Tundu disease is caused by:

• Tundu disease, also known as yellow ear rot, is a complex disease of wheat caused by the interaction of two pathogens:
Anguina tritici: This is a seed gall nematode that creates galls (cockles) in place of wheat grains.
Clavibacter tritici (formerly Corynebacterium tritici): This is a bacterium that colonizes the galls created by the nematode.
The combination of these two pathogens leads to the development of tundu disease. The nematode galls provide a protected environment for the bacteria to multiply, and the bacteria, in turn, cause the characteristic yellowing and distortion of the wheat ears.