Potential use of isothiocyanates in branched broomrape eradication.

Abstract

Bulgarian research has shown that branched broomrape, Orobanche ramosa L., germination could be stimulated with various isothiocyanate (iTC) chemicals. These are naturally produced as breakdown products of glucosinolates in brassicas and methyl iTC is the active ingredient in metham sodium and dazomet fumigants. Such fumigants have been used in Bulgaria to cause suicidal germination of broomrape in tobacco, but there has been limited uptake of iTCs as broomrape germination stimulants elsewhere in the world. The potential applicability of iTCs for the branched broomrape eradication program in South Australia was investigated by comparing germination responses to both iTC chemicals and brassica species/lines. Methyl iTC stimulated high levels of branched broomrape germination at 0.1mM. A hydroponic comparison of brassicas did initially show higher branched broomrape germination as the root iTC profile increased. However, this result was inconsistent in subsequent experiments.