Influence of seed priming on ground cover and grain yield of spring and winter rapeseed cultivars

Abstract

This research was carried out during 2007-2008 to investigate the effect of salt priming (0.8% NaCl with electrical conductivity of 15.3 dSm -1 and 0.8% KNO3 with electrical conductivity of 12.5 dSm -1 for 8 hours at 20±1ºC) on a spring rapeseed (Hayola 401) and three winter rapeseed (Okapi, Opera and Talayeh) cultivars under different irrigation intervals. The field experiments were arranged as split plot for spring rapeseed and split plot factorial for winter rapeseeds on the bases of RCB design in three replicates. Irrigation treatments were irrigation after 70, 100 and 130 mm evaporation from class A pan for spring cultivar and irrigation after 80, 120 and 160 mm evaporation for winter cultivars. Seed priming (particularly priming with KNO3) of winter rapeseed cultivars improved grain yield per unit area through enhancing rate and percentage of seedling establishment, ground cover and grains per plant. However, salt priming had no significant effect on field performance of spring rapeseed. Irrigation intervals with 130 mm evaporation decreased ground cover of spring rapeseed, but had no significant effect on yield components and grain yield per plant and per unit area. Almost similarly, field traits of winter rapeseed cultivars were not significantly affected by irrigation treatments. In general Talayeh had the highest ground cover, compared with Okapi and Opera. Poor stand establishment of the latter cultivars was largely compensated by production of more, but smaller grains by Okapi and larger grains by Opera. Consequently, grain yield per unit area did not differ significantly among cultivars.