Some Agricultural weeds are also declared weeds, such as ragwort and Californian thistles. Other agricultural weeds, for example wild radish and capeweed, are not declared but can be costly to control, and in many cases toxic to stock. These include:
- Spear thistle
- Wild radish
Unintentional spread of weeds occurs with
- topsoil on machinery moved from one area to another;
- gravel and quarried materials contaminated with soil stored seed such as gorse and broom;
- soil on peoples boots,
- along roadsides where vehicles produce air currents which move wind blown seed,
- hay making machinery or hay bales moved from one area to another
- fodder, grain or birdseed.
Capeweed is an agricultural weed which can spread quickly, be costly to control and toxic to stock Image: A Fergusson.