ENHANCED DEGRADATION OF IPRODIONE IN A GOLF COURSE SOIL AFTER REPEATED TREATMENTS AGAINST SCLEROTINIA-HOMEOCARPA

A reduced efficacy of iprodione in controlling dollar spot incited by Sclerotinia homeocarpa was observed in a golf course in North Italy. T he evaluation of the sensitivity of the fungicide of several strains o f Sclerotinia homeocarpa isolated from the golf course soil has permit ted to exclude fungicide resistance as a possible explanation to the p henomenom. The comparison of the degradation rates of the fungicide in the golf course soil and in a soil without history of iprodione treat ment collected in a nearby field has pointed out that the loss of effi cacy of the fungicide could be attributed to a process of enhanced bio degradation.