Dry root rot
Dry root rot.
Note the lack of finer roots.
caused by Rhizoctonia bataticola (Macrophomina phaseolina).
The disease appears suddenly when ambient temperatures are between 25-30C.
soil borne disease.
The disease generally appears around flowering and podding time as scattered dried plants.
Drooping of petioles and leaflets is confined to top of the plant. Sometimes when the rest of the plant is dry, the top most leaves are chlorotic.
The tap root is dark, shows signs of rotting, and is devoid of most of its lateral and finer roots.
- Avoiding high fertility will reduce the disease.
- Seed tratment with captan/ thiram/ benlate/ PCNB at 3 gkg-1 of seed.
Submitted by shelly on Wed, 07/01/2009 - 16:14