THE EFFECTS OF DIFFERENT METHODS TO BREAK SEED DORMANCY AND SEED PRIMING ON GERMINATION AND SEEDLING GROWTH OF citrullus colocynthis

Abstract

In order to study the effects of different methods of seed dormancy breaking and priming (presowing seed treatments) treatments on germination and seedling growth of Citrullus colocynthis an experiment was conducted in Department of Agronomy, Faculty of Agriculture, Urmia University in 2014 based on completely randomized design with three replications. Evaluated factors were seed braking 21dormancy methods with four levels (Control, Sulfuric acid 80%, seed scarification with sand and seed stratification for six weeks) and seed priming with four levels (Control, KNO3 2.5%, KH2PO4 2.5%, Hydropriming and Hardening). The results indicated that all studied methods of breaking seed dormancy and combined administration of seed priming effectively improved germination and vigor of Citrullus colocynthis. Sulfuric acid and hardening treatments have greatest impact in improving the germination and vigor. Based on the comparison of the interaction of these treatments the final germination percentage, germination index, mean germination time, coefficient of velocity of germination were 85%, 40.03, 8.3 and 35.00 respectively. Also recorded seedling dry weights of sulfuric acid and Hardening treatments were 58.74 and 46.02 mg, respectively, which was significantly different from other treatments