A Comparison of Priming Agents for Tomato and Asparagus Seeds

Abstract

Tomato ( Lycopersicon esculentum Mill.) and asparagus ( Asparagus officinalis L.) seeds were primed for 1 week in –0.8 MPa (20C, dark) polyethylene glycol 8000 (PEG), synthetic seawater (INO), or combinations of Ca +2 , K + , or Na + with Cl − , , , or ) and then were placed in 0.5-fold Hoagland solution at 20C for germination. Priming did not affect percentage germination of tomato seeds; but asparagus germination increased from 85% in untreated seeds to 90% due to priming. All priming treatments reduced the time to 50% germination (G 50 ) of both species but reduced the time between 10% and 90% germination (G 10-90 ) of only tomato seeds. Salt solutions gave lower G 50 values than PEG for tomato seeds but did not provide this advantage for asparagus seeds. The G 50 and G 10-90 of tomato seeds were lower after priming with nitrate salts than with other salts, but the reductions were greatest with sodium nitrate. The G 50 of asparagus seeds was lowered with nitrate salts, but the G 10-90 was unaffected.