ARS | Publication request: Efficacy of Ethanedinitile (C2N2) against some cereal pathogens

Submitted to: Controlled Atmosphere Conference Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: July 21, 2008
Publication Date: December 24, 2008
Citation: Waterford, C.J., Peterson, G.L. 2008. Efficacy of Ethanedinitile (C2N2) against some cereal pathogens. Controlled Atmosphere Conference Proceedings.

Technical Abstract: Ethanedinitrile (EDN) is being investigated by CSIRO Australia as an alternative to methyl bromide for a range of uses, including soil and timber fumigation. EDN is an effective devitalisation agent of cereals and is being evaluated for devitalising feed grain imports into Australia. Part of this process involves assessment of efficacy against target pathogens of concern including Tilletia indica (Karnal bunt), Peronosclerospora sorghi (sorghum downy mildew), Tilletia controversa (dwarf bunt) and Ustilago maydis (boil smut), which is being conducted in collaboration with the USDA ARS. This fumigant was tested on: 1) naked spores; 2) bunted seed, when this is a propagule in the life cycle of the pathogen; and 3) spores dusted on maize. It was applied at 120mgL-1 over a period ranging from a few minutes to 5 days at 5, 17 and 22C. Treated material and untreated control spores of T. indica, T. controversa and U. maydis were seeded onto water agar medium to assess viability based on spore germination. Oospores of S. sorghi germinate poorly, if at all, on artificial medium. Treated oospores where mixed into the upper 5 cm layer of soil in a 2 X 2 inch plastic pot and planted with seeds of a highly susceptible sorghum cultivar and placed in a growth chamber for disease development. The naked teliospores of the three smut fungi were more easily controlled than spores still contained within the fungal structure(sorus) or those spores that were dusted onto maize seed, which were the most difficult to control. Results of the bioassay of P. sorghi showed trace infection of sorghum in the untreated controls, and in one plant that was treated for 1 hr at 17C.