The influence of the root-knot nematode, Meloidogyne incognita, on parsley yields under controlled greenhouse conditions

Parsley growing in the coarse-textured soils of the coastal areas of southern California is sometimes severely infected with the root-knot nematode, Meloidogyne incognita. Affected plants at first appear slightly stunted and the older leaves chlorotic. With each cutting of the parsley greenery, the lower leaves die at a higher level on the plant and the yields lessen because the dead foliage cannot be used by parsley processors. Since yellow and/or dead leaves are harvested along with green foliage, they must be sorted out manually, thereby increasing grower and processor costs. Following the second cutting, many plants fail to produce harvestable foliage and frequently die. This article establishes the effects of root-knot upon yields of a highly susceptible parsely variety under controlled conditions of the greenhouse.