Managing weeds through rotations in Central West New South Wales.

The Central West cropping zone of New South Wales (NSW) is unique in its climatic pattern being in neither the summer rainfall dominant northern zone nor the winter rainfall dominant southern zone. Annual rainfall is evenly spaced through summer storms and winter showers. This poses a problem, as weed control is an issue all year round. As part of a Grains Research and Development Corporation weeds project for the Central West a new manual ‘Weed Control in cropping and pastures in Central West NSW’ has been produced. This manual is a combination of best practice and case studies specific for weed control in the Central West. The main cropping rotation is a phase farming system however farmers are increasingly changing to continuous cropping, stubble retention systems. These changes have resulted in changes to the weed spectrum. Some weed species such as skeleton weed (Chondrilla juncea L.) have been almost eliminated whilst other previously minor species such as fleabanes (Conyza spp.) are increasing. Rotational cropping is an important part of integrated weed management (IWM). Planning usually considers disease control and nutritional issues but often forgets to consider the weed spectrum and herbicides registered for use in rotational crops. Successful weed managers are using their rotations to effectively manage weeds. They are planning ahead to use their herbicides in rotation to the greatest effect. Precision farming is playing a major role in improving weed control. New technology and greater use of a variety of rotation crops is changing the way weeds are managed.