Fusarium Wilt

  • Symptoms

  • Trigger

  • Biological Control

  • Chemical Control

  • Preventive Measures

Fusarium Wilt

Fusarium oxysporum

Fungus


In a Nutshell

  • Signs of wilt during daytime.
  • Vascular tissue (inside the stem) stained brown or red.

Hosts

Bean

Canola

Capsicum & Chili

Chickpea, Gram

Cotton

Cucumber

Grape

Lentil

Pea

Pumpkin

Red gram, Pigeonpea

Tomato

Zucchini

Symptoms

These fungi show crop-specific patterns of damage. In some cases, the plants show signs of wilting even at a juvenile stage, with leaves turning yellow. On mature plants, a slight wilting often appears on parts of the plants. This is most common during the warmest hours of the day. Leaves later turn chlorotic, often only on one side. Longitudinal sections of the stems show a brownish-red discoloration of the internal tissues, first at the base, later up the stem.

Trigger

Fusarium wilt grows in the transport tissue of plants, affecting water and nutrient supply. Plants can be infected directly via their root tips or through wounds in the roots. Once the pathogen has become established in an area, it stays active for several years.

Biological Control

Several biological control agents, including bacteria and nonpathogenic strains of F. oxysporum that compete with the pathogens have been used to control Fusarium wilt in some crops. Trichoderma viride can also be used to treat the seeds (10g/kg seed). Some soils suppress the growth of Fusarium. Adjusting the soil pH to 6.5-7.0 and using nitrate rather than ammonium as nitrogen source can reduce the severity of the disease.

Chemical Control

Always consider an integrated approach with preventive measures together with biological treatments if available. Apply soil-based fungicides on contaminated locations if no other measures are effective. Drenching the soil with copper oxychloride@3g/l of water before sowing/transplanting is also effective.

Preventive Measures

Plant resistant varieties.,Monitor and remove affected plants.,Keep your equipment clean and avoid damage to the plants.,Rotations of up to 5-7 years can reduce levels of fungi in the soil.,Adjust soil pH to 6.5-7.0 and use nitrate as nitrogen source.,Apply recommended dose of potash fertilizer.,Cover the infected area with black plastic foil in full sun for a month to kill the fungus.,Plow and burn plant debris after harvest.