the top highlight and certainly a point of pride for all of us at Poplar Grove Winery and a fabulous kickoff to a week filled with discovering the amazing food and wine culture that is London. Not to be missed was Chez Bruce Restaurant one of the fine dining establishments leading the rennasaince for London foodies. Of course we did all the touristy things: visiting buckingham palace, strolling Hyde park, wondering at Westminster Abby and boating down the Thames. But we were at our best eating and drinking our way through the trendy addresses of Covent Gardens.
We have only begun our discovery of London and vow to return for more hedonistic pursuits.

-Ian Sutherland

and then … it was spring

For me, I find that there is one day every year when spring finally defines itself. The air seems to throb and the coiled tension in each and every plant, is spontaneously and simultaneously released.

A particular combination of solar warmth and lengthening days seem to be the trigger to the spring start. But what is most surprising is the sheer volume of new life awaking to the starting gun. And it always seems to me to arrive at the same moment.

This defining moment of spring,  has on this one day released a new wave of life.

On a day like today, you can palpably feel the plants wanting to push; their growth surging after waiting all winter for another chance. Once spring really settles in, the plants will evolve into a rhythm of growth that flows continuously through dog days of summer and the cycle of awakening, fruiting and harvest will repeat itself.

But right now, today, it’s like standing on the edge of the spring moment. Before was dormancy ahead is the exuberance and chaos of life.

You merely have be among the plants to recognize that on this day, the 2011 growing season has begun.

The Continuing Perils of Cool Climate Viticulture

An example of girdling Crown Galls on Cab Franc

As if dealing with outright killed vines wasn’t enough, the extreme cold events that we experienced over the 2009 and 2010 winter have left a nasty, lingering hangover in the form of corky, woody growths called galls!

 

The galls are formed by an appropriately named disease known as Crown Gall. Recently renamed as Rhizobium radiobacter, this innocuous sounding bug is an opportunistic bacteria, that infects wounds on damaged grape vine tissue.

Rhizobium radiobacter infecting a carrot cell

Freezing temperatures cause wounds on the vines that allow the bacteria a site to initiate infection.

The bacteria then incorporates part of its own DNA into the DNA of the damaged vine cells and tricks the vine into growing tumours or galls.

The damage arises because the galls ‘disorganize’ the vascular system of the vine, disrupting water and nutrient flows.

In some cases the galls are small, and the grape vine is able to isolate the tumour, eventually sloughing it off. If the infection is large enough, or if the wounded tissue is large enough, a tumour forms that completely girdles the vine. Tumours that large cause the vine to collapse and in some cases die.

a new trunk taken from below a pruned gall

It is possible for a vine to recover from such a large infection, but the vine must produce a shoot from below the gall which will eventually develop into the new trunk. Once a new trunk has formed, it will be free of galls, until a new injury occurs. Then the bacteria will seize the opportunity to once again initiate an infection.

To date, there are no effective cures for crown gall, only preventative measures. Crown gall infection can be limited by maximizing grape vine cold hardiness through balanced growth and correct potassium levels, increasing the use of natural compost fertilizers, minimizing any mechanical damage, removal of all infected wood from the vineyard, and applications of copper sprays.

Reflecting on the pruning we did this winter, we renewed a lot of trunks in areas that were hardest hit by cold damage. I for one, am looking forward to the results of ongoing research into biological controls for crown gall.

 

Pruning … wild, racy and glamourous!

Yeah, I wish! There’s nothing less glamorous than pruning in late winter on a miserable day in a muddy vineyard. The work is often done in crappy weather, it’s long, monotonous and not high-paying. Little public attention is focused on pruning and rarely do Poplar Grove groupies offer to come and prune. Yet done well, pruning is the most important vineyard operation in the production of our wines.

The single largest cost in the vineyard growing season is the pruning of the vines and there are a number of reasons that pruning must be done. Cutting the vine yearly allows for balance between fruiting and wood growth. We build the vine structure through our pruning cuts, maximizing the fruit and minimizing the amount of wood we produce over the growing season. Pruning is the most important step for controlling our fruit yields, and we may remove up to 70% of the potential fruit crop just by removing fruitful buds.

In our vineyards most of our vines are pruned to the double-guyot system. This system is widely used in Bordeaux. Most of the Grand Cru wineries, including Chateau Cheval Blanc employ this pruning style. In our vineyards, we have a short head trained vine to about 26” (0.65 cm) and we leave two new canes to bear fruit.

Another system we occasionally use is cordon royat, where again we have a head trained vine and we leave two older arms with spurs which will produce the new shoots.

Why do we choose double guyot over cordon royat. Should it matter? In many cases, pruning style is determined by the preferences of the vineyard manager or the traditions of a region. However, some varieties can bear fruit more consistently when cane pruned, especially those varieties with poorly fruitful basal buds, that’s the first bud on the shoot, which is always one of the two or three buds left on a spur. Conversely some varieties do better when spur pruned, and can yield inconsistently on a cane. In our region, because of the risk from cold damage and because of the climates varying and sometimes negative effects on the fruitfulness of the basal buds, we tend towards cane pruning. Another benefit of renewing canes each year, is that wood pests and diseases are minimized because old wood that hosts these pests,  is always being removed.

Unlike cordon royat, double guyot cane pruning is really an art. The person pruning must be able to see the vine as a whole, selecting new wood for this season that has good circumference, position and health to improve or maintain the vine structure and to provide the best fruit for this season. As well, the choice of wood must make it possible to renew the cane for the following season, that won’t interfere with shoots growing this year, and maintain a low vine head height. This is challenging work, that skilled pruners enjoy, and done well, will give the best quality fruit while minimizing extra work in the growing season.

As for wild, racy and glamorous? You’ll find that over there … in the winery!