Choose large tubers weighing 75-100 g, pre-treated with a solution of boric acid (10 g per 9 liters of water).
Khetha izilimo eziyizigaxa ezinkulu ezinesisindo esingama-75-100 g, zilandelwa ngesisombululo se-boric acid (ama-gramu ayi-10 ngamalitha angu-9 wamanzi).