Well, guess what? I found it myself! (Just talking to MYSELF here!)
DEFOLIATION and DESICCATION used in cotton and potato crops!
(Great! Lets add more chemicals to our foods!)
"A method that aids in harvesting crops by application to the crop of a certain compound prior to harvest causes crop defoliation or vine dessication.
This method aids in harvesting crops, particularly cotton or potatoes, by application of an alkyl 2-(5-ethyl-2-(4-(1-methyl-6-trifluoromethyl-2,4-(1H, 3H)-pyrimidinedion-3-yl)phenoxymethyl)phenoxy)propionate.
Potatoes on dessicated/dried vines are easier to harvest than those on living vines. In addition, potatoes on the killed vines are less likely to skin and bruise during harvesting. Where skinning occurs, the skinned areas of a potato are susceptible to discoloration and soft rot infection. Furthermore, skinned potatoes lose weight more rapidly and appear untidy. (So it's all for appearance....because we like our veggies to look perfect!)
Compounds that are commonly used for potato vine desiccation are 1,1'-ethylene-2,2'-bipyridyldiylium ion as the dibromide monohydrate salt, also known as diquat, (+/-)-2-amino4-(hydroxymethylphosphinyl)butanoic acid, also known as glufosinate, and 1,1'-dimethyl-2,2'-bipyridyldiylium ion as the dichloride salt, also known as paraquat.
Thus, there is a continuing demand for new substances that promote crop defoliation or vine desiccation at low use rates and in a safe manner. "
So there ya go!