ABSTRACT
Several nematodes, as well as insects and fungi, can cause damage to carrots. One species, Heterodera carotae, is prevalent in areas of intensive carrot production in parts of western France. It also occurs in some other countries. This paper discusses the effectiveness of control measures and indicates prospects. The use of non-host plants is difficult owing to the high specificity of the parasite and a very low tolerance limit (< 1 larva/g). A five year rotation (or ten year for heavy infestations) is recommended. Fumigant treatments are effective, but recolonisation occurs during the growth of the host crop and populations sometimes exceed their initial levels. Treatments must be applied before each carrot crop is sown. Biological control with Paecilomyces lilacinus does not protect crops effectively, even though the fungus colonises the soil. The long term effects remain to be tested. An in vitro test is proposed for breeding for resistance.
