The effects of seed harvesting time on viability of Salsola rigida pall, Zygophyllum eurypterum Boiss & Buhse and Ferula ovina (Boiss.) Boiss in Yazd province

One of the most important plans for range improvement is the production of suitable seeds. To achieve this goal and to detect highest germination rate the harvesting time should be regulated, so that the seeds must be both matured and not scattered. In this study the optimal dates of seed harvesting of three range plants including Salsola rigida, Zygophyllum eurypterum and Ferula ovina are investigated. Seed harvesting was done in different stages from physiological maturation time to seed falling. S. rigida seeds were collected on September 22th, 29th and October 6 th, 13th and 27th and November 3th and 10th at 2004, and Z. eurypterum and F. ovina on June 30th and July 7th, 14th and 21th at 2005. From each stage 400 dried seeds in four replications were tested in petridish. Germinated seeds were counted during 21 days.
The results of this experiment showed, there is a significant difference between various seed harvesting times of S. rigida. The highest germination rate of this plant is on Nov. 10th (75%), and the lowest rate is on Sep. 22th (7.3%). No significant difference was detected for Z. eurypterum. The highest rate of germination of Z. eurypterum was on June 30th (61%) and the lowest one was on July 21th (46%). F. ovina seeds had the highest rate of germination (54%) on July 21th and the least rate of germination on June 30th and July 14th (37%). There is also a significant difference in harvesting rate of this plant referring to different times. According to the achieved results of this study, harvesting delay increases germination rates of S. rigida and F. ovina, while this parameter has no effect on Z. eurypterum. This variable is considered as a clue in selecting optimal time of seed harvesting.