Hydropriming and hot water-induced heat shock increase cotton seed germination and seedling emergence at low temperature

Increasing seed germination ability in cold soil conditions is necessary for effective cotton production. A major aim of cotton producers is to have good stand establishment and healthy seedlings. To determine the effects of hydropriming and heat shock treatment on seed germination and seedling emergence, seeds of 3 cotton cultivars, i.e. Stoneville-468, Maraş-92, and Sayar-314, were primed in distilled water at 5 °C or 25 °C for 2, 4, 6, 8, or 10 h or subjected to a hot water bath (96 °C) for 10, 30, 60, 90, 120, or 240 s. Germination and emergence percentage, and seedling fresh weight were determined at 18 ± 0.5 °C. Hydropriming at 25 °C increased germination rates by 54%, 17%, and 6% for Maraş-92, Sayar-314, and Stoneville-468, respectively. Longer durations of hydropriming at 5 °C decreased germination percentage. Hot water treatment for 10 s increased seed germination rates for Maraş-92 and Sayar-314 by 27% and 71%, respectively. Hot water treatment for 60 s increased germination of Stoneville-468 by 7%. Moreover, emergence percentages of seeds subjected to heat shock for 10 s were higher than those of the control seeds. Seedling fresh weights of hydroprimed seeds and seeds subjected to heat shock for 10 s were higher than those of the control seeds. The results indicate that hydropriming cotton seeds at 25 °C for 4-6 h or heat shock for 10 s increased seed germination and seedling emergence at low temperature. The results could have practical uses in cotton breeding programs.