Effects of pre-sowing seed treatments and temperatures on tomato seed germination and seedling emergence

Abstract

Sowing pre-germinated seeds with radicles 2–3 mm long reduced the time from sowing to seedling emergence to 17 days compared with 41 days in untreated seeds at soil temperatures of 10°C, and to 5 days compared with 11 days at 18°C. Sowing pre-germinated seeds also improved percentage seedling emergence and reduced the variability of times of emergence of individual seedlings. Seeds imbibed for 56 h before sowing (radicles just emerging) emerged about 3 days earlier at both 10°C and 18°C than untreated seeds. Seeds soaked in a solution containing 1.5% each of KNO 3 and K 3PO 4 for 5 days at 24°C, or in “Carbowax 20 M” for 20 days at 15°C, and then dried before sowing, gave results similar to imbibed seeds. Soaking seeds in 70% of their weight of water followed by drying for different lengths of time and for different numbers of cycles of wetting and drying did not improve germination or seedling emergence.