I was taught in high school that ukraine was the breadbasket of the ussr and during the famine all of ussr starved except for the far east and moscow/leningrad. I was also taught that the holodomor was caused by the communist attempt at nationalising the farming industry and taking away land and tool from the peasants had and declaring the peasantry as enemy of the state no matter the nationality. Also was there any reason for stalin to purge ukraine from the ukranians to leave it for the russians since he himself was part of a minority in the ussr?
While waiting for further answers, you may want to take a look at /u/Kochevnik81 's excellent answer on why isn't the Holodomor considered genocide - and in it, they go into some of the other regions affected by the famine. They also have another post more specifically about that famine in Kazakhstan.