Fungicidal resistance management

Table I. Dual Goals of Fungicide Resistance Management...

Inhibition of electron transport in the mitochondrial respiratory chain No cross-resistance to other fungicide classes A good tool for resistance management of other fungicides Resistance management will be required on risky pathogens... 

The purpose of FRAC is to provide guidelines for fungicide resistance management to prolong the effectiveness of at risk fungicides and to limit crop losses should resistance occur. 

This is the first successful case of fungicide resistance management in Japan based on integrated collaboration of molecular biological and epidemiological approaches. 

K. J. Brent, Fungicide resistance in crop pathogens. How can it be managed FRAC Monograph No. 1, GIFAP, Brussels, 1995,48pp. 

Industry Involvement. Agrochemical companies did not escape being caught off guard by the relentless progression of resistance, nor was their response either coordinated or uniformly effective at first. In a candid assessment of the early days of resistance management, Delp wrote that "Industry s response to fungicide resistance problems varies from denial to active participation in the solution" (4 ). 

Table VIII. Management of Fungicide Resistance in Practice... 

Management of Fungicide Resistance by Using Computer Simulation... 

Management of fungicide resistance requires some means of predicting the quantitative response of the target fungus population to various management alternatives. 

General models of the selection of fungicide resistance have given us overall management strategies (2-8). However, the fungi... 

Table IV. Predicted relative effects of various management strategies on fungicide resistance and disease suppression using PhyCophthora infesCans Solanum tuberosum and protectant and systemic fungicides via simulation analysis Data are from Milgroom and Fry (1)...

Fitness. Fitness of the resistant isolates may be a potentially important factor in identifying strategies to manage fungicide resistance. If the resistant isolates are considerably less fit than sensitive ones, then reversion to sensitivity in a population becomes a realistic consideration. Unfortunately, if fitness of resistant types is very similar to that of sensitive types, there are few options. However, relative fitnesses of resistant and sensitive biotypes are rarely known, and knowledgeable application of model results awaits empirical evidence. 

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