Management of fusarium wilt in cut flowers
Fusarium wilt impacts a number of cut flower species, but is a particular problem in cut flower column stocks, requiring growers to regularly steam sterilise soils to keep the pathogen in check. New work as part of AHDB funded project FV/POBOF 452 is looking to detect and quantify fusarium species which attack key crops in horticulture. The project has three broad aims – to develop a quantitative test for Fusarium oxysporum f.spp affecting onion, narcissus and column stocks, to develop tools to help identify the entire community of organisms associated with Fusarium disease complexes (do some fungi help to exacerbate the pathogen, do others help to suppress it?) and determine inoculum levels which cause economically damaging levels.
In combination with this project, one of the production tunnels at the Cut Flower Centre has been inoculated with a strain specific to column stocks to determine the specificity of the pathogen, the levels at which crop damage occur and to see if there are any signs of resistance in the range of column stocks varieties currently grown.
At the CFC open day on 8 August, delegates were able to see first-hand the devastation that the pathogen has on the crop, but also its specificity – the remaining green plots are lisianthus, another crop which is also susceptible to Fusarium. As a result of the hot temperatures through June and July, which greatly added to plant stress levels, few signs of potential plant resistance were recorded this year. However, potential variations in the pathogen inoculum level in the soil can be seen as some small pockets of column stocks took a couple of weeks longer before they succumbed to the disease and while severely affected, they are still showing a few green leaves.