They were eventually dismissed for 317 after half-centuries by the left-hander Philip Weston, who made 70, and the all-rounder Stuart Lampitt, 57, on a day dominated by the spinners.
Eddie Hemmings supported Salisbury with 3 for 70 and the only wicket to go to a pace bowler was taken by Worcestershire's Neal Radford as Sussex reached 42 for 1 by the close.
Darren Gough boosted his England claims by taking 6 for 70 - his best return in 11 Championship matches - as Yorkshire dismissed Hampshire for 305 at Headingley. In one impressive burst, the 23- year-old seamer claimed 3 for 6 in 16 balls to polish off the resistance.
Meanwhile, the Hampshire opener Paul Terry carried his bat through a completed innings for the first time, totalling 141.
Tim Munton and the newcomer Graeme Welch joined forces to give Warwickshire the upper hand as Northamptonshire were forced to follow on at the County Ground. The pair carried their last-wicket stand to 68 in the morning session, boosting the visitors to 463, then shared eight wickets to dismiss Northamptonshire for 267.
Northamptonshire closed on 17 without loss in their second innings, still 179 adrift. The home side ran into early trouble as Munton, who took 5 for 53, sent back Nigel Felton and Russell Warren with just 32 on the board.
Rob Bailey (54) and Allan Lamb (81) looked like retrieving the situation, adding 137 in 38 overs and Bailey becoming only the 10th batsman to complete 15,000 first-class runs for the county. But Welch, swinging the ball in heavy conditions, accounted for Bailey, Lamb and Mal Loye in the space of 22 deliveries on his way to a 3 for 58 in his first Championship match.Reuse content