Table 1 Scarification treatment of cotton seeds

1

Pre-sowing high temperature stress (50–70 °C, 24–48 h)

• Heat treatment of cotton seed at 50–70 °C stimulated the seedling emergence and growth of cotton plants

• Untreated seeds have a germination rate of 21% whereas treated seeds have a germination rate of 40%–50% after 7 days of planting

(Khan et al. 1973)

2

Pre-sowing high temperature (60 °C, 10 min)

• Heat treatment of cotton seed at 60 °C increased the seedling emergence

(Basra et al. 2000)

3

Pre-sowing heat stress (60 °C, 8 h)

• Pre-sowing heat treatment of cotton seeds increased the seed vigour to 86% at 60 °C which is similar to the untreated seeds

• Heat treatment at 70 °C increased the germination rate to 80% almost near to that of control (86%)

• Pre-sowing heat stress at 70 °C also decreased the fatty acid content of the treated seed compared with control which indicates the enhanced oil quality

(Basra et al. 2004)