Given how juicy and sweet wolfberries are, it would probably be impossible to have a pesticide-free farm. There is little hard information on this topic, though. One development I learned recently is that Chinese wolfberry farmers  if so motivated  can contract with US-approved organic certifiers who must visit the farm in China to perform their qualification tests. This is expensive and has been discouraging. 

 I have a bottle of the Young Living wolfberry juice called NingxiaRed (www.ningxiared.com). It has a label stating "Certified Organic". 

 On another hand, however, China issues its Green Certificate to some wolfberry farmers in Ningxia, a certification that is likely "as best as possible" assuring pesticide practices have been reasonable and minimal as possible. My guess is that is the best one can do given the sweetness of this fruit on the vine (attracts pollinators and pests of all kinds). 

 Serious wolfberry product marketers in the US can have their products tested for pesticide levels. I have seen the lab results from one in Seattle that shows negligible levels in their dried berries and pulp or juice powders. I have not seen these results on the various wolfberry juice products on the US market.