• Wiesner, C.J.
  New Brunswick Research and Productivity Council
  
• Addison, J.B.
  New Brunswick Research and productivity Council
  
• Silk, P.J.
  New Brunswick Research and productivity Council
  

Chemical changes within an actual; drifting spray cloud were investigated by air and deposit sampling downwind of a 600 m spray line. No detectable photo conversion took place with either Fenitrothin or Matacil during the maximum residence times of 4 and 4.5 minutes respectively. Fenitrothin and Matacil (Aminocarb) were also photolyze win a laboratory vapor phase photo reactor using simulated sunlight. The half-lives for photo conversion were 61 minutes and 38 minutes respectively in the absence of ozone. Addition of ozone too the system significantly accelerated the conversion.

It is concluded that under current application conditions atmospheric photo conversion of the active ingredients in both Fenitrothion and Matacil sprays is an insignificant process during near field drift.