North American Fruit Explorers mailing list at ibiblio

["Alan Haigh" <alandhaigh@gmail.com>]

Dennis, I was aware of the systemic nature of S I and Strobe fungicides but I had never heard of your equation about wash off.  It's interesting and I wonder if you know what research it is based on.  Here Captan is partly recommended as a co-fungicide with the SIs because rain spreads it to leaves that grow out after spray. 

 

I have never seen any research about the efficacy of spreader stickers when used with compounds designed to apply without them.  If they made a significant difference in reliability and staying power in regions that tend to get spring rain I'd expect their use would be recommended by Cornell.  There is no mention of their use in Cornell's tree-fruit spray guideline book and reducing pesticide volume is a major part of their mission.  We usually get rain between applications, often hard rain.  They only recommend their use when the label calls for it.  I have asked local commercial growers about this who agree that spreader-stickers are usually unnecessary and not helpful but I'm still open to new information especially if it transscends the anecdotal.

 

My original question was actually primarily about how much drying time after an Imidan application is required before heavy rain because I assume that a certain amount of drying is needed to obtain significant rain-fastness. In that context I'm also curious about how much rain would remove a spray that hasn't dried.

 

I am thankful for all advice including anecdotal but if anyone has research based info that would be especially appreciated.  I will contact Gowan tomorrow who manufactures Imidan and share with all any pertinent info.