Sclerotinia rot/ White Mould (Sclerotinia sclerotiorum)

Symptoms

• Infections may occur on the stem at the ground level, on the leaves at their bases, or where the foliage comes in contact with the soil.
• The infected leaves lose their turgor during day time and droop down to the ground, but regain turgidity during night or early morning.
• The yellowing starts from tips of the older leaves downwards which shed, prematurely.
• The infections begin as water-soaked, circular areas, which soon become covered by white, cottony fungal growth.
• The affected tissue becomes soft and watery as the disease progresses.
• The fungus eventually colonizes the entire cabbage head and produces large, black, seed like structures called sclerotia on the diseased tissue.

Management

• Rows should be planted in the direction of the prevailing winds to promote free flow of air movement within the plants.
• Fields with a history of white mold should be planted with non-susceptible crops such as grains (corn, rye, wheat, etc.).
• Cabbage and other susceptible crops (cauliflower, beans, peas, etc.) should not be planted in fields where white mold has become a problem because continuous cropping of susceptible crops will result in a buildup of the fungus in the soil and increased disease incidence.
• Mechanical injuries to cabbage heads during harvesting operations should be avoided.
• Remove infected leaves at weekly intervals.
• Soil amendment with oil cakes like sunflower and mustard and mulching with pine needles and sunflower inflorescence also reduces the disease incidence.
• Some antagonistic fungi like Trichoderma harzianum, T. viride, Gliocladium virens and Coniothyrium minitans have been found promising in managing this disease.
• These fungi either inhibit the development of new sclerotia or destroy the developed ones by colonizing them.

Chemical Control

Extremely Toxic

Highly Toxic

Moderately Toxic

Slightly Toxic