This will depend on whether you are planting outside in the field or in a greenhouse. Normally work on about 70% usage within the greenhouse area (after taking walking space etc) into account. Plant out in metre wide rows and actual density will depend on tuber size. We would normally plant 50-60 2cmT1 tubers per metre. These will produce larger tubers in the second cycle so density will reduce to say 20-25 x 4-5cm diameter tubers.