powdery mildew | amarchinthevines

The mild weather over winter was followed in the Languedoc by a slow start to summer heat. The resulting warm, humid weather brought disease as it did in many regions of France. Mildew, oidium and couloure are all vine diseases which occur regularly and 2016 was no different but with a bigger hit than usual.

Mildew (downy mildew)

Sadly, humid days in the mid 20s and cool nights are exactly the conditions favoured by downy mildew, and it prospered. The humidity in the soils created ever more favourable conditions for mildew. Downy mildew lives as spores in the soils and any rain splashes them onto the vines. Mildiou is not a fungus as commonly believed, it is a one celled spore which germinates in warm, humid conditions especially between 16 and 24 Centigrade – exactly the conditions we saw in April and May of this year.

Jeff Coutelou spent many nights out on his tractor spraying the vines to try to protect them. As an organic producer (and much more) he cannot (and does not want to) use manufactured, chemical sprays. Instead he used sprays based on rainwater with seaweed, nettles, horsetail and essential oils of sweet orange and rosemary. These are better absorbed by the vines in the cool of the night.

Mildew on top of leaf

Mildew on the under side

Mildew appears as small yellow / green spots on the upper surface of the leaf which gradually turn brown and spread to leave an unsightly vine. Underneath downy white /grey spots appear, the mildew is well established by this point. It affects the grape bunches and leaves them dried out and shrivelled.

Mildew on a Carignan bunch, organic spray residue on the leaves

By the time harvest arrives the bunches contain a mix of healthy and diseased grapes. Severe triage is required. Bunches such as the one in the photo above will be discarded immediately. Where there are health sections though the bunches will arrive at the triage table and be sorted rigorously. Jeff reckoned that in some vineyards, especially the white vines of Peilhan, losses were up to 60% from mildew. Seriously damaging.

Here is a clear demonstration of the advantage of hand harvest (vendange manuelle), machines would simply swallow the lot and in less thorough domaines or caves the bunches will all go into the wine.

Oidium (powdery mildew)

Oidium on buds and leaf

Oidium is a related problem to mildew but slightly different. It too thrives in warm days and cold nights (so springtime is its peak period) , it too loves humidity. So, spring 2016 was ideal though oidium was less rampant than mildew. Unlike mildew it is a fungal based spore.

Conventional treatments would be chemical and even organic producers will use sulphur, a naturally occurring element. Organic producers are limited to the amounts they can use as sulphur does damage the fauna of the soils. Jeff Coutelou uses less than a quarter of the permitted amounts because he sees it as a last resort. Instead he prefers treatments based on horsetail weed, nettles and other beneficial plants made into a tisane which can be sprayed. It may not be as all-destroying as synthetic chemicals but Jeff prefers the soils to be healthy in the long term by using these natural plant based treatments.

These photos show grape bunches hit by oidium in 2016, the powdery residue is clear though the bunches are less damaged than mildew affected ones. Nevertheless oidium is destructive and spoils wine so, again, careful work in the vineyard and cellar is needed to keep oidium out of the grape juice.

Coulure

Like most fruit plants vines grow flowers which then develop into the fruit. Vine flowers are very beautiful but also very delicate and don’t live long on the plants, a matter of a few days.

If heavy rain and wind hits the vines at this stage of their development then the flowers can be easily damaged or broken off the plant.

Peilhan 2016

La Garrigue 2016

The result is that fruit cannot develop where there is no flower, coulure. Where flowers are damaged then berries might grow very small and seedless, this is called millerandage. Similarly berries might ripen unevenly within a bunch, green berries alongside healthy, ripe grapes.

There is nothing that the vigneron can do of course, the damage is done by the weather and no producer can successfully combat weather. Nature wins in the end. So, once again, the vendangeur and those sorting in the cellar are crucial in ensuring that only healthy fruit goes into the wine.

I cannot emphasise enough the importance of all stages of wine growing and production. From their budding through to vendanges the vines must be tended, and in the cellar observation, determination and care are needed too. To make good wine requires hard work, healthy grapes and love as Jeff has said many times.

And have a look at one of those last photos again.

snail-and-uneven

In the top right corner you will see another of 2016’s natural problems, one subject of the final part of this series.

Colourful Cinsault

Version française

All photos taken on August 2nd unless otherwise stated

It was June 12th when rain last fell on Margon and the vines in the region, although generally doing well, were starting to show signs of fatigue and heat stress; leaves curled in upon themselves, some yellowing, a slight shrivelling.

Vines near Pézenas showing some stress

Vines in Margon which were not pruned in spring and are really suffe

A few drops fell on July 25th but the skies had been very dark and had promised much more, it was almost cruel to have that rain, a tease of what might have been. However, July 31st brought around 10mm to Puimisson. A decent rainfall, enough to give the vines a drink and to stop the drying out process. Not enough of course after weeks of lack of moisture and some more rain in the next few weeks would be very much welcome to swell the grapes and the harvest. The vines are now pouring their energy into their fruit rather than their vegetation, but they need the nutrients to do so.

