VASCM: Resistance management strategy

[Mary Lindsay, Muns Vineyard]

A little over a year ago we had a VASCM meeting with Larry Bettiga, UCCE 
Advisor for Santa Cruz and Monterey Counties, and he talked about just 
this subject.  He was/has been involved in a UCCE research project 
looking at spray resistance. I believe that the results that he 
presented can be found in this document, available on the UCD website as 
a pdf at http://www.ipm.ucdavis.edu/PDF/PMG/fungicideefficacytiming.pdf. 
In any case, this document addresses the resistance issue by looking at 
the different classes of fungicides and their level of resistance, and 
recommending rotation - which is what Larry's presentation was about. 
You have to wade through pages having to do with other fruit crops, but 
start with the overview pages and then you can jump to the specific crop 
pages having to do with grapevines:
- page 35: Fungicide efficacy for grapevines
- page 38:Suggested disease management programs by fungicide FRAC groups 
for grapevines

Larry and the UCCE viticulture program produces an online newsletter 
(monthly I believe, or about that frequent) and you can sign up for it
at:http://cemonterey.ucanr.edu/news_880/Central_Coast_Vineyard_News/. 
The newsletter also includes meeting announcements for University of 
California vineyard and winery related meetings, as well as the annual 
Central Coast Wine Grape Seminar in the Spring.

Regards,
Mary Lindsay
Muns Vineyard


On 5/27/2013 4:57 PM, Jim Varano wrote:
> Dear Members, I have been a bad boy and haven't sprayed as much as I should have in the Past 4 years as my small vineyard was getting established . Now it seems I have a very bad case of Powdery Mildew that is reeking havoc on some of my vines.
> I have started a spray schedule this year... I have done 2 sprays of Stylet Oil @ 1.5 %.
>
> I was under the impression that you can spray 3 times with one product then switch to another for 3 sprays then go back to your original ..... But my memory fails me....
>
> So......what do you folks do for a resistance management strategy ? What products and time intervals?
> I plan on spraying this Thursday weather permitting...so I have time to get what's needed.
>
> Now I know if you ask 10 people you might get 10 answers...but there might be a common thread. And I know I could hire an outside consultant...but I believe that this forum and it's members expertise can help...If I totally botch it,I can save my pennies to hire someone.
>
> Thanks in advance for your help
>
> Novice
> Jimmi Varano
> Spider Mountain Vineyards
> Boulder Creek
>
> Sent from my iPad
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