GRAPEVINE QUESTION

Hi Jenn. The bit in inverted commas is lifted from the BBC (quite legal - it is in the public domain).

'Grapes encounter various pests and diseases, such as:

* Aphids - small insects that feed off plants.
* Glassy-Winged Sharpshooter - a pest that spreads diseases such as Pierce's Disease causing the plant to die.
* Curculio - beetles otherwise known as weevils.
* Flea Beetle - a small beetle that can jump long distances and creates a larva that poses problems to plants.
* Leafhopper - an insect that injects plants with toxins as it feeds off it.
* Grape Phylloxera - insects related to aphids such as vitifoliae4.
* Rootworm - the larvae of certain leafbeetles
* Webworm - a moth caterpillar that weaves a web around its desired plant.
* Erysiphe necator or Uncinula necator - creates a powdery white mildew on grapes.

These horticultural horrors however, have not been the only pests to be found on grapes over time. The poisonous black widow spider has also been found lurking on red grapes.'

Don't let this put you off, if we only looked at plant diseases and pests no one would grow anything.

I have never heard of slugs attacking grapes, I've got a couple of vines myself and more than a couple of slugs, but if they can't find anything in the vicinity that they prefer then I believe these horrors would eat just about anything. I do however suspect something else could be responsible, especially as I have to remember that you are just coming up to summer whilst we are just coming into winter.

The problem with replacing your vine is that whatever is attacking the old one would no doubt turn its attention to the new one, so nothing gained. If it has picked up a systemic disease then you may have to 'biff' it out anyway then not replant in the same area in case it has gone into the soil.

May I suggest you start by spraying the vine with Bordeaux Mixture which is just a mixture of lime and copper sulphate suspended in water in the ratio 4:4:50. It is however readily available at garden centres, certainly in the UK, and I assume that as New Zealand is a wine producing country that it will be easily available there, so you won't have to turn chemist. Spray it every couple of weeks and see if there is any sign of new growth in about 6 or 8 weeks. You could also treat it for vine weevil which, although it attacks the roots does cause the leaves to die off. If however you are certain that the leaves are being eaten and not just dying then it can't be that.

If you could post a couple of close-up pics of an 'eaten' leaf and the vine itself it may help with diagnosis.

Sorry I can't be more specific at the moment but whilst my efforts may not work, they certainly won't do any harm until we find out what it is.

John.

Thank you so much for you're detailed information John, it's is much appreciated. I've just gone to check on the grapevine and all that is left is a shrivelled brown stem? It looks like it's completely died. So obviously it wasn't snails and slugs, this is the first time I've attempted grow a grapevine. When I purchase another one I'll plant it in a different spot entirely to see if it makes a difference. I do believe this vine has 'kicked the bucket'. I'll keep an eye out for the Bordeaux Mixture just in case it happens to my new vine. Mucho gratis ! Jen. :-)