Salinity effects on germination properties of Kochia scoparia

In order to examine seed germination responses of kochia to different levels of salinity, an experiment was performed in the Institute of Sustainable Agriculture (CSIC), Cordoba, Spain, in a completely randomized design with two replications. Treatments were different levels of salinities equal to 0,5, 10, 15, and 20 ds/m, obtained by mixing NaCl and CaCl2 in a 2:1 molar ratio. Evaluated properties were germination percentage, rate and final number of germinated seeds. The results showed that the germinated seed number and the germination percentage had a converse relation with salinity levels. About 91% of seeds were germinated in distilled water. This value reduced to about 36% in 20 ds/m. Increasing salinity up to 10 ds/m did not have any significant effects on germination, but after that, the germination rate and percentage begun to reduce significantly. Salinity also increased the time required for 50% germination from 28 hours in distilled water to 78 hours in 20 ds/m, showing a delay in germination as salinity increased. Regarding linear reduction in germination rate in response to increase in salinity, it seems that as salinity exceeds 30 ds/m, germination rate of kochia approaches zero. This perhaps could be accepted as the threshold of kochia germination tolerance to salinity. According to the results, the germination stage of kochia has a good tolerance to elevated levels of salinity and it seems that a good stand establishment in saline soils and water conditions could be insured, if proper management is exerted in farms.