What is this

[harleydmn]

My second year Marquette has these bumps on the leaves. Not sure what it is or what can I use to get rid of it? Any help would be great. Thanks

 

[grapeman]

This is a common question of beginning growers. It looks from the picture that it is the foliar form of phylloxera. Severity varies from year to year and generally is not a big concern. There are few effective sprays for it. If the leaves get too bad, generally the vine will send out laterals which make up for the lost photosynthesis.

 

[harleydmn]

If I would spray for it should I wait till next spring? I see Double A sells Movento for it but it is very expensive. I only have 40 plants. Grapeman what would you suggest doing? Thanks, just hoping I can make as good of a Marquette wine as you do. We really enjoyed it.

 

[rob]

You have to spray for it in the spring

 

[harleydmn]

You have to spray for it in the spring

Thanks, is Movento what I should use or is there a better product available?

 

[grapeman]

Movento is one of a couple products you can use, but I choose not to endorse chemicals specifically for liability issues. It is best to get exact recommendations for each state from their extension teams. Like others have said, spring is the time to apply it. Honestly in most cases the foliar phylloxera is more of a cosmetic fix than a physical one. It looks ugly but is not very serious for the vine. Marquette has wild American graps in it's genes and carries a resistance to phylloxera, so even though the vines can get it, it isn't serious.

 

[harleydmn]

Thanks, not only saving me from using harsh chemicals but also a lot of money. Will see how next year goes.

 

[salcoco]

some time Sevin will work if sprayed at proper time. the bumps are egg clusters
the insect overwinters in ground, the crawls up to inject eggs. if sprayed at right time kills the insect before injecting eggs.

 

[grapeman]

To understand the life cycle of phylloexera, here is a datasheet from Ohio. http://ohioline.osu.edu/hyg-fact/2000/2600.html

and the following gives some control measures, but these aren't for homeowners.
http://www.uaex.edu/Other_Areas/publications/PDF/FSA-7074.pdf

lastly here is some information from Tim Martinson about when treatment might be justified.
http://blogs.cornell.edu/nnygrapeupdate/2013/05/27/phylloxera-on-frontenac/