Agriculture Reference
In-Depth Information
'Grossbohne vom Lötschental' (large bean from Lötschental), a Swiss fava bean variety with black-speckled white blossoms
The most common pest infestation is that of the black bean aphid (
Aphis fabae
). Remove affected
shoots as early as possible. Earlier sowings help prevent infestations. Spray rhubarb compost tea for
mild infestations, a pyrethrum-based or other natural insecticide for more serious infestations. Aphids
are often vectors for viral infections, which cause visibly stunted growth. Their excretions encourage
colonization by
Botrytis fabae
fungi and the resulting chocolate spot disease. Do not further propagate
affected plants. Chocolate spot disease appears as chocolate-colored spots, about 0.25 in. (5 mm) in
diameter, whose centers are often more lightly colored.
Botrytis fabae
typically infests plants only
when there is high humidity, so low-lying, dense stands in wind-protected areas are at higher risk. The
fungus overwinters on infected plant tissue in the soil. This relatively widespread fungal disease can be
seed-borne, so remove and dispose of affected plants (compost only if you are confident your compost
pile gets hot enough to kill pathogens). Prevention: sow early and not too densely.
Broad bean with tell-tale exit hole of the broad bean weevil
