Someone (mang-) cuts off the stems of vines or creepers with tubers (-en) in order to harvest the tubers or use the stems for planting.
Mangyāpas ka so imoha mo a wakay.
Cut off the stems (of the sweet potato plants to use) to plant (a new field) of sweet potatoes.
Yāpasen mo dokay mo tan maydamnay ka manwat.
Cut the stems of your yams so that it is easy for you to dig up (the tubers).