Some Physiological Responses and Yield of Maize Affected by Seed Aging and Priming Duration

Seeds of maize (cv. SC AR68) were divided into three sub-samples, one of which with a 100% germina-tion was kept as high vigor seed lot (V1). The other two samples were artificially aged at 40°C for 2 and 3 days, reducing normal germination to 98% (V2) and 93% (V3), respectively. Each of these samples was subse-quently divided into four sub-samples, one of which was kept as unprimed and three other samples were hy-dro-primed at 15°C for 7, 14 and 21 h, and then their moisture content reduced to about 20% in a room at 20–22°C. The experiment was undertaken in 2016 as factorial based on randomized complete block design in three replicates. seed aging and hydro-priming had no significant effects on leaf temperature, Fv/Fm, CCI and plant biomass due to regular irrigation. Seed aging reduced, but hydro-priming enhanced LAI, grain yield and harvest index of the resultant plants. Grain yield of plants from high vigor seed lot (V1) was 23.5% and 64.5% greater than that of V2 and V3 plants. Seed hydro-priming for 21 h also increased grain yield of maize by about 32%. Therefore, hydro-priming for 21 h is the best pretreatment to improve field performance and yield of maize.