Black Foot

black foot, fungal disease found in young vines in both vineyards and nurseries which can lead to the decline and death of young vines. One of the so-called trunk diseases, its symptoms include poor growth, chlorotic leaves, brownish-black discoloration of rootstock trunks, roots, graft unions, and a reduction in root biomass. Affected young vines usually die during the growing season or in the following winter. Causal agents vary geographically but are soil-borne fungi in the genera Campylocarpon, Cylindrocladiella, and Ilyonectria. Ilyonectria liriodendri and I. macrodidyma are known to be the most prevalent and widespread. Control measures include field rotation, planting clean vines (see hot-water treatment), and avoiding planting in heavy, wet, and poorly drained soils. The most common phylloxera-resistant rootstocks used today are susceptible to black foot.