Dr. John Wise at Michigan State University Trevor Nichols Research Station is doing research on this very topic. Factors that influence decisions include Precipiation characteristics (amount, duration, size and velocity of droplets), as well as "Chemodynamics of insecticide and plant" - binding potential of compounds to plant cuticle, penetrative and translocative properties, depth of penetration, drying time, etc.
There may be differences between apple trees vs. peach trees, and also between leaves vs. fruit. There's a page in the 2010 Michigan Fruit Management Guide (Extension bulletin E-154) that discusses some of his results. -----Original Message----- From: apple-crop@virtualorchard.net [mailto:apple-c...@virtualorchard.net] On Behalf Of Mark Angermayer Sent: Tuesday, June 15, 2010 3:34 PM To: Apple-Crop Subject: Apple-Crop: Rainfastness of sprays Apple-Crop: Scaffolds 6/14Today, the forecast was supposed to be clear of rain. I needed to get a spray on peaches. I applied Delegate at the full rate. About 15 minutes afterward, it rained about 1/4". My question - I know a locally systemic material like spinosad is supposed to be very resistant to wash off, but how long does it take for enough of it to be absorbed in the tissues to become rainfast? Was this a wasted spray? Thanks, Mark Angermayer Tubby Fruits Bucyrus KS -------------------------------------------------------------------------- The 'Apple-Crop' LISTSERV is sponsored by the Virtual Orchard <http://www.virtualorchard.net> and managed by Win Cowgill and Jon Clements <webmas...@virtualorchard.net>. Apple-Crop is not moderated. Therefore, the statements do not represent "official" opinions and the Virtual Orchard takes no responsibility for the content. -------------------------------------------------------------------------- The 'Apple-Crop' LISTSERV is sponsored by the Virtual Orchard <http://www.virtualorchard.net> and managed by Win Cowgill and Jon Clements <webmas...@virtualorchard.net>. Apple-Crop is not moderated. Therefore, the statements do not represent "official" opinions and the Virtual Orchard takes no responsibility for the content.
