Anthracnose is a fungal disease spread by infected seed and rain-splash of spores from infected plants. All lupin species are susceptible to anthracnose where albus lupins are more susceptible compared to that the narrow leaf lupin. Anthracnose is common problem in medium to high rainfall areas. The symptoms of anthracnose include that of twisting and bending of stems with lesions on the crook of the bend (Dept of Ag WA).
Anthracnose is largely a seed borne disease, but may be spread on old lupin trash, machinery or by animals and birds. Seedlings that emerge from infected seed can develop lesions on the root, hypocotyl or cotyledons. Lesions are generally oval shaped brown – beige to pink colour and up to 2 cm long. These cause the stem to bend and may progress to infect the pods and seeds.
Lesions produce an abundance of spores that are spread through the crop by rain-splash. Anthracnose can survive over summer on crop residues; spores are subsequently spread by rain-splash to infect newly emerged seedlings.
- Treat the seed with a recommended seed treatment
- Increase the length of rotation between lupin crops
- Sow disease free seed
- Select varieties with moderate resistance