Effect of sand burial depth on seed germination and seedling emergence of Calligonum L. species

A greenhouse study was conducted to determine the effects of sand burial on seed germination and seedling emergence of ten Calligonum L. species. The results suggested that the deeper the seeds in sand, the lower and slower their germination and seedling emergence. Seedling emergence occurred from a maximum depth of 12 cm with most seedlings emerging from 2 and 4 cm depths. The percent seedling emergence, number of days of first emergence, percent seed germination and percent of dormant seeds were significantly affected by different species and burial depth. There was a significant positive correlation between the number of days to first emergence and burial depth. Both mean percent germination and percent seedling emergence were negatively correlated with depth significantly for each species. (C) 2002 Published by Elsevier Science Ltd.