Influence of different methods of seed priming on maize germination irrigated with saline water.

About half of the irrigated soil is seriously interested from salinity and/or secondary alkalinity. Strogonov in 1964 proposed that the salt tolerance of plants could be improved with different pre-seeding treatments at the seeds. This research has evaluated the germination of maize seeds treated with different methods of priming under saline stress conditions (irrigation water and soil). The experiment has carried in Portici during the summer 2007. The cultivation has been made in a rainout-shelter, in 60 soil plastic pots with a top area of 0.39 m2. Three pre-seeding treatments on maize seeds were compared: 1) soaking with saline solutions (halo-priming); 2) soaking with distilled water (hydro-priming); 3) thermic treatment (thermo-priming). 76 seeds per pot were sowed. Three levels of soil salinity were used for halo-priming: low (LSS): 0.34 mS cm-1; middle (MSS): 0.72 mS cm-1; high (HSS): 3.69 mS cm-1. The ECw of irrigation water was 3.5 dS m-1. During the trial 11 waterings were made twice a week, with an average volume of 1.77 l pot-1. In total for every pot 19.5 l of water and 30 g of salt were given. Every three days it was made the count of germinated seeds. The seed treatments didn’t reduced the germination injury due to the irrigations with saline waters. Particularly for the halopriming the germination was further reduced by the initial soil salinity; in any case, the treatment with the middle salinity determined the greatest percentage of germinated seeds. The treatments with the highest temperatures improved the germination percentage; a similar effect was shown by the smaller duration of thermic treatment. The duration of soaking in distilled water determined positive effects on germination with increases higher than 2% per hour of soaking.