Question: query regarding seed treatment in coriander
Answer: seed treatment: for ensuring good germination, seed should be soaked in water for 12-24 hours. floated seeds should be discarded. seeds should be treated with captan 50 wp @ 2 g/kg seed before sowing and rubbed or crushed between palms until the pericarps separate. 
spacing: directly sown in lines spaced at 30 cm and later on thinned to 20 cm within rows at 35-40 days after sowing