An expert system for the management of Botrytis cinerea in Australian vineyards .1. Development

An expert system was developed with the aim of improving decision-making by grape growers in their management of Botrytis cinerea. Knowledge was obtained from the refereed literature on B. cinerea and also from the more general literature on plant pathology and viticulture. The decision to apply a fungicide was based on estimated disease risk, economic threshold, and duration of protective cover provided by fungicides. Up to six factors were used to estimate disease risk. These were 'Growth Stage', 'Conidial Infection', ?Mycelial Infection', 'Injury','Symptoms' and 'Cultivar Susceptibility'. The economic threshold depended on whether grapes were destined for premium or bulk wine, and length of protective cover of a fungicide was estimated from use patterns advocated on product labels. The knowledge was structured into a dependency network of objects, with the object determining the need to apply a fungicide at the apex of the network. The knowledge was then represented in the knowledge base of the expert system in a series of IF-THEN rules. (C) 1997 Elsevier Science Ltd.