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IPM Message for Cranberry Growers: May 13, 2010

May 13, 2010

All insects are out.  Be diligent with your scouting.  Even if you did not see anything last time you were out, go sweep at least once per week.  If you have BHF, you should treat ASAP (see below).  Interestingly, we sprayed Avaunt on Friday and Marty fed larvae on treated uprights that were collected on Monday and the larvae are now dead or dying.  Marty collected BHF larvae off the bog earlier this week and they have pupated already.  The second generation may likely coincide with bloom.  With the warm weather we had in April, the plants AND insects are accelerated and you need to be prepared accordingly.  You may want to get your trap equipment together over the next week or so and be ready to put the pheromone traps a bit earlier than June 1 this year.

For those of you who can use QuinStar, you can use up to 12.5 fl oz/A of the 4L in a single application, not to exceed 16 fl oz/A total with two applications; recommended rate is 8 oz/A.  With the DF, you can use up to 8 oz/A in a single application, not to exceed 10 oz/A total with two applications; recommended rate is 5.3 oz/A.  Include a NIS (non-ionic surfactant) at 0.25% v:v if broadcasting and 2-4 pt/A if chemigating.  A COC can be used at 2 pt/A when chemigating.  Allow at least 30 days between applications; QuinStar has a 60-day PHI.

We have had a couple of questions about mixing pesticides.  Always do a jar test before tank mixing a whole load.  Be careful with DF formulations as they may tend to clump more than liquid formulations.  With Avaunt, the manufacturer has recommended not to add oils, surfactants or ECs prior to DF since they will prevent adequate wetting and dispersion of the dry products.  We have heard of no issues mixing Delegate or Intrepid with Callisto; we have no reports of mixing Avaunt with Callisto.  The other issue has been when to apply amidst all the frost nights and rain.  There is no easy answer here.  Sometimes you have to juggle letting the vines dry out but yet allowing enough dry time for the chemical prior to the next wet event.  This may mean that you might have to spray late morning-early afternoon.

With all the frost events and puddling on the bogs, Frank mentioned that you should be on the lookout for potential Phytophthora problems.  If you think you might have Phytophthora, contact Frank ( or ext 18 to get specifics on collecting a sample.

We wanted to highlight pesticides that are restricted for OS growers, that is, no use allowed.  These are simazine (Princep), maneb products (mancozebs are ok), aziniphos-methyl (Guthion and others), quinclorac (QuinStar), fluoxastrobin (Evito), novaluron (Rimon), spiromesifen (Oberon), and carbaryl (Sevin and others).  Do not use these products or your fruit could be rejected!  Growers selling to other handlers should confirm if they have any restricted compounds.