Cavity spot is a serious and recurring disease of commercial carrots in the UK. Current control systems rely on the use of a single soil-applied fungicide treatment that is only partially successful and growers need improved understanding of the disease and better control methods.
Led by Plantsystems' David Martin, ongoing HDC project FV 373 aims to document the conditions relating to new outbreaks of cavity spot that together with site history and site conditions will add to our knowledge and should help identify situations to be avoided.
Some 30 commercial production sites provided by members of the British Carrot Growers Association were monitored for total water input, soil moisture and soil temperature. At each site, the incidence and severity of cavity spot was established by sampling before harvest and relationships were sought between recorded site conditions and disease incidence.
In 2010, data showed that total water input in August seemed to be the main climactic factor in determining whether disease was going to occur. Soil temperature and soil moisture did not appear to have a significant effect.
In 2011, the relationship between total water input and disease was again positive. Higher soil moisture gave higher levels of disease. The effect was most clear particularly during August. As in 2010, soil temperature had no significant effect.
Date for your diary
25 September HDC outdoor cucurbits R&D strategy meeting, Stoneleigh, Warwickshire.
For details on all HDC activity, visit www.hdc.org.uk