I have almost exactly the same problem at the moment and my raspberries do look like they are suffering a bit because of it. Perhaps my neighbour should live next to yours and save us both some grief.
Dave Hunt wrote:It might depend on when the neighbor sprayed the roundup. Personally I would wait a while until I ate any berries from a round up sprayed plant. Maybe a few months or even a season.
Cornell university reckons 1 to 174 days for half of it to break down. So that is potentially around a year, I think I will offer to do the weeding on his side to get round the problem.
"Glyphosate is highly adsorbed on most soils especially those with high organic content. The compound is so strongly attracted to the soil that little is expected to leach from the applied area. Microbes are primarily responsible for the breakdown of the product. The time it takes for half of the product to break down ranges from 1 to 174 days. Because glyphosate is so tightly bound to the soil, little is transferred by rain or irrigation water. One estimate showed less than two percent of the applied chemical lost to runoff (4). The herbicide could move when attached to soil particles in erosion run-off. Photodecomposition plays only a minor role in environmental breakdown. "
http://pmep.cce.cornell.edu/profiles/extoxnet/dienochlor-glyphosate/glyphosate-ext.html
That being said its an old study and it suggests it's not carcinogenic.