North American Fruit Explorers mailing list at ibiblio

[<dmnorton@royaloakfarmorchard.com>]

Alan,

 

I forgot to mention that Strobilurin (Sovran, Flint) and sterol inhibitor (Nova, Procure, Rubigan) fungicides are absorbed into the leaf and fruit tissue after application (once the residue has dried) and are not affected by rain wash-off. The protectant (Dithane, Manzate, Penncozeb, Captan, Ziram, Thiram, Polyram) fungicide residues can be affected by rain.  I usually mix Nova with Dithane or Captan and Flint with Captan or Dithane so I have rain pretty much covered.

 

Dennis Norton
Royal Oak Farm Orchard, Zone 5
http://www.royaloakfarmorchard.com
http://www.theorchardkeeper.blogspot.com
http://www.revivalhymn.com

----- Original Message -----

From: Alan Haigh

To: nafex@lists.ibiblio.org

Sent: Sunday, May 25, 2008 6:28 AM

Subject: [NAFEX] required time to set Imidan before rain

This question is addressed to the experienced applicators out there.  Unusually cool spring weather has altered and extended bloom period considerably here in Z.6, SE NY.  It creates quite a dilemma on the decision of when to put down first insecticide application when the first apples to set on a given tree are being ravaged by curculio while there are still unopened blossoms on the same tree.

 

In the past I've been able to wait until the latest flowering apple varieties drop their petals to make first Imidan application to all species in mixed fruit orchards and have avoided serious curc damage even on the earliest plums.  To further complicate matters, frequent showers are limiting the opportunity to set spray.  I need at least an hour of good drying conditions following spray to have any confidence of adhesion. 

I'm not even sure this is enough time and I'm interested in the experience of some of you veterans on this issue.  How much setting time before rain seems to be required for Imidan?  How heavy a rain will erase the application before it sets?  I already know that mist and drizzle are fine but a specific number like 1/8th an inch would be useful. Thanks