Lupine (Lupinus spp.)-Fusarium Wilt

Latest revision: 
March 2023

By C. M. Ocamb

Cause The fungus, Fusarium oxysporum f. sp., which may overwinter on infected plant residues or as durable spores (chlamydospores) in soil. This fungus may be seedborne. The pathogen can be spread through soil movement on equipment, tools, and footwear as well as infested soil being windborne or waterborne and can be introduced into a new region through the movement of infected transplants or the sowing of infected seed. Fusarium oxysporum can also produces additional spore types (macro- and microconidia) that can be moved with wind or water.

Symptoms Plants are susceptible at any stage. Early symptoms include yellowing of lower leaves, sometimes one-sided or V-shaped in appearance, and stunting of the plant. Leaves may die, and leaf yellowing as well as defoliation may progress up an affected plant. Wilting of plants is observed more commonly once flowering commences. The entire plant may die. Dark-brown to blackish discoloration can be found around vascular elements in roots and in stems. Vascular discoloration precedes wilting symptoms. A brown rot may develop on the tap root or the lower stem of affected plants. The root system may also be stunted with a brown rot of the lateral roots present.

Cultural control

  • Plant pathogen-free seed in pathogen-free soil.
  • Avoid planting lupine in soils where previous lupine wilt has occurred in the past few years.
  • Remove and destroy infected plants.
  • Clean soil from equipment, tools, and clothing after working in an infested field.
  • Long rotations are required to rid infested ground of these Fusarium strain; rotate out of lupine for at least four years.

Reference Abdel-Monaim, M.F., Abo-Elyousr, K.A.M., and Morsy, K.M. 2011. Effectiveness of plant extracts on suppression of damping-off and wilt diseases of lupine (Lupinus termis Forsik). Crop Protection 30(2):185-191.