Influence of Seed Priming and Seed Size on Wheat Performance under Different Tillage Systems

This field study was conducted to assess the effect of seed priming and seed size on emergence, growth and productivity of wheat under conventional and conservation tillage during winter season 2012-2013. Seeds of wheat cultivar Punjab-2011 were separated into small sized (1000 grain weight = 22.5 g) and bold sized (1000 grain weight = 44.4 g) seeds by winnowing. Both bold and small sized seeds were soaked in aerated solution of CaCl2 (psi s -1.25 MPa; osmopriming) for 24 h while untreated (dry) seeds were taken as control. Osmoprimed and dry seeds of both sizes were sown under conventional and conservation (zero tillage) tillage practices. Results indicated that wheat sown under conventional tillage observed quick, uniform and better early stand establishment compared with zero tilled wheat. However, seed primed with CaCl2 significantly lowered the days to start emergence, mean emergence time and improved final emergence count compared with dry seeds sown, particularly of zero tilled wheat. Zero tilled crop observed a significant cut in leaf area index (LAI), crop growth rate (CGR) and net assimilation (NAR), while bold seed size and osmopriming improved the LAI, CGR and NAR under both tillage practices, zero tilled wheat in particular. Moreover, zero tilled wheat observed a significant yield penalty due to significant increase in yield related traits; however, osmopriming and bold seed size improved wheat productivity due to substantial expansion in yield related traits under conventional and zero tillage, zero tillage in particular, practices. In conclusion, bold sized seed osmoprimed with CaCl2 was better able to produce higher yield of conventionally tilled and zero tilled wheat. (C) 2016 Friends Science Publishers.