This variation has specific bow division markings which vary according to the colour or dynamic of the phrase. For instance bars 1-8 have a strong character and use whole bows. From bar 17 it is pp with just a small amount of bow in the middle of the bow. Bars 9 to 16 don’t have a dynamic marking, but Ševčík’s indication to play all but the dotted crochet in the upper half fits with the descending melodic contour and colour of the harmony.
The up-bow groups have a mixture of slurs and up-bow spiccato. Since these up bows generally phrase off as we move towards the heavier part of the bow, it may help to use an ‘active elbow’ upper arm. That is, raise the right elbow on the down bow to increase friction at the tip and lower the elbow on the up bow to reduce friction as you get closer to the heavier part of the bow.