Effects of Salinity and Temperature on Germination of Dill (Anethum graveolens L.)

Experiments were carried out to investigate seed germination responses of dill Anethum graveolens L. at different salinities (0, 2.5, 5, 7.5, 10 and 12.5 dS m 1 NaCl) and under different temperature regimes (10:20, 15:25, 20:30 and 25:35 C), both in a 12 h dark : 12 h light photoperiod. The highest percentage of germination (about 100%) was obtained at 0, 2.5 and 5 dS m 1 NaCl at 20:30 C and a further increase in salinity resulted in a gradual decrease in germination. Less than 5% of seeds germinated at 12.5 dS m 1 NaCl. Germination under salinity treatment at 15:25 C was slightly more inhibitory than the optimal temperature regime, whereas under both 10:20 and 25:35 C temperature regimes, seed germination was substantially reduced and few seeds germinated at concentrations higher than 5 dS m 1 NaCl. Germination rate was fastest at 20:30 C and slowest at 10:20 C.