In the cyclamen trial, young plants were examined for latent disease. Plants were also tested after potting. There was little evidence to suggest the disease arises from latent infection of plug plants in the first two years, but the disease was confirmed in young plant material in the third year. It was found that moisture and temperature conditions during transport over long distances may induce the development of bacterial soft rot.
For potted-on plant material, plant losses were recorded in material from different propagators, especially in material from early delivery dates. It was shown that bruising the corm increased levels of disease over the 10 weeks after potting. Grazing by sciarid fly larvae may exacerbate the infection, but an immersion treatment resulted in greater levels of disease.
In the case of bacterial leaf spot diseases on ivy and impatiens, several preventive spray treatments were tested. Foliar sprays of Cuprokylt FL helped to control the disease in both plant species, and Amistar had some impact on the disease on impatiens.
The surface being treated had an impact on the level of disinfection achieved; Mypex-type matting and concrete are more difficult to disinfect than glass and aluminium. It was found that Sanprox-P and Virkon S (at one per cent solutions) disinfected all surface types of all three bacteria after 30 minutes.
Horticultural Development Company
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