Managing Insensitivity to Group 11 (strobilurin) Fungicides in Ascochyta in Chickpea

Insensitivity of Ascochyta rabiei to Group 11 (strobilurin) fungicides has been documented by Dr. Michelle Hubbard with Agriculture and Agri-Food Canada in Swift Current. In 2019, 48 fields were surveyed for Ascochyta and every field that was confirmed with the disease had insensitivity to Group 11 fungicides. Ascochyta is the most damaging disease in chickpeas and managing the disease starts with scouting and preventative action using good agronomics, combined with effective fungicide applications.

To reduce the development of insensitivity in the pathogen it is important to use fungicides that have multiple modes of action that are effective on Ascochyta and avoid solo applications of Group 11 fungicides. It is also important to rotate groups of fungicides to prevent development of multiple insensitivity. Table 1 below outlines the current fungicide products registered for Ascochyta control and identifies the options available to help reduce the development of insensitivity or to manage those Group 11 insensitive populations.

*Fungicide components are represented as:

• Red = group 11 only.
• Yellow = group 11 + non-group 11 tank mix partner with no label statement “including group 11 insensitive biotypes” or similar.
• Green = non-group 11 OR group 11 + non-group 11 tank mix partner with label statement “including group 11 insensitive biotypes” or similar.