RELATIONSHIP BETWEEN NET PHOTOSYNTHESIS AND TUBER YIELD IN POTATO GROWN UNDER SHORT DAYS

Field studies with segregating populations under short days showed a s ignificant positive correlation between tuber yield and the light-satu rated net photosynthetic rate (P-N) in the 4(th) leaf from the top, at the tuber formation stage, in two seasons. The leaf area per plant (A ) at this stage and also at the tuber bulking stage had a significant positive correlation with tuber yield. The product of P-N and A also s howed a significant positive correlation with tuber yield at both of t hese stages, a stronger one than that between tuber yield and A at the tuber formation stage.