Quantifying Germination response to temperature of hibiscus tea (Hibiscus sabdariffa)

Germination rate and percentage are maximal at optimum temperatures and then reach to zero at the base and ceiling temperatures. An experiment was conducted at the Gonbad Kavous University laboratory as a completely randomized design with 4 replications, to study germination response to temperature and evaluation of cardinal temperature on germination rate and percentage of hibiscus tea. Seeds germinated at 0 to 45 0C by 5 0C intervals. Results indicated that the response of germination percentage and rate adequately fitted with dent like and segmented functions, continually. Base and ceiling temperatures were 1.66 and 43.33 0C for germination percentage and 4.53 and 42.95 0C for germination rate. Optimum temperatures were 30 0C for germination rate and 11.56 and 33.63 0C for germination percentage. In conclusion, base and favorable temperatures for hibiscus tea seeds were 11 and 35 0C. Therefore it is recommended to cultivate at Gonbad kavous weather condition.