1. Late Blight of Potato Description: Symptoms:
This disease caused by fungus called Phytophthora infestans.
The disease may attack almost any time after the crop has put up a fairly good foliage.
Initially the lower leaves infected.
Symptoms:
They show water-soaked lesions especially towards margins.
The spots enlarge if proper humidity and temperature are a available. .

2. In humid atmosphere, the growth of the fungus can be seen on lower side of these spots as whitish cottony growth.
The spot turn black as the affected leaves start rooting.
Similar symptoms may be observed on stems also.
Decaying leaves often omit offensive odour.
The tubers under the ground also decay before harvest.
On tubers greenish sunken area may be seen.

4. Management
Use potato tubers for seed from disease free areas to ensure that the pathogen is not carried through seed tuber .
Spray Metalaxyl formulations like Ridomil MZ or Motco or Krilaxyl at the rat of 2 gram/liter water when whether is congenial and continuous fog and intermittent rains. Spraying should be repeated at days interval.
The infected plant material in the field should be properly destroyed.
Grow resistant varieties like Kufri Jawahar, Kufri Chipsona-1, Kufri Chipsona-2, Kufri Sutalj etc.