EFFECTS OF THE HOST, THE PATHOGEN, THE ENVIRONMENT AND THEIR INTERACTIONS, ON FUSARIUM-WILT IN CARNATION

Fusarium oxysporum f.sp. dianthi causes severe wilting in carnation (D ianthus caryophyllus L.) worldwide. The pathogen is present in the soi l profile in which carnation roots are distributed and may infect the plants at any time during the growing season. To minimize the losses i nduced by Fusarium wilt, growers use carnation cuttings free of Fusari um spp. and fumigate the soil with methyl bromide prior to planting. T he severity of epidemics and the resulting losses are governed by the main and interacting effects of the three components of the disease sy ndrome: the host, the pathogen and the environment. Host variables inc lude the type and the degree of cultivar resistance (i.e., complete, p artial or tolerance); pathogen variables include the race, its virulen ce and infectivity, and the amount of initial inoculum; environmental variables include solar radiation intensity, photoperiod, temperature and the growth substrate. In the present review the information availa ble on the effect of the host, the pathogen and the environment, and t heir interactions, on Fusarium wilt in carnation is summarized.