The three forms of skeleton weed (Chondrilla juncea L.) in Australia differ in their susceptibility to herbicides

I.D. Black, R.N. Pederson and D.W. StephensonA, South Australian Research and Development Institute, Plant Research Centre, GPO Box 397, Adelaide, South Australia 5001, Australia.

A Present address: Mid Hills Animal and Plant Control Board, PO Box 54, Mount Barker, South Australia 5351, Australia.


Summary

Experiments on seedling and mature plants of three forms of skeleton weed (Chondrilla juncea L.) occurring in Australia demonstrated that there were differences in their short- and long-term susceptibility to the herbicides metsulfuron-methyl, clopyralid and 2,4-D amine. The narrow-leaved form was more susceptible to metsulfuron-methyl and 2,4-D than the other forms in the first three months after herbicide application. However it recovered more rapidly from the effects of 2,4-D than the intermediate and broad-leaved forms. Clopyralid and metsulfuron-methyl were less effective in killing the broad-leaved form than the intermediate and narrow-leaved forms. Clopyralid was the most effective herbicide on all forms. Clopyralid, metsulfuron-methyl and 2,4-D labels should be altered to take account of the form of skeleton weed targeted.

 

Plant Protection Quarterly (1998) 13 (1) 29-32.