​A cluster of Parkinson's disease has been discovered in a key Victorian barley, chickpea and lentil farming region where researchers say its prevalence is up to 78 per cent higher than the rest of the state.

The discovery by a team of health researchers and scientists has sparked calls for urgent research into links with pesticides and other farming techniques used in the Grampians and Loddon Mallee regions.

The abnormally high rates were found in four neighbouring local government areas in the state's north-west that all produce barley and pulses (chickpeas, beans and lentils), by a joint Monash University and the Florey Institute of Neuroscience and Mental Health study.

They report the rate of Parkinson's is 78 per cent higher than the state average of .5 per cent in the Buloke​ Shire, 76 per cent higher in Horsham, 57 per cent higher in the Northern Grampians and 34 per cent higher in Yarriambiack​.