ASA Southern Regional Branch (February 5-7, 2017)

February 05 - 07, 2017

Seed vigor in cotton is often tested by assessing seed germination response of a seed lot to official, predefined incubation temperatures and times. However, information on cultivar variation in dynamic seed germination response to temperature over time is limited.

Defining cultivar variation in time or temperature requirements to attain acceptable germination levels may play an important role in determining stand establishment and seedling vigor. Thus, six cotton cultivars were screened for percent seed germination over 9 times (0.25, 0.5, 1, 2, 3, 4, 5, 6 and 7 days) and six temperatures (10°C, 18°C, 25°C, 28°C, 30°C, 32°C) in April-May, 2016. 10 seeds were incubated per  Petri dish in a given experimental run and three replications were conducted over the course of the study. Number of seed germinated were counted and removed from the Petri dishes at each sampling interval. Percent instantaneous and percent cumulative germination were calculated and analyzed using JMP Pro 12 and Sigma Plot 12.0. Significant variation was observed for percent germination among different cultivars over time and temperature. Cumulative percent germination increased with temperature and incubation time for all cultivars. Importantly, cultivars differ in time required to reach maximum percent cumulative germination with increasing incubation temperature.