he present study was conducted to evaluate the TEMPeffect of seed aging (seed quality) on germination, emergence and seedling growth of wheat under optimum (control) and stressful conditions including salinity (2 levels), drought (2 levels) and deep sowing depth (physical stress). Seeds (cv. Zagros) were kept at a high temperature (43 °C) and high relative humidity (90-95%) to create different classes of seed aging. Factorial combinations of 5 seed aging treatments (0, 48, 72, 96 and 144 h accelerated aging periods) and 6 levels of environmental factor were treatments of the experiment. Maximum and rate of emergence reduced significantly with increase in the duration of accelerated aging. The ranking of the stress factors from most to least harmful for maximum emergence were: severe drought, severe salinity and sowing depth of 7 cm, medium drought and medium salinity. Seed aging significantly decreased leaf area and seedling dry weight at the first harvest, but reduction in these characteristics was not significant at the second harvest. The ranking of the importance of stress conditions in terms of harmful effects on the leaf area and seedling dry weight were severe drought, medium drought, severe salinity and sowing depth of 7 cm and medium salinity. Seed aging had no a pronounced effect on the number of leaf at the first or second harvests.

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