A smoke-derived butenolide, 3-methyl-2H-furo[2,3-c]pyran-2-one, has previously been shown to improve seedling vigour of various crop species. The aim of this study was to examine the effect of butenolide priming treatments on seedling emergence and growth when it is applied to peat moss in which seeds are sown (post-sowing) rather than pre-sowing imbibition of the seed itself. Pepper (Capsicum annum L.) and salvia (Salvia sp.) seeds were sown in peat moss in modules and subjected to either butenolide priming (10(-7) M, 25 degrees C) or water for 24 h at 25 degrees C in the dark. Following this technique, seeds are imbibed, not subsequently dried and placed in a growth cabinet at 18 degrees C for germination. Butenolide-primed seeds emerged faster (lower MGT) and produced larger seedlings as indicated by fresh and dry weight compared to the water controls for both species. Butenolide-primed seeds had higher catalase activity than that of the controls suggesting that the enhancement obtained from priming may be due to changes in enzymatic activity. Butenolide priming may be used to enhance pepper and salvia seedling performance via the sowing medium. (C) 2011 SAAB. Published by Elsevier B.V. All rights reserved.