Lupine Stem Canker Problems

Botrytis Stem Canker

• Botrytis stem canker results from a fungal infection of the lupine plant. The areas where cankers appear depress into the stem and change colors, usually from a healthy green to a brown or yellow color. The cankers mold over into a grayish color if the surrounding air is very humid for a significant period of time. Lupine stem health will decline and the plant will die without immediate attention. A fungicide should clear up the canker problems.

Ascochyta Stem Canker

• Ascochyta stem cankers affect most legume plants like the lupine. Cankers appear on the stem and overall lupine stem health is affected, but symptoms start with the leaves. If this fungal problem infects a lupine, leaves will develop brown circular spots that lighten in hue and deform in shape as time elapses. The lupine stem cankers look similar to these spots, except they sink in and stretch out to an oblong shape. A fungicide should be used to eliminate this issue.

Lupine Anthracnose

• A fungus called Colletotrichum gloeosporioides causes canker problems when it infects lupine plants. Initial symptoms include folding of the plant when it is in the early stages of development and brown spotting on leaves. Lupine stem cankers occur once the infection has progressed. As in the case of other fungal infections, the cankers appear yellow or brown and sink into the stem. Most fungicides effectively treat lupine anthracnose.

Avoiding Lupine Stem Cankers

• After stem cankers appear, a fungicide is the best way to regain control and restore the plant to normal health, but some practices can help in preventing cankers. Irrigation should be kept to a minimum, as the plant tolerates dry soil and overwatering creates conditions conducive to the growth of fungi that cause cankers. The use of too much fertilizer also opens the door to fungus infections, so fertilizer should be applied sparingly.