b=findobj(gca,'Type','Quiver');
Now b has the property of both Quiver. set there visibilty to off or whatever you want (use set for that purpose)
It still has the text x y z
c=findobj(gca,'Type','text');set(c,'String','');
But it will also remove any other text type you have in figure. so
findobj(gca,'String','x','-or','String','y','-or','String','z')
will give you object with string equal to x or y or z