Emex spp. in South Australia
Graham Fromm, Primary Industries South Australia, Murray Bridge, South Australia 5253, Australia.
Emex australis (three-cornered jack) is found throughout the agricultural areas of South Australia, although it is of greater importance in the cropping and Riverland horticultural areas than in the high rainfall zones of the state. E. spinosa (lesser jack) is not as widespread. In the cropping areas Emex spp. can contaminate grain, in particular pulse crops. However, current herbicide strategies have kept the number of declined or contaminated loads to a minimum. In the horticultural areas E. australis has caused problems as a contaminant of dried fruit. Emex spp., if not managed effectively by urban councils, can reduce the amenity value of sports fields and parklands.
Plant Protection Quarterly (1996) 11 (4) 146-150.