In texture menu is only World and Brush to choose I have a stupid question... Where is an object or particles to choose in texture menu? I need to add for the plane a voronoi texture for not to have the same length of grass. See attached image. Blender version 2.79. Works on Mac. Thanks for your reply.
Problem solved I guess... When I change render mode to Blender render and add new voronoi texture, change influence to length then change it back to cycles... the effect retained... suddenly the particles appeared in rolled up menu above. Thanks everything for helping me :-D