Posted 3/30/2010 08:34 (#1143271 - in reply to #1143255) Subject: RE: Crop oil or Surfactant.
This really depends on which glyphosate you use. A fully loaded product like weathermax or powermax shouldn't need additional surfactant, whereas some of the cheapest products do need additional surfactant. I don't mean to overgeneralize, but for the most part the more expensive glyphosate products will have more surfactant than the cheapest and as such typically will work better. If you are having a tougher time killing weeds that you were able to kill easily just a few years ago, I'd either add surfactant or add more roundup to the mix.
As far as the crop oil vs. methylated seed oil vs. surfactant debate, very specific to the product you are using. For the most part it is a balance of weed control and crop injury; crop oil really heats things up, MSO slightly less, and surfactant the least, at the recommended rates of each. Surfactant will have a much lower use rate than crop oil or MSO.