The dry matter production and partitioning efficiency of dry matter to different plant parts were studied in sweet potato under different levels of irrigation based on irrigation water/pan evaporation ratio (IW/CPE). At lower levels of irrigation (IW/CPE ratio, 0.6, 0.4 and 0.2) the dry matter production reduced significantly compared to higher levels of irrigation (IW/CPE ratio, 0.8 and 1.0). In treatment with lower levels of irrigation, i.e. 0.6, 0.4 and 0.2, total dry matter production was comparatively less, but the allocation of drymatter towards shoot was relatively higher as compared to the treatments with higher irrigation level (IW/CPE ratio 1.0 and 0.8). A singificant linear association was observed between total dry matter and only tuber dry matter in treatment 1.0 (r= 0.9927**) and 0.8 (r = 0.9941**) whereas at lower level of irrigation 0.6, 0.4 and 0.2, total dry matter showed significant association with both vine dry matter (r= 0.9744** to 0.9874**) and tuber dry matter (r= 0.9902** to 0.9985**) Thus both reduced dry matter production rate along with more dry matter accumulation in shoot at lower level of irrigation (IW/CPE ratio 0.6, 0.4 and 0.2) contributed towards yield reduction in sweet potato.
