Now is the time when you should be checking for symptoms of diseases, insects and disorders on ginseng berries. It is important not to confuse symptoms associated with diseases or insects with those of heat and moisture stress. Here are the most common pests and disorders of ginseng berries and how to distinguish them.

Botrytis causes developing berries to become shrivelled and dark brown or purplish in colour. In moist conditions, these will be covered in a grey fluffy growth, which are the spores of the fungus. Infected berries often remain attached to the berry cluster.

Botrytis infected berries are often covered in fluffy spores.

Alternaria causes similar symptoms to Botrytis, but dark and shrivelled berries infected with Alternaria will eventually fall off of the plant. There will not be any fluffy growth associated with Alternaria infection, but occasionally the dark, powdery spores will develop around the berries. There are several pest control products registered for the control of both Botrytis and Alternaria on ginseng.

Alternaria infected berries become dark and shrivelled and often fall off the plant.

Moisture stress will cause berries to shrivel slightly, but the berries will not discolour. Affected berries will easily fall off of the cluster well before they turn red. Moisture stress can also be caused by root or stem diseases blocking the flow of moisture to the berries. Even if affected berries do not fall off of the plant, they may not develop properly.

Slugs chew the berries, especially as they start to turn red. They often do not penetrate deeply into the berries. Berry damage will often be found in conjunction with slug damage to leaves.

Slug chewing damage to ginseng berries.

Planthoppers are rare pests of ginseng. When present they can cause depressions in the berries that appear as holes. However, the most distinctive feature of planthoppers is the white sticky coating they leave on the berry cluster.

Planthopper damage and white residue on ginseng berry clusters. Note the depression in one of the developing berries.