Submitted to: Proceedings American Society of Horticultural Sciences
Publication Type: Abstract Only
Publication Acceptance Date: 7/21/2004
Publication Date: 7/21/2004
Citation: Vaughn, S.F., Isbell, T., Weisleder, D., Berhow, M.A. 2004. Biofumigation potential of field pennycress (thlaspi arvense) seedmeal [abstract]. Hort. Sciences 39(4):745.
Technical Abstract: Field pennycress (Thlaspi arvense L.) seedmeal was found to completely inhibit seedling germination/emergence when added to a sandy loam soil containing wheat (Triticum aestivum L.) and arugula [Eruca vesicaria (L.) Cav. subsp. sativa (Mill.) Thell.] seeds at levels of 1.0 % w/w or higher. Covering the pots with petri dishes containing the soil-seedmeal mixture decreased germination of both species at the lowest application rate (0.5 % w/w), suggesting that the some of the phytotoxins were volatile. CH2Cl2, MeOH and water extracts of the wetted seedmeal were bioassayed against wheat and sicklepod (Senna obtusifolia (L.) H.S. Irwin & Barneby) radicle elongation. Only the CH2Cl2 extract was found to be strongly inhibitory to both species. Fractionation of the CH2Cl2 extract identified two major phytotoxins, identified by GC-MS and NMR as 2-propen-1-yl (allyl) isothiocyanate (AITC) and allyl thiocyanate (ATC), which constituted 80.9 and 18.8 %, respectively, of the active fraction. When seeds of wheat, arugula and sicklepod were exposed to volatilized AITC and ATC, the germination of all three species were completely inhibited by both compounds at concentrations of 5 ppm or less.