Abstract
Glasshouse trials were conducted in order to examine the effect of lime or gypsum amendments on the development of cavity spot disease of carrots in a field soil artificially infested with Pythium coloratum. Each amendment was applied to the soil at 4000 or 8000 kg ha-1. Only the lime applications significantly reduced the incidence of cavity spot disease. In unamended soil, the calcium concentration of carrot roots was significantly less than that of carrots grown in amended soils. There were no significant differences in the calcium concentration of carrot roots grown in soils with lime or gypsum added in the presence or absence of the pathogen. Calcium did not appear to play a direct role in the reduction of cavity spot disease. Reduction of the incidence of cavity spot appeared to be related to the increase in soil pH associated with the application of lime.