Symptoms:
White growth, often with a yellow
margin, on the surface of leaves and stems. Leaves
eventually turn brown, die and fall off the plant.
Symptoms typically appear first on the plant’s
lower leaves and progress upward. Lesions do not
appear on fruit, but fruit may suffer from sunscald
due to defoliation in severe cases. Warm,
humid weather favors development of the disease.
Spores are carried by the wind, and entire plantings
may be quickly infected. Note: This disease
appeared for the first time in tomato fields and
home gardens throughout North America in 1996.
Solutions:
If tomato plants already show symptoms
of tomato powdery mildew, spray Bacillus
subtilis to boost plants’ natural defenses and
repeat at 7-day intervals, as needed, to control
the disease. If powdery mildew has been a problem
in the past, use the biofungicide as a preventative;
begin spraying foliage when conditions
favor disease and repeat weekly until harvest.
We recommend Plant Guardian™ Biofungicide Wettable Powder.