The economic value of haying and green manuring in the integrated management of annual ryegrass and wild radish in a Western Australian farming system

Most cropping farms in Western Australia must deal with the management of herbicide- resistant populations of weeds such as annual ryegrass ( Lolium rigidum) and wild radish ( Raphanus raphanistrum). Farmers are approaching the problem of herbicide resistance by adopting integrated weed management systems, which allow weed control with a range of different techniques. These systems include non- herbicide methods ranging from delayed seeding and high crop seeding rates to the use of non- cropping phases in the rotation. In this paper, the Multi- species RIM ( resistance and integrated management) model was used to investigate the value of including non- cropping phases in the crop rotation. Non- crop options investigated here were haying and green manuring. Despite them providing excellent weed control, it was found that inclusion of these non- cropping phases did not increase returns, except in cases of extreme weed numbers and high levels of herbicide resistance.