Organic Grape Growing
Davenport Vineyards produce modern organic products, and see the organic production methods as a science - a blend of nature and modern intelligent thinking.
Many people think that organic farming is simply conventional farming, but avoiding the use of chemical pesticides. While this is an essential part of an organic system, it is only a part of the full picture. Davenport Vineyards organically grown grapes are different because:
- They have not been subjected to synthetic chemical fungicide sprays.
- They have not been subjected to insecticides (any insecticides at all).
- The vineyard soil is not treated with weed killers.
- The soil fertility is not maintained by the addition of chemical fertiliser compounds.
All of the above are harmful to the environment, cause pollution and kill the vital life in the soil, plus there is the risk that some chemical residues will end up in the wine. Most conventional vineyards would not be able to make any of the above claims, but without these chemical aids, what do we have to do to maintain fertile soils and healthy vines?
Building soil fertility
We can only use naturally occurring materials to
help us, so we build soil fertility with green manures, compost, composted grape
skins, straw, comfrey, hop waste and cow manure. Poultry manure (a very rich
fertiliser) can be used to correct particular deficiencies. All material used
for our composting must be GM free and approved by the Soil Association
The other main soil management feature is the
use of winter cover crops. These are plants sown between the rows to grow during
the winter. The choice of plant species can be made for nitrogen fixing plants,
deep rooting plants to break up soil compaction, insect attractant flowers (to
attract predatory insects) or a mixture of these. The plant roots bind up the
soil, preventing soil erosion during winter.
Mildew control
To prevent mildew developing in the crop, we can spray with sulphur and copper, two minerals which have good ability to protect the vines against powdery and downy mildew. We also are putting more faith in the use of compost tea as a combined foliar feed and mildew suppressant. Canopy management is a vital tool used to increase air flow through the vineyard and prevent humidity build-up.
Canopy management, pruning and training
We are constantly adjusting the way we prune and train the vines, in an attempt to get the right balance between the soil fertility and the growth habit of the vine. Ideally the vine should grow enough to ripen the crop while also maintaining the vine's health, and no more. Excess leaf shades the sun out from the crop and creates a humid atmosphere around the bunches - ideal growing conditions for botrytis and mildew. Not many vines grow to the ideal text book pattern, so we need to work through the vines regularly, thinning some leaves to assist good air flow.
Pest control
The only pests that we need to guard against are
birds and wasps. Any other pests are normally eradicated by the natural life existing
in the vineyard (ladybirds, spiders etc.) For the control of birds we go to the enormous
trouble of netting the whole area. We tried various forms of bird scarers, but
they never deterred the birds for long enough. We tend to harvest late (sometimes
into November), and this can only be done if we have complete confidence in our ability
to keep the crop safe from birds. Wasps cause relatively little damage. They attack
the earlier ripening varieties, and then after a few cold nights in October, their
numbers rapidly decline. We place traps around some parts of the vineyard which
contain a mixture of jam and sugar solution (don't use honey - you will catch
all the bees). The wasps fill up the traps rather than eating grapes. Very easy
and almost completely effective every year.
Winemaking
The organic standards go on in the winery. Click here to discover the difference that organic standards make in the winery.
Articles
Will Davenport has written a series of articles for the UKVA magazine about organic viticulture and winemaking.