National Symposium on “Plant Pathology in the Changing Global Scenario” held at National Bureau of Plant Genetic Resources, New Delhi on February 27–28, 2009
White rust and Alternaria blight caused by Albugo candida and Alternaria brassicae, respectively, are important diseases on Indian mustard causing considerable losses. Mustard crop was exposed to different thermal environments by sowing on three dates i.e. 20th October, 5th November and 20th November during Rabi season 2007–08. It was observed that seed yield attributes of mustard cv. PBR-91 and cv. PBR-210 were decreased with delay in sowing. A perusal of the data revealed that the crop sown on 20th October had moderate but prolonged incidence of white rust and Alternaria blight due to cool and dry weather conditions. However, in November sown crop higher severity of both white rust and Alternaria blight for short duration was recorded. Mean maximum temperature positively correlated with disease index in both the diseases. Maximum temperature ranging between 26–29°C coupled with humid weather favoured the development of both the diseases. Rainfall was found to be negatively correlated with the disease index of white rust.
