Effect of different priming treatments and priming durations on melon germination behavior under suboptimal conditions

The objective of this work was to compare the effect of different priming osmotic agents and durations on melon germination in: 1) low temperature stress; 2) saline stress; and 3) low temperature and saline stress. The osmotic agents were polyethylene glycol 6000, KNO3 + K3PO4, CaCl2 and NaCl, with -1.5 MPa osmotic potential. Priming durations were 3 and 6 days (d). Germination percentage (GP) and mean germination time (MGT) were measured. At 12 degrees C the best GP was 14% with CaCl2/3-d,without germination in control. At 25 degrees C the best GP was 100% with CaCl2/3-d.MGT was reduced one day. At -0.7 MPa GP was 100% with CaCl2/3-d and NaCl 3d. At -1.0 MPa the best GP were 46 and 50% for 3d with NaCl and CaCl2 respectively without germination in control treatment. At 12 degrees C and -1.0 MPa the best GP were CaCl2/3-d and CaCl2/3-d (14 and 10% respectively). It is concluded that at 12 degrees C, the increase in GP would not justify the use of priming. At 25 degrees C priming increased GP and reduced MGT. At -0.7 MPa priming increased germination, while at -1.0 MPa the increase is not agronomical considerable. At 12 degrees C and -1.0 MPa the increase of germination is not agronomical important.