Three seed lots viz., L-1 (Morden), L-2 (Morden) and L-3 (PKV SF-9) having a low in germination Le. 55,67 and 41 per cent respectively were treated with different chemicals and hydration treatment and used for laboratory study. The results revealed that among seed lots, L-2 with 67 per cent germination had highest vigour followed by L-1 and L-3. The mean germination, vigour index, seedling dry weight and field emergence were significantly superior in L-2. As regard the seed treatment, seed treated with KCL (0.5%), KH 2PO 4 (0.5%), MnSO 4 (0.5%), KN0 3 (300ppm), GA 3 (50 ppm), hydration with distilled water (16 hr), Thirarn (@ 2.5 g kg -1 seed) and Trichoderma herzianum (@ 4 g kg -1 seed) have showed invigoration effection treated seed over untreated control. However, hydration with thiourea (0.5%) had deleterious effect on the viability of sunflower seed.