Seed size effects on above-ground stem number and yield of potato crop

The seed is an important production factor in the potato crop since the seed-tuber has a high price cost in Portugal, where almost the seed is imported. On the other hand, the mean national harvest is low. 15 Mg/ha (FAO, 2005), subjected to adverse environmental conditions, particularly the high temperatures during the cropping season (Rodrigues, 2000)