So, how had the vines responded to the rain which fell? Well a tour on Sunday (August 2nd) showed the vineyards of Mas Coutelou to be in rude health, a decent harvest is now predicted though that extra rain would be most welcome.

Segrairals in full bloom, healthy, happy vines

Segrairals, biggest of the vineyards, showed some healthy Cinsault, Syrah and Grenache with no signs of stress or disease. As the home of Classe, 7,Rue De La Pompe and 5SO this is especially welcome, as they are some of the big sellers.

Cinsault in Segrairals

To Rome, my favourite vineyard. The gobelets were looking well, plenty of grapes both the white varieties and the Cinsault. There was a little mildew around the entrance but minimal, no cause for concern. Could there be a cuvée of Copains in 2015? Jeff tells me that no decisions are made as yet, caution prevails and he will wait to see what the harvest gives him before he makes final choices about how to use the grapes and the wines which result.

Rome’s centurion vines in good health

Muscat Noir grapes, a tiny bit of mildew top left

Sainte Suzanne (Metaierie) suffered from coulure in May with the strong winds blowing off some of the flowers on the vines, which will reduce yields a bit. However, the grapes there are growing well, what might have been a problem looks now a much brighter picture, good news for fans of Vin Des Amis.

Peilhan, just a little more tired and suffering

The only vineyard parcel which has shown stress is Peilhan, There was a lot of regrafting and replanting in the spring and the dryness has caused problems for these new vines. There was also oidium in this parcel, the only vineyard to be attacked by this powdery mildew. Yet amongst those problems there are plenty of healthy grapes, some careful picking and sorting will be needed but it will produce good wine.

The famous Castets grapes of Peilhan

La Garrigue was blooming, the white varieties such as the Muscats are swollen and changing hue to lovely golden shades.

Muscat a Petits Grains in La Garrigue

The Syrah is well advanced, a dark purple colour across virtually the whole bunches, the pips though betray a little immaturity as they taste and look green and sappy. A little more time and patience will pay dividends. As the world’s biggest fan of La Vigne Haute, I have my fingers crossed.

Syrah in La Garrigue, ripening beautifully in the shade of the vine

The Grenache in La Garrigue, despite facing south, is a little more delayed in colour but getting there and very healthy.

Grenache in La Garrigue

In fact despite risks of disease earlier in the year (see here) Jeff has been able to use minimal treatments in 2015. Oidium and mildew (powdery and downy mildew) can be controlled by copper sulphate, sometimes called the Bordeaux mix when added to slaked lime. This is a bluish colour when sprayed by conventional and organic vignerons and is often seen on the leaves of vines. Vignerons might also use chemical fungicides if they are not organic producers.

Neighbouring vineyard which was given herbicide shortly after harvest last year and whose new vines have been treated regularly

Some neighbours have also irrigated their vines and one alarming consequence is the changing of the soil and its pH as the calcium carbonate in the water shows through, you can see it in the white parts of the soil in this photo taken on July 22nd.

The irrigation is also causing the vines to grow quickly and tall with thin trunks as seen below. It should be acknowledged that there are many conventional producers who take great pride in the health of their soils and vines and would be horrified by some practices described here.

As a proud holder of Ecocert organic status and as a natural wine maker Jeff must use natural products only. Tisanes of plants which fight mildew such as horse tail, fern and nettles can be sprayed and this is the basis of many biodynamic treatments. However, the two main weapons in the armoury of organic producers are copper and sulphate, both natural products.

Copper is used against mildew, but is harmful to the soils and kills life in them if used in significant quantities. Organic producers are limited to 30kg per hectare over a 5 year period, allowing more to be used in years with more downy mildew for example but only if less is used in the other years. In fact Jeff has used just 200g per hectare in 2015 and this after years of well below average use, his use of copper is on a major downward trend. He is reluctant and very careful in using copper as he is aware of its danger to the soils, yet mildew has not been a major threat this year.

Oidium seen in May

Similarly Jeff has used sulphur in soluble form at doses much lower than the permitted level, three treatments over the course of the growing season. In addition one dose of sulphur powder was sprayed when the risk of oidium was high (May) and a second spraying for Peilhan only as it is the vineyard which was attacked by oidium. In contrast to neighbouring vignerons who have sprayed every 10 days including after the bunches closed up (so more than a dozen treatments) this really is minimal intervention.

So July’s parting gift of 10mm of rain was welcome, August might like to follow by offering some rain soon. Too near the harvest is bad as it would dilute the juice rather than help the grapes to reach a good size. Things look promising, let us hope that nature completes its bounty. There is an old saying that June makes the wine and August makes the must, ie the character of the wine with its colour, yeast and flavour. With 3 weeks or so until picking begins it is an exciting, and nervous, time, waiting to see what that character will be.