[crushed grapes]

Greetings,
I have a small backyard vineyard, 24 French hybrid vines, six varieties, 4-6 years old. I recently found an odd growth on 40-50 leaves of one of my Frontenacs. I suspect a parasite of some sort. It curls the leaves and appears to be sucking the life out of them. I would not care if it stays localized and does not come back next year but I fear otherwise. I have been growing grapes in Denver for 28 years and making wine for 21 years and this problem is new to me. I could provide better photos if necessary. Does anyone recognize this? Thanks, Mark
 leaf 2.jpg (8.75K)
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[Cana Springs]

That is foliar phylloxera. If you have Danitol available it will kill them. They are a different form of the root phylloxera. They suck the juices out of the leaves and the leaf forms the galls around them. Frontenac is well known for this problem. There are other chemicals that would kill them also but I don't know what they are.

Dennis

[crushed grapes]

Cana Springs, on 28 July 2010 - 10:18 AM, said:

That is foliar phylloxera. If you have Danitol available it will kill them. They are a different form of the root phylloxera. They suck the juices out of the leaves and the leaf forms the galls around them. Frontenac is well known for this problem. There are other chemicals that would kill them also but I don't know what they are.

Dennis

[crushed grapes]

Thanks Dennis for the lightning fast reply! I can now research, find Danitol or something else appropriate, and hopefully save my vines. My initial google of foliar phylloxera bummed me out -- I had read about past nearly worldwide infestations and did not make the connection. My initial research bums me out as I have read that treatment should be at bloom time and then again 10-14 days later -- and that treatment this late in the year is a waste of time and money. Anyone have any luck treating this late? Does cutting off all the affected portions of the vines slow the spread of the bugs? I would love to hear from anyone else that has had success with something other than Danitol in case I can not readily find it. Thanks much, Mark

Mark

[PEL]

crushed grapes, on 28 July 2010 - 12:47 PM, said:

Thanks Dennis for the lightning fast reply! I can now research, find Danitol or something else appropriate, and hopefully save my vines. My initial google of foliar phylloxera bummed me out -- I had read about past nearly worldwide infestations and did not make the connection. My initial research bums me out as I have read that treatment should be at bloom time and then again 10-14 days later -- and that treatment this late in the year is a waste of time and money. Anyone have any luck treating this late? Does cutting off all the affected portions of the vines slow the spread of the bugs? I would love to hear from anyone else that has had success with something other than Danitol in case I can not readily find it. Thanks much, Mark

Mark

It is not uncommon here in the Mid Atlantic where I am located. I and other growers have ignored it and the vines have been fine. Don't panic.

[aspuhala]

Don't panic is great advice. Frontenac is a first generation offspring of pure vitis riparia which is nearly immune to the nasty root louse. Considering the rampant foliar growth capability of Frontenac, I wouldn't worry about it.

CHEERS!
Aaron

[knotsorich]

I also agree with the others. Foliar phylloxera looks ugly, but isn't that serious. Generally it forms a bit later in the season like this. If it gets too serious, the vine will push laterals to replace the leaf area it needs to ripen the crop. I have seen relative newcomers to grapegrowing cut almost all the tops off the vines to get rid of it (and you never will that way) only to have there grapes fail to ripen well. Leaf them alone (pun intended). If you really want to treat them, start next year at the right time.