Lisa Kelly from the Department of Agriculture & Fisheries in Toowoomba explains about bacterial and fungal diseases in mungbeans and their treatment options.
Powdery mildew in mungbean is caused by the fungal species Podosphaera xanthii and is widespread in Australia. A second powdery mildew, preliminary identified as Erysiphe sp. was recently found infecting mungbean in southern Queensland.
Field trials over a number of years have shown the most effective treatment is to spray the crop with one of the two fungicides (currently under permit for use on powdery mildew in mungbean) at the first sign of the disease and then a second spray 14 days later (if needed).
Halo blight & tan spot
These bacterial diseases are observed in mungbean most seasons, however due to seasonal conditions one might be more prevalent than the other.
Halo blight is more often found when the conditions are cooler and wetter with tan spot being more suited to hotter and drier conditions. Halo blight causes a leaf spot, whilst tan spot causes a leaf blight. Both of these diseases are seedborne with no in-season spray options available.
To best prevent against these diseases it is recommended that clean seed be used and crop rotations are practiced. Australian Mungbean Association (AMA) approved seed is sourced from crops inspected for disease symptoms during the growing season.
Further information links
GRDC Communities – Mungbean powdery mildew management with fungicide
GRDC Update Paper – Fungicide management of mungbean powdery mildew
GRDC Groundcover article – Research equips northern growers with mungbean disease advice
Images used in the video of powdery mildew and halo blight provided by Adam Sparks, USQ
Image used in the video of tan spot provided by Dante L. Adorada, USQ