Efficacy of a Calcium Functional Fertiliser with a Calcium Transport Stimulant in Managing Cavity Spot of Carrot (Daucus carota subsp. sativus)

The marketable yield of carrot is reduced by carrot cavity spot disease (Pythium violae and P. sulcatum). In the UK, metalaxyl-M is the only approved fungicide. Good calcium nutrition can manage cavity spot, but calcium is not generally mobilised to the maturing carrot root. We report field-based studies testing the effect of Albina, a novel calcium functional fertiliser, which contains a calcium transport stimulant (MCAS) LoCalTM (Levity Crop Science, UK) that mimics the effect of auxin in relation to the transport of calcium across cell membranes. Its effect on cavity spot was compared with calcium nitrate (calcium fertiliser without MCAS) and metalaxyl-M in an inoculated ‘macrocosm’ plot experiment (cv. Nairobi), and in grower-managed field trials where it was compared with standard fertiliser and fungicide applications over two years (cvs. Nairobi and Octavo). In the macrocosm trial, the functional fertiliser gave significantly reduced cavity spot (12% incidence) compared with the inoculated (untreated) control (24% incidence) and had similar efficacy to the fungicide. In the grower-managed field trials, the functional fertiliser resulted in significantly improved cavity spot control with a mean reduction of 14%. The functional fertiliser could provide a cost-effective and environmentally friendly means for reducing cavity spot in carrots.