New strategies in the integrated disease management of the vascular wilt of carnation (Dianthus caryophyllus L.) caused by Fusarium oxysporum f.sp. dianthi (Pril. & Del.) Snyd. & Hans.

摘要

The effect of the inoculation of unrooted carnation cuttings and soil with isolates of Trichoderma spp., selected by their antagonistic effect on Fusarium oxysporum f.sp. dianthi, were evaluated. A relationship between F. o. f.sp. dianthi and the nematode Heterodera trifolii was observed, with mycelium developing around the eggs and even chlamydospores of the fungus inside the cyst of the nematode. Every time a biological control agent was tested against the cyst, it was rejected due to the growthof Fusarium from it. To succeed in the biological control program of F. o. f.sp. dianthi, it was necessary to implement a program for the control of the nematode. When the nematode was controlled along with the use of the most promising isolates of Trichoderma spp., it was possible to grow susceptible varieties of spray carnations in areas heavily infested with the F. o. f.sp. dianthi without the need of chemical disinfestation of the soil. It is suggested that after any steam treatment or chemical disinfestation of soil, the use of an antagonist of F. oxysporum should be used as soon as possible to prevent the rapid reinfestation of the soil with the pathogen.