We all know Konrad is unreliable.

“Jawohl” is the formal version of “yes”, more like “Yes Sir!” In standard German (what Hans speaks), it gets shortened to “Ja.” In other dialects, ,”Ja” can become “Je”, “Jo”, “Jou”, “Joa”, “Jop”, “Jau”, or “Ju”. “Jo” specifically like Reineke uses here can be found in Austrian dialects and Yiddish.