1. Macrophomina rot: Macrophomina  phaseolina
2. Pink root : Pyrenochaeta tattestris
3. Mosaic
4. Aspergillus rot: Aspergillus niger

1. Macrophomina rot: Macrophomina  phaseolina

Symptoms Dough situation in soil favours the occurrence of the disease. Rotting of bulb & presence of black sclerotia and pycnidia. Management Dipping of bulbs in 0.03% formalin or 2% boric acid immediately after harvest helps to avoid or minimize storage rot.

2. Pink root: Pyrenochaeta tattestris

Symptoms:

• The fungus attacks onion from the seedling stage onwards.
• The roots are affected and they turn pink or reddish and sometimes darken to a red or purple colour black spores form on the diseased roots which eventually shrivel and die.
• Diseased plants can be easily pulled. The above ground symptoms are shunting and yellowing tip burn and die back of the leaves.
• Affected seedlings may be killed. Older plants are not normally killed but bulb formation is affected and yields are low.
• Bulbs are not attacked although the outer scales may be penetrated.
• New roots are formed throughout the season and these may be infected and killed successively.

 Management

• Long rotations should be practiced to prevent build up of inoculum in the soil.

3. Mosaic: Garlic mosaic virus

Symptoms

• Mosaic is transmitted by eriophyid mite, Aceria tulipae.
• Typical mosaic mottling of leaves

Management

• Spray acaricide

4. Aspergillus rot: Aspergillus niger A. alliaceus , A. repens, A.sclerotionum 

Symptoms

• Rotting of garlic cloves show black, brown, white pink coloured rotting.
• Rotting may be partial (basal, tip or lesions) or complete.

Management

• To control this disease garlic bulb should be stored in dry airy place.
• Infected bulbs should be discarded before storage.
• Fumigation of bulbs with 0.03% formalin is effective