Pink rot infection varied from 1.8% (Matiyana) to 8% (Shimla) in Shimla hills. Mixed infection of pink rot and late blight was also prevalent in tubers in the range of 3.1 – 6.0%. Six out of 21 hybrids/cultivars showed pink rot infection; highest incidence being in Kufri Chandramukhi and lowest in JH-222. Growth of Phytophthora erythroseptica on rye agar and colonization in tuber tissue was six times faster than P. infestans. Tuber treatment with chemicals prior to their inoculation gave better control than the post inoculation treatment. Pre-inoculation tuber treatment with metalaxyl (9.2%) and oxadixyal (0.2%) were the best and gave cent per cent control in pre-inoculation tuber treatment and 84 – 100% control in post-inoculation treatment, when the tubers were treated within 4–8 h. of inoculation. Possible reasons for flaring up of pink rot in Shimla hills have been discussed.
