Disease of Garlic
Macrophomina rot (Macrophomina phasoolina)
Garlic types 1069-9,1069-5,1069-6,1075-6,were resistant and 1029,1037,1040, 1073 -3, 073-5, 1073-7, 1073-9, 1073-10, 1073-14 and 1073-17 were moderately resistant.
Pink root (Pyrenochaeta tattestris)
Pink root of garlics is caused by the fungus. (Hansen) Gorenz, walker and Larson Pehoma terrestris (Hanson) it has been reported from all the garlic growing areas.
SymptomsThe 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.
Spread of the disease
The pathogen is soil borne and infection is mostly from mycelia in the soil. Optimum soil temperatures for disease development are 24-28° C.
Long rotations should be practiced to prevent build up of inoculum in the soil.