I heard of this initially with potatoes and wheat. I asked my farmer uncle about the wheat and he said they do it in the wetter parts of the midwest but he thought any wheat from the Dakotas or Montana wouldn't need it.
Since then I've heard that this practice is also used on dry beans, sugarcane and any other crop where you want the plant to be deadish for harvest.
I've always wonder how pervasive this practice actually is. This article doesn't really give me confidence, due primarily to the chart of data and this associated tidbit:
Glyphosate use by farmers averages 70% or more for some crops. These include almonds, walnuts, figs, plums, prunes, grapes, kiwi, lemons, grapefruit, pistachios, and pomegranates.
I'm not a glyphosate expert but I believe if you apply it to any of those aforementioned perennial crops they will kill the tree. No farmer would do that except for insurance fraud reasons. Am I missing something?