Saturday, May 19, 2007

Why are there rose bushes in vineyards?

We just came back from a vacation in Margaret River and as usual, there are so many locations to visit with great food & wine awaiting us.

A friend of mine commented on the beautiful rose bushes that appeared at the end of vineyard rows while looking through my photographs. They are planted not just for aesthetic reason though. Both roses and grape vines are susceptible to the same diseases. Indeed, roses act as early warning of mildew which is a fungal disease. There are two main kinds of mildews: Powdery mildew (Oidium) which develops on all green parts of the vine. We can see white powdery growth of spores on the surfaces. If this mildew sets on the grapes, the fruit will not grow properly and will eventually split and rot. This fungus likes warm and shady environment and does not need a damp condition to survive.

The second deadly mildew is called Downy mildew which was brought over from American to Europe in the 19th century. It attacks all the green parts of the vine and leave behind patches of oily stains on the surface. Once attacked, the leaves will drop and photosynthesis inhibited. This fungus likes damp condition unlike that of Oidium.

Both fungus diseases can be treated by sprays of sulphur (for powdery mildew) and copper sulphate + lime solution (for downy mildew) once detected. Rose bushes help the vineyard team to catch sights of the fungus disease in its early stage to apply the proper treatment. Systemic application of fungicides is quite commonly used these days to keep the vines from such diseases. Rose bushes in such cases serve a greater aesthetic function.

Also on the photo, the nesting over the vines is used to protect the plants from birds and other animal attacks. Birds like to eat ripe grapes and they have learned to ignore bird-scarers. Animals like deer, boar also like ripe grapes. Young vines are very attractive food for them too. Therefore, the nesting is used often as a form of protection.

Copyright of Wine Treasures Pte Ltd

By Cher Lim
Wine Treasures Pte Ltd



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